The Henryk NlewodniczanskiInstitute of Nuclear Physics

Main site:ul. Radzikowskiego 15231-342 Krakdwtel: (48 12) 37 00 40fax:(4812)375441tix:3224 61e-mail: korfyna@bron.ifj.edu.pl

High Energy Department:ul. Kawiory 26 A30-055 Krakdwtel: (48 12) 33 33 66, 33 68 02fax: (48 12) 33 38 84tlx: 32 22 94e-mail: hepsec@chopin.ifj.edu.pl

Annual

1993Krakow 1994

Report No 1669

PRINTED AT

THE HENRYK NIEWODNICZANSKI INSTITUTE OF NUCLEAR PHYSICS

Cover designed by J. Grebosz

Editorial Board:

J. Bartke, D. Erbel (Secretary), B. Fornal,

L. Friendl, J. Grebosz, M. Krygowska-Doniec,

P. Malecki, M. Waligorski and H. Wojciechowski.

e-mail: wojciech@bron.ifi.edu.pl , erbel@bron.ifi.edu.pl

Kopia offsetowa, druk i oprawa: DRUKARNIA IFJWspotpraca wydawnicza: SEKCJA WYDAWNICTW

DZIAtU INFORMACJI NAUKOWEJ IFJ

Wydanie I zam. 29/94 NaWad 450 egz.

Henryk Niewodniczanski 1900 - 1968

25 years ago, on 20 December 1968, Professor Henryk Niewodniczanski, the founder of ourInstitute, died. To commemorate this event, we held a small session to recall his achievementsas a scientist, teacher and administrator.

Professor Niewodniczanski, a brilliant experimental physicist, began his research in the earlytwenties in the field of atomic optics. He discovered the forbidden dipole magnetic transition inPb atoms. His interest in nuclear physics was aroused by Lord Rutherford of Nelson in whoselaboratory he worked in the middle 'thirties. After World War II Professor Niewodniczariskiinitiated research in nuclear physics at the Jagellonian University. His enthusiasm and greatorganizational talent resulted in the establishment of the Institute of Nuclear Physics in Krakowunder his directorship. Thanks to his prolific vision, international reputation and managingabilities, the Institute in Krakow soon reached the position of an advanced research centrehighly respected in Poland and abroad. Professor Niewodniczanski was also an accomplishedteacher. Many of his pupils are now spread all over the world continuing the spirit of goodscientific research instilled by their great Master.

This volume describes our research activities through 1993. We have pursued our traditionaldirections of research, i.e. elementary particle physics, nuclear reaction and nuclear spectroscopy,physics of condensed matter applying nuclear methods, theoretical physics, nuclear geophysicsand hydrology, radiobiology, radiochemistry, nuclear medicine including NMR imaging, envi-ronmental studies with nuclear and non-nuclear methods, TLD dosimetry and several technicalenterprises, such as the construction of particle accelerators, semiconductor detectors for low,intermediate and high energy physics, ion implantation and development of computer networksfor scientific purposes.

The 3.5 MeV pressurized Van de Graaff accelerator installed in 1992 has successfully com-pleted its first full year of operation. Several experiments in various fields such as sample analysisfor medicine and for evironmental studies as well as studies of the surface structure of solidswere performed using its beam.

The 144 cm isochronous cyclotron was tested with a high-intensity accelerated beam. Aninternal deuteron beam of 300 /*A was obtained. The cyclotron has now been taken over by theoperation team and is waiting (due to lack of funding) to be moved to a permanent site whereit will be exploited.

The ion implantation plant has been upgraded and is now able to use two ion beams forproducing multilayer surfaces.

In spite of severe financial difficulties we were able to maintain our staff of about 580 persons.We consider it as a good prospect for the future that 15 fresh postgraduates and postdoctoralworkers have joined our staff this year.

Our main collaboration partners were: the CERN Organization in Geneva, the Hahn-MeitnerInstitute in Berlin, the Julich. Kernforschungszentrum, the University of Munster, GSI Darm-stadt, CRN Strasbourg, Laboratoire du GANLL Caen, DESY Hamburg, KfK Karlsruhe, LNLLegnaro, Argonne National Laboratory, Purdue University, Brookhaven National Laboratory,Fermilab, Louisiana University at Baton Rouge, the JENR in Dubna and the Institute of NuclearPhysics of the Ukrainian Academy of Sciences in Kiev.

The Institute has actively participated in the preparation of experiments for the new colliders:the LHC at CERN (ATLAS and ALICE) and the RHIC at Brookhaven (PHOBOS). Considerableeffort has been undertaken in preparing experiments for the cooler synchrotron COSY at Julich(COSY 10 and COSY 11), the Vivitron accelerator at Strasbourg and the Alpi facility at Legnaro(Eurogam and Gasp).

We have published over 400 papers, of which about 200 were accepted by highly regardedinternational journals.

We are particularly proud of two distinguished prizes received by our scientists: The MariaSklodowska-Curie prize of the Polish Academy of Sciences was awarded to Professor Jan Kwie-cinski for his brilliant results on the physics at small x. Dr Wojciech Florkowski was awarded theHenryk Niewodniczanski prize of the Jagellonian University for his excellent work on multihadronproduction.

The Institute organized together with CERN, the European School of High Energy Physicsin Zakopane-Zgorzelisko, Poland, which was highly praised by its participants and by the CERNadministration. The international conference on "Meson-Nucleus Interactions" held at the In-stitute was also a considerable success, as were many other scientific meetings and conferencesheld on the Institute's premises.

A. Budzanowski

DIRECTORATE:General Director: Professor Andrzej BudzanowskiDeputy Directors: Assoc.Prof. Piotr Malecki,

Dr Maria Pollak-Stachurowa,Prof. Michai Turaia

SCIENTIFIC COUNCIL:Chairman: Prof. Krzysztof Rybicki

A. REPRESENTATIVES OF SCIENTIFIC STAFF:

Jerzy Bartke, Prof., Jan Lasa Prof.,Rafal Broda, Prof., Leonard Lesniak, Assoc.Prof.,Andrzej Budzanowski, Prof., Piotr Malecki, Assoc.Prof.,Tomir Coghen, Prof., Jacek Okolowicz, Dr,Zygmunt Chyliriski, Assoc.Prof., Krzysztof Parliriski, Prof.,Jan Czubek, Prof., Grzegorz Polok, Dr,Andrzej Eskreys, Prof., Jan Styczen, Prof.,Jacek Hennel, Prof., Michai Tuxala, Prof.,Andrzej Hrynkiewicz, Prof., Michai Waligorski, Assoc.Prof.,Jerzy Janik, Prof., Tadeusz Wasiutyriski, Assoc.Prof.,Edward Kapuscik, Prof., Kacper Zalewski, Prof.,Jan Kwiecinski, Prof., Andrzej Zuber, Prof.

B. REPRESENTATIVES OF TECHNICAL PERSONNEL:Bronislaw Czech, E.Eng., Ewa Krynicka, M.Sc,Jan Godlewski, M.Sc, Mieczyslaw Kubica,Wieslaw Iwanski, M.Sc., Piotr Skora, M.Sc.,Ewa Kozynacka, Zbigniew Szklarz,Zbigniew Krol, M.Eng., Wladyslaw Wiertek

C. REPRESENTATIVES FROM OTHER INSTITUTES:

Andrzej Bialas, Prof. - Jagellonian University,Wieslaw Czyz, Prof. - Jagellonian University,Jerzy Niewodniczanski, Prof. - Academy of Mining and Metallurgy,Head of The Polish Atomic Agency.

CONTENTS: page

Department of Nuclear Reactions 1 i ',1

Department of Nuclear Spectroscopy 33 '

Department of Structural Research 101 ' , :

Department of Theoretical Physics I l l • - '

Department of High Energy Physics 135 ' *

Department of Environmental and Radiation Transport Physics 213 ' -•

Department of Radiation and Environmental Biology 223 ' 14

Department of Nuclear Radiospectroscopy 237 ''"'

Department of Nuclear Physical Chemistry 249 '

Health Physics Laboratory 267 ' ! •-->

Cyclotron Laboratory 279 ' . <

Cyclic Accelerator R & D Laboratory 283 : '

Electronics Laboratory 288

Computing and Networks 295 •'• i

Division of Mechanical Constructions 297

Energy Efficiency Center 302 < '• U

INP Author Index 305 ' - i

Department ofNuclear Reactions

DEPARTMENT OF NUCLEAR REACTIONS

Head of Department: Prof. Andrzej BudzanowskiDeputy Head of Department: Assoc. Prof. Stanisław DrożdżSecretary: Jadwiga Gurbieltelephone: (48) (12) 37-02-22 ext.: 210e-mail: gurbiel@bron.ifj.edu.pl

PERSONNEL:

Research staff (physicists):Andrzej Adamczak,Ludwik Freindl,Elżbieta Gula,Piotr Kamiński,Stanisław Kliczewski,Jerzy Łukasik,Jacek Okołowicz,Regina Siudak,Irena Skwirczyńska,Paweł Staszel,Jarosław Szmider,Roman Wolski,

Technical staff:Edward Białkowski,Bronisław Czech,Wiesław Kantor,

Administration:Jadwiga Gurbiel

GRANTS:

Henryk Dąbrowski,Kazimierz Grotowski, Professor,Jacek Jakiel,Waldemar Karcz,Ewa Kozik,Marian Madeja,Michał Palarczyk,Artur Siwek,Tomasz Srokowski,Antoni Szczurek,Henryk Wojciechowski,Michał Ziółkowski,

Janina Chachura,Marek Gruszecki,Kazimiera Pogorzelska,

1. Prof. A. Budzanowski,grant No 203349101, (The State Committee for Scientific Research),"Investigation of resonances in ^O^C) system".

2. Assoc. Prof. S. Drożdż,grant No 224099102, (The State Committee for Scientific Research),"Investigation of strong interactions in nuclear many-body systems".

3. Assoc. Prof. S. Drożdż,grant No 2P30215704, (The State Committee for Scientific Research),"Nonlinear and topological effects in nuclear dynamics".

PL96009764. Dr. S. Kliczewski,

grant No 2P30202505, (The State Committee for Scientific Research),"Experimental investigation of low-lying states of pionic atoms at COSY (Julich)".

5. Dr A. Adamczak,grant US National Science Foundation No INT 91-19223,"Theory of scattering of muonic hydrogen atoms on molecular targets".

OVERVIEW:In 1993 we have maintained the main directions of research in the field of nuclear reactions.

We have studied experimentally the 28Si(4He,16O)16O reaction and have found the proper an-gular momenta in the entrance and outgoing channels which provide a good Hauser Feshbachdescription of the data. Search for multifragmentation in the 32S + 58Ni reactionat 840 and960 MeV resulted in finding the contribution from three expected processes namely evapora-tion, fission and multifragmentation. The emission of three intermediate mass fragments wasfound to be preponderantly of sequential fission character.

New results have been obtained in studying chaotic properties of nuclear systems. 57 yearsafter Bohr's hypothesis of the formation of compound nucleus we have succeded in describingthe time dependence of its formation and decay in terms of classical molecular dynamics. Newresults have been obtained in chaos driven decay of nuclear giant resonances and chaotic proper-ties of nuclear spectra. The onset of colour transparency has been studied in (ee'p) reactions.

Multifragmentation of heavy nucleus excited without compression was found for the a + 197Asystem at the energies 1 GeVA and 3 GeVA.

Tunneling of generalized wave packed in the presence of external driving in N-body systemwith SU2 control was also studied.

The elastic, inelastic and single-nucleon transfer cross sections in the collision of 116 MeV14N ions with 12C, 13C and radioactive 14C targets were analyzed using the coupled reactionchannel method. Good agreement between measured and calculated cross sections was obtained.

For the first time the external beam of protons at the energy 600 MeV from the COSYsynchrotron was registered in the GEM detector (based on the Big Carl Spectrometer within theCOSY 11 collaboration). Our traditional partners were: FZ Julich, JINR Dubna, Hahn-MeitnerInstitute, LAMPF and Institute of Nuclear Physics of the Ukrainian Academy of Sciences. Weorganized a Conference on the Meson-Nucleus Interactions which turned out to be a success.

REPORTS ON RESEARCH:PL9600977

Modeling Complex Nuclear Spectra"> -, - Regularity versus Chaos

S. Drozdz, S. Nishizaki", J. Spethh and J. Wambach6

a) College of Humanities and Social Science, Iwate Univ., Maiioka. 020, Japan,b) IKP (Theorie), Forschungszentrum Julich GmbH, Julich, Germany.

In the quantum many-body description of a collective state the full Hilbert space is usuallydivided into two sectors consisting of 'simple' states, |1), and 'complicated' states, |2). Atthe same time, the Hamiltonian is represented as H = Ho + V, such that (l|_ffo|l') = €°8u<,

2') = €|622» and (l\Ho\2) = 0. The collective state defined as \f) = £ 1 Al1) is not aneigenstate of H but rather a wave packet which 'leaks' into the space of complicated states. Thisconstitutes a mechanism for dissipation. For the time-dependent state one has:

1/(0) = £ A(*)ii>+£ />(*)|2), ih{t = o) = o) (i)1

and the Schrodinger equation reads:

\ [fvldt[h\ ~ [HiV H

Applying the Nakajima-Zwanzig projection technique [1] by redefining the basis |2) such that itbecomes diagonal in H, i.e (2| j | 2 ' ) = ^ii'i yields:

TM E £ f drfv{t - T)VU,(T), (3)i' i' ^°

where:«H'(T) = -i E Hi2H21> exp(-ze2T). (4)

2

The matrix elements H\t — {\\H\2) describe the degree of mixing between the simple and thecomplicated states.

Ideally, the space of complicated states should contain all possible npnh excitations andthus reflects the complexity of the nuclear compound spectrum. This, however, does not seemnecessary. The nuclear Hamiltonian involves predominantly two-body interactions and thuscouples the collective state chiefly to 2p2h excitations. Restricting to this subspace the questionarises as to whether there are signatures of chaotic motion already at this level. More specifically,is the energy distribution of 2p2h levels, especially the fluctuations, consistent with the GaussianOrthogonal Ensemble (GOE) of random matrices [2] thus rendering the underlying dynamicschaotic?

To make the analysis as conclusive as possible we have chosen a realistic Hamiltonian Hensuring a proper description of the transition strength distribution. To obtain a manageablenumber of 2p2h states, monopole excitations (J* = 0+) in 40Ca have been selected. We thenobtain about 2800 2p2h states which is a meaningful statistical sample. The most obviousmeasure of spectral fluctuations is the nearest-neighbor spacing (NNS) distribution of energyeigenvalues, e2. A standard procedure is to normalize the spectrum so that the fluctuations ondifferent energy scales become directly comparable. We perform the corresponding unfolding [3]by fitting the integrated density of states to a 12th-order polynomial. Depending on how the2p2h subspace is treated we find three qualitatively different situations as illustrated in Fig. 1.Part (a) shows the NNS distribution for the spectrum of unperturbed 2p2h states in which theresidual interaction V has been neglected. Such a spectrum is not generic and is characteristicfor a narrow class of integrable systems involving extra correlations in the Hamiltonian [4]. Thepronounced peak for small nearest-neighbor separations illustrates a strong tendency of states forclustering because of degeneracies. Including residual interaction effects but retaining only ppand hh matrixelements immediately brings the spectrum (Fig. l(b)) to the known universalityclass of generic integrable systems [4] characterized by a completely uncorrelated sequence ofeigenenergies. The other important element which makes the spectrum uncorrelated is that,at this level, the 2p2h space remains a product of two subspaces in which only particle pairsand hole pairs are interacting. The crucial step is the inclusion of the ph-type matrix elements.Now the two subspaces can mix and the resulting NNS distribution (Fig. l(c)), almost perfectly,follows a Wigner distribution, i.e. is consistent with the GOE. In fact, considering only these

types of matrixelements and ignoring the others gives the same result. The GOE-like behavioris also robust to variations in the strength of the residual interaction, V, as well as the size ofthe 2p2h space, within reasonable limits (upper part of Fig. 2).

O.B*•"a.

0.4

0.8I?a.

0.4

0.0

a

fV\ b

c

Fig. 1. Nearest-neighbor spacing distributions(histograms) for the sequence of 2p2h states cou-pled to JT — 0+ as a function of the normalizedrelative distance s. Part (a) displays the unper-turbed case, (b) corresponds to the results from adiagonalization including pp-and hh interactionsonly and (c) includes all effects of the residual in-teraction. The dotted lines represent the Poisson

Fig. 2. Nearest-neighbor spacing distribution(histogram in the upper part) and the A3 statis-tics (diamonds in the lower part) for a sequenceof 400 low-energy states. The dotted lines referto the Poissonian spectrum and the solid lines toGOE predictions.

and the solid lines the Wigner distributions.As another indicator of chaotic dynamics we have considered the A3 statistics [5] which are

a measure of the rigidity of the spectrum. The A3(L) statistics are calculated as an averageof the mean-square deviation of the integrated density of (unfolded) states from a straight lineat an interval of length L. A comparison with the corresponding Poisson and GOE predictions[2] (lower part of Fig. 2) reiterates that, when the full residual interaction in the 2p2h space isincluded, the level statistics signal chaoticity.

References

[1] S. Nakajima, Prog. Theor. Phys. 20, 948 (1958);R. Zwanzig, J. Chem. Phys. 33, 1338 (1960)

[2] T.A. Brody, J. Flores, J.B. French, P.A. Mello, A. Pandey and S.S.M. Wong, Rev. Mod.Phys. 53, 385 (1981)

[3] 0. Bohigas, M.J. Giannoni and C. Schmit, in "Quantum Chaos and Statistical NuclearPhysics", edited by T.H. Seligman and H. Nishioka, Lecture Notes in Physics Vol. 263(Springer-Verlag, Heidelberg, 1986)

[4] M.V. Berry and M. Tabor, Proc. R. Soc. Lond, A356, 375 (1977)

[5] F.J. Dyson and M.L. Mehta, J. Math. Phys. 4, 701 (1963)

PL9600978

Chaos Driven Decay of Nuclear Giant Resonances:Route to Quantum Self-Organization

S. Drozdz"-6'0, S. Nishizakic'd, and J. Wambachoc X

a) Department of Physics, University of Illinois at Vrbana, IL 61801, USAb) Institute of Nuclear Physics, PL - 31-342 Krakow, Polandc) Institut fur Kernphysik, Forschungszentrum Jiilich, D-5170 Jiilich, Germanyd) College of Humanities and Social Sciences, Iwate University, Ueda 3-18-34,Morioka 020, Japan

Nuclear giant resonances carry a large fraction of the total transition strength and are locatedmany MeV above the ground state, in the energy region which is expected to be dominatedby chaotic dynamics. They, therefore, constitute an interesting phenomenon for studying thecoexistence of collectivity and chaos.

The giant resonance, as a short time phenomenon, involves simple configurations of a one-particle one-hole (lp-lh) type. Chaos may influence the subsequent decay of these componentswhich occurs on longer time scales and gradually evolves into more and more complex configu-rations. Eventually, the initial energy deposited in the nucleus is redistributed over all availabledegrees of freedom and the limit of the compound nucleus is reached. This is the limit of fullydeveloped chaos. The process of giant resonance formation and its subsequent decay towardsthe compound nucleus occurs in a closed system, and the most basic approach is in terms of asingle Hamiltonian acting in a rich enough Hilbert space so that the relevant degrees of freedomare included. This also provides the most natural scheme for the coupling between a collectivestate and the complex background. In quantum mechanical terms one can then speak about thelarge and the small components of the nuclear wave function. It is the purpose of the presentstudy to work out such a scheme, to identify which ingredients are relevant, to study the role ofchaos on the giant resonance physical observables and finally, from a more general perspective, tocontribute to the understanding of the universal aspects of the coexistence between collectivityand chaos in small many-body quantum systems.

For the specific case of the isovector quadrupole response in 40Ca, considered here, we havechosen the mean field and residual interaction as in ref. [2] including two major shells above andbelow the Fermi level. Our study is based on an explicit diagonalization which involves morethan 11000 states out of which only 26 are lp-lh states. Computational restrictions require thelimiting of the number of 2p-2h states. It turns out that, including those up to 50 MeV excitationenergy, there are sufficient for a realistic description of the measured response function. Thisyields altogether 3014 of 2+ states which is numerically manageable. The result displayed inFig. 1 yields a mean excitation energy (E) of 30.84 MeV for the isovector transitions, independentof the mixing with 2p-2h states. Motivated by our previous results [1] on the level fluctuationsin the prediagonalized 2p-2h space we distinguish three cases: (1) no residual interaction in thisspace (the corresponding strength distribution is shown in Fig. lb) for which the nearest-neighborspacing distribution is sharply peaked near zero, because of degeneracies, (2) the inclusion ofparticle-particle and hole-hole two-body matrixelements (Fig. lc) which results in a Poissoniandistribution, (3) the use of the full residual interaction (Fig. Id) which yields the fluctuations ofthe Gaussian orthogonal ensemble (GOE) characteristic of classically chaotic systems. All threecases introduce significant modifications of the lp-lh 'doorway' strength distribution (notice thechange in magnitude of the transition matrixelements) resulting in a gradual reduction of thelarge components accompanied by a simultaneous amplification of the smaller ones when goingfrom case (1) to case (3).

The most interesting effect is that the isovector strength is distributed much more uniformly,not only in excitation energy but also in magnitude. A bit of imagination may even suggest acertain kind of self-similarity regarding the clustering and the relative size of the transitions. The

picture in Fig. Id becomes reminiscent of a self-organized system at its critical state [3, 4] wherethe equilibrium balance reduces the dimensionality. This observation finds confirmation in morequantitative terms. Fig. 2 shows the total number N of transitions of magnitude smaller thana given threshold value Sth, as a function of Sth- For the isovector resonance in the chaotic case(Fig. Id) we find, except for the largest transitions, a scaling law of the form N ~ Sfh (a ss 0.50)(indicated by the straight line fit in Fig. 2) which indeed signals a reduction of dimensionality.The two nonchaotic cases (Figs, l b and c) display a more complicated behavior.

CaJ*=2* isovector200

150

100

50

40

30

20

10

40

30

20

10

12

9

6

3

0

(a)

(b)

(c)

(d)

10 20 30 40 50

Energy (MeV)

-16 -10

log Sth

Fig. 1. The isovector quadrupole strength dis-tribution in 40Ca: (a) no coupling to the 2p-2h subspace (b) no residual interaction in 2p-2hsubspace (c) including only particle-particle andhole-hole tnatrixelements in the diagonalizationof the 2p-2h subspace (d) diagonalization of thefull residual interaction in the 2p-2h subspace.

Fig. 2. The total number N of transitions ofgiven strength below a threshold value Sth as afunction of Sth.. The open triangles refer to thecase (b), the open squares to the case (c) andthick dots to the case (d) of Fig. 1. The solidline indicates the best lit to the later case. Thethin solid lines represents the same quantity de-termined from a Porter-Thomas distribution [7].

The strength distribution can be considered as an attractor for the decay process startingout of equilibrium. It is nothing but the Fourier transform of the time correlation function(F(0)\F(t)) which, in the form of an envelope [5], describes the process of gradual convergenceto such an attractor and, thus, resolves it. This sets the parallel to a procedure [6] whichresolves the self-similarity and the scale invariance in classical chaos. This analogy provides

further arguments for interpreting the above scaling law as another manifestation of 'l/f'-typebehavior. So far, such behavior has been identified mostly on the classical level for a variety ofobservables and models. In the present case of an 'avalanche' of the decaying giant resonance itis reflecting the chaotic properties of a strictly quantum mechanical phenomenon.

References

[1] S. Drozdz, S. Nishizaki, J. Speth and J. Wambach, Phys. Rev. C49, No. 2 (1994), to appear[2] B. Schwesinger and J. Wambach, Nucl. Phys. A426, 253 (1984)[3] P. Bak, C. Tang and K. Wiesenfeld, Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A38, 364

(1988)[4] L.P. Kadanoff, S.R. Nagel, L. Wu and S. Zhou, Phys. Rev. A39, 6524 (1989)[5] E.J. Heller, J. Chem. Phys. 72, 1337 (1980); Phys. Rev. A35, 1360 (1987)[6] S. Drozdz, J. Okotowicz and T. Srokowski, Phys. Rev. E48, no. 6 (1993)[7] C.E. Porter and R.G. Thomas, Phys. Rev. 104, 483 (1956)

PL9600979Molecular dynamics approach:

from chaotic to statistical aspects of nucleiA. Budzanowski, S. Drozdz, J. Okolowicz and T. Srokowski

In the description of compound nuclei molecular dynamical approaches [1] (MDA) generatingchaotic behaviour appear to provide an interesting alternative to quantum stochastic methods[2] based on the random matrix theory. Indeed, the resulting exponential decay of the classicalsurvival probability reflects the presence of Ericson fluctuations as can be seen [3] from the semi-classical energy autocorrelation function of an S-matrix element. The corresponding unitaritydeficit allows one to determine [1] the probability for the compound nucleus formation. Animportant related issue which, however, finds no quantitative documentation in the literatureso far is the problem of statistical properties of compound nuclei formed within the moleculardynamics frame. These properties are responsible for the decay characteristics such as energeticand angular distributions of the outgoing particles. The Maxwell form of the energy distributionand the symmetry with respect to TT/2 of the angular distribution are considered to constitutethe most convincing signatures that memory is lost and that a certain kind of equilibrium isreached. Because of an explicitly dynamical character MDA offers a very attractive frameworkfor addressing the related questions. In particular, under what conditions the system reachesequilibrium and what are the time scales involved.

The results of our investigations using the model of ref. [1] are summarized in Figs. 1 and 2.Even though effectively only six constituents (a-clusters) are involved in these numerical

experiments one observes a clear evidence of stochasticity for those events which survive timesof the order of 2 • 10~21s before the compound system decays. Already, within such time intervalsthe energies of the particles approach the stable distribution which has the Maxwell form (Fig.l)and the angular distribution of the emitted a-particles becomes symmetric with respect to x/2(Fig.2). By comparing the time intervals listed with the form of the corresponding survivalprobabilities one concludes that the onset of the attributes of stochasticity is correlated withtime the decay becomes exponential, i.e. the dynamics is governed by hyperbolic instabilitiesgenerating chaotic behaviour. These are, thus, responsible for the underlying memory losteffects.

- 1 2- 5 0 5 10

E [MeV]

£

n/2 3n/4T> [rad]

Fig. 2: Yield of outgoing a-paiticles horn the a +20Ne head on reaction (I = 0) at 15 MeV incidentenergy as a function of scattering angle. Trianglesrepresent those cc-particles escaped before t = 11 •10~22s and circles represent those escaped aftert = 50 • 10"22s. Full line is a linear fit to thelatter.

Fig. 1: Energy distribution of particles for 1 2C +12 C head on reaction at 20 MeV incident energy:before collision (full circles - solid line is to guidethe eye), at the initial stage (t = 0 in our timescale) - when the relative momentum of the two12 C becomes zero (squares - solid line representsGaussian fit), at t = 6 • 10~22s (triangles - longdashed line represents exponential fit), at t = 16 •10~22s (diamonds - short dashed exponential fit),and at t = 24 • 10~22s (open circles - dot-dashedexponential fit).

References:

[1] T. Srokowski, J. Okolowicz, S. Drozdz and A. Budzanowski, Phys. Rev. Lett. 71 (1993)2867

[2] J.J. Verbaarschot, H.A. Weidenmuller and M.R. Zirnbauer, Phys. Rep. 129 (1985) 367[3] R. Bliimel and U. Smilansky, Phys. Rev. Lett. 60 (1988) 477

Tunneling controlin the driven SU(2) n-body systemP. Kaminski1'2, M. Ploszajczak1'2 and R. Arvieu3

PL9600980

1 Institute of Nuclear Physics, Radzikowskiego 152 , PL-31-342 Krakow, Poland2 GANIL, BP 5027, F-14021 Caen Cedex, France3 Institut des Sciences Nucleaires, 53 Avenue des Martyrs, F-38026 Grenoble Cedex, France

We present results for the tunneling of a generalized wave packet in the presence of externaldriving in the iV-body system with the SU(2) symmetry [1] . The Hamiltonian written in termsof the quasispin operators Ko, K+, K-, has the form:

= eK0- (1)

The classical limit of the model can be constructed using the SU(2) coherent state repre-sentation of Slater determinants (SD). Performing a suitable change of variables [1] , one obtainsthe Hamilton equations for canonical variables q and p with the classical Hamiltonian 7ici =

8

{i>SD I Ho I ipSD)/Ne . These equations are equivalent to the time-dependent Hartree-Fock(TDHF) equations for the evolution of coherent states. The static (p = 0) part of Hci can beinterpreted as an analog of the potential energy. For V > s/(N — 1) it displays two symmetricminima at ±qeq separated by a barrier whose height increases with V.

The time-dependent driving in the Lipkin SU(2) model is introduced by adding the time-periodic term a sin9(f3t) (K+ + K-) to the unperturbed Hamiltonian Ho.

We consider quantum tunneling of the wave-packet starting with q0 = +qeq and p0 = 0, i.e.the coherent state centered in the static HF minimum, to the region q < 0 on the other sideof the classical potential barrier. For the purpose of our analysis, we use the Husimi function:W^{q,p;t) ~ \(ipsD(q,p) | *(*))|2 = l(0»P I *(0)|2 > which for any quantum state | ¥) is thepositive definite, normalized distribution function in the classical phase-space spanned by theparameters (q, p) of coherent states. We calculate the integral of the Husimi distribution over thehalf of the phase-space (q < 0, p): P(t) = J <Q dqdp W${q,p; t) which represents the probabilityto find the quantum system on the other side of the classical potential barrier.

In the absence of the time-dependent driving, the initial wave-packet tunnels slowly fromone minimum to the other. The process will be coherent and time-periodic.

For the time-periodic Hamiltonian, the Floquet theorem ensures that a solution of the time-dependent Schrodinger equation $(£) can be written in the following form:\P(t) = Ylkak^k = Ylk afcexp(-iefc£)$fc(t) , where e*. are referred to as the quasienergies and$fc(£) = $fc (t+ ~jp) i n = 0, ±1,±2,... are the time-periodic quasienergy eigenstates. Thequantum evolution is completely determined by the quasienergy spectrum and the overlaps ofthe quasienergy eigenstates with the initial wave-packet. When almost the whole wave-functionis concentrated in two quasienergy states, $3- and $*, its time-dependence is approximately givenby: \t(t) ~ -4= (e~*e>*$j + e~"k*$fc) . The tunneling frequency can be well given by the "tunnelsplitting" A =| €j — ejt |. A particularly interesting case takes place when this "tunnel splitting"tends to zero, i.e. the oscillation period goes to infinity. We have found in the TDSU(2) modelmany such quasienergy crossings. In Fig. 1 we present the quasienergy spectrum as a functionof the driving amplitude a for the driving frequency /? — 4.5 . The calculation is performed forsix fermions and V = 1. At a = 1.154 the two dominant quasienergies form an exact crossing.In Fig. 2 we show the quantity P(t) for two values of the driving amplitude: a = 1.154, 1.16.The coherent tunneling is restored for a = 1.16, i.e. away from the crossing point, whereas fora — 1.154 one finds the strong suppression of tunneling. In principle, one could take as an initialcondition, the wave-packet which is the combination of two degenerate quasienergy eigenstates.In this case one would be able to see a complete localization in one of the metastable states ofthe otherwise unstable quantum system.

2.5 i

0 0.5 1.0 1.5 2.0

Fig. 1. The quasienergy spectrum of theTDSU(2) model with six fermions (N = 6)for V = 1, as a function of the driving ampli-tude a for the driving frequency fi = 4.5. Thearrows indicate the states having the largestoverlap with the initial coherent state locatedin the HF minimum (q > 0) of the unper-turbed problem.

- 2 .

a =1.16

2000 4000t

0(=1.154

6000

Fig. 2. The probability to find the quantumsystem on the other side of the classical bar-rier for the driving amplitudes: a = 1.154 atthe crossing point of the dominant quasiener-gies, and away from it at a = 1.16.

For a two-level system it is possible to calculate the quasienergy splitting using perturbationtheory [2]. Diagonalizing the one-period propagator one derives the splitting of the quasienergylevels:

A') •

(2)

The crossing of quasienergies occurs for zeros of the Bessel function Jo.In the range of /3 from 0.5 to 4, one can observe the linear amplitude - frequency dependence

for the points of the exact crossings. For larger frequencies, the crossings take place at smalleramplitudes of driving, and from some critital /3 value, they do not occur at all. Our results agreequalitatively with the finding reported in ref. [3].

References

[1] H. J. Lipkin, M. Meshkov and A. J. Glick, Nucl. Phys. 62 (1965) 188.[2] J. M. G. Llorente and J. Plata, Phys. Rev. A45 (1992) R6958.[3] F. Grossmann, P. Hanggi, Europhys. Lett. 18 (1992) 571.

1- Flavour, spin and electromagnetic aspects of the meson cloud

in the nucleon I l l l l l l l l l l l l lA. DzczureK PL9600981

Different aspects of the meson cloud of the nucleon have been analysed [1-6]. The cut-off pa-rameters of the underlying vertex form factors have been found by fitting to high-energy baryon(n, A, A) production data [4]. The universal cut-off parameter for processes involving baryonsoctet was found, if the correct functional form factors had been chosen. The phenomenologi-cal determination of the form factors allows one to obtain the flavour and spin content of thenucleon. Both pseudoscalar and vector mesons have been included in the present analysis.

The Gottfried Sum Rule obtained from the present analysis [3,4], without any free parame-ters, agrees with that obtained by the New Muon Collaboration. The -dependence of the d — uasymmetry resembles the one found by Martin-Stirling-Roberts by fitting to the world data ondeep-inelastic scattering and Drell-Yan processes.

The predictions of the Meson Cloud Model for the asymmetry can be tested in the plannedFermilab experiment [2], measuring relative dilepton yield in proton-proton and proton-deuteroncollisions. The Meson Cloud Model predicts a very small z-dependent asymmetry between s(x)and s(x) distributions.

10

The calculated axial coupling constants for semileptonic decays of the octet baryons agreewith experimental data [4]. The Bjorken Sum Rule obtained from the calculation agrees withthe classical value. Although, in comparison with the naive quark model, some reduction of theEllis-Jaffe Sum Rule for the proton is obtained, the model is unable to reproduce the spin EMCexperimental result.

From the analysis of electromagnetic form factors [5] of the nucleon the quark core radius isobtained. The analysis strongly suggests that the quark core radius is only about 10% smallerthan the nucleon radius. Analysis of the renormalization of the total nucleon-nucleon crosssection for the presence of the pionic cloud suggests a similar core radius.

The presence of the meson cloud in the nucleon leads to a new mechanism of slow (fixedtarget experiment) proton production in deep inelastic scattering of leptons on nucleons. Therate of the slow proton production by the new mechanism has been calculated for the (anti)neutrino charged-current deep inelastic scattering [6]. The predictions of the model have beencompared with the BEBC results at CERN. The momentum distribution of protons has beencalculated.

References

[1] A. Szczurek and J. Speth, Nucl. Phys. A555 (1993) 249.[2] A. Szczurek, J. Speth and G.T. Garvey, Julich preprint, KFA-IKP(TH)-1993-13, in print

in Nucl. Phys. A.[3] A. Szczurek and H. Holtmann, Acta Phys. Pol B24 (1993) 1833.[4] H. Holtmann, A. Szczurek and J. Speth, paper in preparation.[5] N.N. Nikolaev, A. Szczurek, J. Speth and V. ZoUer, Julich preprint, KFA-IKP(TH)-1993-35,

submitted to Z. Phys. A.[6] A. Szczurek, paper in preparation.

PL9600982

Nuclear transparency in (e,e'p) reactions and the onset of ?colour transparency

N.N. Nikolaev l>\ A. Szczurek 1-s, J. Speth 3, J. Wambach 3'\ B.G. Zakharov 2 andV.R. Zoller 5

1 IKP (Theorie), Forschungszentrum Julich GmbH, D-52425 Julich, Germany2 L.D. Landau Institute for Theoretical Physics, GSP-1, 117940, V-334 Moscow, Russia3 Institute of Nuclear Physics, PL-31-342 Krakow, Poland4 Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA5 Institute for Theoretical and Experimental Physics, 117259 Moscow, Russia

The nuclear transparency in the (e, e'p) reaction on nuclei has been carefully studied [1-5]. Ithas been shown that multiple rescattering effects are extremely important in order to understandthe onset of the colour transparency effect predicted by quantum chromodynamics.

A realistic model for colour transparency effects in (e,e'p) reactions on nuclei has beenconstructed [1]. In comparison to early works on colour transparency effects in (e, e'p) scatteringwe differ significantly in the treatment of the coherency constraint which is treated withincoupled-channel theory. The model correctly describes the quantum interference effects in theejectile propagation through the nuclear medium. It has been found that quantum filtering ofthe ejectile wave packet from the hard ep scattering on bound nucleons puts stringent constraintson the onset of colour transparency. Even after optimizing the ejectile-state scattering for weakattenuation, a rather slow onset of colour transparency has been found. This can be understood

11

in terms of the large number of excited states needed to produce wave packets of small transversesize.

As a side effect we have investigated the role of two-body correlations in nuclear transparencyfor the quasielastic (e,e'p) reaction [2]. Two different effects (spectator and hole) have beendiscussed. We find large cancellation of the spectator and hole effects. It has been concluded inRef. [2] that at low Q2 the uncorrelated Glauber model estimates of nuclear attenuation shouldbe accurate.

Another side effect has been discussed in [3]. It has been shown that the electron scatteringkinematics, in conjuction with the Fermi motion of the bound nucleons, allows one to controlthe composition of the ejectile wave packet. Using the diffraction operator technique developedin [1] we derive the dependence of the colour transparency signal on the Bjorken variable x ofthe scattered electron. The Fermi-motion bias obtained in [3] is much weaker than has beenclaimed recently. Nonetheless, the observation of the effect and of its specific asymmetry aroundx = 1 would be a very important test of the colour transparency ideas.

The transverse-momentum distribution of struck protons in (e, e'p) reactions at CEBAFenergies has been calculated in [4]. At large p± we find significant contributions from multipleelastic rescatterings in the nucleus. These occur in a region where the effect of short-rangenucleon-nucleon correlation is thought to play an important role, making the extraction of thelatter more difficult. In [4] the multi-nucleon emmision has been estimated. A significant effecton the nuclear transparency from finite transverse momentum acceptance in the experimentshas been found.

This effect is particularly important for the correct interpretation of results of the recentSLAC NE18 experiment [5]. We find that the effect of the p±-broadening is large even for thedeuteron.

In conclusion, we have found a rather slow onset of colour transparency in the (e, e'p) reac-tions on nuclei. Nevertheless, for light nuclei the predicted colour transparency signal is foundsufficiently strong for a decisive test of colour transparency ideas at a new European ElectronFacility currently under discussion (the ELFE project). Our analysis strongly suggests, however,that electron beams of around 30 GeV are desirable, especially to observe a colour transparencysignal for heavy nuclear targets.

References

[1] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, in printin Nucl. Phys. A.

[2] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Phys.Lett. B317 (1993) 281.

[3] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Phys.Lett. B317 (1993) 287.

[4] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, Julichpreprint, KFA-IKP(TH)-1993-33, submitted to Phys. Lett. B.

[5] N.N. Nikolaev, A. Szczurek, J. Speth, J. Wambach, B.G. Zakharov and V.R. Zoller, paperin preparation.

12

PL9600983 PL9600984 PL9600985O,

Diffusion of muonic deuterium and hydrogen atomsD.J. Abbott, P. Gus, J.B. Kraiman, R.T. Siegel, W.F. Vulcan, D.W. Viel (College of Williamand Mary, Williamsburg, Virginia, U-S-A.^C Petitjean, A. Zehnder (Paul Scherrer Institute,Villigen, Switzerland),VJ.H. Breunlich, P. Kammel, A. Scrinzi, J. Marton, J. Zmeskal (Institute

for Medium Energy Physics, Austrian Academy of Sciences, Vienna, Austria} J.J. Reidy,H. Woolverton (University of Mississippi, Oxford, U.S.A.),F.h Hartmann (TechnicalUniversity München, Garching, Germany)^ A. Adamczak (Institute of Nuclear Physics,

Krakow, Poland), V. Markushin (Russian Scientific Centre, Moscow, Russia)t V. Melezhik(Joint Institute for Nuclear Research, Dubna, Russia)

submitted to Physical Review A

Diffusion of muonic deuterium d/i and muonic hydrogen pfi atoms in D2 and H2 at 300 K wasstudied at pressures of 47—1520 mbar by measuring the distributions of time intervals betweenentry of negative muons into the gas and the arrival of the resulting d/x or p\i atoms at foilsspaced regularly along the muon beam axis. Results indicate atom energy distributions whichare différent for dfi and p/x, and vary with pressure, having mean energies ranging from 1.4 eVfor d/j, at 94 mbar to 9.5 eV for pfi at 750 nabar. The interpretation of the data is also sensitiveto scattering cross- sections for d\i and pfi, and satisfactory fits required the use of cross-sectionsobtained from current theoretical calculations.

Spin — flip cross sections in muonic hydrogen scattering on / Ohydrogen molecules

A. Adamczak (Institute of Nuclear Physics, Krakow, Poland^ V. Korobov, V. Melezhik (JointInstitute for Nuclear Research, Dubna, Russia)

submitted to Hyperfine Interactions

The results of calculations of the total cross sections of spin-flip processes in low energymuonic hydrogen scattering on hydrogen molecules are presented. These calculations are basedon the respective set of cross sections for muonic hydrogen scattering on hydrogen nuclei, ob-tained within the framework of the multichannel adiabatic method. All combinations of thethree hydrogen isotopes are considered. Molecular binding effects are described in terms of theFermi pseudopotential method. Electron screening effects are calculated in the distorted waveBorn approximation. Rotational and vibrational transitions of the molecules, due to collisionswith muonic hydrogen atoms, are taken into account. The molecular and electron screeningcorrections do not exceed a few tens of a per cent for the lowest collision energies.

Neutron multiplicity in deep inelastic collisions:380 MeV Ar -f Tb system

E. Kozik, A. Budzanowski, M. Bürgel1, H. Homeyer1 and J. Uckert1

1) Hahn-Meitnei Institut für Kernforschung, Berlin, Germany

Energy spectra of projectile-like fragments ( Z=6-20 ) in coincidence with neutrons ( M n =l -16 ) were measured for the 40Ar +1 5 9 Tb system at E;a(,=9.5 MeV/u. Neutron multiplicitydistributions for 20 MeV total kinetic energy loss bins were obtained in the TKEL range 0-240MeV. In the region between 120 and 220 MeV of TKEL multiplicity distributions exhibit

13

PL9600986

two bell-shaped components, the first one at low multiplicity ( Mn ~ 1.5), and the secondone at higher multiplicity, shifted increasingly toward increasing the TKEL (see fig.). The lowmultiplicity neutrons detected in coincidence with the PLF's may originate from 2 differentsources:

i) at high total kinetic energy loss the TLF excitation energy permits the evaporation of lightcharged particles accompanied by the emission of a few neutrons,

ii) excitation energies shared between the PLF and TLF in proportion to their masses aresufficient for emission of one or two neutrons from PLF.

Now we concentrate our attention on the determination of the source of the low multiplicityneutrons.

= 1 6

200-

100 :

0

TKEL=140 MeV TKEL=160 MeV

0i—r~i—i—|—i—

5 10 15 20 10 15 20

MULTIPLICITY

Heavy ion emission in the 28Si(a,16O)16O reaction1

I. Skwirczyriska, L. Freindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz,J. Szmider and R. Wolski

Two possible competing reaction mechanisms : compound nucleus formation followed byfission and cluster transfer, have been suggested for nuclear reaction induced by low-energy lightparticles. The strong absorption of the incident projectiles favors an evaporation process asdescribed by the statistical model. The cluster structure of 325'[1] suggests the direct clustertransfer contribution to the 28Si(a,16 O)16O reaction cross section.

The angular distributions at E a = 24.9 and 25.9 MeV for the reaction 2SSi{a,16 O)16O weremeasured in 4° steps from 28° to 64° in the lab. system.

Experimental data were analysed assuming the presence of the compound nucleus mechanismand the one-step transfer reaction. The Hauser- Feshbach model calculations were done with thecomputer code HAUFES [2], using the Lang's level density formula [3]. The used optical modelparameters and necessary angular momenta limitation in the entrance and exit channels havebeen described in [4]. The comparison of Hauser- Feshbach model prediction with the excitationfunction at 90°[4] and the angular distribution (Fig.l) for the 28Si(a,16 O)16O reaction indicatesthat the average trend is quite well described by this model.

The direct part of the cross section was calculated in terms of the exact finite range DWBAtheory using the revised version of the code LOLA [5]. A minor modification was made to thecode since we assumed the reaction amplitudes as the coherent sum of two terms correspondingto the 12CGS and 12Cex(the 2+ state at 4.44 MeV). Assuming that the transferred cluster x is

1Research supported by The State Committee for Scientific Research under Grant No 2.0334.91.01

14

bound to cores A or b with angular momenta l2 and l\, respectively, the differential cross sectionfor reaction A(a,b)B where a = b + x , B = A + x , and can be expressed as :

da_

In1 h

EbEa ka

whereA(EX) =

sx, 1, and Ex are spin, angular momentum and energy of the transferred particle, respectively.The number of nodes, N, for the radial wave functions is determined by the harmonic oscillatorrelation

12

2Nt = i

where L is the angular momentum of the 12C cluster in the target and the final nucleus and n;,lj is the number of nodes and orbital angular momentum of nucleon with respect to the core,respectively. The values 2N+L were caluculated to be 8 and 7 for the 2sSi nucleus and 2,1 for the160 nucleus. The finite range DWBA calculations were normalized to the experimental data andthe 12C cluster spectroscopic factors were extracted. The direct and compound contributionswere added incoherently. The calculations reproduced quite well the general features observedin the experimental angular distribution (Fig.l).

10 -D

(lib/sr)

1 -

0.1

28Si(a,16O)16O

30.00 50.00 70.00 90.00

'cm

Fig.l The energy averaged angular distribution for the 2 8Si(a,1 8 O)16O reaction. The solid linerepresents sum of DWBA and Hauser-Feshbach contributions and the dashed line represents the Hauser-Feshbach contribution alone.

The experimental spectroscopic factors of 12C- cluster in the 16O nucleus [6] were equal to0.57 and 1.5 for the ground and excited states, respectively. These values were used to extractthe experimental spectroscopic factors of 12C-cluster in 2SSi nucleus. The absolute values of thespectroscopic factors for the ground and excited states of 12C cluster in 2sSi nucleus extractedfrom the present data are 5.4 x 10~3 and 2.05 X 10~~3, respectively. The theoretically predicted[7] spectroscopic factor for l2Cex is about five times greater then the one we have obtained.

15

PL9600987

The observed disagreement can be explained as the influence of the sequential clusters transfer(8i?e-nucleus and a particle or three a particles).

References

[1] A.C. Merchant and W.D.M. Rae, Nuci. Phys. A549 (1992) 431[2] R. DaSilveira, Program Haufes (Saclay 1976)[3] D.W. Lang, Nucl. Phys. 77 (1966) 545[4] I. Skwirczyńska, L. Preindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz,

J. Szmider, R. Wolski and J. Czakański, Report IFJ No. 1649/P1[5] R.M. De Vries, Phys. Rev. C8 (1973) 951[6] T. Yanaya, K. Umeda, T. Suehiro, K. Takimoto, R. Wada, E. Takada, M. Fukada,

J. Schimizu and Y. Okuma, Phys. Lett. 90B (1980) 219[7] D. Kurath, Phys. Rev. C7 (1973) 1390

Investigation of the multifragmentation of target nuclei in4 He+ m Au collisions at relativistic energies

S.P. Avdeyev, V.A. Karnaukhov, V.D. Kuznetsov, L.A. Petrov (Joint Institute for NuclearResearch, Dubna, Russia), R. Barth, V. Lips, H. Oeschler (T.H. Darmstadt, FRG),

O.V. Bochkarev, E.A. Kuzmin, L.V. Chulkov (Kurchatov Institute, Moscow, Russia),W. Karcz (Henryk Niewodniczanski Institute of Nuclear Physics, Kraków), W. Neubert

(IKEP-Rossendorf, Dresden, FRG), E. Norbeck (University of Iowa, Iowa, USA),A.S. Botvina (Institute of Nuclear Research, Moscow, Russia)

The experimental studies of multifragment emission have been conducted in the last yearsby means of 4x-setups on heavy ion beams at both intermediate [1] and high energies [2]. Inthis paper we present the first results of our investigations using the extreme case of the veryasymmetric system 4He + 197Au at incident particle energies up to 3.6 GeV/N. This selectionis favoured for various reasons: (i) all detected IMF (intermediate mass fragments) are emittedfrom the target spectator, (ii) the low center-of-mass velocity allows one to determine with highprecision the relative velocities and the relative angular correlations, (iii) with He projectilesdynamical effects are small and the compression of the target nucleus is negligible.

The experiments were performed at the synchrophasotron of the JINR (Dubna) using thenew 47T-device FASA [3].

The mass yield in IMF region is well described by A~T dependence. The exponent r isshown in Fig.l as a function of the LCP (light charged particles) multiplicity, and a minimum isobserved at measured multiplicities of 2-4 LCP. The minimum in dependence of the r-parameteron the excitation energy is expected at the critical point for a liquid-gas phase transition [4].

The total cross-section for the fragmentation process for higher incident energy was estimatedto be equal to <JM ~400 mb. It is a significant part of the total inelastic cross-section (15-20 %).In fact all the "central" collisions are followed by a multifragment decay of the target spectator.

Fig.2 shows the multiplicity distributions measured by the multiplicity detector. Two distri-butions are shown: one of them for the events selected by requiring one IMF in a time-of-flight(TOF) telescope (open circles) and the second one for the events selected by fission fragmentcoincidences in the TOF-telescope and PPAC (parallel-plate avalanche chamber) (open boxes).The mean primary IMF multiplicities observed in coincidence with the fission or for events withone IMF in one of the TOF-telescopes is given in Table 1.

16

Table 1Event classFissionIMF

1 GeV/Nl.l±0.23.6±0.6

3.65 GeV/Nl.l±0.25.3±0.8

alfa+Au3.65 GoV/N

alfa+Au (3.65 GeV/N)

Fission trigger

FMD multiplicity (LCP) n 9 - 12 3 4 3 S 7 8 9

FMD multiplicity (IMF) Fig.2.

Fig. 1 Fig. 2

The excitation energies were deduced from the measured fission fragment mass spectra ac-cording to the procedure described in [5]. The values of Eea. equal from 500 MeV to 700 MeV.The relative velocities of IMF-IMF coincidences for the large correlation angles are shown onFig.3. For incident energy 3.65 GeV/N the mean value of the relative velocity decreases by 0.2cm/ns. This reduction of the Coulomb repulsion is either due to a larger breakup volume or toa lighter breakup system or to both effects.

Information on the time scale of the multi-fragmentation process can be obtained fromthe study of the angular correlation betweencoincident fragments at the small correlationangles. The quantitative analysis of the datais in progress now. It is expected from themagnitude of the effect observed that themean life-time of the system is not largerthan 10~21 sec.

i500

450

400

350

300

250

J 200

ISO

100

SO

alfo+Au,IMF-IMFcoinc.large correlation angles

1

1/I (I/f

•

11

\\ \

a

\

V

1C

\

V

if/H1

*>>1.50 1.93 2.40 2.85 3JO 3.73 4.20 4.S5 5.10 3.53 6.00

Vrelcm/nsec) Fig.3.

References:Fig. 3

1. D. Fox et al, Phys. Rev. C47 (1993) R421.T. Li et al., Phys. Rev. Lett. 70 (1993) 1924.

2. B.V. Jacak, Nucl. Phys. A488 (1988) 352c.J. Hubela et al., Phys. Rev. C46 (1992) R1577.

3. S.P. Avdeyev,... W. Karcz,...et al., Nucl. Instr. Meth. A332 (1993) 149.4. P.J. Siemens, Nature 305 (1983) 410.5. G. Klotz-Engman et al., Nucl. Phys. A499 (1989) 392.

17

PL9600988

Study of properties of Ne - Al neutron rich isotopes at nearn=20 magic shell using elastic scattering in inverse kinematicA.G. Artukh1, S.N. Ershov1, F.A .Gareev, G.F. Gridnev1, M. Gruszecki, S. Kliczewski,M. Madeja, S. Yu. Shmakov1, J. Szmider, Yu. G. Teterev1, V.V. Uzhinski1, K. Holy2,

P. Povinec2, B. Sitar2, Yu. M. Sereda3 and I.N. Vishnevskî3

1 Joint Institute for Nuclear Research, Dubna, Russia2 Comenius University, Faculty of Mathematics and Physics, Bratislava, Slovakia3 Institute for Nuclear Research, Kiev, Ukraine

The experimental studies of the neutron drip-line position in C, N and 0 isotopes have shownthat neutron number N = 16 is a new shell closure, while the shell closure at N = 20 tends todisappear. The anomalies in behavior of the neutron binding energy of the Na isotopes, theabnormal ground state spin of 31 Na and the very low excitation energy of the 2 + state of 32Mgsuggest a large ground state deformation what contradicts expectations of the standard shellmodel [1,2]. The observed overbinding energies of the neutron rich nuclei can considerably shiftthe boundary of nuclear stability to super neutron rich isotopes. The existence of shape isomerscan lead to the appearance of quasi stable islands of quasi neutron nuclei.

Information about the shapes of exotic nuclei can be obtained from the scattering experi-ments. In this work, the conditions and expected results of elastic scatterings of the heavy (Ne- Al) isotopes on protons have been analysed and are presented. Existing at JINR, Dubna,facilities, e.g. the high intensive accelerators, the magnetic separator and the 4TT detectors fulfillall the conditions necessary to perform an investigation with low intensity secondary beams.The time projection chamber, TPC, is planned to be used as a detector. The TPC allowsthe reconstruction of multitrac events with high spatial resolution, the identification of chargedparticles and the rough determination of their energies. Additionally, if necessary, gas fillingthe chamber can be used as a thick target. Thus, using the TPC one can: measure all tracksof reaction products, their energies and angles of emission, determine trajectories of projectiles,separate with high accuracy elastic, inelastic and rearrangement processes and obtain excitationfunction, simultaneously.

The optimal reaction for production of the (Ne-Al) isotopes seems to be fragmentation of40 Ar nuclei. The angular distributions of heavy isotopes, elastically scattered on protons arefocused inside a narrow forward cone ( QLAB < 3° ). So the registration of scattered projectilesdemands a very high precision of angle measurements, while associated recoiled protons have awide angular distribution and are convenient for registration. Considering a very low intensityof the expected for example, 32Na beam, and calculated cross-sections, angular distributionsonly in the angle region QLAB ~ 0° - 2° for 32Na or QLAB = 55° - 90° for protons can bemeasured. The dependence of the {Q LABIAL AB) angle-angle correlations in the inelastic ofthe scattering process shows an extremely high sensitivity of recoiled proton angles on evensuch small variations of excitation energy as 1 MeV in comparison with the 1.6 GeV of theinitial energy of the 32Na beam. From dependence of energy on angle it follows that separationof the elastic scattering from the inelastic one needs an energy resolution better then 2% forrecoiled protons. Assuming that the intensity of the 32Na beam will be 102 particles/s and usingthe reasonable surface density of protons and cross-section calculated for the second diffractionmaximum, it was estimated that two hours are necessary to measure angular distribution witha 1% statistical error.

References:[1] X. Campi, Nucl. Phys. A251 (1975) 193[2] Yu.S. Lyutostansky et al., Proc. 5-th Int. Conf. on Nuclei Far from Stability, Ontario, Canada,(1987) 727

18

PL9600989

Diagnostic software for read-out electronics of Lt ime- pro cect ion- chamb er

A.A. Artukh1, M. Gruszecki, S. Kliczewski, M. Madeja, A.A. Semionov1,Yu. M. Sereda2, J. Szmider, Yu. G. Teterev1, F. Than Chang1 and D. Ushakov1

1 Joint Institute of Nuclear Research, Dubna, Russia2Institute for Nuclear Research, Kiev, Ukraine

Nuclear reactions at high energies, as well as reactions induced by heavy ions produce mul-tiplicity of particles and elements. Detection of as many as possible outgoing fragments, theiridentification and the determination of their energies and angles of emission provide basic in-formation about correlations among these reaction products. Analyses of these correlationsallow one to establish a reaction mechanism and in many cases to deduce the complete dynamicof process. In spite of the development of the acceleration and separation techniques, whichresulted in production of secondary radioactive beams, their intensities are still low, 102 - 108

p/sec. Investigation of the interaction between these exotic ions and nuclei promise a new insightinto the problem of quasi neutron matter [1] and on the properties of nuclei with large ratio ofN/Z. Experimental studies of these problems require a system of detection which would providethe measurements of a full multiparticle kinematics and simultaneously carry out unambiguousidentification of all types of particles.

The time projection chamber, TPC, as an electronic tracking detector allows a three-dimensio-nal reconstruction of multitrack events with a high spatial resolution and identification of chargedparticles by ionization sampling [2,3]. Furthermore, the principle of the TPC operation permitsone to use effectively the detector itself in the mode detector-gas target-detector. A detaileddescription of the TPC is presented in the report [l].

Signals from the anode wire are splited in preamplifier, than they feed the fast flash ADCand Multistop TDC, which detect the time of incoming signals with an accuracy 2ns in the16 mks period. A 6-bit FADC measures the charge of the signals from anode wires for a 64nssampling period. In both converters there is a possibility to measure up to 256 different pulsesat once. Such multi-pulses converters enable one to measure many close spaced particle tracksin the TPC detector. Pulses from both ends of the delay line, feed an appropriate preamplifier,income to a discriminator, which detects the time of the highest point of signals and then feedsMHTDC. The digitized time and charge signals are read-out to a computer via a CAMACsystem. The TPC anode consists of several separated strips. Four electronic channels cooperatewith each of the strips, three of them provide time information (MHTDC), the fourth is chargesensitive. At JINR Dubna are available two TPC, a big one and a much smaller one withthree strips only. The small TPC aquisition software enables the perfomance of the followingtasks: the trimming of parameters in each charge-sensitive channel, the transfer of data andtheir acquisition in the computer, the sorting of spectra, the monitoring of sorted time or chargespectra, the reconstruction of particle tracks.

For checking the TPC electronics a special programable generator is used. It can simulate anycombination of signals on the front of MHADC or MHTDC in both analogue and time channels.Diagnostic software for the rest of electronics enables the following tasks: the programing of asequence of pulses from a 2-channel generator in the 256 time position, the checking of linearityof MHADC or MHTDC converters, the testing of acquisition in MHADC or MHTDC converters,the acquisition of data in MHADC or MHTDC converters.

Using the diagnostic software, mentioned above, the following measurements have been done:charge transfer characteristics of MHADC (linear and nonlinear mode) and charge sensitivetrack, time transfer characteristic of MHTDC (linear mode) and measuring tracks, test spectra

19

PL9600990

of amplitude and time, measured in MHADC, test spectra of time measured in MHTDC, testacquisitions of amplitude and time pulses from external random generator.

The charge transfer characteristics of 6-bit MHADC have a dead zone in the starting part anda saturation zone in the final part of the charge range. Thus nonlinear characteristic of MHADCenables the dynamic range to be extended to 8.5 bit, but with deterioration of the resolution.The charge transfer characteristics of the charge sensitive track have small nonlinearities, thathowever can be calibrated. For reconstruction of the energy spectra it would be better to havethe linear transfer characteristics. The integral nonlinearities should not be larger than an errorof particle energy, measured by the TPC detector. The calculations show that linearity of theMHADC and its charge sensitive channels are poor. Their dynamical ranges are also small.The integral and differencial nonlinearities distort information about the time the of incomingsignals, which spoils the spatial resolution of the detecting system. On the other hand thetransfer time characteristics of a 14-bit MHADC and time sensitive track are linear in a largedynamical range.

References:[1] A.G. Artukh et al., 2-th. Int. Conf. on Rad. Nucl. Beams, August 19-21, p. 27, Belgium,Louvain (1991)[2] F. Sauli, Z. Phys. , C38 (1988) 339[3] B.E. Bonner et al., Preprint BNL-42189 (1988)[4] Yu.A. Budagov et al., Preprint JINR, P13-88-927 (1988)[5] Yu.A. Budagov et al., Preprint JINR, 13-85-585, p. 85 (1985)[6] Yu.A. Budagov et al., Preprint JINR, 13-84-395 (1984)[7] Yu.A. Budagov et al., NIM, A234 (1985) 302

/( First External COSY Beam at the BIG KARL II MagneticSpectrometer

S. Igel, K. Kilian, G. Lippert, H. Machner, C. Nake, P. von RossenInstitut fur Kernphysik, Forschungszentrum Jiilich, Germany

L. Jarczyk, S. Kistryn, J. Smyrski, A. Strzalkowski, P.A. ZolnierczukPhysics Institute, Jagellonian University, Krakow, Poland

M. DrochnerInstitut fur Kernphysik, T.U. Dresden, Germany

A. Budzanowski, L. Freindl, S. KliczewskiInstitute of Nuclear Physics, Krakow, Poland

A. Berg, G. Bolscheid, J. Ernst, C. Henrich, R. Jahn, R. Joosten, R. Maschuw,T. von Oepen, D.E. Rosendaal, K. Scho, R. Tolle

Institut fur Strahlen- und Kernphysik, Universitat Bonn, Germanyand the GEM and MOMO collaboration

A GEM detector system for the investigation of meson production, meson-nucleoninteractions as well as pionic atoms properties was invented and developed in the Institut furKernphysik, Forschungszentrum Jiilich, Germany. The GEM system consists of the germaniumwall (a stack of position sensitive germanium detectors) and magnetic spectrometer BIG KARLH. At the focal plane of the BIG KARL II magnetic spectrometer two sets of Multi-Wire-Drift-Chambers for measuring particles trajectories are positioned. These detectors are followedby the trigger hodoscope consisting of two, double-layer organic paddle-like scintillators for thetime-of-night measurements to reduce background. Recently the first accelerated COSY (CoolerSynchrotron) proton beam was focused in the chamber placed at the entrance of the magneticspectrometer BIG KARL II. The momentum of protons was 660 MeV/c and intensity was 2 X 106

20

3

PL9600991

particles per 300 ms burst. Repetition rate of the beam was 6 - 9 s. The beam was focused ina circle of 1.5 mm radius. The halo of the beam was measured with a set of 5 scintillators (thesame as in the hodoscope) and was less than 1% at a 3 mm distance from the centre of gravityof the beam. The first on-line tests of the focal plane detectors and of the first two layers ofscintillation hodoscope were also performed. The callibration measurements using the reactionspp —> dir+ and pd —> 3He x° are in progress.

Scattering and One-Nucleon Transfer in the 14C +14 NInteraction at Energy of E(14iV) = 116 MeV

A. Budzanowski, YJEC. Chernievski1, E.N. Dovzhenko1, L. Glowacka2, E.I. KoshchyM. Makowska-Rzeszutko, Yu.G. Mashkarov3, V.V. Lutsenko1, Yu.G. Mashkarov2,

A.V. Mokhnach1, W.Von Oertzen4, V.N. Pirnak1, O.A. Ponkratenko1, A.T. Rjidchik1,S.B. Sakuta5, R. Siudak, J. TurkTewicz2; T. Wilpert4 and V.A. Ziman1

institute for Nuclear Research, Kiev, Ukraine2Soltan Institute for Nuclear Studies, Warsaw, Poland3Kharkov State University, Kharkov, Ukraine4Hahn-Meitner Institute, Berlin, Germany5Kurchatov Institute of Atomic Energy, Moscow, Russia

The elastic scattering, inelastic scattering and single-nucleon transfer cross sections in the col-lision of 116 MeV 14N ions with radioactive 14C target were measured using the Kiev isochronouscyclotron. The channels with radioactive nuclei often appear as exit ones in some nuclear re-actions. For studies of such reactions it is necessary to know the effective optical potentialsof the radioactive channels. The 14<7(14AT,14iV), (14iV,14C), (14JV,13C) and (14iV,13iV) nuclearreactions were analysed using the coupled reaction channels method. Reasonable agreementbetween measured and calculated cross sections was achieved. As an example the theoreticaland experimental cross sections for one-nucleon transfer reaction to chosen excited states of 15iVare compared in Fig.l. The isotopic effects in the 14JV scattering and one-nucleon transfers forthe carbon isotopes 1 2C,1 3 C and 14C were investigated. This interest was forced by the factthat 14C nucleus has a closed neutron shell that can strongly influence the reaction mechanismsin the 14C+14iV collision in a comparison with the same for the 12C and 13C isotopes.

uOT\

JQ

Ba

1O1

101

10-1

10 •

1 0 -^ l O " 4

bi o -i o -10 "T

\

I 4C( I 4N. I SC) I 5N#

E(I4N)

tot\

= 116 MeV

5/2'//1/2*

_ •

50 100 150

Figure 1: Angular distributions forthe 14C(14N,1SC)15N* reaction forboth | and | excited states in15N with theoretical CRC calcula-tions (dashed lines) and with co-herent sum of proton and neutrontransfers (solid line).

21

PL9600992

Detection System for the Study of Meson Product ion at theEnergy Threshold

A. Budzanowski1, P. Cloth2, A. Djaloeis2, M. Drochner 3 ' 4, V. Drüke2., J. Ernst5,W. Erven4, D. Filges2, L. Freindl1, D. Frekers6, D. Grzonka2, J. Holzer4, R. Jahn5,

L. Jarczyk7, K. Kilian2, S. Kliczewski1, J. Konijn 8 , S. Kistryn7, D. Kolev9,T. Kutsarova10, B. J. Liebe ł l , G. Lippert2, H. Machner2, H. P. Morsch2, C. Nake2,

L. Pentchev10, H. S. Plendl12, D. Protic2, E. Roderburg2, P. von Rossen2, D. Schwierz3,R. V. Srikantiah13, J. Smyrski 7, A. Strzałkowski7, R. Tsenov9, P. Turek2,

K. Watzlawik 2, P. A. Żołnierczuk7 and K. Zwoll4

1H. Niewodniczański Institute of Nuclear Physics, Krakow, Poland2Institut für Kernphysik, Forschungszentrum Jülich, Germany3Institut für Kernphysik, T. U. Dresden, Germany4Zentralinstitut für Elektronik, Forschungszentrum Jülich, Germany5Institut für Strahlen- und Kernphysik, Universität Bonn, Germany6Institut für Kernphysik der Universität Munster, Germany7Institute of Physics, Jagellonian University, Kraków, Poland8NIKEF K, Amsterdam, The Netherlands9Faculty of Physics, University of Sofia, Bulgaria10Institute for Nuclear and Neutron Research, Bulgarian Academy of Science, Sofia,Bulgaria1 1 George Mason University, Fairfax, Virginia, USA12Florida State University, Tallahassee, Florida, USA13Bhabha Atomic Research Centre, Trombay, Bombay, India

The hybrid detector system for the investigation of meson production and meson-nucleusinteraction was developed and partially mounted at the COSY accelerator in the Forschungszen-trum Jülich (Germany). The system enabling the 4x detection consists of a germanium walltogether with the magnetic spectrometer BIG KARL II (common name GEM) and of the twosets of Multi-Wire-Drift-Chambers (MWDC) coupled with a trigger hodoscope. This last deviceconsists of two double-layer scintillation counters with a variable path of about 2 m in between.Each layer consists of 10 to 12 organic plastic scintillators which are similar in form to the pad-dles. Each paddle is 10 cm wide and 4 mm thick being connected via light guides to phototubes.The slit width between the paddles doesn't exceed 3 mm. The light diodes mounted on somescintillators and driven by a fast puiser enable time adjustment.

In November 1993 the proton beam accelerated at COSY was extracted for the first time[1]. The 1.5 mm radius spot of the beam of some 2-106 particles per burst was achieved in thetarget place. The burst duration time was 300 ms with a 6-9 sec repetition period. The abovedescribed detection set-up was used to observe and establish the beam parameters.

Reference:1. A. Berg et al., IKP Annual Report 1993 (to be published)

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PL9600993

Multifragmentation in the reaction 32S -f 58Ni at 30 AMeVA. Siwek1, A. Budzanowski1, H. Fuchs2, H. Homeyer2, W. Kantor1, G. Roeschert2,

C. Schwarz2, A. Sourell2 and W. Terlau2

1 Institute of Nuclear Physics, Krakow,2 Hahn-Meitner-Institut, Berlin.

The decay of the compound nuclei formed in the reaction 32S + 58Ni at 30 AMeV bombardingenergy was studied.1) The outgoing charged products were detected in the ARGUS detectorwhich consisted of 123 phoswich type detectors (4.4° < 0 < 41.5°) and three semiconductordetectors (0 = 5.5°, 14.0° and 23.5°) which served as independent triggers. In the phoswichdetectors a class of slow fragments (E < 7 AMeV for 7Li and E < 14.5 AMeV for 20Ne) with acharge higher than 2 was selected (HSF - heavy slow fragments). The fragments registered in thetrigger detectors were separated into three classes according to the multiplicity of the registeredHSF's. We thus denned the fragments corresponding to evaporation (with no HSF), fission(with one HSF) and multifragmentation (with two HSF's). The mass and velocity distributionsof fragments from the three processes were analysed. In addition the polar-angle distributionsand the azimuthal-angle correlations were studied for three-fragment emission.

The experimental results were compared with predictions of three different models of multi-fragmentation:• the Berlin statistical multifragmentation model (GROSS),2)• the Copenhagen statistical multifragmentation model (CRACKER),3)• the sequential-fission simulations (sequential multifragmentation) (SMF).1)

The first two models are modifications treating the same process - the quasi-instantaneousformation of fragments by critical density fluctuations close to the liquid-gas transition of excitednuclear matter.

In order to introduce the entrance channel dynamics to the statistical models we made thecalculations for eight different compound nuclei formed in the reaction and sumed them up withthe weights calculated from the Mohring model.4) As an alternative scenario of multifragmentemission we used simulations of two subsequent fissions preceded by light-particle evaporation.For the three models the dependence of the relative decay probabilities on excitation energy wasextracted. In the case of the sequential fission simulations the excitation energy dependence wasobtained by the adaptation of the theoretical results to the experimental data. The qualitativesimilarity of the three models seems to indicate that the phase spaces sampled by sequentialfission and statistical multifragmentation are not too different.

A significant difference between the models can be observed in mass and velocity distribu-tions. Both theories of statistical multifragmentation yield the events with too low masses andtoo high velocities in comparison with the experiment, whereas sequential fission simulationgives a much better description underestimating the data only in low-mass region (Fig. la).

The calculated azimuthal angle correlations and the polar angle distributions of HSF's are ingood agreement with the experimental data. There is only a little difference between predictionsof simultaneous break-up and sequential fission, slightly favouring the latter (Fig. lb).

The calculations suggest that the emission of three heavy fragments is a mixture of the twoprocesses with significant domination of the sequential fission.

23

MUL TIFRA CM E NT A TION

CROSS Sr CRACKER

MUL TIFRA GMENTA TION

GROSS — SF CRACKER

r 50 ,MASS [a.m.u.] PHI3 [deg]

Fig. la. The mass distribution of the frag-ments with velocity v < 4cm/ns registered insemiconductor detector at three different an-gles in coincidence with two HSF's detectedin the phoswich array.

References:

Fig. lb. Relative azimuthal-angle distribu-tion between HSF registered in phoswich ar-ray and the fragment registered in one of thetrigger detectors at 5.5°, 14.0° and 23.5°.

1) A. Siwek, Ph.D. Thesis, INP Krakow 1994.2) X. Zhang et al., Nucl. Phys. A461 (1987) 668.3) H.W. Barz et al., Nucl. Phys. A448 (1986) 735.4) K. Mohring et al., Nucl. Phys. A533 (1991) 333.

LIST OF PUBLICATIONS:

I. Articles:

1. A. Adamczak,Differential Cross Sections for Muonic Hydrogen Scattering on Hydrogen Molecules,Hyperfine Interactions 14 (1993) 1056;

2. S.P. Avdeyev, (W. Karcz) et al.,FAS A- A 47r Detector Setup for the Investigation of Target Multifragmentation in Nucleus-Nucleus Collisions,Nucl. Instr. and Meth. A332 (1993) 149-156;

3. S.P. Avdeyev, (W. Karcz) et al.,Elektronnaya apparatura i programnoye obespetshenye ustanovki 'FAZA',Pribory i Technika Eksperimenta 3 (1993) 104;

24

4. D.P. Beatty, (M. Palarczyk) et al.,Pion Double Charge Exchange on 16O at Tv = 300-500 MeV,Phys. Rev. C48 No 3 (1993) 1428-1430;

5. Z. Chyliriski,Gravity and Non-Extensive Nature of Mass,Acta Phys. Pol. B24 (1993) 1475-1479;

6. Z. Chylinski, E. Obryk,Internal Geometry of n-Body Systems and One-Particle States,Acta Phys. Pol. B24 (1993) 1179-1191;

7. S. Drozdz, J. Okolowicz, T. Srokowski,Coexistence of Hyperpolic and Nonhyperpolic Chaotic Scattering,Julich preprint KFA-IKP(TH)-1993-93; Phys. Rev. E48 (1993) 48-51;

8. J.D. Johnson, (M. Palarczyk) et al.,Search for an 77 Bound State in Pion Double Charge Exchange on 18O,Phys. Rev. C47 No 6 (1993) 2571-2573;

9. P. Kaminski, S. Drozdz, M. Ploszajczak, E. Caurier,The Even-Odd Anomalous Tunneling Effect,GANIL preprint P-92-19; Phys. Rev. C47 (1993) 1548;

10. H. Machner, (A. Budzanowski, H. Dabrowski, I. Skwirczynska) et al.,Quasi-Free Production of Pionic Atoms in Low-Lying States,Physica Scripta 48 (1993) 175-178;

11. R.S. Mayer, (H. Dabrowski, B. Fornal, L. Freindl) et al.,Investigation of Pion Absorption in Heavy-Ion Induced Subthreshold n° Production,Phys. Rev. Lett. 70 (1993) 904;

12. N.N. Nikolaev, (A. Szczurek) et al.,The Fermi Motion Effect in the Signal for Color Transparency in (e, e'p) Scattering,Julich preprint KFA-IKP(TH)-1993-21; Phys. Lett. B317 (1993) 287-292;

13. N.N. Nikolaev, A. Szczurek et al.,Correlation Effects in the Final-State Interaction for Quasielastic (e,e'p) Scattering,Julich preprint KFA-IKP(TH)-1993-14; Phys. Lett. B317 (1993) 281-286;

14. E. Obryk,Reaktory wysokotemperaturowe - mozliwosci ich wykorzystania i perspektywy rozwoju,Archiwum Energetyki 22 (1993) 95 (in Polish);

15. J. Pluta, (P. Stefanski, H. Dabrowski) et al.,Possible Observation of Medium Effects Using a Pion Correlation Technique,Nucl. Phys. A562 (1993) 365-388;

16. C. Schwarz, (A. Siwek, A. Budzanowski) et al.,Projectile Break-up with Two Outgoing Intermediate-Mass Fragmentsin 26 MeV 32S+197Au, Z. Phys. A345 (1993) 29-35;

17. T. Srokowski, J. Okolowicz, S. Drozdz, A. Budzanowski,Fusion Cross Section from Chaotic Scattering,Phys. Rev. Lett. 71 (1993) 2867-2870;

25

18. A. Szczurek,Meson Cloud in the Nucleus and Search for u-d Asymmetry,Proc. of the Int. Conf. on Meson-Nucleus Interaction, Przegorzaly, May 14-19, 1993, in:Acta Phys. Pol. B24 (1993) 1833-1848;

19. A. Szczurek, J. Speth,Role of Meson Degrees of Freedom in Deep-Inelastic Lepton-Nucleon Scattering,Nucl. Phys. A555 (1993) 249-271;

II. Contributions to Conferences:

1. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al.,The COMBAS Projectile Fragment Separator. Present and Future,Proc. 3rd Int. Conf. on the Radioactive Nucl. Beams, May 24-27 1993, Michigan, USA;Abstr. of Int. School-Sem. on Heavy Ion Phys., May 10-15, Dubna (1993) 163;

2. COSY-11 Collab., K. Kilian, (M. Ziolkowski) et al.,Antiproton und Proton Induzierte Produktion von Mesonen am LEAR und am COSY,Abstr. Verhandlungen der DPG(VI) 28 (1993) 578;

3. S.I. Gogolev, (R. Wolski) et al.,Energetic Particle Emission in the 16O-Induced Reaction on 27A1 at E/A=19.3 MeV,Abstracts of Int. School-Seminar on Heavy Ion Physics, May 10-15, 1993, Dubna, Russia(1993) 105;

4. M.G. Nagaenko, (M. Gruszecki) et al.,Fragment-Separation Method. Ion Optics and Magnetic Structure of COMBAS,Proc. of Int. Workshop on Radioactive Nucl. Beams Produced by Fragment-SeparationTechnique, Varna, October 12-15 (1993) ;

5. E. Obryk,Nuclear Coal Synergism as an Option for Future Energy System,Proc. of the 2nd JAERI Symposium on HTGH Technologies, Tokaimura, Japan (1993)377;

6. PS185 Collab., K. Kilian, (M. Ziolkowski) et al.,Antihyperon-Hyperon Production am LEAR,Abstr. Verhandlungen der DPG(VI) 28 (1993) 579;

7. PS185 Collab., K. Kilian, (M. Ziolkowski) et al.,Polarisationsdaten fur AA-Produktion in pp-Reaktionen des Experiments PS185,Abstr. Verhandlungen der DPG(VI) 28 II (1993) 579;

8. PS185 Collab., K. Kilian, (M. Ziolkowski) et al.,Spinkorrelation und Singulett-Anteil in der AA Produktion,Abstr. Verhandlungen der DPG(VI) 28 (1993) 580;

9. PS185 Collab., K. Kilian, (M. Ziolkowski) et al.,Der Dreiteilchenkanal AA7T0 in der pp-Wechselwirkung,Abstr. Verhandlungen der DPG(VI) 28 H (1993) 580;

10. PS185 Collab., K. Kilian, (M. Ziolkowski) et al.,New Limits on CP and CPT in Hyperon Decays,Abstr. Verhandlungen der DPG(VI) 28 (1993) 717;

11. N.K. Skobelev, (R. Wolski) et al.,Cross-Section Measurements of 6He-Induced Fission of Bismuth,Abstracts of Int. School-Seminar on Heavy Ion Physics, May 10-15, 1993, Dubna, Russia(1993) 93;

26

12. Yu.G. Teterev, (M. Gruszecki) et al.,Radioactive Beams Diagnostic System of the Fragment-Separator COMBAS,Proc. of Int. Workshop on Radioactive Nucl. Beams Produced by Fragment-SeparationTechnique, Varna, October 12-15 (1993) 1;

13. W.A. Ziman, (M.H. Makowska-Rzeszutko) et al.,Rassiejannyje i Odnonuklonnyje Pieriedaczi w Stolknowienijach 14C + 14N pri E(14N) =118 MeV (in Russian);Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23Apriela (1993) 281;

III. Reports:

1. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al.,Study of Properties of Ne-Al Neutron Rich Isotopes at and Near iV=20 Magic Shell UsingElastic Scattering in Inverse Kinematics,JINR Dubna Report E7-93-74 (1993);

2. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al.,Magneto-Optic Structure of the COMBAS Fragment Separator,Scientific Report 1991-1992 in: JINR Dubna Report, p.262-264 E7-93-57 (1993);

3. A.G. Artukh, (M. Gruszecki, S. Kliczewski, M. Madeja, J. Szmider) et al.,The COMBAS Projectile Fragment Separator,Scientific Report 1991-1992 in: JINR Dubna report, p. 260-261 E7-93-57 (1993);

4. S.P. Avdeyev, (W. Karcz) et al.,Multifragmentation in 4He+Au Collisions at Relativistic Energies Studied with the 4TT-Setup FASA,JINR Dubna preprint E7-93-278 (1993);

5. J. Balewski, (M. Ziolkowski) et al.,Status of the Preparation for the COSY-11 Installation,KFA Julich Annual Report 3 (1993);

6. P.D. Barnes, (M. Ziolkowski) et al.,The PS185 Threshold Irregularity - A Detailed View,KFA Julich Annual Report 2 (1993);

7. B. Czech,Programowany sterownik urzadzen elektrycznych do 32 kW,Raport IFJ 1645/E (1993) (in Polish);

8. S. Drozdz, S. Nichizaki, J. Wambach,Chaos Driven Decay of Nuclear Giant Resonanses: Renote to Quantum Self-Organization,Illinois Preprint P-93-12-106 (1993);

9. A. Gorski, Chr.V. Christov, K. Goeke,Electromagnetic Nucleon Properties and Quark Sea Polarization in the Nambu-Jona-Lasino Model,Bochum Univ. preprint RUB-TPII-56/93 (1993);

27

10. M. Gruszecki,Spektrometryczne przetworniki analogowo-cyfrowe. (cz. II. Kodowanie interwałów cza-sowych). Stan obecny i perspektywy analogowych metod kodowania,Raport IFJ 1638/PL (1993) (in Polish);

11. D. Grzonka, (M. Ziółkowski) et al.,Light Output of Twisted Scintillator Segments,KFA Jiilich Annual Report (1993);

12. H. Holtmann, A. Szczurek, J. Speth,Consistent Treatment of Pseudoscalar and Vector Mesons in Deep-Inelastic Scattering ofNucléons,Jülich preprint KFA-IKP(TH)-1993-33 (1993);

13. P. Kamiński, M. Płoszajczak, R. Arvieu,Quantum Tunneling in the Driven Lipkin N-Body Problem,GANIL preprint P-93-13 (1993);

14. S. Kopp, A. Szczurek et al.,Final State Interaction Effects in Exclusive and Inclusive Quasi-Elastic Electron Scatteringfrom 1 2 C ,Jülich preprint KFA-IKP(TH)-1993-20 (1993);

15. J. Majewski, (M. Ziółkowski) et al.,Fast Pulse Integrator,KFA Jülich Annual Report 1 (1993);

16. N.N. Nikolaev, A. Szczurek, J. Speth, V.R. Zoller,Pions in the Light-cone Nucleón and Electromagnetic Form Factors,Jülich preprint KFA-IKP(TH)-1993-34 (1993);

17. N.N. Nikolaev, A. Szczurek et al.,Multiple-Scattering Effects in the Transverse-Momentum Distribution from (e, e'p)Reactions,Jülich preprint KFA-IKP(TH)-1993-31 (1993);

18. J. Pluta, (H. Dąbrowski) et al.,Possible Signature of Medium Effects with Pion Invariant-Mass Correlations,Rapport Interne Lnp-93-16 (1993);

19. I. Skwirczynska, L. Freindl, S. Kliczewski, M. Madeja, A. Budzanowski, W. Karcz,J. Szmider, R. Wolski, J. Czakański,Heavy Ion Emission in Alpha-Induced Reaction on Silicon in the Energy Range E a=24.9- 27.85 MeV,Raport IFJ 1649/PL (1993);

20. A. Szczurek et al.,Meson Cloud in the Nucleón and ü — d Asymmetry from the Drell-Yan Processes,Jülich preprint KFA-IKP(TH)-1993-13 (1993);

28

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. A. Budzanowski,

"Nuclear Big Bang", Masurian School of Nuclear Physics, Piaski, 18-28 August 1993.

"Big Bang in Nuclear Physics", XXXII Meeting of the Polish Physical Society,Krakow, September 1993.

2. 5. Drozdz,

"Modeling complex background spectra", Conference on Nuclear Spectroscopy andNuclear Structure, Dubna, April 20-23, 1993.

"Modeling complex nuclear spectra - regularity versus chaos", Mid-West NuclearTheory Conference, Argonne, September 17-18, 1993.

3. A. Szczurek,

"The role of the meson cloud in deep inelastic scattering of leptons", Conference ofMatter as Revealed with Electroweak Probes, Schladming, February 24 - March 5,1993, Austria.

"Strong form factors", Workshop Exclusive Reactions at High Momentum Transfer,Marciana Elba, June 22-23, 1993, Italy.

"Meson-cloud of the Nuclear in Deep-Inelastic Scattering and the Drell-Yan pro-cesses", Meeting of German Physical Society, Mainz, March 22-26, 1993, Germany.

"Consistent description of exclusive 12C(e,e'x) reactions", Meeting of German Phy-sical Society, Mainz, March 22-26, 1993, Germany.

SCIENTIFIC DEGREES

Ph.D. Theses:

1. Regina Siudak - "Multistep Direct Reaction Analysis of Inelastic Scattering and Charge-Exchange Processes at Intermediate Energies".

LECTURES, COURSES AND EXTERNAL SEMINARS:

A. Budzanowski"Selected Topics in Theoretical Physics"Lectures for students of physics at the Jagellonian University, Krakow.

5. Drozdz"Hadronic Matter Physics"Lectures for students of physics at the Jagellonian University, Krakow.

A. Gorski (with S. Drozdz)

29

"Hadronic Metter Physics"Lectures for students of physics at the Jagellonian University, Krakow.

5. Drozdz1. "Nuclear Chaotic Scattering"Seminar - University of Illinois, Urbana, September 15, 1993.2. "Chaos Driven Decay of Nuclear Giant Resonance"Seminar - University of California, Berkeley, November 18, 1993.

INTERNAL SEMINARS:

1. Z. Majka: "Information on the subject of european forum of nuclear mechanisms".2. R. Siudak: "MSDR model of preequilibrium reactions".3. P. Kaminski: "Quantum tunneling in the SU(2) interacting fermion systems".4. H. Holtman - KFA Julich, FRG: "Spin and flavour in the proton".5. A. Gorski: "Electromangetic formfactors of nucleon in the Namub-Jona-Lasinio model".6. H. Lenske - University of Giessen, FRG: "Relativistic mean-field theory of hypernuclei".7. R. Broda: "Discrete gamma radiation in HI reaction studies - new regions of nuclear

spectroscopy".8. P. Kamiriski: "Quantum tunneling in the SU(2) models - even-odd effect".9. J. Lukasik - Institute of Physics, Jagellonian University: "CHIMERA - microscopic

description of intermediate energy heavy ion collisions".10. A.T. Rudchik - Kiev Institute of Nuclear Researhch, Ukraine: "Current problems of heavy

ion nuclear physics at low energy".11. H. Fuchs - HMI Berlin, RFC: "Fire ball, hot spots and related problems in heavy-ion

collisions in the Fermi energy domain".12. A. Gorski: "Chiral solution model of the NJL type".

SHORT TERM VISITORS TO THE DEPARTMENT:

1. A. Artiuch - JINR Dubna, Russia.2. A. Karnaukhov - JINR Dubna, Russia.3. H. Holtmann - Forschungszentrum Julich, FRG.4- E.J. Koschchy - Kharkov University, Ukraine.5. V.K. Chernievski - Kiev Institute of Nuclear Research, Ukraine.6. V.Z. Ziman - Kiev Institute of Nuclear Research, Ukraine.7. A. Rudchik - Kiev Institute of Nuclear Research, Ukraine.8. W. Protic - Forschungszentrum Julich, FRG.9. P. Hamayer - Forscungszentrum Julich, FRG.10. H. Fuchs - HMI Berlin, FRG.

APPENDIX:

In Annual Report 1992 the following items have been omitted

page 33, Section: List of Publications, Subsection: Articles,

30

13. A.S. Demyanova, (M.H. Makowska-Rzeszutko) et al.,Pieredacza tiazolych klastrov w reakcji 12C(4He,12C)4He,Yademaja Fizika, 55, No 10 (1992) 2731-2734 (in Russian).

page 34, Subsection: Contributions to Conferences,

3. A.S. Demianova, (M.H. Makowska-Rzeszutko) et al.,Pieredacza Tiasholych Klastrov w Reakcji 12C(4He,12C*)4He,Proc. of Conf. "Jadiernaja Struktura i Struktura Atomnovo Jadra",Alma-Ata (1992) 261 (in Russian).

31

Department ofNuclear Spectroscopy

DEPARTMENTOF NUCLEAR SPECTROSCOPY:

Head of Department: Professor Andrzej Z. HrynkiewiczDeputy Head of Department: Professor Jan StyczeńSecretary: Małgorzata Niewiaratelephone: (48) (12) 37-02-22 ext.: 202, 477e-mail: niewiara@vsb01.ifj.edu.pl

PERSONNEL:Laboratory of the Structure of NucleusHead of the Laboratory: Professor Rafał Broda

Research Staff:Piotr Bednarczyk* Adam Maj Barbara WodnieckaBogdan Fornal Marta Marszałek Paweł WodnieckiMarian Gąsior Witold Męczyński Jacek WrzesińskiWojciech Królas* Tomasz Pawłat Kazimierz ZuberMałgorzata Lach Antoni Potempa

Technical Staff:Jerzy Grębosz Jan Jurkowski Mirosław ZięblińskiMieczysław Janicki Antoni Szperłak

Laboratory of Applied Nuclear SpectroscopyHead of the Laboratory: Dr. Zbigniew Stachura

Research Staff:Kvetoslava Burdova Roman Kmieć Franciszek ManiawskiMarian Cholewa Stefan Kopta Elżbieta Marczewska*Małgorzata Drwięga Janusz Kraczka Bogusław RajchelEwa Dryzek Wojciech M. Kwiatek Małgorzata SowaJerzy Dryzek Jadwiga Kwiatkowska Jagoda Urban

Technical Staff:Erazm M. Dutkiewicz Piotr Leśniewski Tomasz NowakLuba Glebowa Ewa Lipińska Zbigniew SzklarzRoman Hajduk Janusz Łachut Andrzej SeUmanJanusz Lekki Stanisław Łazarski* Ph.D. student

Administration:Małgorzata Niewiara

33

GRANTS:

1. Prof. R. Brodagrant No 224319203 (The State Committee for Scientific Research),"Heavy-ion reaction mechanism studied by discrete gamma-radiation"

2. Prof. A. Hrynkiewiczgrant No 204579101 (The State Committee for Scientific Research),"PAC studies of hyperfine interactions in Hf and Ce compounds"

3. Prof. J. Styczengrant No 204519101/P01 (The State Committee for Scientific Research),"Properties of "hot" atomic nuclei studied by means of gamma rays"

4. Prof. J. Styczengrant No 204519101/P02 (The State Committee for Scientific Research),"Investigations of high-spin excitations and superdeformation in nuclei"

5. Dr J. Dryzekgrant No 2P30202804 (The State Committee for Scientific Research),"Badanie rezonansowego wychwytu pozytonow w dele stalym"("Studies of positron resonance trapping in solids")

6. Dr B. Rajcheljoint grant with Mining Academy, Krakow,grant No 773269203 (The State Committee for Scientific Research),"Investigation of high-temperature corrosion in metals doped by the ion-implantation"

7. Dr Z. Stachuragrant No 2P30204505 (The State Committee for Scientific Research),"Modyfikacja powierzchni cial statych i jej badanie z uzyciem wybranych metodspektroskopowych" ("Modification of solid surfaces and their investigationby methods of nuclear spectroscopy")

Dr J. Kwiatkowska and Dr. F. Maniawski also participate in following grants:grant No 201829101 at the Department of Structural Research, andgrant No 223509102 at the Warsaw University (Bialystok branch)

34

OVERVIEW: PL9600994

The scientific activity of our Department in 1993 was as earlier continued predominantlyin two research programs i.e. the nuclear structure and heavy-ion reaction studies by gammadetection techniques and condensed matter investigations with application of various atomicand nuclear spectroscopy methods. The short reports which follow include selected results fromnumerous scientific projects, seven of which were approved by the State Committee for ScientificResearch and received special grants.

Extensive studies were performed on some fp-shell nuclei. The experimental data obtainedrecently prove the 68Ni neutron-rich isotope to be a double closed-shell nucleus. While in 45Sc,the collective degrees of freedom seem to manifest pronouncedly. A collective band of states wasobserved in this nucleus up to possibly spin 39/2+ .

The collective motion in heavier nuclei (rare earth and lead regions) was investigated withspecial consideration of superdeformed bands in 149Gd where the dynamic moment of inertiaat high frequencies shows staggering which may be due to the C4 symmetry. The giant dipoleresonance studies revealed, among others, the presence at low bombarding energies of the dipolegamma radiation (5 - 60 MeV) which is a bremsstrahlung type radiation due to nucleon-nucleoncollisions.

The perturbed angular correlation and Mossbauer spectroscopy techniques have furnishedseveral new data on hyperfine interaction properties for some intermetallic and three-metal com-pounds. The Compton spectrometry studies of Ag single crystals shed some light on electronicstructure in that metal. Properties and structure of some alloys were investigated with thatmethod and also with the positron annihilation spectroscopy method.

The successful use of the Van de Graaff accelerator, recently installed, has resulted in anumber of works on trace element analyses in various parts of the human body (cooperation witha hospital) by the PIXE (proton induced X-ray emission) method. The role of ion implantationin changing surface properties of solids was studied by the RBS (Rutherford back scattering)measurements.

The rich program for that year was to a great deal accomplished due to broad internationalcooperation which made it possible to perform several experiments with the use of multidetectorgamma-arrays and other highly sophisticated instruments and facilities.

In total, 95 publications with 44 in journals demonstrate the activity.Strong effort has also been devoted to the development of various instruments and detectors

as well as to data storage and reduction. The present computer network allows one to perform thereduction of data from various multidetector systems (GASP, EUROGAM, OSIRIS, HECTOR).Much advanced has been the construction of: i) the AFM (atomic force microscope) whichwill enable both ultra-high resolution microscopy and investigation of mechanical propertiesof surfaces of solids in the atomic scale, ii) the RFD (recoil filter detector) for filtering therecoiled nuclei in heavy-ion fusion evaporation reactions for spectroscopic studies planned withthe EUROGAM in Strasbourg.

Worth mentioning is the upgrading of the old mass separator which is now used for surfacemodifications by the IBAD (Ion Beam, Assisted Deposition) technique, after the addition of anauxiliary ion beam.

Two international meetings were organized in 1993: the XXVIII Zakopane School on "Con-densed Matter Studies by Nuclear Methods" and "High Resolution Compton Scattering as aProbe of Fermiology" attracting 90 and 55 participants respectively.

rof, Jan Styczen

35

REPORTS ON RESEARCH: PL9600995

The 208Pb -f- Ni collisions studied by discrete 7—ray analysis

W. Krolas, R. Broda, B. Fornal, J. Gr§bosz, T. PawlatM. Schramm1, H. Grawe1, J. Heese1, K.H. Maier1, R. Schubart2

In several previous reports [1] we presented a few initial results obtained from a complexanalysis of the 7 radiation accompanying the collisions of 350 Mev 64Ni projectiles with the208Pb target. One of the aims of this analysis was to obtain as complete as possible distributionof the final product nuclei, which would allow one us to inspect detailed features of the energyand mass transfer and of the N/Z equilibration process. This part of the analysis involvedevaluation of the in-beam and off-beam coincidence data as well as of the measured radioactivedecay 7 spectra and allowed to extract the production yields for more than 300 nuclei.

The emerging picture is quite complex and clearly the interpretation of the results demandsspecial efforts to extract the transparent information concerning specific features of the heavyion deep-inelastic collisions. At the starting point of this interpretation work we present here fewresults, which display the quality of the obtained experimental material. In Fig. 1 the obtainedproduct distribution is presented in N, Z frame for the heavy fragments localized around andbelow the 208Pb target nucleus. The projection of the complete distribution on the Z - atomicnumber axis is shown in Fig. 2. The lines drawn in a somewhat arbitrary way mark regionswhere various processes, from quasielastic A, through deep-inelastic B, to fusion-fision C play adominant role. It has been earlier established [2] that in the energy range below 6.1 MeV/u thefusion process is supressed due to the requirements of an additional extra-push energy; smallyields in the region C apparently correspond to the residual probability of the compound nucleusformation.

85

80

75

70

210.

Ebeam = 350 MeV

heavy fragments

200

A =165

160Q stable nucleus

[Vj a = 10 units

HI ^ P b target

N100 105 110 115 120 125

Fig. 1. Distribution of heavy fragments of the 208Pb + 350 MeV6ANi reaction.

36

t—4

CD

105 f

104

20 30 40 50 60 70 80

atomic number (Z)90

Fig. 2. Element distribution of reaction products. Yields are given in arbitrary units. Targetand projectile element numbers are marked by dashed lines. Thin lines are drawn to markschematically contributions from different processes (see text).

The presented production yields refer to the secondary products which are formed from theprimary excited fragments by a subsequent neutron evaporation. Since in the considered regionof nuclei the charged particle evaporation can be neglected one can extract the average numberof evaporated neutrons for each combination of exit channel partner nuclei with Z\ + Zi =82 + 28 = 110. The sum of average masses of all Z\ and Zi products is smaller than the mass ofthe compound system and the difference must be attributed to the neutron evaporation. Fig. 3shows the average number, obtained in this way, of evaporated neutrons as a function of thenumber of protons transfered from the 208Pb to 64Ni projectile. The correlation between theproton transfer and the energy transfer is evident.

- 6 - 4 - 2 0 2 4 6 8 10 12 14 16 18number of protons transfered

Fig. 3. Number of evaporated neutrons for givenproton transfer. Lines are drawn to guide the eye.

References:

[1]. W. Krolas et al., IFJ Krakow, An-nual Report 1992, p. 43,W. Krolas et al., Acta Phys. Pol. B24(1993) 449,W. Krolas et al., Acta Phys. Pol. B(in press),[2]. R. Bock et al., Nucl. Phys. A388(1982) 334.

1 Hahn-Meitner-Institut Berlin,Germany

2 Universitat Gottingen, Germany

37

PL9600996

High spin states in the 45Sc nucleus

P. Bednarczyk1, J. Styczeri, R. Broda, M. Lach, W. M^czyriski,G. de Angelis2, D. Bazzaco3, S. Lunardi3, R. Menegazzo3, L. Muler3 , C. Petrache2,

C. Rossi-Alvarez3, G.F. Segato3, F. Scarlassara3, F. Soramel4

The nuclei in the /7 /2 shell exhibit properties which reflect an interplay between dominantsingle-particle motion and collective degrees of freedom which become more and more importantespecially for the nuclei in the middle of the shell [1,2]. The experimental data for high spinstates is still rather scarce due to an unsatisfactory efficiency and limited selectivity of thetechniques used. Now available multidetector arrays and the use of Recoil Mass Spectrometerin reduction of the Doppler broadening, which enhance and improve considerably the data, canbring new insight into the excitation mechanism of high excited and high spin states.

The present report is a continuation of the studies [3] which we have performed recentlyusing the RMS and GASP at LNL. The level scheme of 45Sc reported in [3] is now extended upto I* = 39/2+ state, also additional transitions for the negative parity states have been found.The analysis of DCO ratios has allowed one to establish spin assignments for the most observedlevels.

In Fig. 1, plots of the angular momentum against the rotational frequency defined as a halfof the 7-ray energy are shown, for three spin sequences in 45Sc. Striking is the smooth behaviorof the moment of inertia for the positive parity A and B bands which points to their collectivecharacter, whereas negative parity "normal" /™,2 configuration states display a more irregularcharacter typical for the single—particle states.

22

17

-i—i— r

= 6 positive parity states _

' Band 0

negative parity states _

0.5 1.5 0 0.5

Tito [MeV]

1.5

Fig. 1: The angular momentum versus rotational frequency plot for bands observed in the 45Scnucleus

38

Ex[MeV)

• 13/2"

. 11/2"' 9 / 2 "

7 / 2 -

expcriment shell model

Fig. 2: The comparison between shellmodel calculations and the observednegative parity levels.

50

40

30

10

0.4 0.5 0.6 0.7 0.8 0.9 1.0rot. freqency (MeV)

I.J

Fig. 3: The dynamic moment of inertia(j(2) = A^* ) of the positive parity

collective band A in 45 Sc as a functionof rotational frequency.

In fact, a shell model calculations per-formed for 51Cr [4] which is a cross conjugatenucleus to 45Sc reproduce well the sequenceand excitation energies for the tentatively ob-served negative parity states (Fig. 2).

The "staggering" of the dynamic mo-ment of inertia (Fig. 3) for the band A athigh angular frequencies resembles somewhatthe staggering of the moment of inertia ofheavy superdeformed nuclei [5]. This effecthas been related to the influence of the C4 ro-tational symmetry at high angular momenta.

A crude estimate obtained from thethick target measurement shows that thelifetimes for the positive parity A bandabove 15/2+ state are below 0.2 picosecond.Such lifetime limits imply that the high en-ergy transitions are rather fast (more than15 WU). In order to determine this enhance-ment more precisely, an experiment concern-ing the lifetime measurement of the high spinstates in 45Sc nucleus with the DSAM tech-niques will be performed at LNL.

References:

[1]. J. Styczen et al., Nucl. Phys. A262(1976) 317[2]. J.A. Cameron et al., Phys. Lett. B235(1990) 239[3]. P. Bednarczyk et al., IFJ Ann. Rep.1992[4]. A. Yokoyama et al., Phys. Rev. C31(1985) 1012[5]. S. Flibotte et al., Phys. Rev. Lett. 71(1993) 4292

1 Institute of Nuclear Physics, Krakow, Polandand INFN, Laboratori Nazionali di Legnaro, Italy2 INFN Laboratori Nazionali di Legnaro, Italy3 Dipartimento di Fisica dell'Universita andINFN, Padova, Italy4 Dipartimento di Fisica dell'Universita andINFN, Udine, Italy

39

PL9600997

The N — 40 neutron subshell closure in the Ni nucleus

R. Broda, B. Fornal, W. Królas, T. Pawłat, D. Bazzacco1, S. Lunardi1,C. Rossi-Alvarez1, R. Menegazzo1, G. de Angelis2, P. Bednarczyk2, J. Rico2,

D. De Acuña2, P.J. Daly3, R.H. Mayer3, M. Sferrazza3, H. Grawe4, K.H. Maier4,R. Schubart5

The proton Z = 40 subshell closure is clearly demonstrated by the well known level structureof the 90Zr nucleus [1], for which the lowest excitation is the 0+ state, the first 2+ state appearsat 2.19 MeV and the energy favoured particle-hole (j?i/2<79/2) excitation produces the long-lived5 isomeric state. Obvious difficulty to study similar features for the neutron number N = 40comes from the fact that the nuclei in question lie very far from the stability line and are noteasily available for spectroscopic investigation. Out of two possibilities, which can be consideredas realistic, the extremely neutron defficient Z = N — 40 80Zr nucleus was found to be stronglydeformed and does not show any trace of the shell closure signature [2]. The only other candidatewith the proton closed shell is the N = 40 68Ni nucleus. It lies much closer to the stability line,but it is located on the neutron-rich side and cannot be produced by the fusion process. In fact,the only known excitation in 68Ni, the 1.77 MeV 0+ state was assigned using the 70Zn(14C,16O)reaction [3]. In our effort to search for excited states in 68Ni we used the deep-inelastic processestaking place in heavy ion collisions.

Recently we exploited such processes to study the neutron-rich Ni isotopes produced inthe 208Pb + 350 MeV 64Ni collisions [4]. The 7-7 coincidences measured with the OSIRISarray at the HMI Berlin allowed us to extend significantly the level schemes of A — 64 to 67Nickel isotopes. The isotopic identifications were based on the observation of cross-coincidencesbetween the 7-rays of two product nuclei present in the reaction exit channel. In that experiment

5-1

4 -

3 -

2 -

1 -

o-J

4.48

4.16

3.85

( 4 + , 3 -

.+ 2.70

2033

0 +

561 58Ni30 60Ni32

62Ni34 "Ni «bo !32 34 l3668 N i

40

Fig. 1. Systematics of selected states in even Ni isotopes and 6SNi results.

40

the production of 6 8Ni was clearly indicated, but no 7-ray could be positively identified withthis isotope due to insufficient statistics. To improve the experimental conditions we performedat the INFN Legnaro a similar measurement for the 130Te + 6 4Ni system, using the much morepowerful GASP multidetector array. The 275 MeV 6 4Ni beam bombarded the 1.2 mg /cm 2 130Tetarget located in the array center and placed on a 14 mg/cm 2 2 0 8 Pb backing to stop all reactionproducts. The 7 -7 coincidences were stored without any restriction on the multiplicity andthe beam was pulsed with 200 ns repetition time in order to separate the prompt and delayedevents. The scope of the experiment was much broader and the obtained data are analysed withemphasis on various spectroscopy and reaction mechanism aspects. Here we report this part ofthe analysis which led to the positive identification of the 68Ni excited states.

Fig. 1 shows the systematis of even Ni isotopes and already includes the results obtained for6 8Ni from the present analysis. In our search we were guided by a simple shell model expectationwhich predicts in 6 8Ni, similarly as in 9 0Zr, a likely appearance of a long-lived 5~ isomer as wellas a significant increase of the 2 + excitation energy as compared to the lighter Ni isotopes.The scanning of the appropriate energy region of the 7^7 coincidence data revealed the cascadeof two coincident transitions of 814 keV and 2033 keV energy, which were perfect candidatesfor the 5~ —> 2 + —• 0 + transition cascade in 6 8Ni. Both transitions were found to follow thedecay of the long-lived isomer (T a /2 > 0.5/xs) and appeared in both, the 2 0 8 Pb and 1 3 0Te targetexperiments with intensities, which matched the expected production yields of the 6 8Ni isotope.In an a t tempt to provide the final identification one has to realize that the long-lived isomerrestricts the possibility to observe cross-coincidences to those events only, which correspond tothe direct, prompt population of the presumed 2033 keV 2 + state. Nevertheless, the superiorstatistics of the GASP data for the 1 3 0Te + 64Ni system allowed one to establish the promptcoincidences between the 2033 keV line and several transitions of the Te isotopes with massnumbers A = 125 to 122. This pat tern of Te partner products uniquely assigns the 2033 keVtransition to the 6 8Ni nucleus, which is formed by a transfer of at least four neutrons to the 64Niprojectile and subsequent evaporation of one to four neutrons from the primary products.

The high energy section of the prompt coincidence spectrum taken with the 2033 keV gaterevealed the 1114 keV line; much weaker than the strong 814 keV isomeric transition, butclearly belonging to the nucleus. It establishes yet another state in 6 8Ni, lying 300 keV abovethe 5~ isomer. From the Fig. 1 systematics we assign tentatively this state as the 4 + excitation,although the 3~ assignment cannot be excluded.

The progressing analysis is now directed towards a search for higher lying states in 68Niand an a t tempt to locate the 8 + <j2,2 excitation. The planned experiment devoted to themeasurement of the isomeric half-life should further clarify the E3 character of the 814 keVtransition and consequently the spin-parity assignment of the isomer.

References:

[1] L.P. Ekstrom and J. Lyttkens-Linden, Nucl. Data Sheets 67 (1992) 579[2] C.J. Lister et al., Phys. Rev. Lett. 59 (1987) 1270[3] M. Bernas et al., J. Physique Lett. 45 (1984) 851[4] T. Pawlat et al., submitted to Nucl. Phys. A

1 Dipartimento di Fisica dell'Universita and INFN, Padova, Italy2 INFN Laboratori Nazionali di Legnaio, Italy3 Purdue University, West Lafayette, Indiana, USA4 Hahn-Meitner-Institut Berlin, Germany5 Universitat Gottingen, Germany

41

PL9600998

Spectroscopy of neutron-rich A=93-97 Zr nuclei

B. Fornal, R. Broda, W. Krolas, T. Pawlat, D. Bazzacco1, S. Lunardi1,C. Rossi-Alvarez1, R. Menegazzo1, G. de Angelis2, P. Bednarczyk2, J. Rico2,

D. de Acuiia2, P.J. Daly3, R.H. Mayer3, M. Sferrazza3

To explore yrast spectroscopy of the neutron-rich nuclei, which are not accessible by fusion-evaporation reactions, we performed an experiment, in which the target of 130Te (backed withPb) was bombarded with a pulsed beam (200 ns repetition time) of 64Ni (12% above barrier)from the Tandem XTU at Laboratori Nazionali di Legnaro. The in-beam and off-beam 7 - 7coincidences, taken with the multidetector system GASP, gave valuable information concerningthe deep-inelastic reaction products with A~64 and A~130. For example, low lying excitedstates 2 + , 5~ and 4+ in 68Ni have been identified for the first time revealing the double shellclosure character of this nucleus [1].

The data include also intense 7-rays from the fusion-fission fragments; in particular from theZr isotopes with A= 93-98, which are products of the symmetric fission. The quality of this datagives a very good opportunity to extract spectroscopic information in this poorly known area.Whereas the Zr isotopes with A<92 could be studied in fusion-evaporation reactions and, onthe other hand, the Zr nuclei with A>98 were reached in fusion-fission processes [2,3], missingis any information about yrast excitations in 93Zr, 95Zr and 97Zr. Also in the even isotopes 94Zrand 96Zr the highest identified spins are only 6 and 8, respectively.

C/)

600

500

400

96-gate: 1750 keV in aD2r

450 650 850 1050 1250 1450 1650

Ey (keV)

Fig. 1. Representative 7 - 7 spectrum for 9eZr product of the 130 Te + 272 Me V MNi reaction.

Fig.l shows the spectrum associated with the gate on the 2+—*0+s transition in 96Zr. Clearlyvisible are 7-rays in 96Zr itself, among which one can recognize gammas depopulating knownstates as well as the new ones, presumably originating from the higher yrast levels. In addition,one can see 7-rays from the other Zr nuclei with A=92, 94 and 95; those are the exit channelreaction partners to the 96Zr associated with different numbers of evaporated neutrons. Thecoincidences between 7-rays from the different reaction partners, so called "cross-coincidences",happen to be very intense in the Zr case and they can serve as a powerful tool for assigningunknown transitions. In fact, by setting gates on a 7-transition in a specific nucleus, the intensity

42

PL9600999

pattern of the displayed cross-coincidence transitions from other nuclei is characteristic for thatnucleus thus providing a unique isotopic assignment.

We have just started the part of the data analysis concerning the fission products spec-troscopy. In the first approach, we are going to study excitations in the mentioned 93~97Zrisotopes and then to extend these investigations to other fission products, which are otherwisehard-to-reach.

References:

[1] R. Broda et al., another contribution to this Ann. Rep.[2] J.L. Durell, Ada Phys. Pol. B24 (1993) 105.[3] M.A.C. Hotchkis et al., Nucl. Phys. A530 (1991) 111.

1 Dipartimento di Fisica dell'Universita and INFN, Padova, Italy2 INFN Laboratori Nazionali di Legnaro, Italy3 Purdue University, West Lafayette, Indiana, USA

Spectroscopy of neutron-rich sdf shell nuclei produced indeep-inelastic processes

B. Fornal, R. Broda, R.H. Mayer1, I.G. Bearden1, Ph. Benet1, P.J. Daly1,Z.W. Grabowski1, I. Ahmad2, M.P. Carpenter2, R.V.F. Janssens2, T.L. Khoo2,

E.F. Moore3

In an earlier study [1] of the 92Nb + 60Ni reaction, just above the Coulomb barrier, we foundthat thick target 7-7 coincidence measurements using a Compton-suppressed Ge detector arraycan yield useful information about the binary products of such heavy ion collisions. Similarly,the high quality 7-7 data, aquired in studies of superdeformed bands in Hg and Tl nuclei atthe Argonne ATLAS accelerator, appeared to be a source of valuable spectroscopic informationabout light neutron-rich products of binary reaction of 34S, 36S and 37C1 beams on 160Gd thicktarget. We have therefore performed detailed analysis of lower multiplicity subset of these 7-7data searching for new spectroscopic information on neutron-rich sdf nuclei, which are otherwisehard-to-reach.

For many product nuclei near 160Gd, yrast 7-ray cascades were already well known up tohigh spins, but much less was known about 7-rays in the less accessible nuclei around 3 6S.During analysis, gates placed on known 7-rays in specific A~160 products selected individualreaction channels and identified coincident 7-rays in light product partners. For example, asshown for the 160Gd + 37C1 reaction in Fig.l(a), known 39C1 7-rays appeared in coincidencewith yrast cascade 7-rays of 158Gd and gating on 39C1 transitions, (Fig. l(b)), sharply enhancedthe prominence of the 39C1 coincidence peaks. Among those we have identified a new 695 keVtransition in 39C1 depopulating probably the 7rd3/2("f7/2)2 15/2+ v=3 yrast state.

Likewise, for the 160Gd + 36S reaction 7-rays of the 2n transfer product partners 158Gd and38S were observed in coincidence. A new 849 keV yrast 7-transition in 38S, deexciting a stateat 3674 keV was also found. It is very likely that this level is identical to the one located in the(t,p) study of 38S at 3690±16 keV and given a tentative V = 6+ assignment.

In N=20 products 3 4S, 35P, 36S and 37C1 the 7-rays deexciting known yrast states up to I~6were observed as well. Each isotone was produced with similar yields in at least two of thereactions studied.

The present studies yielded also some information about the spectroscopy of the very poorlyknown 33Si and 34P N=19 nuclei. The 34P nucleus was found to be a product of 2 proton and1 neutron transfer in the 160Gd + 37C1 reaction and 7-ray transitions in this nucleus could be

43

displayed by setting gates on 7-rays in the appropriate Dy-like partner products. Identificationof a new 1876 keV 7-transition in 34P, feeding the known 1 + level at 429 keV, estabilishes astate at 2305 keV which is a good candidate for the yrast state of the type ^^\i2vhli with V— 3~ or 4~. The 2305 keV level located in the present work is almost certainly the same as the2309±10 keV level populated in the (t,3He) reaction.

Similarly, for the 160Gd + 36S reaction, inspection of the appropriate 7-ray coincidencespectrum gated on Dy-like products lines revealed a strong 1435 keV 7-ray that we interpret asa ground state transition in 2pln transfer product 33Si, deexciting the (7/2~) level first locatedat -1.47 MeV in the (13C, 14O) study.

The present 7-ray analysis has shown that the spectroscopy of certain neutron-rich productsof deep-inelastic heavy ion reactions can be explored. However, since the production method de-livers many product nuclei with rather low yields, the data analysis is often difficult. Obviously,the newer, larger 7-ray detector arrays open, in this respect, new possibilities.

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301

o•

1

• 1

keV in

158G d

39CI

(jK,i*fjiA»=rf-

1 11 IkeVin1 5 8Gd

39CI

1 -

158Gd .

-

-

•

3 9CI•

I

—

0 200 400 600 800 1000 1200 1400

E y [keV]

Fig. 1. Representative 77 coincidence spectra for 158Gd and 39Cl products of the reaction160Gd +167 MeV37Cl.

References:

[1] R. Broda et al., Phys. Lett, B251 (1990) 245.

1 Purdue University, West Lafayette, Indiana, USA2 Argonne National Laboratory, Illinois, USA3 North Carolina State Univ., Raleigh, USA

44

PL9601000

Multi-particle excitations and identical bands in thesuperdeformed 149Gd nucleus

S. Flibotte1, G. Hackman2, Ch. Teisen1, H.R. Andrews3, G.C. Ball3, C.W. Beausang4,F.A. Beck1, G. Bélier1, M.A. Bentley5, T. Byrski1, D. Curien1, G. de France1,

D. Disdier1, G. Duchene1, P. Fallón6, B. Haas1, V.P. Janzen2, P.M. Jones4,B. Kharraja1, J.A. Kuehner2, J.C. Lisle7, J.C. Merdinger1, S.M. Mullins2, E.S. Paul4,

D. Prévost1, D.C. Radford3, V. Rauch1, J.F. Smith4, J. Styczeń8, P.J. Twin4,J.P. Vivien1, J.C. Waddington2, D. Ward3 and K. Zuber8

Superdeformed excited bands in 1 4 9Gd have been studied using the 124Sn(30Si,5n)149Gdreaction . The beam was supplied by the tandem accelerator of the Daresbury Laboratory(U.K.). Gamma rays were detected in the EUROGAM multi-detector array comprising 44large-volume HPGe Compton-suppressed detectors.

Eight superdeformed rotational bandsbelonging to this nucleus have been found[Fig.l]. Several excited bands have part-ners in neighboring nuclei which differ byup to four nucléons, with nearly identi-cal dynamic moments of inertia and quan-tized 7 -ray phasing. These observationscannot be easily explained by theoreticalmodels including an intrinsic scaling withmass of the moment of inertia. The mo-ment of inertia of the yrast superdeformedband in 1 4 9Gd shows an unexpected stag-gering [Fig.2]. At high rotational fre-quencies the AI=2 rotational band is per-turbed and two AI=4 rotational sequencesemerge with an energy splitting of about120 eV. The feature suggests the remnantof a quantum number associated with aninvariance of the Hamiltonian under a ro-tation of 90° around the rotation axis (C4-symmetry).

800 1000 1200 UOOy-roy energy (keV)

1600

Fig. 1. The -y-ray spectra of the five ex-cited SD bands in 149Gd.

CRN, Strasbourg, FranceMcMaster University, CanadaChalk River Lab., CanadaUniversity of Liverpool, U.K.SERC, Daresbury, U.K.NSC, Berkeley, USAUniversity of Manchester, U.K.Institute of Nuclear Physics,Cracow, Poland

"5S ÖT> Ö T ~Rotational frequency (MeV)

Fig. 2. Dynamical moment of inertia ofthe yrast superdeformed band in 1 Gd.

Work is partly supported by the Pohsh KBN grant nr 204519101/p.02,published in Ph. Rev. Lett. 71 (93) 688 and Ph. Rev. Lett. 71 (1993) 4299.

45

PL9601001

First results from spectroscopy of 199Atwith the Recoil Filter Detector

M. Lach, J. Styczeri , W. M§czynski, K. Spohr1, H. Grawe1, J. Heese1, H. Kluge1,K.H. Maier1, R. Schubart1, J.C. Merdinger2

A not yet explored region of deformed nuclei exists for neutron numbers N < 126 and protonnumbers Z > 82. In previous work very low lying prolate deformed bands in 1 8 6 .1 8 8pD [1] andlikely oblate intruder states in 196>198po [2] have been seen. This indicates that the transitionregion is close. As deformation is caused by the proton-neutron interaction the governing pa-rameter is (126 - N)x(Z - 82). Therefore an attempt was made to establish excited states in199At (Z=85) with the 175Lu (28Si,^n)199At reaction at E(28Si) = 141 MeV. The heavier oddisotopes of At are known. The experimental problem is that these nuclei are only producedwith very low cross sections as fission of the compound nucleus dominates. The recoil filterdetector (RFD) [3] identifies evaporation residues in coincidence with the 7-rays measured byOSIRIS and hereby selects the wanted events from the background. The cross section of 199Athas been calculated from the data as 0.10(5)m6, while a PACE calculation gives 100m6 in totalfor fusion, and Coulomb excitation is very strong too. Fig. 1 shows a total projection of the7-spectrum with and without i?FZ>-coincidences. A summed coincidence spectrum for 199At, asidentified by X-ray coincidences, is shown in Fig. 2. The counting rate is too low to deduce alevel scheme. But it is fairly clear that the 608 keV line is a crossover parallel to the cascadeof the 236 and 372 keV transitions and the strongest 433 keV transition is coincident with theother lines. Unless these prompt transitions are on top of an isomer, therefore the first excitedstate of 199At has dropped to 433 keV (or even 372 or 236 keV) from a rather stable positionabove 600 keV in 201At and the heavier isotopes.

2.0x10

1.5x10

. X-Rays 199,,* Po

199A At

© not yet ident.

200 400 600 800Energy (keV)

1000

Fig. 1. Total •projection of 7-7-coincidences for the reactions of 141 MeV 28Si with 175Lu(lmg/cm2). The lower spectrum is in coincidence with the RFD, lines in 199At are marked bytheir energy. In the upper spectrum the otherwise dominant Coulomb excitation is suppressedby a window on the sum energy of the ball and requiring ball multiplicity between 1 and 11.

46

oo

10 r

0 :

- 10b0 200 400

Energy (keV)600 800

Fig. 2: Summed spectrum in coincidence with 199At lines and the RFD.

The RFD worked well and reliably. Lowering the voltage and thereby the gain of the phot-multipliers and some other minor improvements led to a much more stable operation and bettercontrol of the threshold adjustments. Only the efficiency, that was 16% in this measurement, isstill below the anticipated value of 30% to 50%. But the individual elements varied appreciably.The best elements would give a total efficiency of >25%. This shortcoming is mainly due toelevated noise between beam pulses caused by the scattered beam ( >1 hit per beampulse) anda smaller than expected signal height. In this experiment the energy of the recoiling nuclei wasso low, that about 8% were stopped in the electron emitting 2 /xm Mylar foil. The detectorfoils will now be replaced by 0.5^m thick ones. The higher energy at the exit of the foils meanslarger signals, because the electronic energy loss is higher, and more than likely the design aimof >30% efficiency will be reached soon.

A second version of the RFD is under construction for EUROGAM at Strasbourg, whichhas 100 times the efficiency for 7-7-coincidences. This efficiency and the clean spectra achievedwith the RFD will allow one to measure cross sections of 10 fib.

References:

[1] J. Heese et al., Phys. Lett. B 302 (1993) 390.[2] D. Alber et al., Z. Phys. A339 (1991) 225.[3] J. Heese et al., EMI Bereich Schwerionenphysik Annual Report 1992, HMI-B507, ISSN

0944-0305, p. 90 and Proc. of the International Conf. on Nucl. Structure at HighAngular Momentum, Ottawa and Chalk River May 1992, AECL-10613 Vol. 2 p. 439, andAda Phys. Polonica B24 (1993) 61.

1 Hahn-Meitner Institut, Berlin2 Centre de Recherches Nucleaires, Strasbourg

47

PL9601002

Search for Jacobi instability in hot and rotating 46TiA. Maj, M. Kiciriska-Habior1, W. Krolas, J. Styczeri, J. Kownacki1,

J.J. Gaardh0je2, T. Tveter2, Z. Zelazny1'2,M. Mattiuzzi3, F. Camera3, A. Bracco3, B. MiUion3

In a number of experimental studies in which the spectra as well as the angular distributionsof 7-rays from Giant Dipole Resonance decay were measured, the predicted nuclear shape-changefrom prolate to oblate at specific temperature and angular momentum has been verified. Athigher angular momenta, nuclei are expected to undergo another, so called Jacobi, transitionfrom oblate shapes via triaxial to prolate ones. In this connection nuclei of medium-light massesattract a special attention since for them, contrary to the heavier ones, the critical angularmomentum for such a shape-transition is predicted to be lower than the fission limit. An ob-servation in an inclusive experiment of such a transition in the 45Sc nucleus has been recentlyreported by M. Kicinska-Habior and the Seattle group [1].

To investigate this problem further we have carried out an exclusive study of the GDR decayfrom hot and rotating 46Ti nucleus performed at the Tandem and Heavy Ion Booster acceleratorof the Niels Bohr Institute, Copenhagen. The employed reactions were 18O + 28Si at .Ef,eam = lOOand 69 MeV, leading to the 46Ti nucleus at £ '=80 and 61 MeV, and with lmax=Mh and 27h,respectively. The 7-rays emitted in the reaction were measured by the multi-detector arrayHECTOR, which consisted of 8 large volume BaF2 detectors located at different angles (seeFig. 1). HECTOR was also equipped with a multiplicity filter HELENA: 38 small BaF2 crystalscovering 80% of the full solid angle. This high efficiency enabled one to select relatively narrowwindows of the angular momenta of the decaying compound nucleus.

Helena

Fig. 1. The experimental setup used for the experiment.

48

-0.1

-OJ

-OJ

OJ

-Owl

- 0 . 2

0.1

o.o

-0.1

-OJ

-OJ

FoldSB

•

•

10100M«V>«D

FoldS

^L n n•

•

" "

• • • • •

15

".HI

" I•0

. . M l 1

Told 9•

OJ

OJ

0.1

. J

-• .1

-OJ

- "

0.1

OJ•.1

<? ••»

- 0 J

OJ

OJ

0.1

-0.1

-OJ

100 U.V -O..WS!Fold 4

•••••f l

Fold 7

•00U>V»Oa>"TCFold 10

I

. 2. Spectra of At angular distribution coefficient for different folds. Thein MeV.

-ray energy is

Fig. 2 shows the spectra of the A2 angular distribution coefficient for the high energy gammarays from the reaction at 100 MeV. They were obtained by gating on different folds in the mul-tiplicity filter. The behaviour of the spectra associated with low folds is in general agreementwith that obtained by the Seattle group: the magnitude of the low energy component is similarand, moreover, there is a peculiar lack of change of the sign of A2- values around the GDR ave-rage energy (19 MeV). On the other hand the spectra gated by folds>8 (what corresponds toangular momentum of the compound nucleus l>28h) begin to show positive A2 values for theGDR high energy component. This makes the trend of the A2-spectra, though the statistics arerather poor, closer to the expectations for deformed nuclei. This observation might indicate apresence, at the bombarding energy of 100 MeV, of a low multiplicity component that is notrelated to the formation of the compound nucleus. The component can only be filtered out bymeans of a multiplicity filter. A more detailed data analysis as well as a comparison to thestatistical model calculations are in progress.

We would like to thank Mrs. Andree Meens from CRN Strasbourg for preparing the Sitarget. This work was partly supported by the State Committee for Scientific Research underGrant No. 204519101/p.Ol.

References

[1]. M. Kicinska-Habior, K.A. Snover, J.A. Behr, C.A. Gosset, Y. Alhassid, N. Whelan, Phys.Lett. B308 (1993) 225

1 Instytut Fizyki Doswiadczalnej, Uniwersytet Watszawski, Warsaw, Poland2 Niels Bohr Institute, Copenhagen, Denmark3 Milano University, Milano, Italy

49

PL9601003

Entrance channel effects in GDR decayfollowing heavy ion fusionZ. Zelazny1, J.J. Gaardh0je1, A. Maj,

F. Camera2, A. Bracco2, M. Mattiuzzi2, T. Tveter1

In order to be selective in both excitation energy and spin a difference method has to beused. The idea is to produce in heavy-ion fusion reactions two compound systems with massnumbers differing by one neutron. The excitation energies are chosen so that they differ by theaverage energy removed by the first evaporated neutron. The 7-ray emmision from these twonuclei and from their daughters is measured and the resulting energy spectra are subtractedafter normalization to the same number of fusion reactions. Determined in this way the differ-ence spectrum contains gamma radiation from the first step of the CN decay. With the selectivemultiplicity filter HELENA we have been able to make full use of this idea, which requiresthat spectra that are subtracted correspond to the same angular momentum. The followingthree pairs of reactions have been investigated: 17'18O + 144Sm=161 '162Yb , E*=39 and 51 MeV,29,28Si + 128,130Te = 157,158Dy) E * = 6 4 a m J 75 M e V ) 48T i + 113l114Cd=161,182Yb, E ' = 64 and 75 MeV.

As is shown in Fig. 1 the relative intensity of difference spectrum measured for an oxygen beamis very close to the value predicted by the statistical model.

60

- 2 0

48Ti-bearrr

20 30 40 50 60 70

Fig. 1. Relative intensities ofdifference spectra (in % of theintensity of the total spectracorresponding to higher exci-tation) in the GDR energyrange. Data are plotted asa function of the average ro-tational angular momentum Iof the selected bin.

For Si projectiles we observe a very distinctive dependence on spin: the difference yield de-creases from close to the cascade value at low / to almost zero at higher / while for Ti inducedreactions the intensity is close to zero at all covered angular momenta. This is in dramatic con-flict with statistical model expectations. In all three cases we produce very similar compoundsystems (N=91 and 92). It is a challenge to understand the reason for the lack of an extra GDRemission from an extra E* in cases of nearly symmetric projectile-target systems possessing highangular momentum. It is tempting to think about some preequilibrium process in these colli-sions which may have long relaxation times. In the near future we will complement some of themeasurements by explicitly gating high-energy photon spectra with specific low-energy discretetransitions identified in the fusion residues using a Ge detector in order to make absolutelycertain that we are dealing with pure fusion events.

1 Niels Bohr Institute, Copenhagen, Denmark2 Milano University, Milano, Italy

50

PL9601004

Pre-fission 7-decay in hot superheavy 272Hs

T.S. Tveter1, J.J. Gaard^je 1 , A. Atac, B. Herskind1, W. Körten1,T. Rams0y1, G. Sletten1, Z. Żelazny1, J. Bacelar2, A. Buda2, H.v.d. Ploeg2,

W. Krolas, A. Maj, A. Menthe3, H. Nifenecker3, J.A. Pinston3,F. Schussler3, A. Braceo4, F. Camera4, B. Million4, M. Pignanelli4

Measurements of neutron multiplicities from hot fissile nuclei at various initial excitationenergies reveal that the number of pre-fission neutrons emitted increases with the excitationenergy, while the number of post-fission neutrons stays approximately constant [1]. This resultsuggests that fission is a slow process, taking place only when the nucleus has been cooled tosome lower excitation energy, contrary to statistical expectations. Since neutron evaporation isobviously able to compete favourably with fission at high temperatures, this should also be thecase for GDR 7-ray emission. Recent experiments measuring 7-rays from fissioning systemsconfirm this idea: Both a pre-fission and a post-fission component can be discerned in the7-spectra, at different 7-energies due to the different radii of the compound nucleus and thefragments [2]. The pre-fission GDR radiation offers insight into nuclear behaviour at extremeconditions with respect to spin and nucleón number, a region which has previously been closedto direct scrutiny.

At the SARA Cyclotron Laboratory in Grenoble, the superheavy nucleus io|Hs has beensynthesized employing the reaction 4 0 Ar+ 2 3 2 Th—> 2 7 2 Hs. A pilot experiment was carried throughby the HECTOR collaboration in 1989, using beam energies of 6.8 and 10.5 MeV/,4 [3]. Themain experiment was carried out in 1991, with beam energies of 10.5 and 15.0 MeV/A. Theexperimental setup included the 8 BaF 2 HECTOR detectors, mounted in the plane perpendicularto the beam axis. An array of small BaF 2 crystals defined the events in time and servedas a common start for time-of-flight measurements. Four PPACs (Parallel Plate AvalancheCounters) were used for the detection of fission fragments.

Due to the disappearance of shell effects at high temperature, hot thermalized fissile nucleitend to decompose into two fragments of approximately the same mass. By gating at symmetricfission of very heavy systems formed using heavy projectiles, we can select events connectedwith complete fusion reactions and full thermalization.

106

105

Vi

'S 1 0 4

102

g 101o 300

:iOMeV/u it»,ljf

Diff.

pre-fission post-fission

Fig. 1. The normalized 7 -spectrarecorded in coincidence with symmetricfission for the 15.0 and 10.5 MeV/Aruns after subtraction of an exponen-tial bremsstrahlung component, and thedifference spectrum, representing thepre-fission component. Bottom: ra-tio of the difference spectrum and the10.5 MeV/A spectrum. The arrows in-dicate the expected location of the pre-fission component (*72Hs) and from thefission fragments.

51

PL9601005

Assuming that the excitation energy at which fission takes place is essentially independentof the initial excitation energy, the energy differential method [3] can be employed to obtaininformation about the earliest decay steps. We have normalized the coincident 7-spectra fromthe 15.0 and 10.5 MeV/^4 runs to the same number of symmetric fission events. The twototal 7-spectra and their difference, corrected for bremsstrahlung, are displayed in Fig. 1. Thedifference spectrum shows a narrow distribution, centered at the 7-energy at which we expectthe GDR radiation from the heavy composite system, N.o significant intensity is present in theenergy region associated with fission fragment GDR radiation. This indicates that fission onlytakes place after cooling of the system down to an excitation energy below the one initiallyintroduced by the 10.5 MeV/A beam. On the other hand, the difference between the totalcoincident 7-spectra from the 10.5 and the 6.8 MeV/yl runs (not shown here) reveals strongGDR contributions from both the superheavy compound nucleus and the fission fragments.

The yields of pre- and post-fission GDR 7-rays at the three beam energies contain valuableinformation about the time constant for the fission process, which is related to the viscosity ofnuclear matter. Our plans are to compare the 7-spectra extracted in coincidence with sym-metric fission, with theoretical calculations performed with a modified version of the programCASCADE. In this way we will try to extract a lifetime for the hot fissile "gHs nuclei and thecorresponding nuclear friction coefficient 7.

This work was partly supported by the State Committee for Scientific Research under GrantNo. 204519101/p.Ol.References:[1]. D.J. Hinde et al., Nucl. Phys. A502 (1989) 497[2]. M. Thoennessen et al., Phys. Rev. Lett. 59 (1987) 2860[3]. J.J. Gaardh0je and A. Maj, Nucl. Phys. A52O (1990) 575Permanent addresses:1 Niels Bohr Institute, Copenhagen, Denmark2 KVI Groningen, The Netherlands3 ISN Grenoble, France4 Milano University, Milano, Italy

Rotational frequency dependence of orientation fluctuationsM. Mattiuzzi1, A. Bracco1, F. Camera1, B. Million1, M. Pignanelli1,

J.J Gaardh0je2, A. Maj, Z. Zelazny2, T. Tveter2

An interesting point that was found in a recent work [1] is the very different sensitivity ofthe GDR strength function and angular distribution to nuclear deformation. Analyses of thespectral distribution and of the size of the angular distribution can lead to different conclusionsabout the effective deformations of excited nuclei. This difference is expected to vary with therotational frequency of the hot compound nucleus. We have started the study of the dependenceof the effective nuclear deformation on rotational frequency in 176W at E*= 96.7 MeV.

Making use of the multiplicity filter of the HECTOR detector array, high energy spectraassociated to narrow spin intervals were measured. The analysis of the spectral shape and ofthe angular distribution is in progress. The final objective is the comparison of the effectivedeformations extracted from the two observables.

References:[1]. F. Camera, A. Bracco, B. Million, M. Pignanelli, J.J Gaardh0je, A. Maj, Z. Zelazny,T. Rams0y, Nucl. Phys. A (in print)

52

1 Milano University and INFN, Milano, Italy2 Niels Bohr Institute, Kopenhagen, Denmark

PL9601006

Thermal and quantal fluctuationsas probed by the GDR observables

A. Bracco1, F. Camera1, M. Mattiuzzi1, B. Million1, M. Pignanelli1,J.J. Gaardh0je2, A. Maj, Z. Zelazny2, T. Tveter2

A study of the strength function and of the angular distribution of the high energy gammarays from the giant dipole resonance in the hot rotating 110Sn nucleus at T ~ 2 Mev was mademaking use of the HECTOR array. The two GDR observables were obtained at different narrowangular momentum intervals of the compound nucleus. The simultaneous measurement andanalysis of the two observables is expected to help to disentangle the different effects due tolarge amplitude thermal fluctuations from those due to small amplitude quanta! fluctuations.In fact, as shown in ref. [1] an increase of the apparent GDR width can be due to either one orboth effects. In case the width increase is due to thermal fluctuations, that increase the effectivenuclear deformation, the associated angular anisotropy also becomes larger. This is the casewith the present data, shown in the figure, which for the first time demonstrate that the GDRintrinsic width remains unchanged and that the total width increase that occurs as a functionof increasing rotational angular momentum arises almost solely from the GDR splitting due toincreasing deformation.

V

au

CO

uV

en

10 15 207 Energy (MeV)

10 15 20y Energy (MeV)

0.30.20.10.0

-0.1-0.2-0.3

0.30.20.10.0

-0.1-0.2-0.3

<I> = 43

, f

10 15 207 Energy (MeV)

<I> = 51 f

VII

10 15 207 Energy (MeV)

Fig. 1. Comparison between the strength function and the 02(E-y) at temperature T~ 2 MeVfor average spin 4$h (top row) and 51 ft (bottom row). The curves are the best fitting statisticalmodel calculations and the width of the strength function at 51h is 1.5 MeV larger than at 43h.

53

D , PL9601007Keierences:[1]. A. Braceo, F. Camera , M. Mattiuzzi, B. Million, M. Pignanelli, C. Volpe, J.J Gaardli0je,A. Maj, Z. Żelazny, T. Tveter, Nuci. Phys. A (in print)

1 MUano University and INFN, Milano, Italy2 Niels Bohr Institute, Kopenhagen, Denmark

Ultradipole radiation in 12C-f24'26Mg collisionsM. Kicińska-Habior1, K.A. Snover2, A. Maj, Z. Drebi2, D. Ye2, M. Kelly2

Photon production mechanism in heavy-ion collisions at projectile energies up to E/A=5-6 MeV/u has been well understood in terms of the statistical decay of an excited compoundnucleus taking into account the giant dipole resonance (GDR) built on excited states [1,2]. Inthe intermediate beam energy region {E/A > 20 MeV/u) the nonstatistical excess of high energyphoton yield beyond the GDR region over the statistical model predictions called ultradipoleradiation (UDR) or bremsstrahlung radiation occur and is well described by collisional modelswhere photons are produced in first chance incoherent proton-neutron collisions [3]. At projec-tile energies E/A x 10 MeV/u UDR has been also observed with the 7-ray angular distributionimplying a source moving at the nucleón-nucleón center-of-mass velocity [4,5]. It was found,however, that the yield of the UDR vary more strongly with the projectile-target combinationthan expected from scaling to the average number of the first chance p-n collisions [4,5]. Atthese low projectile energies the relative importance of the Fermi motion of nucléons in collidingnuclei and the Pauli blocking is expected to increase what can be manifested in the sensitivityof the UDR yield to the differences in the neutron-proton phase space distribution [4,6].

We have studied 7-ray emission in 1 2 C + 2 6 M g reaction at 6, 8.5 and 11 MeV/u and in1 2 C + 2 4Mg reaction at 11 MeV/u using 1 2 C beams from University of Washington tandem linac.Gamma ray spectra at 40°, 55°, 90°, 125° and 140° with respect to the beam axis have beenmeasured in a large Nal(Tl) crystal with plastic anticoincidence and lead shields. Coincidence7-ray spectra have been also measured using a multiplicity filter consisting of 23 small Nal(Tl)crystals. We have chosen these reactions to study UDR at relatively low projectile energy forlight targets and the mass asymmetric entrance channel, to check a influence of UDR on 7-rayangular distribution, to check the amount of UDR at projectile energy about 6 MeV/u in col-lisions providing to A ~40 nuclei previously studied in a more symmetric entrance channel [7]and also to look for 7-ray cross section dependence on difference of proton-neutron number inthe target. Additionally, in 1 2 C + 2 4Mg reaction an effective dipole charge is zero and possiblecontribution of the nucleus-nucleus bremsstrahlung vanishes. In this reaction the projectile andthe target has isospin T=0 so the statistical contribution should be diminished due to the pureisovector character of the GDR excitation [8].

Measured inclusive 7-ray spectra and angular distribution coefficients a-y and a2 are shown inFig. 1. In the top row preliminary statistical model CASCADE calulations are also shown (solidline). In the lower rows simple calculations assuming that the total cross section is described onlyby the a=croexp[ — E^/EQ] component with angular distribution isotropic in the nucleus-nucleusCM system are shown, where the slope parameter EQ is in agreement with UDR systematics [3].It is clear that for E >30 MeV at two higher projectile energies, the positive ax coefficient isin good agreement with pure UDR mechanism. At the lowest projectile energy the statisticalcontribution has to be included. The a2 coefficient has a large negative value around meanGDR energy and it stays negative at energies above the GDR as it was observed earlier [7].

54

Multiplicity data up to fold> 2 show very similar behavior. It is intriguing that the ratio of the7-ray yield for 26Mg and 24Mg targets is nearly constant with E-, energy above 2^=20 MeVand is equal 1.7, when the scaling factor corresponding to the average number of first chancen-p collisions is 1.03. More detailed calculations are in progress.

i o 2

- 1Ong 10°

EproJ= 134.6 MeV Epro,= 134.6 MeV E p r o ] - 103.3 MeV 73.0 MeV

1 0

io~ 3

- 4r- ' • , - i r ••-ir- "•. -ir- »• - i• I I « - • I I * !i I I • ! ! I «ti !

"I I I I I I I I I I t ! i t l I I I I I I • I I I 1T1 • i I i i i i I i « t i T i i • I i • i • t . m •-

i o 2

6

w"

5-

Cd

IO- 4

1.0

0.5

0.0

-0.5

0.50

0.25

0.00

-0.25

-0.50

i i ' I i ' i i I i l f i *

26'Mg

+-H- I I I I -i f 4-H—I I I I I I I I. .1 I I I I I I -TH

-*-> i i I I I I I I I I i-l

26Mg

' ,' ' I 1 ' ' I—I—L

•••„". { . 1 . I 1 1 1 li

26Mg

1

t i i I . I. l 1. L->' ' *' l"

H—H-++

iLvV

20 40 20 40 20 40 20 40

Er [MeV]

Fig. 1. Measured "f-ray spectra and angular distribution coefficients a^ and a<i (points witherrors) with preliminary statistical model calculations (top row) and simple UDR calculations(lower rows). The f-ray energy is in MeV.

This work was partly supported by the State Committee for Scientific Research under GrantsNo. 2 2396 9102 and 204519101/p.Ol.

References:

[1]. K.A. Snover, Ann. Rev. Nucl. Part. Sci. 36 (1986) 545[2]. J.J. Gaardh0je, Ann. Rev. Nucl. Part. Sci. 42 (1992) 483[3]. W. Cassing et al., Phys. Reports 188 (1990) 365[4]. R. Vojtech et al., Phys. Rev. C40 (1989) R2441[5]. C. Gosset et al., Phys. Rev. C42 (1990) R1880[6]. M. Kicinska-Habior et al., Phys. Lett. B308 (1993) 225[5]. M.N. Harakeh et al., Phys. Lett. B176 (1986) 297

55

1 Instytut Fizyki Doswiadczalnej, Uniwersytet Warszawski, Warsaw, Poland

2 Nuclear Physics Laboratory, University of Washington, Seattle, USA PL9601008

Electric quadrupole interaction at 181Tain hexagonal HfPd3 compound

B. Wodniecka, P. Wodniecki and A.Z. Hrynkiewicz

The HfPd3 compound was prepared by argon arc melting followed by 4 days of annealing at1100 K in an evacuated and sealed quartz tube. The powder X-ray diffraction pattern confirmedthe TiNi3-type structure of the investigated compound. The sample was neutron irradiated inorder to produce the 181Ta probes and after 2 days of annealing at 1000 K the perturbed angularcorrelation (PAC) spectra were recorded in the temperature range 15 K - 1100 K. The leastsquares fits of the perturbation factor to the experimental spectra yielded two equal fractionsii of probe atoms exposed to the different electric field gradients corresponding to quadrupolefrequencies UQ{ and asymmetry parameters r/i = 0, reflecting the existence of two nonequivalentaxially symmetric 2a and 2c sites in the DO24 structure of the investigated sample.

The room temperature spectrum for the HfPd3 sample and the measured temperature de-pendence of quadrupole frequencies, fitted using the formula

vQ{T) = uQ(0)[l-bT*'*],

are shown in Fig.l. The fitted quadrupole interaction parameters are collected in Table 1.Particular note may be taken by the relatively very low value of the temperature dependenceslope parameter b for the higher frequency component.

0.05 -

-0.05800 1200

Tm [K]

Fig. 1. Room temperature PAC spectrum and the temperature dependence of quadrupoleinteraction frequencies for 181Ta in HfPd3 sample.

Work is supported by the State Committee for Scientific Research (Grant No. 2 0457 91 01).The careful sample X-ray analyses of dr. A. Bajorek are gratefully acknowledged.

56

PL9601009

Table 1: The fitted quadrupole interaction parameters of 181Ta in HfPd3.

f

0.47(1)0.53(1)

I/Q(300 K) [MHZ]

614(1)30(1)

V0.00.0

uQ(0) [MHZ]

615(1)31(1)

6[10-5iif-3/2]0.02(1)0.9(2)

lattice site2a2c

1 oi

PAC measurements at l o l T a in Hf2Pd and Zr2Pd tetragonalMoSi2-type phases.

B. Wodniecka, M. Marszalek, P. Wodniecki, H. Saitovitch1, P.R.J da Silva1

and A.Z. Hrynkiewicz

In view of recent progress in the theoretical description of the electric field gradients inmetals it seems important to enlarge the available base of experimental data. Temperaturedependence of the electric field gradients (EFG) for most normal metal systems follows the T3/2

law, however, that is not the case if the transition metals are involved [1].The temperature dependence of the electric field gradients in transition metal compounds

was not studied extensively. The present PAC studies of Hf2Pd and Zr2Pd compounds starta systematic investigation of 181Ta quadrupole interaction in MoSi2-type intermetallic phases.This Cllf, family (space group D ^ - I/mmm) occurs at A2B stoichiometry. The A atomsoccupy the unique 4e (4mm) site and the B atoms the 2a (4/mmm) lattice positions. Most ofthe MoSi2 phases involve an element of the titanium group or a lanthanide as the A componentand palladium or a member of the copper group as the B component [2].

The Hf2Pd sample was obtained by argon arc melting followed by 100 hours of annealingat 1100 K in an evacuated and sealed quartz tube. The powder X-ray analysis verified a singlephase product of C l l j structure. The 181Ta probes were produced by neutron irradiation of theHf2Pd compound. In order to remove the irradiation defects the sample was annealed for 2 daysat 1000 K. The perturbed angular correlation (PAC) spectra were measured in the temperaturerange 15 K - 1100 K using the 4 BaF2 detector setup.

The (Zr 99Hf oi)2Pd sample was prepared and measured in Centro Brasileiro de PesquisasFisicas in Rio de Janeiro. The stoichiometric amounts of the respective constituent elements,including neutron irradiated Hf, were melted together in an argon arc furnace. The sample wasthen annealed for 48 hours at 923 K in vacuum. The PAC measurements for 181Ta probes wereperformed in the temperature range 15 K - 1123 K using the equipment with 2 BaF2 and 2 NaJdetectors with an experimental time resolution of 1.8 ns FWHM.

All samples showed evidence of nonrandom orientation of the crystallites and the PAC datahad to be fitted with free s2n parameters. The least squares fits of the perturbation factor

i=l n=0

to the experimental spectra measured for Hf2Pd and Zr2Pd compounds yielded in each casean electric interaction with a single quadrupole frequency VQ and asymmetry parameter 77 = 0,reflecting the existence of one axially symmetric probe site in the Cllf, structure of the inves-tigated samples. The broadening of the EFG described by a Lorentzian distribution having awidth 8 was for HfaPd sample of % 4.5% for lower measurement temperatures decreasing to lessthan 2% above 800 K. In the case of the Z^Pd sample this broadening was about two timeslarger.

57

The room temperature spectra for Hf2Pd and Z^Pd samples and the measured temperaturedependence of the quadrupole frequencies are shown in Fig.l.

The quadrupole interaction frequency values VQ at room temperature resulting from thefitting procedure were 305(2) MHz for Hf2Pd and 291(4) MHz for Zr2Pd. The correspondingEFG's are of about 0.5 xlO18 V cm"2. These almost identical values of vq reflect the chemicalsimilarity of Hf and Zr and the very close lattice constants of both compounds [2]. The pointcharge model calculations of the ionic contribution to the EFG with the assumption of +4charge on Hf and Zr atoms and 0 charge on Pd atoms yield the values of -2.1 xlO18 Vcm~2

and -2xl01 8 Vcm~2 for Hf2Pd and Z^Pd, respectively. Thus, the substitution of Zr 4e-sites byprobe atoms in the Z^Pd sample was confirmed.

As can be seen in Fig.l the decrease of the quadrupole interaction frequency with the mea-surement temperature is very fast for both Hf2Pd and Zr2Pd compounds and can not be wellreproduced neither with T3/2 nor a linear function of the temperature in the whole measuredrange. The estimated slopes of both ^ Q ( T ) curves are very similar and equal to as 5xlO~4 K"1.

R(t)

0.15

0.10

0.05

0.00

0.15

0.10

0.05

0.00

1 Hf2Pd

1 1

Zr2Pd

\[ A ,\ J XJ

1

\

vQ[MHz]

350

300

250

200

350

300

250

200

•

•

* • •

Hf2Pd

* •

Zr2Pd

*

•

10 20 30 40t ins]

50 60 200 400 600

TIKIBOO 1000 1200

Fig. 1. Room temperature PAC spectra and the temperature dependence of quadrupole inter-action frequencies for 181Ta in Hf2Pd and Zr2Pd samples.

Work is supported by the State Committee for Scientific Researche (Grant No. 2 0457 91 01).The careful sample X-ray analyses of dr. A. Bajorek are gratefully acknowledged.

References:

[1] H.C. Verma and G.N. Rao, Hyp. Int. 15/16 (1983) 207.[2] M.V. Nevitt, in Intermetallic compounds, eds. J.H. Westbrook, John Willey and Sons,

Inc, New York, 1967.

1 Centio Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brasil

58

PL9601010

PAC studies of ion beam mixed Al-Sb multilayersP. Wodniecki, M. Uhrmacher1, F. Shi1 and K.P. Lieb1

Heavy ion irradiation of metallic multilayer is a new technique to produce intermetallic oramorphous phases by ion beam mixing. The PAC method is sensitive just to the neighbourhoodof the probing atom. Different micro-phases arising during the irradiation can easily be detectedalready in an early stage if hyperfine interaction of i n C d in these phases is known from separatecontrol experiments. PAC studies of the Ni-Sb system [l] demonstrated that ion beam mixingcan lead to crystalline intermetallic phases. Here we present the preliminary results for Al-Sbmultilayer (four layers of Al and Sb with the total atomic stoichiometry 50:50).

Experiments were performed at II. Physikalisches Institut der Universitat Gottingen using900 keV Xe++ ions from IONAS ion implanter. m I n ions as a tracer were implanted at 400keV into the Al/Sb multilayer of 200 nm thickness prior to Xe irradiations. PAC as well as RBSexperiments were performed before and after each of ion mixing. The corresponding sequenceof the obtained spectra is presented in Fig.l.

/yW^s-*****^^ L

1 1 1 1 f—4

100 200 300t(ns)

Fig. 1. PAC and RBS spectra for m I n doped Al/Sb multilayers mixed with 900 keV Xe ions.

Our former PAC studies of pure Al, Sb and AlSb crystalline phases allowed us to identifyin "as implanted" (not Xe- irradiated) sample ss50% of n l I n probes situated in Sb lattice.The rest of l u I n tracers exhibit the not perturbed angular correlation characteristic for the

59

PL9601011

cubic Al. Xe-irradiations performed at room temperature caused mixing of the layers leadingto the subsequent dissappearance of both electric field gradients, characteristic for pure metalsubstrates in favour of a new, typical for the amorphous phase. After the Xe rradiation to thetotal fluence of 5xlO15 Xe/cm2 the RBS spectrum visualizes a homogeneous mixture of bothmetals while the corresponding PAC result indicates the formation of the amorphous phasein the whole sample. Further ion beam mixing experiments performed at low temperatureare planned to confirm the result of XRD experiments [2], where the formation of crystallineSb5oAl5o B3-phase was observed after the ion beam mixing at 77 K.

Work is supported by the German-Polish WTZ project X082.8 and the State Committee forScientific Research (Grant No. 204579101).

References:

[1] M. Uhrmacher, P. Wodniecki, F. Shi, T. Weber, and. K.P. Lieb, Appl. Phys., A57 (1993)353.

[2] F. Shi, W. Boise, K.P. Lieb, and J. Wilbrandt in press.

1 II. Physikalisches Institut, Universitat Gottingen, Germany

Xe-induced cavity formation in aluminium observed by PACtechnique

P. Wodniecki, M. Uhrmacher1, and K.P. Lieb1

The interaction of implanted gases with substitutional i n I n probes in different metals wasstudied by Schumacher and Vianden [1,2]. It was shown that the gas implantation initiates thegrowth of large threedimensional vacancy clusters (usually called cavities) at indium impurityand the observed electric field gradient (EFG) is due to indium atoms situated at the innersurface of the cavities.

We report on measurements performed at II. Physikalisches Institut der UniversitatGottingen, where an Al sample containing implanted i n I n probes was irradiated with Xe ionsof 700 keV. The sequence of PAC spectra (see Fig.l) demonstrates that also in this case thecavity formation take place, causing the EFG described by the hyperfine interaction parameters/ ^ Q = 1 4 3 ( 1 ) MHz and 77=0.1. These values are close to the results of Schumacher [2] obtainedfor Al irradiated with Ar ions (VQ = 132.6(3) and 77=0.1). The fraction of l u I n probes placed incavities increased significantly (up to «50%) after subsequent annealing for 30 min at 200 °C.

60

I I I I I I I

I I I I I I

0.00

100 200 300t (ns )

0 . 0 0 . 2 0 . 4 0 . 6 0 . 8f r e q u e n c y [GHz]

Fig. 1. PAC spectra with Fourier transforms for m I n doped Al irradiated with 900 keV Xeions.

In a check experiment we have annealed an aluminium sample at 400 °C after m I n implan-tation in order to remove the In-correlated radiation damage prior to the Xe irradiation. Then,the quadrupole frequency characteristic for the cavity in Al did not appear directly after xenonbombarding (as was observed for the not annealed sample) but after the additional thermaltreatment in vacuum at 200 °C, which can be a hint that 111In probes migrate into the cavitiescreated earlier from vacancies produced by Xe ions. The fraction of the discussed EFG was inthis experiment much smaller («20%) than in the case of the not annealed sample, which indi-cates that the vacancies correlated with m I n implantation play a decisive role in the formationof cavities containing indium impurity.

Work is supported by the German-Polish WTZ project X082.8.

References:[1] R. Schumacher, and R. Vianden, Phys. Rev. B36 (1987) 8258.[2] R. Schumacher, PhD thesis, Institut fur Strahlen- und Kemphysik der Universitdt Bonn,

(1991).

1 II. Physikalisches Institut, Universitat Gottingen, Germany

61

PL9601012

Electric field gradient and its temperature variation atin Zr2Fe and Zr2Co intermetallic compounds.

M. Marszalek, H. Saitovitch1 and P.R.J. da Silva1

Binary compounds formed between Zr metal and late transition metals (Fe, Co, Ni) haveattracted recently a great deal of attention due to their unique physical properties; they'are ableto absorb large amounts of hydrogen and easily form amorphous systems.

In this paper we report a TDPAC study of Zr2X (X=Fe,Co) intermetallic compounds( C16 crystallographic structure) performed at Centro Brasileiro de Pesquisas Fisicas.

Samples of Zr2Fe and Zr2Co with a small addition of Hf (less than 2 at.%) containingradioactive 181Ta probe atoms were prepared by argon arc melting. A further heat treatmentwas necessary to obtain pure samples of the required crystal structure. A sample of Zr2Co wasannealed for 72 hours at 923 K in an evacuated and sealed quartz tube. It is known [1] thatZr2Fe exists as a high temperature phase between 1050 K and 1250 K. Because of peritectoiddecomposition of this phase at 1250 K a long annealing time (480 hours) at 1173 K was performedand the sample was next quenched to the liquid nitrogen temperature as fast as possible.

TDPAC measurements were performed in the temperature range 14K-1150K using equip-ment with two BaF2 and two NaJ detectors with an experimental resolution of 1.8 ns FWHM.In order to avoid the decomposition of Zr2Fe, phase PAC spectra were taken from 20 K to roomtemperature and in the range of existence of the phase.

Examples of G2(t) patterns obtained for investigated samples at room temperature are shownin Fig.l. together with the measured temperature dependencies of electric field gradient (EFG).In both cases we have observed only one strong asymmetric quadrupole interaction, according toone possible crystallographic position of the probe atom in the studied structure. The strengthof the interaction was equal to 1039(8) MHz with asymmetry parameter 77=0.82 and 889(7) MHzwith 77 = 1 at room temperature for Zr2Fe and Zr2Co, respectively. The measured temperaturedependence of EFG showed alinear character. The parameters of the fit of VQ{T) = VQ(0)[1-O.T}

relation to the experimental data are presented in Table 1.

MHz]

1100

1000

900

800

1100

1000

900

800

Zr2Fe

ZraCo

> _

40 50 0 200 400 600 800 1000 1200T[K]

Fig. 1. Room temperature PAC spectra and the temperature dependence of quadrupole inter-action frequencies for 181Ta in Zr2Fe and Zr2Co samples.

62

PL9601013

Table 2: The fitted quadrupole interaction parameters of 181Ta in Zr2Fe and Zr2Co samples.

compound

Zr2FeZr2Co

J/Q(300 K) [MHZ]

1039(8)889(7)

V

0.821.0

uQ{0) [MHZ]

1125(5)956(4)

2.6(1)2.2(1)

Work is partially supported by the State Committee for Scientific Research(Grant No. 2 0457 91 01)

References

[1] F. Aubertin, U. Gonser, S.J. Campbell and H.-G. Wagner, Z. Metallkde 76 (1985) 237.

1 Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brasil

FIDIAS - Fifteen Parameters Data Acquisition System

J. Gre,bosz, W. Me.czyriski, M. Zie.blinski, W. Iwanski, M. Kajetanowicz, K. Korcyl

The FIDIAS, a new 15 parameters data acquisition system for single and multiparametermeasurements at Krakow cyclotron has been developed. The system is composed of two mainelements:

A. hardware, in Camac and NIM crates,B. program, running on an IBM PC computer.

A. The HardwareThe hardware consists of:- up to 30 ADC in NIM crates,- system controller in a CAMAC crate, designed in the Electronics Division,- a CAMAC - IBM PC interface.

The Hungarian ADCs, type EMG 38098, are used. They have the following features: doubleintegration conversion method, result length set to 10, 11, 12 or 13 bits, maximum conversiontime 80/rni (13-bit result), input range 0-10 V and integral nonlinearity smaller than 1.3*10~4.

ADCs have been equipped with internal 8k x 16 bits memory where the histogram is auto-matically built from all conversion results. Maximum number of counts in a histogram channelis 65535.

ADCs are divided into two groups: ADC converting coincidence events (max. 15) and ADCbuilding single spectra (max. 15).

ADCs and the system controller are connected by a separate bus.A pattern defining ADCs in the coincidence event is supplied to the controller with each event.

A data compression based on the pattern is made. The result is transferred autonomously intoan internal 4096 word FIFO memory.

When more than the half of the memory is filled with data, an interruption to the IBM PCis generated. The computer reads a data block of an event by event type. The block length is2048 words.

63

B. The ProgramThe aim of program is to control the work of the system. Its main task is to read periodically

the blocks of data from the hardware and store it on the EXABYTE magnetic tape.The program allows also for:- denning parameters of every ADC directly by the user - from the IBM PC,- collecting in a memory some coincidence spectra (projections) of chosen ADCs; these

spectra can be shown on the screen,- transfer of a single spectrum from the ADC memory and displaying it on the screen,- evaluating of the single spectra and projections,- building pictures of two dimensional spectra (matrices); up to 32 matrices can be shown

on the screen simultaneously - parameters of the matrices can be denned by the user at anymoment,

- all basic operations with the EXABYTE magnetic tape like rewinding, initializing openingand closing files, making a directory of the tape, etc.,

- all basic operations with Camac such as: resetting crates, single Camac commands, aninfinite loop of single Camac command, denning longer sequences of Camac operations etc.,important during the developing and testing of the system,

- storing (and retrieving) the setup of the whole program on the disk.The program is written in an object oriented technique, in the C + + programming language.

The communication with the user is based on menu and window environment.

Presently, the data processing capabilities of the system like the counting rate limit -bothas trigger frequency and as Kilo words per second processed - versus the number of parametershandled are being extensively tested. This test is performed using 6 parameter events, generatedfrom three Nal scintillator counters working in coincidence for different radioactive sources. Fig.lshows an example of two-dimensional coincidence spectra collected during the test.

s*.

Fig. 1. Two-dimensional gamma-gamma and gamma-time coincidence spectra measured withNal scintillator counters and a 22Na source.

64

PL9601014

Development of data analysis software for UNIX systemsapplied to NORDBALL and EUROBALL data sets

J . Wrzesinski*

The multidetector arrays (NORDBALL, EUROBALL) deliver large sets of coincidence data.Wi th the new EUROBALL III instrument which will start to operate in 1996 it will be possibleto collect approximately 1012 4-fold events in less than a week. We have therefore developedthe program JUGGLER to handle such extreme data sets. It is a C package for off-line sortingof high-spin nuclear spectroscopy data adopted to a UNIX computer. The program is speciallydesigned to sort da ta into large 3-D array (2048*2048*2048), but with a large flexibility, enablinga variety of sort functions in 1-2-D spectra, and corresponding file formats. The format of the3-D array is based on that used by the program ANA [1]. Interactive communication with theprogram is made through a simple command language which is organised in a menu structurewith a context oriented on-line help function. This facilitates easy and reliable application ofthe program.

The task of analysis is handled in several independent steps: 1) Automatic calibration andgain matching of detectors including correction of gain shifts from the experiment. 2) Calibratingand filtering data (only good events and parameters, with energy dependent gating on time)and storing on tape in compressed format. 3) Sorting of compressed data in large 2-D and 3-Darrays. In a 2-D sort, different combinations of two parameters are available. In 3-D sort, a7 — 7 - 7 cube is created. In both cases, gates on gamma-ray energy or extra parameter arepossible. 4) Conversion of 1-2-3-D output da ta into formats suitable for the most commonlyused analysis programs like SAP [2], GELIFT2 [3], ESCL8R [3], LEVIT8R [3] and TRIHAN [4].These routines include format matching between VMS and UNIX systems.

The program has been applied to sorting two sets of data from experiments performedat the EUROGAM detector array in Daresbury. Data sets of 1.8 and 2.9 Giga 3-fold eventswere obtained using the reaction 1 2 4Sn(4 8Ca,4-6n)1 6 8 '1 6 7 '1 6 6Yb at 210 MeV beam energy and1 0 8Pd(4 8Ca,4n)1 5 2Dy, respectively. At a first replay of the data, calibration and gain matchingcoefficients were obtained requiring 28 and 43 hours sorting time, respectively. In the second step,the initial amount of 46 and 68 GBytes of data after filtering and calibration were compressedto 5.3 and 13 GBytes (compression factors: 8.7, 5.2), respectively. Then, 1 Giga of 3-fold eventswas sorted in 20 hours into 3 7 - 7 - 7 cube with 10243 ch on a Solbourne S4000DX UNIXcomputer. In the present case, 0.9 GBytes of disc space was used . We have tested the 3-D sortperformance and found it strongly dependent on available disc space.

References

[1] Program ANA: W. Urban.[2] Program SAP: F . Videbaek, A. Holm.[3] Programs GELIFIT2, ESCL8R, LEVIT8R: D.C. Radford.[4] Program TRIHAN: K. Shifter.

* This work was performed within the fellowship at the Niels Bohr Institute, Copenhagen, Denmark

65

PL9601015

Study of Sn-In alloys by positron annihilation

J. Dryzek and E. Dryzek

Many experiments on alloys were performed using positron annihilation methods in order todetect the electronic structure or properties of vacancy type defects. However, sometimes oneforgets about specific structures of the alloys which could influence the positron annihilationcharacteristics by creating new types of positron traps. It may be important in analysis ofthe behaviour of positron mean lifetime or S-parameter as a function of temperature. Theinterpretation of these results without taking into account the structure elements of the alloyscould lead to the wrong conclusions.

In our studies we prepared the Sn-In alloys which can exist at room temperature in fourphases. Additionally, one eutectic and two peritectic points are also observed. Changes in theDoppler broadening spectra of the annihilation line were described by the classical line shapeS-parameter defined as the ratio of the area under the fixed central channels to the total areaunder the annihilation line. Fig.l presents the results of measurements of the S-parameter atroom temperature together with the phase diagram of the Sn-In alloys. The solid line in Fig.lbwas drawn through the closed points measured for samples after long annealing and slow coolingso in such a case the number of defects was reduced . The dashed line in the Fig.lb was drawnthrough the open points which were obtained after deep plastic deformation of the samples(50% reduction of thickness). In such a case a great number of defects which can act as traps forpositrons were produced. In Fig.l one can see that in the regions in where two eutectic or mixedphases exist in the alloy, there are no distinct differences between the annealed and deformedsamples. The reason is that in the case of these alloys the positron traps can occur easily on theboundary between two phases or can be generated in the stress field. The differences betweenthe two measurements are observed for the region where the alloy exhibits only one phase. Thisis obvious because in the annealing process the number of defects is reduced, and after theplastic deformation defects are generated so an increase of S-parameter should be observed.

200

^150

U

55S.100£

50

0

212-

\

1\\\r \

\

i

\ Liquid\

\

\ ^

.... ^ ^\\\

157"

P \ \\ \

y

Q)The conclusion is that the results of positronannihilation measurements should be re-ferred to the phase diagram and the struc-ture of the investigated alloys.

b)

Fig. 1: Phase diagram of Sn-In alloys (a).The S-parameter measured in the room tem-perature vs. concentration of In (b). Theclosed points present the measurements per-formed for samples after long annealing pro-cess, the open points for samples after deepplastic deformation.

20 '.0 60

Wt.% In

80 100

66

PL9601016

Mossbauer effect investigations of the short range order in the vicinity ofmagnetic transition in ErT2Sn2 (T = Ni, Cu) phases

R. Kmiec, E.A. Gorlich1 and K. Latka1

The electronic properties of novel ternary compounds ErNiiSrii and ErCv.2Sri2 were inves-tigated with the attention focused on the temperature region of the magnetic ordering transi-tions. The phases were found to crystallize with the CaBe2Ge2-type of structure (space groupPi/nmm). The samples are not free from a certain degree of disorder connected with the oc-cupation of 3d-transition metal and tin sublattices. This may eventually lead to the occurrenceof the regions of the body-centered lattice of the T/iCr25i2-type rather than that of the abovementioned primitive one. Thermal processing was not effective in shifting the equilibrium ei-ther way. Magnetic susceptibilities of these compounds reveal regular Curie-Weiss behaviour inthe temperature range 15K to 250K with the values of the effective magnetic moment hardlydifferent from that of a free trivalent erbium ion [1].

G 1 0 ° "o"m 0.99 -wB 0.98 -m

g 0.97 -

H 0.96 -CJ

£ 0.95 -<d•« 0.94 -06

0.93 -

ErNi2Sn2

7 K

w\w//

x1 = i - i i

-7.0 -3.5 0.0 3.5Velocity mm/s

7.0

C 100 -o :8 0.98 -

a :5 0.96 -H ;£ 0.94 :

j> 0.92 '-

aS ° - 9 0 :

0.88 :

ErCu2Sn2

78 K

— T— r -r- r • •, T . - 1 — , . . r . r . T . - r - T -

\i • - • ' /\ / /

1V

= 0.87f • t -^—p-^—|—|—

-8.0 -4.5 -1.0 2.5 6.0Velocity mm/s

g 1.00 i0n 0.99 -m

fi 0.98 -

« 0.97 -

H 0.96 -01J 0.95 -08

"3 0.94 -K i

- 7~ i

.0

ErNi2Sn2

1.6 K

-1 1 I I 1 | 1 1 I r

-3.5

\ ' " " " • ' /1 /I //\ /v /X* = 1 + 8

I I | | " I1 T ' T ~T " | | I \ I—T~T~r~"

0.0 3.5 7.

C 1.00 -oM.2 0.98 -S :% 0.96 -u ~_

a. 0.94 -

2 0.92 -

06 :0.90 -

ErCu2Sn21.8 K

i i 11 i i i 11 i i i i

\ \ ' \ • • ' / /

%fX\

\J x' =

f

1.37i I i i i

-8.0 -4.5 -1.0 2.5Velocity mm/s

e.oVelocity mm/s

Fig. 1. 119Sn Mofibauer absorption spectra ErNi2Sri2 and ErCu2Sn.2

A drop in the temperature dependence of electrical resistivity is indicative of a long rangemagnetic ordering which develops in these compounds at temperatures (Tpf) of 5K and 3.5K,respectively. The resistivity of ErNi2Sn2 attains a local minimum at about Tm = 8K followedby the resistance increase upon further cooling the sample [2]. While a slight deviation fromthe linear temperature dependence at higher temperatures may be tentatively ascribed to thecrystalline field effects the behaviour below Tm (and above T#) is reminiscent of a Kondo-type conduction electrons scattering. However, finally long-range magnetic order establishes oncooling.

Taking advantage of the presence of a convenient Mofibauer isotope as a regular constituent inthese compounds the resonance 7-absorption experiments with 23.8fceF radiation of 1195n have

67

been performed down to 1.6K. At higher temperatures (T > T/v) spectra of both compoundsshow a similar character with two components in agreement with the presence of tin atomsin two crystallographicaly distinct sites. Each of the components presents a doublet whichresults from the coupling of u9Sn nuclear quadrupole moment with an electric field gradientoriginating from the distribution of charges in the crystal lattice around a given nuclear site. Inthe magnetically ordered state the overall shape of the ErNi2Sn2 spectrum does not changesubstantially while in the case of a copper compound, one of the spectral components splitsfurther into two patterns. The different values of the angle between the main axis of the electricfield gradient (originating from the crystal lattice) and the magnetic hyperfine field for thetwo above mentioned sub-components indicate a more complex, probably non-colinear spinarrangement in ErCu2Sn2. Moreover, although the Neel temperature of ErCu2Sn2 is distinctlylower than that of ErNi2Sn2 values of transferred hyperfine fields induced at tin nuclei ( of oneof the two tin sites - that for which splitting into two sub-components is observed) are muchlarger for the former compound (4O(l)fc0e and 24(l)fcOe when extrapolated to T = 0) than anyof the saturation fields (inferred from the lines broadening) in nickel compound (the larger is5.3(5)ife0e, Fig.l).

The observation of the hyperfine interactions of tin nuclei with the 119Sn Moflbauer effect(Fig.l) in the vicinity of the transition region allows one to trace the spin correlations and ashort range magnetic order, taking full advantage of the sensitivity of this method to the localprocesses.

0.80

0.60 -

• - 0.40 -

~ 0.20 -

nIVoxw

0.005 10 15Temperature [K]

Fig. 2: Mdfibauer absorption lines broade-mng in ErNi2Sn2 as a function of temperature

The correlation time of the Er3+ spin S fluc-tuations is substantially shorter than the char-acteristic precession time of 1 1 95n nuclear mo-ment in the effective hyperfine field Hhf at itssite implies that the latter quantity attains itsaverage value which is proportional to the av-erage value of the spin < S >. The smallnessof the transferred hyperfine field Hhf results ina mere broadening of the absorption spectrum.The careful and consistent analysis of the dataallowed to deduce the temperature dependenceof the excess spectrum widening (AT) for bothcomponents connected, respectively, with the

™ l a t t i c e s i t e s o f t i n f o u n d i n t h e

structure variation of these compounds.

The dependance is well described under the assumption of the proportionality of the localfield Hhj to the two-spin correlation function: A r oc< Si • S2 >2 (solid line in Fig.2). The least-squares fit brought the values of the effective erbium-erbium exchange integral of -0.96(5)meFand -1 .15( l l )meF for the neighbourhood of each of the two tin positions in ErNi2Sn2 , re-spectively.

References:

[1] E.A. Gorlich, R. Kmiec , K. Latka, A. Pacyna and A. Gleifiner, to be published in J.Phys.: Condens. Matter

[2] E.A. Gorlich and R. Kmiec, accepted for publication in Ada Phys. Pol. A

1 Institute of Physics, Jagellonian University, Krakow, Poland

68

PL9601017

Mossbauer study of iron in axiniteJ. Kraczka, A. Pieczka 1, A. Hrynkiewicz and W. Zabiriski 1

Axinites form an accesory group of borosilicates that can be found in geological formationsof various ages. The crystal structure of axinite was studied by many authors, e.g. Takeuchi [1]and others [2,3], and according to their results, there can be a "tetrahedral layer" distinguished.It is built of [B2Sig03o] groups with a six-member ring of [S1O4] and [BO4] tetrahedra connectedto an "octahedral" layer. The latter is composed of Fe2+ and A13+(1) and A/3+(2) octahedralinked by distorted CaO$ and CaOs(OH) polyhedra.

Mossbauer spectroscopy was applied to study the role of iron ions in axinite. The studiedsample was collected in the Strzegom granite massif [4]. Testing various possibilities of spectraresolutions and their dependence on the mineral structure, it has been found that the resolu-tion of the spectra into four quadrupole doublets, each two of them resulting from Fe2+ andFe3+ ions, is the best one. The doublets of the octahedral Fe2+ differentiate cations of thesecond coordination shell (B3+, Al3+). Comparison of structural calculations and results of theMossbauer measurement indicates that the doublet with the higher value of quadrupole splittingcan be attributed to a structural arrangement with Al3+ in the Il-nd coordination shell whilethat with the lower value of Q.S. - to the presence of B3+ in the Il-nd shell. The doublet ofFe3+ with smaller isomer shift we allocate to the presence of iron ions in tetrahedral positionsresulting from substitution:

[iV]St++ +[VI] R2+ =[IV] R3+{AijFe) +[Vl) R*+(Al,Fe).

The other Fe3+ - doublet is caused by iron ions in the octahedral position. This occupancyreflects deprotonation of the structure:

2~=tv/l R3+(Al,Fe) + O

and the above mentioned substitution.The following chemical formula of axinite, assuming the presence of 32(0, OH) ions, was

calculated on basis of the chemical and Mossbauer data: (Ca3.9i3 iVao.o55 ^0.014){Fe\\00 Mno.622 Fel+

156 A/0.125 M$ro.ii3 ^0.009 ^"0.004) Al2.ooo (S*7.893 ^0.107) (-81.679 -^0.321)

- 5

Fig. 1: Mossbauer spectrum of axinite taken at room temperature.

69

PL9601018Table 1.

The best resolution of the Mössbauer spectrum of axinite.

I.S.[mm/s](a - Fe)0.140.591.121.13

Q.S.[mm/s]1.601.622.191.99

S[%]85

2165

Interpretation

[VI]Fe3+

WFe2+(Al)WFe2+(B)

References:

1. Y. Takeuchi, T. Ozawa, T. Ito, T. Araki, T. Zoltai and J.J. Finney, Z. Kristallogr. 140(1974) 289

2. J.S. Swinnea, H. Steinfink, L.E. Rendom-Aiaz Miron and E. de la Vega, Amer. Miner. 66(1981) 428

3. A.V. Astakhov, Yu.B. Voitkovskii, O.N. Generalov and S.V. Sidorov, Sov. Phys. Cristal-logr. 20 (1976) 471

4. J. Janeczek, Geol. Sudetica 20 (1985) 2

1 Academy of Mining and Metallurgy, Kraków

Site occupancy of iron in vesuvianitesas studied by Mössbauer method

J. Kraczka and W. Żabiński 1

Vesuvianite is an ortho-pyro-silicate of approx. formula Ca19(ylZ, Fe)w{Mg,[SÍOA\IÜ(O,OH,F)10 [1]. In its crystal lattice Fe3+ and Fe2+ ions can be distributed amongat least three different sites, labeled: 5-coordinated B-site (tetragonal pyramid), 6-coordinatedAlFe site (octahedron) and 8-coordinated C-site (square antiprism) [2]. Until now only few dataconcerning Mössbauer studies of iron in vesuvianites have been published and only Manning'sand Tricker's reports [3,5] deserve notice.

In this study several vesuvianite samples from different localities (Transvaal, Piz Longhin,Monzoni, Canzoccoli, Cziklowa, Telemark) have been investigated by means of the Mössbauermethod. The first two samples represent so-called low-temperature ordered vesuvianites, theother four - high-temperature disorderd ones [4]. Due to the relatively small amount of iron inthese minerals and the distribution of this element between several lattice sites a high quality pro-portional counter and relatively high number of counts per channel were necessary. Mössbauerparameters calculated for some spectra at room temperature and probable site occupancies arepresented in Table 1.

In most of the investigated samples Fe2+ ions occur only in subordinate amounts or arepractically absent (Piz Longhin). Fe3+ ions are located predominantly in AlFe positions (CN6). Some quadrupole doublets seem to be indicative of ferric as well as ferrous ions in B-sites(CN 6). No doublets due to Fe2+ or Fe3+ in C-sites (CN 8) have been observed.

In the spectrum of vesuvianite from Transvaal, recorded at room temperature, out of 3doublets (one due to a small Fe2+ content) a faint sextet of Zeeman splitting can be observed.In the spectrum of this mineral recorded at helium temperature ( due to the kindness of prof.

70

St. Hafner in his laboratory in Marburg ) this sextet is much more pronounced and is mostprobably due to a fine, submicroscopic admixture of an iron oxide mineral. In the Mossbauerspectrum of the same sample recorded after heating it for 20 hrs at 1073 K, the doublet coiningfrom Fe2+ ions disappeared. However, no other distinct changes in the site occupancy of ironions, suggested by EPR investigations, have been observed.

Table 1. Mossbauer parameters of some natural vesuvianites

Locality

Transvaal

Monzoni

Canzoccoli

Iron content(as FeO wt.%)

2.88

4.59

4.01

LS.(a - Fe)[mm/s]

0.340.331.140.370.380.801.090.380.801.04

Q.S.[mm/s]

0.580.332.690.501.080.512.500.630.412.60

S{%]2463134225191481415

InterpretationIonsFe3+

Fe3+

Fe2+

Fe3+Fe3+

Fe2+Fe2+

Fe3+

Fe2+

Fe2+

Coord.VIVIVVIVIVVIVIVVI

References:

1. W.A. Deer and R.A. Howie, J. Zussmann, An Introduction to the Rock-Forming Minerals,2nd ed. Longmans (1992) 47

2. A. Yoshiasa and T. Matsumoto, Miner. Journal 13 (1986) 1

3. P.G. Manning and M.J. Tricker, Canad. Miner. 13 (1975) 259

4. F.M. Allen and Ch.W. Burnham, Canad. Miner. 30 (1992) 1

5. M.J. Tricker and P.G. Manning, J. de Physique C2 40 (1979) 477

1 Academy of Mining and Metallurgy, Krakow

71

PL9601019

Study of trace elements distribution in various tissuestructures

W.M. Kwiatek and E. Marczewska

Many papers have been written during the past ten years about TE study in cancer andnormal tissues describing the use of different methods for detection of trace elements. Concen-tration of TE depends strongly on the sample measured. However, according to our knowledge,the role of TE in cancerous tissue is still not known. Therefore, we propose to perform anexperiment which will hopefully give us more information about the relationship between theconcentration of elements in different tissues.

The developing industry localised near Cracow has become a serious danger for the healthof it's inhabitants. The negative influence of air pollution on living organisms is seen not onlyin nature but also in humans. Therefore we want to analyse the trace element contents in theair. Such investigation will give information about the pollution level in the City. The pollutionhas an obvious negative influence on health and contributes to toxic the element concentrationlevel in blood. It is interesting to check if the placenta plays an effective role in foetus protectionagainst toxic metals. In order to study this problem, the trace element analysis of placentatissues will be done by means of synchrotron microbeam.

The determination of the concentration of trace elements in human cancerous tissues and inhuman placentas done by means of SRIXE at DORIS storage ring makes it possible to measureelemental distribution with a spatial resolution of around 20 /an.

Such determination seems to be important due to the difference between the concentrationof trace elements in normal and cancerous tissues. There are several questions to be answered.

-What occurs on the boundary of tissues?-What kind of correlations are observed between concentration of various elements?-What is the distribution of trace elements along the distance from the centre of the canceroustissue to the normal tissue ?

We expect that the placenta investigations will give us the answers to the following questions:-What is the distribution of TE concentration along the distance between the mother-side andchild-side of the placenta?-Which structures in placenta tissues work as filters for toxic TE, if they do?-What is the protection level of the foetus against the heavy metals?

With the synchrotron radiation, two-dimensional mapping will be done. All samples will beinvestigated histologically which should help to find the correlations from the medical point ofview (correlation between the morphological and functional changes).

In all biological experiments it is very important to keep always the same sample and targetpreparation technique. This diminishes the systematical errors which otherwise may occur.

All cancerous samples will be obtained during surgical operations. The cut of tissue willbe frozen, and then cut by a microtome into sections of 20-/xm thickness. That thickness isalready sufficient for analysis. Two adjacent layers will be used for analysis, one for histological,treatment and the other for target preparation. The thin micro- target will be placed on 7.3/nn(1/3 mil) Kapton or other clean foil supported by a slide frame. Before targets mounting, thefoils will be checked for impurities. In the same way the placenta samples will be prepared.

In order to calculate trace element concentrations in investigated samples one should applya technique of either external or internal standard, otherwise fundamental calculations shouldbe done. In this study the external standard technique is proposed. A thin gelatine standard

72

PL9601020

containing various amount of different elements will be prepared according to the requirementsof the "membrane preparation technique" described by Th. Brandenburg in his Masters Thesis.The 20 /im thick standard section will be analysed in advance using the TXRF technique.

White-light Synchrotron Radiation Induced X-ray Emission (SRIXE) is an ideal techniquefor Trace Element (TE) analysis in "thin" samples. During the past few years it has been appliedto biological research. The biological samples are mostly light-Z organic matrixes. This type ofsample often requires a special selection of the experimental conditions for the measurements.

An electron storage ring producing X-rays (i.e. Synchrotron Radiation) has many propertiesthat makes it attractive for TE analysis. The advantages are: high photon brightness and flux,high degree of polarisation, and low divergence emission (small opening angle). These propertiescan be used for rapid non-destructive measurements with good spatial resolution, and very lowMinimum Detectable Limit (MDL).

The use of Total reflection X-ray Fluorescence Analysis (TXRF) with synchrotron radiationwill help in thin standard investigation.

The SRIXE work will be done on the beam line L at the DORIS X-ray storage ring atthe HASYLAB in Hamburg, FRG. The experimental set-up fully described by S. Garbe et al(presented at HASYLAB User's Meeting in January 1993) seems to be adequate for the purposeof the proposed experimental work.

Acknowledgements:This work is supported by the State Committee for Scientific Research (KBN), Poland as wellas by the HASYLAB and DESY, Hamburg, Germany. Our thanks are extended to prof.A. Knochel's group from Hamburg.

Temperature and matrix effects in PIXE elemental analysis

W.M. Kwiatek, J. Lekki and C. Paluszkiewicz1

Trace element determination using the PIXE technique is affected by two significant effects:- composition of a sample may change due to temperature effects introduced by beam heating(particularly true for biological samples)- in thick target, matrix dependent attenuation of X-rays and their energy dependent productioncross sections require proper corrections introduced in computational procedures (particularlytrue for heavy matrices and light traces).

The procedure is based on the use of FTIR (Fourier Transform InfraRed) and EBS (ElasticBackScattering) methods as complementary techniques for PIXE experiments. FTIR gives arough estimation of sample chemical composition while EBS is used for the determination of theproper stoichiometry of major elements that form the sample matrix.

The experimental set-up for PIXE/PIGE/EBS experiments is schematically presented in IFJAnn.Rep. (1993) pp. 95-97. For this experimental work different samples were analysed. Thoseinclude IAEA Standard Reference Materials: A-13 (animal blood), H-8 (horse kidney), and Cl-1(cabbage). All samples were prepared according to an external standard technique of pellets of10 mm in diameter and 1 mm thick. Such thickness is big enough to stop a whole irradiatingproton beam and decrease characteristic X-ray intensity. The exact sample preparation proce-dure followed the IAEA requirements for thick samples.

73

00I

I<

Da:

100 =

1 0 :

1 =

0.1 \

-

m -

j

.;I

i

1F11•

Jl11

= f

Elements: K, Ca. Fe. Zn

| romm temperature 600 C no correction 6 00 C corrected

Fig. 1. Elemental concentration ratio between A-13 and H-8 for K, Ca, Fe, and Zn.

The results show the importance of a multi-technique approach to the single sample measure-ment. As is shown in bar-graphs (above) the correction for matrix change is significant andgives different results in elemental concentration than simply using traditional calculation withthe use of an external standard technique. The figures below show the results obtained.

1 0 S

200 'I 4001' 600

Channel Number800

Fig. 2. The comparison of two normalized blood (IAEA A-13) PIXE spectra (higher spectrumcorresponds to matrix change).

74

0.8-

0.6-

0.4-

0.2-

I I I I I I I I500 1000 1500 2000 2500 3000 3500 4000

Wavenumbers

Fig. 3. The comparison of two normalized blood (IAEA A-13) FTIR spectra (higher spectrumcorresponds to matrix change).

1500n

1000-

c

OO

500-

0.5 1.0 1.5 2.0 2.5

Energy MeV

Fig. 4- The EBS blood (IAEA A-13) spectrum after matrix change.

A cknowledgement s:The authors wish to thank dr Boguslaw Rajchel for his help in EBS data taking and Erazm

M. Dutkiewicz for his help in PIXE data analysis. Many thanks are given to the VDG groupfor their hard work during the measurements.

This work has been supported by the State Committee for Scientific Research (KBN), PolandAccount No. IFJ-0000202 and grant No. IFJ-0090267.1. Jagellonian University, SLAFIBS, ul.Kaiasia 3, 30-060 Krakow.

75

PL9601021

Sample preparation procedure for PIXE, PIGE and RBStechniques applied for biological studies in Henryk

Niewodniczanski Institute of Nuclear Physics

W.M. Kwiatek, E.M. Dutkiewicz, L. Glebowa, E. Marczewska, M. Sowa

Sample preparation technique plays an important role in the whole analytical procedure.The accuracy and reproducibility of the measurements depends on the chosen sample prepa-ration technique. Since different sample types are used as well as analytical techniques it isimportant to follow always the same procedure while analysing a similar type of samples. Thispaper describes the sample preparation procedure applied mainly by the Trace Element Ana-lytical Group of the Henryk Niewodniczariski Institute of Nuclear Physics in Cracow, Poland.

There are several analytical techniques that are applied for biological studies and environ-mental problems in the Henryk Niewodniczanski Institute of Nuclear Physics. They include:PIXE (Proton Induced X-ray Emission), PIGE (Proton Induced Gamma-ray Emission), RBS(Rutherford Back-Scattering technique), EBS (Elastic Back- Scattering technique). In order toapply those techniques some sample preparation before analysis is required. The analyses areperformed on ion beam (protons, alpha particles) obtained from 3MV Van de Graaff accelerator.During the analyses, targets are kept in the vacuum chamber and due to the applied techniquea different electronic set is used.

By thin target one should understand a target which does not stop the irradiating beam. Itmeans that the acceptable thickness depends on the ion beam energy and stopping power factor.The ion beam will pass through a light matrix much easier and therefore the target thicknessfor liquids and organic materials could be larger than for the other samples. In order to analyseliquids and thin (micrometers range in thickness) sections one has to use the support for thetarget.

Usually formvar (polyvinyl formal) film is used. Chloroform (CHCI3) or cyclohexanol aregood solvents for formvar. The 2.5 % or 5 % formvar solution is good enough to be used forsupport preparation. In order to prepare a formvar film one has to lay a drop of the solution ondouble distilled water and spread it on the water surface. Next an aluminium frame is insertedinto the water under the spread formvar and then pulled up on one side. Formvar will stick tothe frame while being pulled up. The foil dries out in the air. The film prepared in this wayis ready to be used for target backing after a few minutes. The usual thickness of formvar filmranges between 100 nm and 300 run. The foils of this thickness are transparent for ion beams.

In biomedical applications mostly human physiological fluids are subject to analysis. Allsamples such as blood or urine are very often analysed according to the so-called "thin sam-ples procedure". In order to avoid any contamination those samples are taken directly to thetubes. Blood is taken to the tubes containing a few drops of blood conservant such as heparin.The known amount of the sample is mixed with yttrium nitrate Y(NOs)3 in the known ratio(usually 1:1) with the known yttrium concentration (usually 100 ppm). Yttrium is an elementthat practically does not exist in human organisms (natural concentration is below 10 ppb) andtherefore it can be used as an internal standard during the analysis. Such a prepared sample isshaken for about 10 min. in order to ensure uniformity. In order to prepare a target one dropof a sample mixture is placed on the formvar film stuck to the frame. Then the target is placedin to the frame holder in the chamber. After target placing, the chamber is closed and pumpedout. All water that exist in the target dries out and the sample is ready to be irradiated with

76

the ion beam. Sometimes a sample put on Formvar dries out in the air and then the secondFormvar film is placed over the target to make a sandwich. Such a procedure is carried out incase when targets will be transported or irradiated several times.

Tissue sections are also recognized as thin targets. Commonly used tissues are taken from thebody during the surgical operations. Then, with a clean sharp scalpel the tissues are trimmedto provide access to the structures and orientation required by the experiment. Usually samplesare cut down to < 5 mm in at least one dimension. The trimmed tissues are frozen in liquidnitrogen (-196 °C). When completely frozen (it takes about 5 min) they are ready for cuttinginto sections. Usually sections of 10/xm to 30/xm are fully sufficient for the experiments. Thesections are cut on a cryo-microtome and placed onto either Kapton, Mylar or Formvar film. Incase of Kapton and Mylar it is important to keep the ratio target thickness to backing thicknessas large as possible.

By thick target, we understand a target, the thickness of which is large enough to stop theirradiating ion beam. Those samples do not require any specific backings to support them.

It is very important to have uniform targets. In order to ensure it the whole sample ishomogenised. In case of biological samples they are dried in the air under a 200 W lamp or inthe oven at a temperature of 100 °C. In case of blood or tissues they are dried in a refrigeratorfilled with silica gel (for about 5 days). In each case the drying time is determined by the drymass factor. For example in the case of blood, the dry mass factor (the ratio of wet mass to drymass) is 4.012 ± 0.002. When a sample is dry it is melted in the agate mortar and then pressedinto a pellet of 10 mm in diameter and about 1 mm in thickness. Usually 100 mg of the samplepowder is used and a pressure of 10 MPa is applied. Such a pellet is attached to the targetholder with regular scotch tape. There is no risk of contamination or extra peaks originatingfrom the tape since there is a thick target on it.

In the case of some samples (i.e. nails, hairs) before preparing targets they have to bewashed out due to surface contamination. Pure distilled water and non-ionic detergent are usedfor cleaning the surface of those samples.

When analysing minerals by PIXE/PIGE technique one has to take into account the grainsizes due to matrix effects.

Sample preparation procedure for trace element analysis is a very significant part of theanalysis. During sample preparation it is very easy to introduce contamination. Therefore a lotof care has to be taken in order to avoid it. A large advantage of PIXE/PIGE analysis is thatfor some bio-medical applications almost no sample preparation is required, thus reducing therisk of contamination.

References:

[1] V. Valcovic, "Sample preparation techniques in trace element analysis by X-ray emissionspectroscopy", IAEA-TECDOC-300.

77

PL9601022

Compton scattering studies of Ni - Cu alloy

S. Kaprzyk1, J. Kwiatkowska, F. Maniawski

The development of the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) method and its further generalization [1] provided the means to calculate electronic struc-ture of disordered substitutional alloys as reliably as that of pure elements. This made it worth-while to study such systems experimentally due to the prospect of comparing the results withthe first-principle, parameter free theory. One of the most direct methods to probe electronicstructure of materials is the Compton scattering technique [2]. The energy profile of Comptonscattered X-rays or 7 rays, the so called Compton profile (CP) is related to the electron-momentum density in the material.

The material chosen to be studied is the Ni-Cu alloy, often regarded as a typical represen-tative of a binary substitutional alloy. It is a simple system with fee lattice for all compositionsand expected complete solid solubility. At the same time the alloy possesses an interesting andcomplex band structure [3].

The specimens for the future Compton scattering studies are single crystals of the alloyof nominal composition 0.75Ni-0.25Cu grown by the Bridgman method. Phase diagram ofthe Ni —Cu alloy shows a gap of about 60°C between the liquidus and solidus line indicatingthat the liquid and solid phase can coexist in a wide range of temperature. This phenomenoncauses that the conditions for single crystal growth are not favourable and thus big crystalsdifficult to obtain. Many attempts at growing the single crystal resulted in obtaining an ingotwhich consisted of four sizable grains the biggest of which was used to prepare the specimens.The crystals were oriented by the Laue X-ray diffraction method and the slices with the threeprinciple orientations [100], [110] and [111] were cut by a spark erosion machine. The sampleswere all given the same shape of disks with $ = llmm and subsequently ground and chemicallypolished down to the thickness of 2mm. The Compton profiles of the specimens will be measuredwith the 7-ray Compton spectrometer at the Warsaw University Branch in Bialystok.

Along with the sample preparation some theoretical calculations have been made for the alloy.The selfconsistent electronic structure calculations using the KKR techniques with the muffin-tinpotential were performed allowing for relativistic nature of the core electron states. The momen-tum density was then determined and subsequently the Compton profiles generated for the threeprinciple crystallographic directions. The calculations were made for various compositions of theNi-Cu alloy. Some of the results are presented in Fig. 1 where one can see the effect of alloyingon the Compton profile; here the profile of pure copper has been subtracted from the profile ofthe Ni —Cu alloy of given composition.

This representation of the Compton profiles reflects the changes in the momentum densitywith alloying and the differences are expected to be directly related to the Fermi surface shapeevolution for different compositions. The differences also vary with crystallographic dirrection.This anisotropy observed in the system indicates that the situation here is far from the free elec-tron predictions. Morover, the pronounced peaks, if experimentally detected, will give uniqueinformation about electronic behaviour close to the Fermi level. The Compton scattering exper-iment performed on the single crystal is to serve this purpose.

78

CP Cui-»NI« - CP Cu

along (1 OO)

CP Cu,-,NI, — CP Cu

along (1 1 O)

<->•>

Fig. 1: Changes in the Compton profilewith alloying i.e. differenes between pro-files of given composition of the Ni- Cu al-loy and the profile of pure Cu, calculatedfor three crystallographic directions.

In addition some new features on the Compton profile derivatives have been recently foundby Kaprzyk, which correspond to the discontinuities in momentum density field resulting fromthe shape of the Fermi surface. These results can be verified experimentally if measurements areperformed with a resolution better than O.lau in the momentum space which is just becomingfeasible at some synchrotron laboratories.

References

[1] S. Kaprzyk and A. Bansil, Phys. Rev. B42 (1990) 7358.[2] M.J. Cooper, Rep. Prog. Phys. 48 (1985) 415.[3] R. Benedek, R. Prasad, S. Manninen, B.K. Sharma, A. Bansil, P.E. Mijnarends, Phys.

Rev. B32 (1985) 7650.

1 Academy of Mining and Metallurgy, Krakow, Poland

79

?-{Co

PL9601023

Construction of the Atomic Force Microscope (AFM)

J. Lekki, U. Voss1, B. Cleff1 and Z. Stachura

Although the process of friction and wear mechanisms has been intensively investigatedfor a very long time, physical models of these effects are still not well developed, especiallywhen one considers the models based on atomic scale interactions. This situation is mainlycaused by the lack of reliable data, because the measurements of friction and wear basing ontraditional techniques are averaged over large heterogeneous samples. Only by the reduction ofthe contact area (even to single contact in atomic scale), may more reliable data be producedas the measurement is betted controlled [1]. One of the most promising tools in this researchfield is the Atomic Force Microscope. Its operation principle is based on the measurement ofthe deflection of a cantilever with a sharp tip at one end, caused by the forces between theinvestigated surface and a tip.

Since its invention in 1986 [2] many different constructions have been proposed [3]. In ourconstruction the cantilever deflection is detected by a laser beam reflected from the cantileversurface with the use of the quadrant photodiode. This idea has proved to be successful inmeasuring both lateral and vertical forces, thus allowing direct microfriction and microadhesionmeasurements [4].

National Instruments AT-MIO16L9Data Acquisition Boord

Quadrant Diode Signals1 2 5 4 Z Coitrol

RTSI Bus

National Instruments AT-AO6Analog Output Board

Scanning InchWormX Y F M B C

Current to Voltage

Converters & Amplifiers

1 2 3 4

HV Piezo

Controller

XYZ

Quadrant Photodiode"nn

HV InchWorm

Controller

F M B C

nchWorm Stepping Motor

Sconner & Fine Approoch

Laser Diode Sample

Atomic Force Microscope - Schematic Diagram

80

The coarse approach of the sample and scanning tip is realised using an Inch Worm steppingmotor (Burleigh UHVL-025). This device assures controlled movement at distances up to 25mm, in steps even as small as several nanometers. The scanning tip, laser diode and detect-ing quadrant diode are in fixed position, with the laser beam focused on the microfabricatedcantilever (Park Scientific Instruments, dimensions 170 X 36 X 0.6 /zm with silicon nitride tip- radius of tip curvature about 500 A). The force constant of the cantilever is 0.1 N/m. Thetip may be easily exchanged or replaced with another one characterized by different mechani-cal parameters. Fine Z adjustment and XY scanning of the tip over the investigated surfaceis performed by moving the sample relatively to the tip. The sample holder is held magneti-cally to a scanner, what assures its stable position and simple sample exchange. The scanneris constructed with the piezo tube divided into four quadrants (Staveley Sensors Inc., piezodisplacement factor about 2-lO~10 m/V). Applying high voltage signals to the quadrants of thepiezo tube one can perform very fine and well controlled movements of the sample in all threedimensions.

The whole instrument is controlled by the IBM PC 486 microcomputer equipped with twodata acquisition cards: AT MIO-16L-9 (multi I/O) and AT-06 (analog outputs) manufacturedby National Instruments. Analog signals delivered by PC boards drive specialized high voltageamplifiers (up to +900 V for Inch Worm and ±400 V for scanning and fine approach system,optimized for large capacitance piezoelectric loads). Scanning of a picture 256x256 points takesseveral minutes. The control and data analysis program is written using Microsoft C 7.0 andruns in MS Windows 3.1 environment.

Our setup is still under development - elements missing include elements of the scanningsystem (two additional HV amplifiers), details of the mechanics and antivibrational dumpingsystem. Estimated time of first experiments is summer 1994.

Acknowledgements:AFM is developed in cooperation with the Institute of Nuclear Physics, University of Miinster,Germany. Work is supported by the State Committee for Scientific Research (KBN), Poland,Grant No. 2P30204505.

References[1] G.M. McClelland and S.R. Cohen, Chemistry and Physics of Solid Surfaces VIII, Eds. R.

Vanselow and R.Howe, Springer Series in Surface Sciences, Vol.22, 1990.[2] G. Binnig, C.F. Quate, and Ch. Gerber, Phys. Rev. Let. 56 (1986) 930.[3] E. Mayer, Progress in Surface Science, Pergamon Press 1992, Vol.41, p. 3-49.[4] 0. Marti, J. Colchero, and J. Mlynek, Nanotech. 1 (1990) 141.

1 Institute of Nuclear Physics, University of Miinster, Germany.

81

PL9601024

WAFM - a Microsoft Windows control programfor Atomic Force Microscope

J. Lekki, U. Voss1, B. Cleff1 and Z. Stachura

The code WAFM has been developed with the aim of software control of the Atomic ForceMicroscope and image processing of the measured data. The microscope setup is described inthe previous report. The program is written entirely in Microsoft C 7.0, runs in MS Windows 3.1environment and uses two specialized PC boards (AT-MIO-16L-9 and AT-AO6 from NationalInstruments) for analog output and input operations. Optimized software libraries deliveredby the manufacturing company are responsible for high level control of analog boards, assuringminimization of interrupt latency, significantly present in the Enhanced mode of Windows.The structure of the program is typical for Windows application, and consists of the followingmodules:

• Inch Worm (Coarse approach),• Quadrants (Option used during initial setting of the laser beam and quadrant diode geo-

metry. Adjusting must be done by hand),• Data Collection (Scanning, fine approach),• Analysis (Filters, data evaluation tools),• File Operations (Data saving, loading etc.),• Setups (Most of the hardware parameters of AFM are software configurable).The coarse approach of the sample to a force sensor is based on an Inch Worm motor. There-

fore three analog signals of a definite shape and timing must be delivered, which after HVamplification are supplied to the piezo motor. This task is performed entirely by software andits characteristics may be easily modified and optimized. The speed of approach is softwarecontrolled and is limited mainly by the response time of HV amplifiers. In the present applica-tion a motor speed of 100 steps per second was found to be sufficient. For the average singleInch Worm step of 2 /xm this frequency produces linear speed determining the approach timeof only a few minutes for scan-sample distances in the range of 20-25 mm, thus assuring fastand convenient sample exchange. Additional safety measures are included into the procedureof coarse approach to avoid damage of the cantilever in close proximity of the sample. The fineapproach is based on a software control of the piezo tube inner electrode voltage. This signalmay be used also for the compensation of small Z-dimension scanning errors caused by the factthat tube scanners scan not a flat area, but the surface of a sphere. The image data collection isperformed using a simple algorithm for position updating and acquisition of the normal and thelateral force values forming two rectangular maps constructed of up to 256x256 points. Everysingle pixel measurement consists of four voltage readouts and the subsequent summing andsubstracting of the appropriate signals. Data are displayed in real time using a 256 degree colorscale corresponding to measured values and may be represented using different color palettes.Every measurement forms an independent window on the screen, therefore many experimentalpictures may be simultaneously displayed and compared.

Evaluation and image processing of the collected data is possible using several tools, suchas dimensional and force calibration, zooming the region of interest, linear cut along a chosendirection, configurable convolution filters and FFT. Three dimensional data representation isforeseen and will be included in the future.

1 Institute of Nuclear Physics, University of Miinster, Germany.

82

PL9601025

Adaptation of the 75 kV INP ion implanter ' <?to IBAD technique

B. Rajchel, M. Drwi§ga, E. Lipiriska, M. Wierba

The ion implanter facility of the Institute of Nuclear Physics in Cracow was used, duringmany years, in different fields of research and technical application [1]. The ion engineeringmethods especially implantation, ion mixing, recoil implantation and ion etching were frequentlyused for the creation or modification of thin surface layers of material. Among all the ionengineering methods, based on the ion bombardment, the IB AD - Ion Beam Assisted Depositiontechnique allows for the most perspective and can give the complex surface layers with excellente.g. mechanical, electrical, chemical or optical properties [2]. Adaptation work on the INPimplanter to Ion Beam Assisted Deposition technique were performed. The ion implanter wasadapted to IBAD technique by the connection of an additional ion beam line equipped with:a pumping system, hollow - cold - cathode ion source, all the systems to control material andelectrical feedings of the ion source and a lens assembly for extraction and formation of the ionbeam, modernized target chamber fitted out with a set of probes, the support of the auxiliarytarget and other control systems. In this new arrangement, the additional ion beam (noblegasses, energy from 5 keV to 45 keV) is used to sputter atoms out of the auxiliary target. Theseatoms are deposited onto the surface of the modified substrate with the deposition rate in therange of 1 nm/min to 10 nm/min and the layer thickness up to 1/zm. Simultaneously withdeposition, the main ion beam from the implanter is employed in the ion bombardment of thegrowing layer (I/A ratio from about 10~3 to 1 or more ; A - number of deposited atoms, I -number of incoming ions in the same time). The geometry of the IBAD setup is shown in Fig.1. As can be seen, the mass analysed, uniform ion beam from the implanter of almost all theelements, with the energy of ions selected ranging from 5 keV to 75 keV (or more, for multiplecharged ions) can be used to influence dynamically the formation of sputter deposited substratelayer in a controlled way (i.e. number of bombarding ions / number of sputter deposited atomsratio, energy of ions, vacuum conditions etc.). Any complex elemental, alloy or compoundsurface layer on the modified substrate can be produced by using this device.

After adaptation, the new equipment was tested by:

1. growing, by sputter deposition, of the thin Ni layer on the Si < 111 > single crystal,

2. preparation of yttrium layer in Si < 111 > single crystal; by implantation of Y+ at thedose of 2 * 1016 ions/cm2 , with the energy of 45 keV,

3. creation, by means of IBAD method, thin Ni\-XYX layer on Si < 111 > single crystal, bysputter deposition of Ni atoms and simultaneous yttrium ions bombardment, at total doseof 2 * 1016 ions/cm2 , with the energy of 45 keV.

For sputtering of Ni target, a beam of AT+ ions with an energy of 45 keV was applied.In both cases, the parameters of the yttrium ions bombardment (ex. 2, 3) and the sputterdeposition (ex. 1, 3) were similar. Rutherford Backs cat tering Spectroscopy method, using thebeam of particles (protons or a particles) from the 3.0 MV Van de Graaff facility at the Instituteof Nuclear Physics, can be applied to investigate the structure and elemental composition of thenew surface layers [3]. The depth profiles of layers of the deposited Ni atoms and of the implantedY+ ions were measured by detection of the a particles backscattered at an angle of 150°. In allcases, the Si < 111 > single crystals were bombarded by the a particle beam, with an initialenergy of 1000 keV, in random direction. In Fig. 2 backscattering spectra for Si < 111 > singlecrystals with: the thin Ni film (2a), implanted Y layer (26) and the thin (about 20 nm) coating

83

of Nii^xYx (x = 0.15) (2c) formed by Ni and Y atoms by IBAD technique, are shown. Firstexperimental a particles RBS spectra measured for the Si < 111 > single crystals with a surfacelayers created by IBAD technique, permits one to suppose, that after adaptation the INP twobeam line ion implanter is a good tool for the formation of complex surface layers by IBADtechnique.

The 75 kV INP ion implanter

Main ion bean line Magnet

Additional ion bean line

Fig. 1: The geometry of the IBAD setup.

10000

9000

8000

ccCOXI

o<Dd

s:

CQ

o

7000

6000

5000

4000

3000

2000

1000

RBS spectrum for Si < 111 > single crystalwith thin (about 20 nm) Ni film

500 750

# Channel

1000 1250

Fig. 2a: RBS spectrum for Si < 111 > single crystal with the thin Ni film.

84

12000

10000

c 8000c(0x:^ 6000

tf>

"c 4000

OO

2000

RBS spectrum for Si <111> single crystal implanted

by Y* at the dose 2*1018 ions/cm2

with the energy 45 keV

Si

.A.250 500 750

# Channel1000 1250

Fig. 2b: RBS spectrum for Si < 111 > single crystal with the thin implanted Y layer.

16000

14000

12000

d)

cJCOL.0)a,

oO

10000

8000

6000

4000

2000

RBS spectrum for Si <111> single crystalwith thin (about 20 nm) N i , . ^ film

created by the I BAD method

Ni

250 500 750

# Channel

1000 1250

Fig. 2c: RBS spectrum for Si < 111 > single crystal with the thin (about 20 nm) coating ofNi!.xYx {x = 0.15).

References:[1] M. Drwi§ga, E. Lipinska, S. Lazarski, M. Wierba, Raport IFJ Nr 1656/AP (1993)[2] G. Dearnaley, NIM B50 (1990) 358[3] S. Kopta, J. Lekki, B. Rajchel, J. of Rad. and Nucl. Chem. 172 (1993) 3

85

PL9601026

Creation of Li - Ni and Li - Mn coatings upgrading the high -temperature corrosion resistance of metals by IBAD method

B. Rajchel1, M. Drwi^ga1, E. Lipinska1, J. Lachut1, A. Sellman1, M. Wierba1

S. Mrowec2, M. Danielewski2, I. Turek - Bednarska2

IBAD - Ion Beam Assisted Deposition of thin layers consisting of elements, alloys or com-pounds is a method in which the growing film is simultaneously bombarded with energetic ions[1], IBAD has become an advantegous method for controlled modifications of surface layersof metals, ceramics, composites and other materials. This technique is one of the most usefulfor production of up to few tens of fim thick adherent surface coatings with special physical,chemical, mechanical, optical and electrical properties. The highest degree of control of eachprocess parameter is obtained with ion - beam - based systems in which the ion bombardmentis independent of the deposition and both can be easily controlled.

At the ion implantation laboratory of the Institute of Nuclear Physics there is a dual ionbeam device with excellent parameters for the IBAD method. In this arrangement, layers areobtained by sputter deposition of atoms onto the substrate and simultaneous ion bombardmentof the growing film by means of a mass analyzed ion beam. This system affords possibilitiesfor controling the IBAD processes by accurate measurement and verification of the parametersof the two ion beams [2]. Providing, above all, the energy to a growing film by means ofion bombardment and the right selection of chemical and physical features of incoming atomsand ions, allows for variation of a lot of film properties like composition, structure, adhesion,intrinsinc stress, density, morphology, porosity, corrosion resistance and others.

Recently the comprehensive, multidirectional investigations on high - temperature, oxygen -consuming and sulfur corrosion resistance of some metals and special alloys have been undertakenin the ion implantation laboratory in cooperation with several research centers in Poland andabroad. So far, the IBAD method was used to prepare Li-Ni and Li-Mn layers on Ni andMn substrates, respectively [3]. A preliminary series of samples with different concentrationsof Li atoms was performed by the proper choice of parameters of the two ion beams and otherconditions during the IBAD process. In order to determine the exact composition of coatings, thenon - destructive inspection was carried out by RBS (Rutherford Backscattering Spectroscopy),a nuclear method, adapted to material investigation (internal structure and composition). A3 MV Van de Graaff accelerator was used to provide an adequate, analysing a particle beam.The oxidation behaviour of Li — Ni/Ni and Li — Mn/Mn test samples was studied at 1373 Kin air or pure oxygen, by means of thermogravimetery. Electron microscopy method was usedto define the morphology of layers. The data handling is carried out and the first results ofinvestigation of high - temperature corrosion resistance of Ni and Mn specimens, modified bythe IBAD method, will be published.

References:

[lj G.K. Wolf, Surf, and Coat. Tech. 43/44 (1990) 920[2] B. Rajchel, M. Drwie,ga, E. Lipinska, M. Wierba,Proc. of the ECAART'3, Orlean (1993)[3] W.C. Hagel, Transactions of the Metallurgical Soc. of AIME, 233 (1965) 1184

1 Institute of Nuclear Physics, Krakow2 Academy of Mining and Metallurgy, Krakow

86

LIST OF PUBLICATIONS:I. Books:

1. J. Gr§bosz, "Symphony in C++. Object Oriented Programming in C++",Oficyna Kallimach, Krakow, 1993 (in Polish).

II. Articles:

1. A. Andrejczuk, (J. Kwiatkowska, F. Maniawski) et al.,Compton Profiles of Silver Single Crystal,Phys. Rev. B48 (1993) 15552;

2. A. Baczmariski, (F. Maniawski) et al.,Calculation of the Rotation Rate Field on the Basics of Experimental Texture Data,Philosophical Magazine A67 No 1 (1993) 155-171;

3. R.C. Barber, (A. Hrynkiewicz) et al.,Discovery of the Transfermium Elements,Pure and Appl. Chem. 65 No 8 (1993) 1757-1814;

4. P. Bednarczyk et al.,First Observation of the Excited States in the Doubly Odd Nucleus 118Cs IdentifiedThrough 7-Recoil Coincidences,Z. Phys. A346 (1993) 325;

5. P.Bednarczyk, E.Bozek, B.Fornal, M.Lach, A.Maj, W. Mgczynski, T. Pawlat, J. Styczen,Cross Section Ratio for pn and d Emission as a Probe of Level Density for Light-MediumNuclei,Acta Phys. Pol. B24 (1993) 451-452;

6. G. Bench, (M. Cholewa) et al.,Applications of Energy Loss Contrast STIM,Proc. of 3rd Int. Conf. on Microprobe Technology and Applications, Uppsala, Sweden,June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 175;

7. A. Bracco, (A. Maj) et al.,Probing the Shapes of Hot Nuclei with the GDR,Nucl. Phys. A557 (1993) 237-246;

8. F. Camera, (A. Maj) et al.,The Shape of Hot Nuclei and the Angular Distribution of Hard Dipole Photons,Acta Phys. Pol. B24 (1993) 437-440;

9. M. Cholewa et al.,Channeling STIM and its Applications,Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala,Sweden, June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 184;

10. M. Cholewa et al.,The Use of a Scanning Proton Microprobe in AIDS Research,Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala,Sweden, June 7-12, 1992; Nucl. Instr. and Meth. B77 (1993) 282;

11. J. Dryzek,Resonance Trapping of Positrons in Solids,Acta Phys. Pol. A83 (1993) 293; Phys. Stat. Sol. (b)179 (1993) 15;

12. S. Flibotte, (J. Styczen, K. Zuber) et al.,AI=4 Bifurcation in a Superdeformed Band: Evidence for a C4 Symmetry,Preprint of Univ. Strasbourg CRN 93-35; Phys. Rev. Lett. 71 (1993) 4299;

87

13. S. Flibotte, (J. Styczeri, K. Zuber) et al.,Multi-Particle Excitations and Identical Bands in the Superdeformed 149Gd Nucleus,Preprint of Univ. Strasbourg CRN 93-36 (1993); Phys. Rev. Lett. 71 (1993) 688;

14. B. Fornal et al.,Neutron Spectra from the 156Er Compound Nucleus Populated by 12C- and 64Ni-InducedReactions,Phys. Rev. C48 (1993) 2072;

15. J.J. Gaardh0je, (A. Maj) et al.,Atomic Nuclei at High Excitation Energy Studied with Giant Resonances,Acta Phys. Pol. B24 (1993) 139-172;

16. J. Heese, (W. M^czyriski, M. Janicki, J. Styczeri, J. Gr§bosz) et al.,Development of a New Recoil Filter Detector for 7-Detector Arrays,Acta Phys. Pol. B24 (1993) 61;

17. J. Heese, (J. Gr§bosz, W.M§czynski, J. Styczeri) et al.,Evidence for Low-Lying Prolate Bands in 188Pb and 186Pb,Phys. Lett. B302 (1993) 390-395;

18. K.M. Horn, (M. Cholewa) et al.,Single Event Upset and Charge Collection Imaging Using Ion Microbeams,Nucl. Instr. and Meth. B77 (1993) 355;

19. A. Hrynkiewicz,Badania naukowe podstawowe i stosowane,Postepy Fizyki 44 (1993) 63-70;

20. A. Hrynkiewicz,Adiunkci bez habilitacji,Przeglad Akademicki 3 (1993) 6;

21. J.R. Hughes, (B. Fornal), et al.,Collective Oblate Bands in 196Pb,Phys. Rev. C47 (1993) 1337;

22. S. KopJ^i, J. Lekki, B. Rajchel,Detection Ability and Elemental Contents Determination by Elastic Scattering of LightIons and by Recoiling Nuclei Measurements,INP Report 1574/AP, J. Radioanal. Nucl. Chem. 172 No 1 (1993) 3-17;

23. VV. Krolas, R. Broda, J. Grgbosz, A. Maj, T. Pawlat et al.,First Results of 208Pb +64Ni Collisions Studies,Proc. of the XXVII Zakopane School of Phys., in: Acta Phys. Pol. B24 (1993) 449;

24. M. Lach et al.,Shell Model Yrast States in the 7V = 79 Nuclei 141Sm and 143Gd,Z. Phys. A345 (1993) 427-428;

25. G.J.F. Legge, (M. Cholewa) et al.,High Resolution Imaging with Energy Ion Beams,Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala,Sweden, June 7-12 1992; Nucl. Instr. and Meth. B77 (1993) 153;

26. A. Maj et al.,E* and I Selection Techniques for Hot Nuclei Studies,Acta Phys. Pol. B24 (1993) 429-432;

27. M. Marszalek, B. Wodniecka, P. Wodniecki, A. Hrynkiewicz,PAC Study of Compound Formation in the In/Pt System,Hypernne Interactions 78 (1993) 315;

28. M. Marszałek, B. Wodniecka, P. Wodniecki, A. Hrynkiewicz,PAC Measurements of In-Pt Intermetallic Compounds,Hyperfine Interactions 80 (1993) 1029;

29. R.S. Mayer, (H. Dąbrowski, B. Fornal. L. Freindl), et al.,Investigation of Pion Absorption in Heavy-Ion Induced Subthreshold IIo Production,Phys. Rev. Lett. 70 (1993) 904;

30. D. Nissius, B. Fornal, LG. Bearden, R. Broda, et al.,Yrast Isomers in Exotic N=81 Nucleus 151Yb Studied Using a Fragment Mass Analyzer,Phys. Rev. C47 (1993) 1929;

31. M. Piiparinen, (A. Maj) et al.,Lifetimes of Yrast States in n o Cd,Nucl. Phys. A565 (1993) 671;

32. P. Rymuza, (Z. Stachura) et al.,Deviation From First-Order Perturbation Theory Observed at Intermediate RelativisticVelocities for the Ionization of Highly-Charged Heavy Projectiles,GSI Scientific Report GSI-93-1 184; J. Phys. B26 (1993) 169-175;

33. A. Saint, M. Cholewa, G.J.F. Legge,PIXE Tomography,Proc. of 6th PIXE Conf., Tokyo, Japan, July 20-24, 1992; Nucl. Instr. and Meth. B75(1993) 504;

34. W. Schmitz, (A. Maj) et al.,Transition Quadrupole Moments of a Large-Deformation Intruder Band in 163Lu,Phys. Lett. B303 (1993) 230-235;

35. M. Schramm, (R. Broda, J. Grębosz, W. Królas, A. Maj) et al.,7-Decay of the Particle-Hole States with the Highest Spins in 2 0 8 Pb,Z. Phys. A344 (1993) 363-367;

36. Th. Stöhkler, (Z. Stachuia) et al.,Electron Capture Studies for Highly-Charged Bi-Ions,Rad. Effect and Defects in Solids 126 (1993) 319-323;

37. S.A. Stuart, M. Cholewa et al.,Investigation of Isolated Chemical Vapour Deposited Diamonds Using STIM Tomography,Proc. of 3rd Int. Conf. on Nuclear Microprobe Technology and Applications, Uppsala,Sweden, June 7-12 1992; Nucl. Instr. and Meth. B77 (1993) 234;

38. M. Uhrmacher, P. Wodniecki et al.,Ion-Beam-Induced Atomic Transport and Phase Formation in the System Nic-kel/Antimony. Part II: Phase Formation in Mixed Multilayers Observed by XRD andPAC,Appl. Phys. A57 (1993) 353;

39. B. Wodniecka, M. Marszałek, P. Wodniecki, A. Hrynkiewicz,Electric Quadrupole Interaction at 1 8 1Ta in Tetragonal C16 Intermetallic Compounds,Hyperfine Interactions 80 (1993) 1039;

40. B. Wodniecka, P. Wodniecki, A. Hrynkiewicz,PAC Studies of Agln2 and Ag2ln Growth Kinetics at Ag-In Interface,Hyperfine Interactions 78 (1993) 323;

41. P. Wodniecki, B. Wodniecka, M. Marszałek, A. Hrynkiewicz,Hyperfine Interaction of m C d in Pd-In Intermetallic Compounds,Hyperfine Interactions 80 (1993) 1033;

42. P. Wodniecki, M. Marszałek, B. Wodniecka, A. Hrynkiewicz,Intermetallic Compound Formation at In-Pd Interface Investigated with 1 1 1 In Local

89

Probes,Hyperfine Interactions 78 (1993) 319;

43. P. Wodniecki, M. Uhrmacher,Ion-Beam-Induced Atomic Transport and Phase Formation in the System Nickel/Anti-mony. Part HI: PAC Measurements in Intermetallic Ni-Sb Phases,Appl. Phys. A57 (1993) 469;

44. C.T. Zhang, (R. Broda, M. Lach) et al.,Energy Inversion of the /7/2 and hg/2 Neutrons in Yrast States of 154Yb,Z. Phys. A345 (1993) 327-328;

45. J. Zukrowski, R. Kmiec, J. Przewoznik, K. Krop,Magnetism of GdMn2 -

155Gd Mossbauer Results,J. Magn. Magn. Mater. 123 (1993) 246.

III. Contributions to Conferences:

1. A. Andrejczuk, (J. Kwiatkowska, F. Maniawski) et al.,Compton Studies of Ag,Proc. of the First Int. Workshop on High Resolution Compton Scattering as a Probe ofFermiology, Cracow, July 3-5 (1993) 150;

2. P. Bednarczyk, J. Styczen, R. Broda, W. M§czynski et al.,Investigation of High Spin States in 45Sc with the Use of GA.SP and RMS,Ann. Report 1992 LNL-INFN Legnaro (1993) 26; Abstracts of Symposium on Perspec-tives in Nuclear Structure, NBI, Copenhagen, June 14-17 (1993) ;

3. A. Bracco, (A. Maj) et al.,Thermal and Quantal Fluctuations as Probed by the GDR Observables,Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", KellogBiological Station Gull Lake, Michigan, USA, August 17-21 (1993) 9;

4. R. Broda,Heavy-Ion Binary Reactions Viewed by Gamma Arrays-Spectroscopy of Neutron-Rich Nu-clei,Abstracts of the Midsummer Workshop on Nucl. Phys., Jyvaskyla, Finland, June (1993) ;

5. F. Camera, (A. Maj) et al.,On Detailed Study of the GDR Lineshape at Finite Temperature,Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", KellogBiological Station Gull Lake, Michigan, USA, August 17-21 (1993) 11;

6. M. Cholewa et al.,A Study of Aluminium-Exposed Fish Using a Scanning Proton Microprobe,Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW,Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 1;

7. M. Cholewa et al.,Three Dimensional STIM Tomography and its Applications,Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW,Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 2;

8. A.E. Gorlich, R. Kmiec,Hyperfine Interactions and Spin Correlations in ErT2Sn2 (T=Ni,Cu) Phases,The European Conf. "Physics of Magnetism '93 - Stongly Correlated Systems", June21-24, 1993. Abstracts (1993) 38;

90

9. R.F. Garrett, (M. Cholewa) et al.,EXAFS and Microprobe Analysis at the Australian National Beamline Facility,Proc. of 8th Australian Conf. on Nuclear Techniques of Analysis, Lucas Heights, NSW,Australia, November 17-19, 1993, (ISSN 0811-9422) (1993) 3;

10. K. Gromov, (A.W. Potempa) et al.,Alfa-Gamma Sowpadienia pri Raspadie 225Ac—>221Fr,Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23Apriela (1993) 114;

11. J. Jedliriski, (B. Rajchel) et al.,The Effect of Composition, Heat Treatment and Surface Modification by Ion Implantationon the Oxidation Behaviour of Aloys from Fe-Cr-Al System,Proc. of the 2nd ASM Conf. on Heat Treatment and Surface Engineering, Dortmund,Germany, June 1-3 (1993) ;

12. J. Jedlinski, (B. Rajchel) et al.,Redistribution of Major and Minor Alloy Components in Scales Formed During EarlyStages of Oxidation on FeCrAl Alloys Studies by Means of SIMS and SNMS,Proc. of the 2nd Int. Conf. on Microscopy of Oxidation, Cambridge, England, March29-31 (1993);

13. J. Jedlinski, (B. Rajchel) et al.,The Effect of Surface and Heat Treatment on the Oxidation Behaviour of the Fe-10Cr-4AlAlloy,Proc. of 12th Int. Corrosion Congress, Houston, Texas, September (1993);

14. R. Julin, (A. Maj) et al.,Band Termination in 110Cd,Abstracts of the NBI Conf. "Perspectives in Nuclear Structure", Copenhagen, June 14-18(1993) 2;

15. R. Kruk, R. Kmiec, K. Latka, K. Tomala,119Sn Mossbauer Effect Investigation of UPdSn,The European Conf. "Physics of Magnetism '93 - Strongly Correlated Systems", Poznari,June 21-24 (1993). Abstracts (1993) 35;

16. K.P. Lieb, (P. Wodniecki) et al.,PAC Studies of Ion-Mixed Metalic Multilayers,Proc. of XXVIII Zakopane School of Physics - "Condensed Matter Studies by NuclearMethods", eds. E. Gorlich, K. Tomala (IPJU and INP, Cracow) (1993) 69;

17. A. Maj et al.,GDR Exclusive Measurements,Abstracts of the NBI Conf. "Perspectives in Nuclear Structure", Copenhagen, June 14-18(1993) 1;

18. A. Maj, W. Krolas, J. Styczen et al.,GDR Decay in Hot 46Ti Studied by Means of the HECTOR Array,Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", KellogBiological Station Gull Lake, Michigan, USA, August 17-21 (1993) 37;

19. W. Mqczyriski, K. Zuber, R. Broda et al.,Directional Polarization of the /in/2 Proton Pair in the g69Dy83 Ground State from a Studyof its Gamow-Teller Decay,Proc. of 6th Int. Conf. on Nucl. far from Stability and 9th Int. Conf. on Atomic Massesand Fundamental Constants, Bernkastel-Kues, 1992, (IOP Publ.Ltd) (1993) 695;

20. J.W. Mietelski, P. Macharski, M. Jasiriska, R. Broda,Radioactive Contamination of Forests in Poland,

91

Proc. of the Int. Conf. on Nuclear Analytical Methods in the Life Sciences, Prague,September 13-17 (1993) ;

21. J.W. Mietelski, P. Macharski, M. Jasinska, R. Broda,Distribution of Radioactive Contamination in Poland (1991),Int. Symposium of Remediation and Restoration of Radioactive-Contaminated Sites inEurope, Antwerp, October 11-15 (1993) ;

22. A.W. Potempa et al.,Opriedielenie Granicznych Energij /?+-Spektrow Korotkozywuszczich Nuklidow Redkozem-lennych Elementow,Int. Meeting: Jadiernaja Spiektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23Apriela (1993) 78;

23. J. Sajdimov, (A.W. Potempa) et al.,Schema Raspada 147Tb (T1/2 = 1.7 h),Int. Meeting: Jadiernaja Spektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23Apriela (1993) 71;

24. Th. Stohlker, (Z. Stachura^ et al.,Spektroskopie Hochgeladener Pb- und U- Ionen am Gastarget des ESR,Proc. of the Conf. EAS-14, April 1993, Riezlern (1993) 63;

25. T.S. Tveter, (W. Krolas, A. Maj) et al.,Pre-fission 7-Decay in Superheavy Nuclei,Abstracts of the "Gull Lake Nuclear Physics Conference on Giant Resonances", KellogBiological Station Gull Lake, Michigan, USA, August 17-21 (1993) 58;

26. E. Wantuch, J. Gawlik, B. Rajchel, J. Stanek, J. Lekki.Wplyw szlifowania w polu magnetycznym na anizotropie, strukturalna warstwy wierzchniejprzedmiotow hartowanych,Zbior prac XVI Naukowej Szkoly Obrobki Sciernej, Koszalin (1993) ;

27. J. Wawryszczuk, A.W. Potempa et al.,Raspad 146Tb, l+(T1/2=8 sek),Int. Meeting: Jadiernaja Spiektroskopia i Struktura Atomnowo Jadra, Dubna, 20-23Apriela (1993) 68.

IV. Reports:

1. U. Bechstedt, (T. Pawlat) et al.,The Magnets for COSY. Review and Status,IKP Annual Report 1992, p.187 Jiil-2590 (1993) ;

2. G. Believ, (K. Zuber) et al.,Fission et Decroissance des Bandes Superdeformees,Annual Report CRN 1992, Strasbourg, (1993) 35 ;

3. F. Bosch, (Z. Stachura) et al.,Cross Section Studies for REC into High-Z Projectiles,GSI Nachrichten 08-93 (1993) ;

4. R. Broda et al.,Yrast Isomers in Tin Nuclei from Heavy Ion Collisions and the yhn /2 Subshell Filling,IKP Annual Report 1992, (ISSN 03666-0885), Jiil-2726 (1993) 76 ;

5. C.N. Davids, (R. Broda, B. Fornal) et al.,Experiments Using the Argonne Fragment Mass Analyzer,ANL Report PHY-7515-HI-93 (1993) ;

92

6. C.N. Davids, (R. Broda, B. Fomal) et al.,Recent Results from the Argonne Fragment Mass Analyzer,ANL Report PHY-7469-HI-93 (1993) ;

7. M. Drwi§ga, E. Lipinska, S. Lazarski, M. Wierba,Implantator jonow IFJ i jego wykorzystanie w inzynierii jonowej,Raport IFJ 1656/AP (1993) ;

8. J. Dryzek, E. Dryzek,Aparatura do pomiaru poszerzenia dopplerowskiego linii pochodzacej z anihilacji pozy-tonow w materii,Raport IFJ 1634/PS (1993) ;

9. R.G. Henry, (B. Fornal) et al.,First Gamma-Recoil Experiment at the FMA,Bull. Am. Phys. Soc. 38 No 2 (1993) 1049;

10. A. Hrynkiewicz,Zasady dozymetrii. Dawki i dzialanie biologiczne promieniowania jonizujacego,Raport IFJ 1639/PL (1993) ;

11. J. Kajfosz,0 alternatywnej interpretacji szczegolnej teorii wzgl§dnosci,Raport IFJ 1625/PL (1993) ;

12. J. Kajfosz,Investigation of Clustering in Sets of Analytical Data,INP Report 1624/PL (1993) ;

13. T. Kandler, (Z. Stachura) et al.,Charge Exchange Processes Utilized for Multi-Charge State Operation of the ESR,GSI Scientific Report GSI-93-1 (1993) 186;

14. B. Kharraja, (K. Zuber) et al.,Degenerate Superdeformed Bands in 151.152Tb, their Interpretation and Possible Con-straints on the "Pseudo-Spin Orbital [200]!/2",Preprint Univ. Strasbourg CRN 93-37 (1993) ;

15. T.L. Khoo, (B. Fornal) et al.,Superdeformation in the Mass of 190 Region,ANL Report PHY-7557-HI-93 (1993) ;

16. K. Krolas, B. Wodniecka,The Quadrupole Moment of the 2083 keV State of 140Ce Derived from PAC Measurements,INP Report 1644/PS (1993) ;

17. W. Krolas, R. Broda, J. Grebosz, A. Maj, T. Pawlat et al.,Neutron and Proton Flow Between the Colliding 208Pb and 64Ni Ions,HMI Annual Report 1992, (1993) 245 ;

18. P.H. Mokler, (Z. Stachura) et al.,Ground State Lambshift Measured for H-like U at the ESR,GSI Scientific Report GSI-93-1 (1993) 181;

19. P.H. Mokler, (Z. Stachura) et al.,X-Ray Emission of H- and He-like Pb and U Ions Measured at the Gasjet of the ESR,GSI Scientific Report GSI-93-1 (1993) 182;

20. T. Pawlat, R. Broda, W. Krolas, A. Maj, M. Zie,blinski et al.,High Spin States in Neutron Rich Ni Isotopes,HMI Annual Report 1992, (1993) 243 ;

21. Th. Stohlker, (Z. Stachura) et al.,X-Ray Emission from Very-Heavy H- and He-Like Ions in Collisions with Gaseous and

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Solid Targets,X'93, 16th Int. Conf. on X-Ray and Inner Shell Processes, Debrecen, July 12-16, 1993;GSI preprint GSI-93-59 (1993) ;

22. Ch. Theisen, (J. Styczen, K. Zuber) et al.,Bandes Superdefonnees dans 149Gd,Annual Report CRN 1992, Strasbourg, (1993) 33 ;

23. Ya. Vavryszczuk, (A.W. Potempa) et al.,Beta-Raspad 147ffTb. Niskospinovye Sostoyanya v 147Gd,JINR Dubna Report P6-93-275 (1993) .

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. R. Broda, J. Styczen, "The Midsummer Workshop on Nuclear" Physics, Jyvaskyla, Fin-land, June 1993;

2. R. Broda, A. Maj, "Perspectives in Nuclear Structure", Copenhagen, June 14-18, 1993;3. R. Broda, W. Krolas, M. Lach, T. Pawlat, J. Styczen, "XXIII Mazurian Lakes Summer

School on Nuclear Physics", Piaski, Poland, August 1993;4. R. Broda, B. Fornal, "1993 Gordon Research Conference on Nuclear Chemistry", New

London, New Hampshire, USA, June 1993;5. M. Cholewa, W. M. Kwiatek, B. Rajchel, "European Conference on Accelerators in Applied

Research and Technology", Orleans, France, August 31 - September 4, 1993;6. E. Dryzek, J. Dryzek, "25th Polish Seminar on Positron Annihilation", Karpacz, June

7-11, 1993;7. E. Dryzek, J. Dryzek, E. M. Dutkiewicz, W.M. Kwiatek, J. Kwiatkowska, J.Lekki, M.

Marszalek, M. Sowa, Zb. Stachura, "XXVIII Zakopane School of Physics", Zakopane,Poland, May 8-15, 1993;

8. W. M. Kwiatek, "Nowoczene Metody Przygotowania Probek i Oznaczania Sladowych Za-wartosci Pierwiastkow", Poznari, April 27-28, 1993;

9. W.M. Kwiatek, "II Krajowe Sympozjum Uzytkownikow Promieniowania Syn-chrotronowego", Krakow-Mogilany, Poland, October 25-26, 1993;

10. J.Kwiatkowska, F. Maniawski, "First International Workshop on High Resolution Comp-ton Scattering as a Probe of Fermiology", Krakow, Poland, July 3-5, 1993;

11. R. Kruk, R. Kmiec, "The European Conference Physics of Magnetism 93 - Strongly Cor-related Systems", Poznan, Poland, June 21-24, 1993;

12. W.M. Kwiatek, "Workshop on Sample Preparation for Accelerator Based Analytical Tech-niques", Wieden, Austria, December 6-10, 1993;

13. J. Lekki, B. Rajchel, Z. Stachura, "Powierzchnia i struktury cienkowarstwowe", RabaNizna, November 4-6, 1993;

14. A. Maj, "Gull Lake Nuclear Physics Conference on Giant Resonances", Kellog BiologicalStation, Gull Lake, Michigan, USA, August 17-21, 1993;

15. W. Me,czyriski, "Meeting on Auxiliary Detectors for EUROBALL and Electronics", CRNStrasbourg, May 26-28, 1993;

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INVITED TALKS:

1. R. Broda "Heavy ion binary reactions viewed by gamma- arrays-spectroscopy of neutron-rich nuclei", The Midsummer-Workshop on Nuclear Physics, Jyvaskyla Finland, June1993.

2. R. Broda "Gamma arrays as a new tool for complex heavy-ion reaction studies: reactionmechanism and prospects for spectroscopy", 1993 Gordon Research Conference on NuclearChemistry, New London, New Hampshire, USA.

3. B. Fornal "Heavy ion collisions from the perspective of gamma-ray studies", InternationalSchool-Seminar on Heavy Ion Physics, Dubna, May 10-15, 1993.

4. W.M. Kwiatek "Trace element analysis using synchrotron radiation", Studsvick, Szwecja,January 1993.

5. W.M. Kwiatek "Wykorzystanie krakowskiego akceleratora Van de Graaff'a do PIXE"("PIXE studies with Cracow Van de GraafF accelerator"), Poznan, April 27-28, 1993.

6. W.M. Kwiatek "Study of trace elements distribution in various tissues structures",Krakow-Mogilany, October 25-26, 1993.

7. W.M. Kwiatek "Sample preparation procedure for nuclear analytical techniques applied inH. Niewodniczanski Institute of Nuclear Physics", Wien, Austria,, December 6-10, 1993.

8. B. Rajchel "Application cyclotron beam in surface material studies", National Seminar onCyclotron in Science and Technology, Ankara, May 3-6, 1993.

9. B. Rajchel "Use of cyclotron beams for trace element analysis", National Seminar onCyclotron in Science and Technology, Ankara, May 3-6, 1993.

10. J. Styczeri "Recoil detection in in-beam gamma-ray measurements - the RFD", The Mid-summer Workshop on Nuclear Physics, Jyvaskyla Finland, June 1993.

11. J. Styczen "Nuclear spectroscopy studies in IFJ", NBI Copenhagen, February 1993.

SCIENTIFIC DEGREES:

1. Ph.D. thesis: Kvetoslava Burdova, "Badanie wybranych ukladow biologicznych przyuzyciu spektroskopii mossbauerowskiej" (Studies of selected biological systems usingMossbauer spectroscopy). Supervisor: Prof. J. Stanek.

2. Ph.D. thesis: Ewa Dryzek, "Badanie beta-brazow wanadowych metoda anihilacji pozy-tonow" (Studies of beta-vanadium bronzes using positron annihilation method). Supervi-sor: Prof. A. Hrynkiewicz.

LECTURES, COURSES AND SEMINARS:

1. R. Broda "Czy rzeczywiscie odkryto podwojny fonon 3~ w 208Pb? Wysokospinowe stany207Pb" ("Was indeed the double octupole phonon in 208Pb discovered? High spin statesin 207Pb"), seminar at Heavy Ion Laboratory - Warsaw University, February 1993.

2. R. Broda "Spektroskopia gamma dzisiaj - Eldorado fizyki jadrowej" (Gamma spectroscopytoday - Eldorado of Nuclear Physics"), seminar at Krakow branch of PTF, October 1993.

3. R. Broda "Dyskretne promieniowanie gamma w badaniu reakcji cie.zkojonowych - noweobszary spektroskopii jadrowej" (Discrete gamma radiation in HI reaction studies - newregions of nuclear spectroscopy"), seminar at Department of Nuclear Reactions, IFJ, Oc-tober 1993.

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4. R. Broda "N/Z equilibration in HI collisions 58Ni + 208Pb experiment project", GASP-usermeeting - Legnaro, November 1993.

5. M. Cholewa et al., "High Resolution Techniques Using Scanning Proton Microprobe(SPM)", ECAART-3, 3rd European Conference on Accelerators in Applied Research andTechnology, Orleans, France, August 31 - September 4, 1993.

6. J. Dryzek, C. Wesselink, B. Cleff "Investigation of vacancies and precipitation processesof carbides in stainless steel made by positron annihilation methods", 25th Polish Seminaron Positron Annihilation, Karpacz, June 7-11, 1993.

7. E. Dryzek and J. Dryzek, "Measurement of Doppler broadening of annihilation line inSn-In alloys", 25th Polish Seminar on Positron Annihilation, Karpacz, June 7-11,1993.

8. B. Fornal "Deep inelastic heavy ion reactions from the perspective of gamma-ray spec-troscopy", seminar at Notre Dame University, USA, January 19, 1993.

9. A. Hrynkiewicz "Metody fizyczne w medycynie i ochronie srodowiska" ("Physical methodsin medicine and ecology") - lectures for students at Jagellonian University, Krakow.

10. A. Hrynkiewicz "Seminarium magisterskie dla studentow V roku Specjalizacji Fizyki Me-dycznej i Ochrony Srodowiska Uniwersytetu Jagiellonskiego" - lectures for students ofHealth Physics at Jagellonian University, Krakow.

11. A. Hrynkiewicz "Nuclear Methods in Materials Research. Impurity Interactions in DiluteAlloys", Purdue University, West Lafayette, Indiana, USA, August 1993.

12. A. Hrynkiewicz "Nuclear Science and Perspectives of Atomic Energy in Poland", ChalkRiver Laboratories, Ontario, Canada, August 1993.

13. A. Hrynkiewicz "Hyperfine Interaction Studies in Materials Research", InternationalSchool and Symposium on Physics in Materials Science Using Nuclear and ComplementaryMethods, Jaszowiec, September 1993.

14. A. Hrynkiewicz "Promieniotworczosci naturalne w srodowisku" ("Natural radioactivity inenvironment"), Uniwersytet Marii Curie-Sklodowskiej, Lublin, December 1993.

15. A. Hrynkiewicz "Warunki fizyczne powstania i rozwoju zycia we Wszechswiecie" ("Physicalconditions of origin and development of life in the Universe"), seminar at Szczecin branchof PTF, December 1993.

16. A. Hrynkiewicz "Nuclear Science in Poland", Nuclear Research Center, Teheran, Iran,December 1993.

17. A. Hrynkiewicz "Hyperfine Interaction Studies in-Beam", Nuclear Research Center,Teheran, Iran, December 1993.

18. W.M. Kwiatek, J. Lekki et al., "Temperature and Matrix Effect in PIXE Elemental Anal-ysis" ECAART-3, 3rd European Conference on Accelerators in Applied Research andTechnology, Orleans, France, August 31 - September 4 (1993).

19. A. Maj, T. Pawlat, B. Fornal, W. Meczynski "Poster - Pracownia Struktury Jadra", 32'ndPTF Meeting, 20-23.09.1993, Krakow.

20. W.M. Kwiatek "Promieniowanie synchrotronowe i analiza skladu pierwiastkowego meto-dami PIXE i SRIXE" ("Synchrotron radiation and PIXE and SRIXE elemental analysis"),lectures for students at Jagellonian University, Krakow

21. W. Krolas, R. Broda, J.Grebosz, A. Maj, T. Pawlat, M. Schramm, H. Grawe, J. Heese,H. Kluge, K.H. Maier, R. Schubart "Neutron and proton flow between the colliding 208Pband 64Ni ions", XXIII Mazurian Lakes Summer School on Nuclear Physics, Piaski, Poland,August 1993.

22. J. Lekki, B. Rajchel, Z. Stachura et al., "Activities of the AGH - IFJ - IKP Surface Lab.at IFJ Krakow", Powierzchnia i Struktury Cienkowarstwowe, Raba Nizna, November 4-6,(1993).

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23. A. Maj "Ekskluzywne pomiary rozkladow katowych wysokoenergetycznych fotonowprobnikiem ewolucji ksztaltow j§der atomowych" ("Exclusive angular distribution mea-surements of high energy photons as a probe of nuclear shape evolution"), Warsaw Uni-versity, March 1993.

24. A. Maj "Giant dipole resonance studies at Copenhagen and Cracow", University of Wash-ington, Nucl. Phys. Lab., USA, August 1993.

25. A. Maj "Preliminary results of the HECTOR experiment on GDR in 46Ti", University ofMilano, Mediolan, Italy, October 1993.

26. M. Marszalek "Intermetallic compounds formation in bilayer metallic systems", CentroBrasileiro de Pesquisas Fisicsa, Rio de Janeiro, Brasil and Universidade Sao Paulo, SaoPaulo, Brasil, 1993.

27. M. Marszalek "PAC study of intermetallic compounds", Federal Universidade de Rio deJaneiro, Rio de Janeiro, Brasil, 1993.

28. E. Pamula, J. Dryzek "Investigation of carbon fiber using Doppler broadening of positronannihilation radiation", 25th Polish Seminar on Positron Annihilation, Karpacz, June 7-11,1993.

29. T. Pawlat, R. Broda, W. Krolas, A. Maj, M. Zieblinski, H. Grawe, K.H. Maier, J. Heese,H. Kluge, M. Schramm, R. Schubart "High spin states in neutron rich Ni isotopes", XXIIIMazurian Lakes Summer School on Nuclear Physics, Piaski, Poland, August 1993.

30. B. Rajchel "CRBS - A Program Simulating Dechanneling of Protons in Complex Crys-tals", ECAART-3, 3rd European Conference on Accelerators in Applied Research andTechnology, Orleans, France, August 31 - September 4 (1993).

31. B. Rajchel, M. Drwiega, E. Lipinska "Adaptation of the 70 kV INP Implanter to IBADTechnique", ECAART-3, 3rd European Conference on Accelerators in Applied Researchand Technology, Orleans, France, August 31 - September 4 (1993).

32. B. Rajchel "Metoda IBAD tworzenia cienkich warstw powierzchniowych. Badanie skladustechiometrycznego cienkich warstw wiazka wstecznie rozproszonych czastek" ("Creationof thin surface layers by IBAD method), seminarium at AGH Krakow.

33. B. Rajchel "Zastosowanie wiazki jonow do badania skladu warstwy wierzchniej cialstalych" ("Determination of element distribution in surface layers by nuclear methods(RBS, NBA)"), seminar at AGH Krakow - SLAFBS.

34. Z. Stachura "Zasady dzialania mikroskopow ostrzowych. Wykorzystanie AFM w bada-niach trybologicznych." ("Tribological investigations using AFM and other microscopesbased on the interaction of a sharp tip with surface"), seminar at Jagellonian University.

35. J. Styczen "The light lead isotopes studied with the use of the recoil filter detector",seminar at Warsaw University.

36. J. Styczen "Neutron activation techniques", lecture at Jagellonian University, Krakow.37. P. Wodniecki "PAC studies of binary intermetallic compounds produced by alloying and

ion-beam-mixing", seminar at II Physikalisches Institut der Universitat Gottingen.

INTERNAL SEMINARS:

1. St. Lazarski, W.M. Kwiatek "Aktualny stan prac przy akceleratorze Van de Graaff'a",(Status of the Van de Graaff accelerator) January 6.

2. M. Lach "Struktura stanow yrastowych jader 141Sm i 143Gd", (Structure of yrast statesin 141Sm and 143Gd nuclei) January 13.

3. J. Kownacki (UW, Warszawa) "Spektroskopia jadrowana wiazce ci^zkich jonow w poblizu100Sn", (Nuclear spectroscopy in the vicinity of 100Sn with heavy-ion beams) January 20.

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4. Zb. Stachura "Wzbudzenia wieloelektronowe w zderzeniach atomowych", (Multielectronexcitations in atomic collisions) January 27.

5. J. Kansy (US, Katowice) "Analiza wynikow eksperymentalnych uzyskiwanych metoda ani-hilacji pozytonow i efektu Mossbauera - prezentacja programow numerycznych", (Analysisof experiments performed with application of the positron anihilation and the Mossbauereffect methods - presentation of numerical codes) February 3.

6. K. Zuber "Superdeformacja w jadrach atomowych z obszaru A sinl50", (Superdeformationin nuclei from the A sin 150 region) February 10.

7. E. Dryzek "Badanie wanadowych brazow tlenkowych fazy beta przy pomocy metody ani-hilacji pozytonow" (Studies of beta-vanadium oxide bronzes using the positron anihilationmethod), February 17.

8. B. Rajchel "Zastosowanie metody IBAD do uzyskiwania wierzchnich warstw cial stalych"(Application of IBAD method for modification of surface layer properties.), February 24.

9. W. Me,czyriski "Poznawanie niedostejmego czyli badania struktur 188Pb i 186Pb przy po-mocy detektora jader odrzutu" (Exploration of inaccessible - studies of nuclear structureof 188Pb and 186Pb with the recoil filter detector.), March 10.

10. F. Maniawski, St. Kaprzyk (AGH) "Badanie ge,stosci elektronow w przestrzeni p§dowprzy pomocy rozpraszania Comptona" (Compton scattering studies of electron momentumdensity.), March 17.

11. B. Fornal "0 badaniu neutrono-nadmiarowych jader produkowanych w zderzeniachcie,zkich jonow" (Studies of neutron-rich nuclei produced in heavy-ion collisions.), March24.

12. R. Kulessa "178m2Hf jako wysokospinowa tarcza do badarl reakcji jadrowych" (178m2Hf asa high spin target for nuclear reaction studies.), April 14.

13. W. Walus "Badanie struktury jadra przy pomocy wiazek radioaktywnych" (Studies ofnuclear structure with radioactive beams.), April 21.

14. T. Pawlat "Wysokospinowe stany wzbudzone w neutrono-nadmiarowych izotopach Ni"(High spin excited states in neutron-rich Ni isotopes.), May 5.

15. A. Balanda (IF UJ, Krakow) "Fotony w reakcji p +115In przy energii protonow 50 MeV(GDR, bremstrahlung)" (Photons fromp"1" 115In reaction at 50 MeV proton energy (GDR,bremstrahlung).), May 12.

16. K. Grotowski (IF UJ Krakow) "Niestabilnosc jadra atomowego przy duzych wzbudzeniach"(Instability of a nucleus at high excitations.), May 19.

17. J. Jastrz§bski (SLCJ Warszawa) "Antyprotony - sonda powierzchni jadrowej" (Antiprotons- a probe of nuclear surface.), May 26.

18. V.A. Karnaukhov (JINR Dubna) "Multifragmentation in 4He + Au collisions at relativisticenergy, studied with Air - setup FASA", July 14.

19. W. M§czynski "Sztuka pomiaru niskich aktywnosci", (Art of low activities measurement.),October 6.

20. B. Fornal "W poszukiwaniu izomerow ksztaltu" (Search for shape isomers.), October 27.21. M. Samek (IF UJ Krakow) "Detekcja skorelowanych par e+ e~ w zderzeniach cie,zkich

jonow" (Detection of correlated e~ e+ pairs in heavy ion collisions.), November 3.22. W.M. Kwiatek, St. Lazarski, Zb. Stachura "Generator typu Van de Graaff'a w IFJ - jego

stan techniczny i wykorzystanie" (Van de Graaff generator at INP - its technical conditionsand applications.), November 10.

23. B. Rajchel "Dynamiczne formowanie warstwy wierzchniej metodami jonowymi" (Dynam-ical modification of surface layer using ion beam techniques.), November 17.

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24. A. Bracco (Uniwersytet w Mediolanie) "Relaxation mechanisms of the collective GDRstates in hot rotating nuclei", November 24.

25. Zb. Stachura "FIM, STM, SFM, AFM, ... - mikroskopy oparte na oddzialywaniu ostrzaz powierzchnia" (FIM, STM, SFM, AFM ... - microscopes based on the interaction of asharp tip with surface.), December 8.

26. R. Kulessa (IF UJ Krakow) »i78m2Hf (I = 16+, T1/2 = 31 y) jako tarcza do badan strukturyjadra" (178m2jjf (I=l6+, T1/2=31y) as a target for nuclear structure studies.), December15.

SHORT TERM VISITORS TO THE DEPARTMENT:Angela Bracco (Italy) Bernd Cleff (Germany)Marco Cinausero (Italy) Gilles de France (France)Olaf Filies (Germany) Wolfgang Garske (Germany)Klaus Grewer (Germany) Peter Kleinheinz (Germany)Sergey Lebed (Ukraine) Boleslaw Pietrzyk (France)Yves Schutz (France) Ulrich Voss (Germany)Stephan Vollschlaeger (Germany)

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Department ofStructural Research

PL9601027

DEPARTMENTOF STRUCTURAL RESEARCH

Head of Department: Prof. Jerzy JanikDeputy Head of Department: Assoc.Prof. Tadeusz WasiutyriskiSecretaries: W. Lisiecka and M.M. Mayertelephone: (48) (12) 37-02-22 ext.: 250e-mail: badstruk@bron.ifj.edu.pl

PERSONNEL:Neutron Laboratory:

Research Staff:Jerzy Janik, Professor, Jerzy Hubert, Assoc.Prof.,Jan Krawczyk, Ph.D., Maria Massalska-Arodz, Ph.D.,Jacek Mayer, Ph.D., Ireneusz Natkaniec, Ph.D.,Ewa Sciesiriska, Assoc.Prof., Jan Sciesinski, M.Sc.,Eng.,Waclaw Witko, Ph.D., Wojciech Zajac, Ph.D.,Piotr Zielinski, Ph.D.,

Technical Staff:Jerzy Brankowski, M.Sc.,Eng., Andrzej Ostrowicz, M.Sc.,Eng.,Janusz Sokolowski, M.Sc.,Eng., Eugeniusz Lisiecki,Tadeusz Sarga

Laboratory of Magnetic Research:Research Staff:

Maria Balanda, Ph.D., Andrzej Pacyna, Ph.D.,Tadeusz Wasiutynski, Assoc.Prof.,

Technical Staff:Waldemar Witek M.Sc.,Eng,

Administration:Wladyslawa Lisiecka Maria Magdalena Mayer

GRANT:Prof. J. Janik,grant No 2-0182-91-01, (The State Committee for Scientific Research),Research on time correlations of condensed matter properties in microscopic and real timescale.

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OVERVIEW:The activity of the Department of Structural Research may be divided into three parts.

The first part covers research on molecular motions in molecular crystals and liquid crystals inrelation to their phase transitions. Studies concern either motions which can be treated as localmotions of individual molecules, or those which have a collective character. One may notice anevolution of this research: from crystals and liquid crystals to glassy states, from ideal crystalsto crystals with surface and interfaces, from the aspects characterized by euclidean geometry tothose of fractals. In this field various kinds of relaxation phenomena were also studied.

The second part of the activity covers the magnetic properties of crystals, both in microscopicand macroscopic scale. In this research one may notice an evolution as well: from the lattice ofatoms and ions to the lattice of fluxons in a superconductor forming either a regular lattice orfluid or glass. A common feature of these two parts is the relaxational character of the dynamics.

The third part of the research is devoted to macroscopic systems which reveal a polymorphismwhich is analogous in many respects to the polymorphism of microscopic systems (molecular andmagnetic). This is an interdisciplinary domain which with the help of methods of the thermo-dynamics of nonequillibrium processes and/or of solving dynamical equations obtains phasescharacterized by various types of attractors. The evolution of such a system may be treatedas a SKI generis relaxation process. In this part of our Department activity some philosophicalextrapolations show up.

Most of the experimental work of the Department was done by means of the followingmethods: neutron scattering, infrared spectroscopy, adiabatic and scanning calorimetry, X-raydiffraction, polarized microscopy and magnetometry. The method of neutron scattering playsa leading role in this research. In this respect of importance is the international collaborationwith the I.M. Frank Neutron Laboratory of the Joint Institute of Nuclear Research at Dubna,Russia, with the Institute for Energy Technology at Kjeller, Norway, and with the RutherfordAppleton Laboratory, England. The majority of the research was done in cooperation withother groups in Poland. The most important are: the Chemical Physics Laboratory of theChemistry Faculty of the Jagellonian University in Krakow, the Solid State Physics Laboratoryof the Faculty of Physics of the Jagellonian University in Krakow, the Institute of Physics andNuclear Technology of the Mining Academy in Krakow.

The review of main studies in the year 1993 is following: The earlier studies of critical effectat the phase transition in Ni(NH3)6(NO3)2 were extended to neutron measurements with higherenergy resolution. The same effect was also studied in Mg(NH3)6(NO3)2-

The quasielastic neutron scattering method was used with the aim of obtaining informationabout various components of intramolecular motions of the reorientation type in liquid crystalline(nematic) di-etoxy-azoxy-benzene (PAP). A theoretical model which takes into account two suchmotions: motion of benzene rings coupled with ethoxy terminals and reorientations within thealkoxy terminals, fits very well to the QNS results.

A detailed study of phase transition in cyclooctanol was completed. Evidence of two plasticphases, both transforming into glassy state, was obtained. An additional phase transition of areversible character was discovered.

Spectroscopic studies of xylenes in their para-, meta-, and ortho- configurations was conti-nued with special attention paid to the dynamics of methyl groups. The temperature behaviorof methyl torsion is different in every member of the family.

In the field of magnetic studies the influence of the substitution of ions Fe3+ by the nonmagnetic ion Al3+ in the rare earth orthoferrites (Er, Tb, Tm)Fei^xAlx0z was investigated.The aim was to establish the magnetic properties of these compounds and also the interactionbetween Re3+ and Fe3+ sublattices+. Another study was devoted to temperature dependenceof the magnetic susceptibility of intermetallic compounds (Dy, Er, Ho)Ni2Ge2- Also some newcompounds of the type: (Ce,Tm)2Fen(H,D)x were studied in order to establish the Curie

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PL9601028 PL9601029

temperatures and the effective magnetic moments.The study of magnetic relaxation in superconducting EUBO.ICUZOT-1 and YBaiCu^O^ with

praseodymium ions substituted in place of rare earth was completed. The measurements wereperformed via observation of diamagnetic susceptibility time dependences. The distribution ofpinning energy of fluxons in the studied substances were obtained and compared with thoseknown for the other superconductors.

Prof. Jerzy Janik

REPORTS ON RESEARCH:

Evidence of Fast Reorientational Motions of Alkoxy Terminalsin the Nematic Phase of Di-ethoxy-azoxy-benzene

R. Podsiadly, J.M. Janik, T. StanekFaculty of Chemistry of Jagellonian University, Krakow, Poland

J.A. JanikInstitute of Nuclear Physics, 31-342 Krakow

K. OtnesInstitute for Energy Technology, Kjeller, Norway

Quasielastic neutron scattering experiments performed in the nematic phase of the secondmember of the PAA series i.e. for H.$CtO.C%K$.0C-iH%, show a large excess of the quasielasticcomponent, when compared with a model in which the reorienting units are benzene rings rigidlycoupled with rigid ethoxy groups. We show that this excess can be explained when a secondmotion — interconformational jumps in the terminals around the O (ethoxy) axis are included.

Magne t i sa t ion of TmFe(1_x)Ala;O3(a; < o.i)A. Bombik, B. Lesniewska

Department of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, 30-059Krakow.

A.W. Pacyna, W. WitekInstitute of Nuclear Physics, 31-342 Krakow.

The investigation of the TmFe(1_x)Alx03 system was undertaken as a continuation of pre-vious research [1] dealing with the influence of nonmagnetic substitutions on the physical pro-perties of rare-earth orthoferrities. The first experiments were limited to a rather low contentof non-magnetic ions. Measurements of powdered samples were performed using a magneticelectrobalance, in a magnetic field H=450 Oe at both increasing and decreasing temperatures.A typical magnetisation dependence on temperature for investigated compounds is shown inFig.l.

It has been found that for all examined samples magnetisation depends strongly on theamount of the substitute (x), the magnetic field and the history of the sample. All characteristictemperatures are visible and can be precisely determined from the differential net curve. Allcharacteristic points: Tc - compensation temperature, Tti , Tt2 - temperatures of begining andending of the spin reorientations process respectively are summarised respectively in Tab.l.

103

PL9601030

50 100 150

TEMPERATURE(K)

200 250

Figure 1: Magnetisation at HFC and ZFC curves.

450 Gs. Curve labeled by FC-ZFC results from a subtracting

X

0.000.030.060.10

T«71219

[K]± 1± 1± 1

27.5

Tti[K]79818586

±±±±

1111

Tt29398102112

[K]x± 1± 1± 1± 1

As can be shown, substituting Fe3+ ions by non-magnetic Al3+ ions causes a noticeableincrease in all characteristic temperatures and the broadening of the spin reorientation region.

References:[1] A. Bombik, A.W. Pacyna and W. Witek, Acta Phys. Pol., A85 (1994) (in press).

Gold Substitution and Superconductivity in YBa2Cu3O7_£J. Stanek, A. Szytula, Z. Tomkowicz

institute of Physics, Jagellonian University, KrakowA. Bajorek, M. Balanda

Institute of Nuclear Physics, 31-342 Krakow.

In this work we report on the properties of Au-substituted YBa2Cu3O7_£, where gold waspartially substituted for Y, Ba and Cu respectively. Au is one of the few elements which increasecritical temperature Tc of transition into a superconducting state. The initial interest of otherresearchers in Au-substitution was to study the influence of Au crucible used to grow singlecrystals of YBa2Cu307_i. It has been stated that gold introduced to the compound from thecrucible was located in the Cul position of the crystal lattice. In our studies gold was introducedin the form of a very fine powder of AU2O3 and mixed with other powders, weighted in the properproportion. The samples in the form of tablets were subjected to sintering in oxygen with anumber of intermediary crushing. The final temperature of sintering was about 950°C and afterthat the samples were cooled in oxygen at a rate of l°/min. The whole process was repeatedseveral times for newly weighted components and some preparation conditions were changed,i.e. the number of intermediary crushing, final temperature and the rate of cooling.

The samples were studied by X-ray diffraction, DC electric resistance method, AC and DCmagnetic susceptibility and Mossbauer effect method on 197Au. The samples showed high qua-lity X-ray diffraction patterns with no impurity peaks up to about 10% gold substituting thecorresponding component. Generally, the quality of patterns for Au-substituted samples was

104

better than for non-substituted samples. The most interesting finding in our studies was thedistinguishing behaviour of (Yi_xAux)Ba2Cu3O7_$ samples which have the best superconduct-ing properties. The smallest transition width (0.6 K) and the highest Tc (92.3 K) were observedfor the sample with x = 0.05. The increasing of lattice constant c with x value shows that Augoes into the structure. The lattice constants a and b remain unchanged. An intergrain criticalcurrent was measured by means of AC susceptibility method. The value of about 160 A/cm2

has been obtained at liquid nitrogen temperature. The lower critical field value Hci observed bymeans of magnetic balance at liquid helium temperature was about 500 Oe.

The Mossbauer spectra (Fig.l) point out that all gold in (Yo.95Au0.o5)Ba2Cu307_i is incorpo-rated into the structure. This result is in agreement with those from other methods which showthat (Yi_xAux)Ba2Cu3O7_£ samples seem to be most homogeneous. Metallic gold componentis seen only in Mossbauer spectra of Y(Bao.96Auo.o4)2Cu307_£ and YBa2(Cuo.97Auo.03)307-$.The valence of incorporated gold is 3+ for all measured samples. The samples were next deoxy-genated by annealing for 3 hours in argon at 600°C and the Mossbauer spectra were measuredagain. As a result of deoxygenation all incorporated gold was reduced to monovalent. Such achange of valence, but for YBa2(Cu0.977Auo.o23)307-i, was interpreted earlier by Eibschutz etal.[l] as a proof that gold is located in the Cul position of the lattice. Thus, in our case, excesscopper atoms could go into the ytrium sublattice or into the vacancies in the ytrium plane.

By varying preparation conditions we obtained an additional (Yo.95Auo.o5)Ba2Cu307_£ sam-ple which, although having a sharp transition into a superconducting state, was composed oftwo phases being in nearly 1:1 proportion with very similar, nearly overlapping X-ray diffractionpatterns. Fig.2 presents a part of the pattern where the third additional peak appears whichmay be connected with the second oxygen poor phase or with a new phase. A new phase ofYBa2Cu307_6 was recently observed by infrared measurements [2]. It is possible that gold is acatalizator in the process of forming a new phase. Further studies are in progress.

0.5-

- 1 0 - 5 0 5 10 15Velocity (mm/s)

- (YAu)-annealed

" (CuAu) l \-annealed |

.1. ... i,. . i .

\(\C11firH

-10 -5 0 5 10 15Velocity (mm/s)

Figure 1: The 197Au Mossbauer spectra of (Yo.95Auo.o5)Ba2Cu307_« at 4.2 K marked as (YAu)and of YBa2(Cu0.97Au0.03)3O7_s marked as (CuAu) for obtained samples and for the samesamples after annealing in argon (3h/600°C). The weak single line in the lower part of the figureorigins from the metallic gold.

105

10000

3100 3tS0 3Z00 3250ANGLE 29

3100 33.50 3A.00

Figure 2: Part of the X-ray diffraction pattern (CuKa) measured for (Yo.95Auo.o5)Ba2Cu307_5sample obtained according to the special treatment (open circles). For comparison also a partof a pattern for (Yo.92Auo.o8)Ba2Cu307_$, having a typical YBa2Cus07 structure, is included(dashed line).

References:

1. M. Eibschiitz, M.E. Lines, W.M. Reiff, B. van Dover, J.V. Waszczak, S. Zahurak,R.J. Felder, Appl. Phys. Lett. 62 (15), 1827 (1993).

2. K.L. Borth, F. Kleimann, Z. Phys. B91, 419 (1993).

LIST OF PUBLICATIONS:I. Articles:

1. R. Podsiadly, J.A. Janik, J.M. Janik, K. Otnes: "Quasielastic scattering of neutrons byliquid crystal substance with flexible molecules", Liquid Crystals 14 (1993) 1510.

2. P. Zielinski, A. Fuith, W. Schranz, I. Rychetsky, H. Warhanek: "Strain anomaly andorientational disorder in the tetragonal phase of KHF2", Phys.Rev. B47 (1993) 8453.

3. P. Zielinski and K. Zabinska: "Green functions in crystals and thin layers with long rangeinteractions", Phys. Rev. B47 (1993) 16447.

4. P. Zielinski and K. Zabinska: "Dynamics and phase transitions in crystals and thin layerswith dipolar interactions", Phys. Rev. B48 (1993) 5505.

5. V. Spasojevic, D. Rodic, P. Nordblad, A. Bajorek: "Magnetic susceptibility of the semi-magnetic semiconductor Hgi-xMnxS", J. Magn. Magn. Mater. 118 (1993) 152.

6. V. Kusigerski, M. Mitric, V. Spasojevic, D. Rodic, A. Bajorek: "Measurements and cal-culation of magnetic susceptibility of low-concentrated semimagnetic semiconductorGdxY2-xO3", J. Magn. Magn. Mater. 128 (1993) 369.

7. V. Spacejovic, D. Rodic, A. Bajorek, A. Szytula: "Magnetic susceptibility calculation ofCd1_!rMna!5", J. Magn. Magn. Mater. 128 (1993) 375.

8. M. Balanda, A. Bajorek, A. Szytula, Z. Tomkowicz: "Flux creep in Pr-substituted systems— A comparative study of Eu1-xPrxBa2CuA06 ", Physica C 205 (1993) 280.

106

9. S. Niziol, R. Zach, D. Fruchart, A. Bombik, A.W. Pacyna and R. Pruchard: "New magneticproperties of (Co1-.xMnx)2P", J. Magn. Magn. Mater. 127 (1993) 103.

10. P. Barta, S. Niziol, M. Zagorska, A. Proii and A. Pacyna: "Low temperature magneticproperties of poly(3-alkylthiophenes) and poly(4,4'-dialkyl-2,2'-bithiophenes)", SyntheticMetals 55-57 (1993) 5003.

11. M. Massalska-Arodz: " Dielectric relaxation in the glass phase of a liquid crystal", Phys.Rev. B47 (1993) 14552.

12. Ch. Selbman, W. Witko, W.D. Koswig: "Studies of Thermooptical Switching Propertiesof Glass Forming Calamitic Liquid Crystals", Proc of 28 Freiburg Arbeitstagung FliisigKristalle, ed. S. Baur and G. Meier, Freiburg 1993.

13. V.K. Fedotov, A.I. Kolesnikov, V.V. Sinicyn, E.G. Ponyatovskii, I. Natkaniec, J. Mayer,J. Brankowski, A.V. Belushkin: "Izlutchenie vodoroda v sverchprovodiashtchei keramikemetodom nieuprugovo rasseyania neitronov", Fizika Tverdovo Tela 35 (1993) 189-197.

14. V.K. Fedotov, A.I. Kolesnikov, V.I. Kulakov, E.G. Ponyatovskii, I. Natkaniec, J. Mayer,J. Krawczyk: "Izlutchenie angarmonizma kolebanii atomov miedi i kisloroda v ytrevoykeremike metodom neuprugovo rasseyania neitronov", Fizika Tverdovo Tela 35 (1993)310-319.

15. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Method of Multicomponent Systems BasicSpectra Construction: Zero Coefficient Correlation Criterion", Zh. Strukt. Khimii 34(1993) 44-53.

16. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Construction of Basic Vibrational Spectra ofa Multicomponent System. 1. Aerosil", Zh. Struk. Khimii 34 (1993) 54-63.

17. I.V. Markichev, I. Natkaniec, E.F. Sheka: "Construction of Basic Vibrational Spectra ofa Multicomponent System. 2. Silica Gel", Zh. Struk. Khimii 34 (1993) 64-76.

18. I.V. Markichev, A.Yu. Muzychka, I. Natkaniec, E.F. Sheka: "Postrojenie basisnych spek-trov kolebanii mnogokomponentnoi sistiemy. 3. Aerogel", Zh. Strukt. Khimii 34 (1993)29-38.

19. E.F. Sheka, I.V. Markichev, V.D. Khavryutchenko, I. Natkaniec: "Sravnitelny analiz kole-batelnych spektrov dispersnych kremniezemov i ich komponentov", Zh. Strukt. Khimii34 (1993) 39-51.

20. E.F. Sheka, I. Natkaniec, V.D. Khavryutchenko, P. Nechitailov, A.Yu. Muzychka, V.M.Ogenko, I.V. Markichev: "Kolebatelnaya spektroskopia dispersnych kremniezemov. Niey-prugoye rasseyanie neitronov", Zh. Fiz. Khimii 67 (1993) 38-46.

21. E.F. Sheka, I. Natkaniec, I.V. Markichev, V.D. Khavryutchenko: "Vibrations of dispersesilicas", Phonon Scattering in Condensed Matter VET, Eds. M.Meissner and R.O.PohlSpringer Series in Solid State Sciences, 112 (1993) 303-305.

22. J. Kalus, J. Wolfrum, F. Worlen, K. Holderna-Natkaniec, I. Natkaniec, M. Monkenbush,M. Prager: "Internal rotation-phonon coupling in lattice dynamics of p-xylene", PhononScattering in Condensed Matter VII, Eds. M. Meissner and R.O. Pohl Springer Series inSolid State Sciences, 112 (1993) 521-523.

23. E.F. Sheka, I. Natkaniec, I. Markichev, A. Chuyko, V. Khavryutchenko V. Ogenko: "Vi-brations of Dispersed Silicas: A Comparative Study", React. Kinet. Catal. Lett. 50(1993) 221-226.

24. A.I. Kolesnikov, V.V. Sinitsyn, E.G. Ponyatovsky, I. Natkaniec, L.S. Smirnov: "Neutronscattering studies of vibrational spectrum of high density amorphous ice in comparisonwith Hi and VI", J. Phys. Condensed Matter 6 (1994) 375-382.

107

II. Contributions to Conferences:

1. T. Wasiutynski: "Modulated Crystal with Multipole Interactions", XXEH Conference onDynamical Properties of Solids, Lunteren, 26-30 Sep. 1993.

2. M. Massalska-Arodz: "Statistical self-similarity", Janik's Friends Meeting, Kalatowki1993.

3. M. Massalska-Arodz: "Searching of the statistical self-similarity in the topological defectpattern of liquid ceystal", Physical Methods in Material Science, Jaszowiec 1993.

4. M. Massalska-Arodz: "Dielectric relaxation of statistically self-similar materials", 2ndConference of Liquids, Florence.

5. I. Natkaniec, S.I. Bragin, J. Brankowski, J. Mayer: " Multicrystal Inverted GeometrySpectrometer NERA-PR at the IBR-2 Pulsed Reactor", Proc. International Collaborationon Advanced Neutron Sources ICANS XII, RAL Abingdon 1993 (in press).

6. I. Markichev, E. Sheka, I. Natkaniec, A. Muzychka, V. Khavryutchenko, Y. Wang.,N. Herron: "Density of vibrational states of thiol capped CdS particles. Inelastic NeutronScattering", 3rd International Conference on Surface X-ray and Neutron Scattering, Dubna1993, Physica B (in press).

7. I. Markichev, E. Sheka, N. Goncharova, I. Natkaniec, A. Muzychka, V. Chukalin, V.Khavryutchenko, E. Nikitina: "Density of vibrational state of silicone nitride", 3rd Inter-national Conference on Surface X-ray and Neutron Scattering, Dubna 1993, Physica B (inpress).

8. K. Holderna-Natkaniec, I. Natkaniec: "Study of internal vibrations of dl-camphene by IINSmethod", XX International Conference on Low Temperature Physics Eugene, Oregon 1993,Physica B (in press).

9. K. Holderna-Natkaniec, I. Natkaniec, S. Habrylo, J. Mayer: "Comparative neutron scat-tering study of molecular ordering in d-camphor and dl-borneole", XX International Con-ference on Low Temperature Physics Eugene, Oregon 1993, Physica B (in press).

10. I. Natkaniec, L.S. Smirnov, A.I. Solovev, S.I. Bragin: "Neutron scattering studies of am-monium dynamics and phase transition in K(l-x)(NH4)(x)SCN at 10K", XX InternationalConference on Low Temperature Physics Eugene, Oregon 1993, Physica B (in press).

11. L.S. Smirnov, V.A. Goncharova, E.L. Gromnitskaya, G.G. Ilina, I. Natkaniec, A.I. Solovev,O.V. Stalgorova: "The acoustic and neutron scattering investigations of NH4SCN phasediagram", XXXI Annual Meating EHPRG, Belfast 1993.

12. A.N. Ivanov, I. Natkaniec, L.S. Smirnov: "The Titanium-Zirconium high pressure cell forneutron scattering", XXXI Annual Meating EHPRG, Belfast 1993.

13. I. Natkaniec, L.S. Smirnov, A.I. Solovev, S.I. Bragin: "Neutron scattering studies of la-ticce dynamics and phase transitions in K(l-x)(NH4)(x)SCN", International School andSymposium on Physics in Materials Science, Jaszowiec 1993.

14. V.D. Khavryutchenko, I. Natkaniec, E.F. Sheka: "Computation chemistry as the necessarycomponent of the inelastic neutron scattering spectroscopy of adsorbed molecules andsurfaces", International School and Symposium on Physics in Materials Science, Jaszowiec1993.

15. L. Bobrowicz, K. Holderna-Natkaniec, M. Mroz, I. Natkaniec, W. Nawrocik, W. Wojtowicz:"Neutron scattering studies of phase transitions in protonated and deuterated ammoniumhydrogen sulphates", International Seminar on Protonic Conductors, Dubna 1993.

16. W. Witko: "Studies of Thermooptical Switching Properties in Glass-Forming Liquid Crys-tals", Freiburg 1993.

17. A. Bombik, A.W. Pacyna, W. Witek: "Phase transitions in ErFei-xAlxO3 systems",Abstracts of the European Conference Physics of Magnetism 93, Poznan.

108

18. M. Balanda: "Magnetic relaxation studies of Pr-substituted superconductors of the 123and 124 structures", Abstracts of the European Conference Physics of Magnetism 93,Poznari.

19. M. Godlewska, A. Kocot, E. Sciesiriska, J. Sciesiriski: "Infrared study of 4-n-pentylphenyl-4'-n-heptyloxythiobenzoate (7S5) ", II National Conference on Molecular Spectroscopy,Wroclaw 1993.

III. Reports:

1. P. Zielinski: Green functions in microscopic models of surface and interfaces, INP Rep. no1632/pf.

2. M. Massalska-Arodz: Zjawisko relaksacji w ukladach nieuporzadkowanych, INP Rep. no1626/ps.

3. L. Bobrowicz, A. Kartusiak, W. Nawrocik, J. Wasicki, I. Natkaniec "Neutron Scatteringin 1,3-Cyclohexanadione", International Seminar on Structutal Investigations at PulsedNeutron Sources, E3-93-65, JINR, Dubna 1993, pp 307-314.

SCIENTIFIC DEGREES:Maria Balanda — Ph.D. degree

INTERNAL SEMINARS:

1. W. Zajac: Reorientation within the ether methyl group of PMMA.2. J. Chrusciel: Dielectric relaxation in liquid crystalline phases of n55.3. J. Janik: Critical effects in neutron scattering. Experimental results from JINR Dubna.4. H. Piekarzowa: Efekt organizacyjny jako szczegolny przyklad synergii.5. S. Taczanowski: Termodynamiczno-informacyjne determinanty podejmowania decyzji i

ich implikacje aksjologiczne.6. J. Chrusciel: Quasielastic neutron scattering in liquid crystalline phases of 855.7. M. Balanda: Magnetic relaxation in high Tc superconductors.8. J. Krawczyk, M.Massalska-Arodz and R.Podsiadly: 2nd Liquid Matter Conference.9. W. Witko: Science in Berlin - its successes and troubles.

10. T. Wasiutynski: Dynamical Properties of Solids, impressions from the conference inLunteren.

11. W. Otowski: Dynamics of the Ceo molecule from a point of view of dielectric relaxationresearch.

12. H. Kresse: Short range correlations in liquid crystals.13. W. Witko: Thermoelectrooptical effects in liquid crystals.14. T. Wasiutynski: Relaxation phenomena in glassy states.15. M. Massalska-Arodz: Dynamics of complex systems: holistic model.16. E. Sciesinska: Spektroskopowe badania polimornzmu substancji cieklokrystalicznej 755.

109

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Jan van Loef, Reaktorcenter Delft, Holland2. K.H. Michel, Universiteit Instelling Antwerpen, Belgium3. Ivar Svare, Trondheim University, Norway4. Ludmila Czernienko, Kiyev University, Ukraine5. Aleksander Chalyi, Kiyev University, Ukraine6. Peter Kleboe, Oslo University, Norway7. Tonnod Riste, Institute for Energy Technology in Kjeller, Norway8. Arne Skjeltrop, Institute for Energy Technology in Kjeller, Norway9. W. Weidlich, Stuttgart University, Germany

10. Werner Press, Universitat Kiel, Germany11. Horst Kresse, Universitat Halle, Germany12. Siergiej Briagin, Joint Institute of Nuclear Research in Dubna, Russia

110

Department ofTheoretical Physics

PL9601031

DEPARTMENTOF THEORETICAL PHYSICS

Head of Department: Prof. J. KwiecińskiDeputy Head of Department: Assoc.Prof. L. LeśniakSecretary: E. Pagaczewskatelephone: (48)-(12)-37 02 22 ext.: 270e-mail: PAGACZEWSKA@VSB01.IFJ.EDU.PL

PERSONNEL:

Research Staff

Piotr BochnackiPiotr BożekWojciech BroniowskiMarcin CerkaskiPiotr CzerskiWiesław Czyż1

Wojciech FlorkowskiKrzysztof Golec-BiernatAndrzej HorzelaEdward Kapuścik2

Marek KutscheraLeonard LeśniakJan KwiecińskiAndrzej MałeckiMarek PłoszajczakStanisław ZubikPiotr ŻenczykowskiRobert Kamiński

Administrât ion

Ewa Pagaczewska

M.Sc.Ph.D.Ph.D.Ph.D.Ph.D.ProfessorPh.D.Ph.D.Ph.D.ProfessorAssoc.ProfessorAssoc.ProfessorProfessorAssoc.ProfessorProfessorM.Sc.Assoc.Professorresearch student

M.Sc., Eng.

1 also at the Institute of Physics Jagellonian University, Chairman of the Sc. Counc. there, Chairman of the Sc.Counc. of the Nicolas Copernicus Astronomical Center2 also at the Krakow Pedagogical University

111

GRANTS:

1. Prof. E. Kapuscikgrant No: 2 0342 91 01 (The State Committee for Scientific Research),The Meaning of the Galileo Relativity Principle in Quantum Mechanics.

2. Assoc.Prof. M. Kutscheragrant No: 2 0204 91 01 (The State Committee for Scientific Research),Dense and/or Hot Hadion Matter.

3. Prof. J. Kwiecinskigrant No: 2 0198 91 01 (The State Committee for Scientific Research),Structure ofHadrons Studied in Particle and Nuclear Interactions.

4. Prof. J. Kwiecinskigrant No: 2 P302 062 04 (The State Committee for Scientific Research),Analysis of Lepton Inelastic Scattering on Nucleons and on Atomic Nuclei.

5. Prof. J. Kwiecinskigrant No: F0408 (British - Polish Joint Research Collaboration Programme),Proton Structure and Small x Physics.

6. Prof. J. Kwiecinskigrant No: 3159 (Cooperation in Science and Technology with Central and Eastern Euro-pean Countries),Theory and Deep Inelastic Processes in QCD.

OVERVIEW:

Research performed at the Department of Theoretical Physics concerns various theoreticalproblems of general physics, low, intermediate and high energy nuclear physics, elementaryparticle physics and astrophysics. Both formal problems as well as the more phenomenologicallyoriented ones are being considered. Department of Theoretical Physics actively collaborateswith other departments of our Institute as well as with several scientific institutions in Polandand abroad. The research program is formally grouped into the following four main subjects:

1. the role of the Galilean relativity principle in classical and quantum mechanics,

2. dense and/or hot hadronic matter,

3. structure of hadrons studied in particle and nuclear interactions,

4. analysis of inelastic lepton scattering on nucleons and on atomic nuclei.

These are the titles of the approved proposals by the State Committee for Scientific Research.The details of the results obtained in various fields are listed below in the abstracts. Besidespure research, members of our Department are also engaged in the graduate and undergraduateteaching program. At present one research student is working for his PhD and one for his M.Sc.

Prof. Jan Kwiecinski

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PL9601032 PL9601033 PL9601034

REPORTS ON RESEARCH:

Intermittency in High Energy CollisionsP. Bozek and M. Ploszajczak 1

1 GANIL, Caen, France

The intermitent multifractal cascade was studied. It was used as a model of the multiparticleproduction cascade with a specific modelling of the hadronization effect. This model has basicallythe same structure if used as a model of the hadronization or as a model of the infrared cut-offin the QCD cascade. It has also the interesting feature that the fluctuations are enhanced atsmall scales according to some universal, but no longer selfsimilar pattern [1]. The perturbativeQCD in the double logarithm approximation follows this universal pattern.

Reference:

1. P. Bozek and M. Ploszajczak, Zeit. Phys. C59 (1993) 585

Instabilities and Fluctuations in Heavy Ion CollisionsP. Bozek and M. Ploszajczak 1

1 GANIL, Caen, France

The developement of the instabilities in the early phase of the intermediate energy heavy ioncollision was modelled. This model was used for the calculation of the production cross sectionsfor the subthreshold meson production. This allows to reproduce, using two free parameters, theproduction probabilities for the pion, kaon and eta mesons at subthreshold energies and also thedifferential cross section versus the pion kinetic energy [1]. The development of the instabilitiesin the expanding anisotropic nuclear matter was studied. The changes of the instability ratesdue to the geometry and the dynamics of the fragmenting nuclei could allow for an experimentalsignal of an unusual geometry of the fragmenting nuclei.

Reference:

1. P. Bozek and M. Ploszajczak, Fluctuations in the Heavy Ion Collisions, GANIL preprint P-93-20(1993)

Multiscaling in the Hadronization in High Energy CollisionsP. Bozek and M. Ploszajczak 1

1 GANIL, Caen, France

We study the multiscaling in the fluctuations of multiparticle distributions at small scales.Similarly to the multiscaling effect, recently found in multifractal models, we analyse the de-pendence of the strength of the fluctuations on the low density cut-off in the cascade. Theeffect changes the scaling behaviour and leads to stronger dependence of the scaled factorialmoments on the resolution than the power law. This could be an explanation of the behaviourobserved recently in the experimental 3-dimensional data on the scaled factorial moments. Themultiscaling analysis allows to restore the universality in the processes with different cut-offsand could be used in the analysis of the experimental data [1].

Reference:

1. P. Bozek and M. Ploszajczak, Z. Phys. C59 (1993) 585

113

•iiniiiiiiiii iwiiiiiiiigiiiiiii Hiniii iniPL9601035 PL9601036 PL9601037

The Even-Odd Anomalous Tunneling EffectP. Kaminski, S. Drozdz, M. Ploszajczak 1 and E. Caurier 2

1 GANIL, Caen, France2 CRN and Univ. of Strasbourg, Strasbourg, France

The analysis of the interacting fermion models with the SU(2) symmetry indicates the dif-ferent behaviour of the splittings of opposite-parity lowest-energy eigenstates for even and oddnumbers of fermions. The imaginary time-dependent mean-field approach reproduces the av-erage results only. For the odd particle numbers, an introduction of the universal logarithmicterm to the action integral is needed. The even-odd effect appears in a wide class of models withthe SU(2) symmetry and is connected with the crossing of the energy surfaces of opposite-paritystates for an odd number of fermions [1].

Reference:

1. P. Kaminski, S. Drozdz, M. Ptoszajczak and E. Caurier, Phys. Rev. C47 (1993) 1548

r * The Analysis of the Charged-Fragment Correlations using aFragmentation-inactivation Binary Model

R. Botet * and M. Ploszajczak 2

1 Lab. de Phys. des Solides, Univ. Paris-Sud, Orsay, France2 GANIL, Caen, France

The fragmentation-inactivation binary model of the fragmentation at the transition linebetween the "oo-duster" phase and the "shattering" phase is applied for analyzing the nuclearmultifragmentation data of ALADIN Collaboration for average charged-particle correlations in600 MeV/u gold induced reactions on various targets. A constant break-up kernel, independentof the sizes of the daughter fragments, is used. By adjusting the strength of the inactivationprobability function to the correlation between the mean-size of the largest cluster and thecomposed particle first moment, we find that the remaining charge correlation data is correctlyreproduced by the fragmentation-inactivation binary model [1],

Reference:

1. R. Botet and M. Ptoszajczak, Phys. Lett. BS12 (1993) 30

I Energy Dependence of Intermittency in Nuclear Reactions atIntermediate Energies

Bao-An Li 1 and M. Ploszajczak 2

1 Hahn-Meitner Inst., Bereich Schwerionenphysik, Berlin, Germany2 GANIL, Caen, France

Using a hadronic transport model we study the beam energy dependence of intermittencyin intermediate energy heavy-ion collisions by analysing the reduced scaled factorial momentsof pion distributions in both pseudorapidity and kinetic energy. It is found that the anomalousdimension obtained from analysing pion pseudorapidity distributions decreases rapidly as thebeam energy increases from about 0.5 to 3.0 GeV/nucleon. On the contrary, the anomalousdimension extracted from analysing pion kinetic energy distributions is almost independent ofthe beam energy [1].

Reference:

1. Bao-An Li and M. Ptoszajczak, Phys. Lett. B317 (1993) 300

114

PL9601038 PL9601039 PL9601040

JVC-Counting Rules and the Axial Vector Coupling Constantof the Constituent Quark

W. Broniowski, M. Lutz 1 and A. Steiner 2

1 Department of Physics, University of Washington, Seattle, WA 98195, USA2 Institute of Theoretical Physics, University of Regensburg, D-8400 Regensburg, Germany

The notion of constituent quarks has been useful in various models of hadronic structureand in the description of low-energy spectroscopy. It is generally assumed that these objectsare Dirac particles, i.e. have no anomalous magnetic moment, and their axial vector couplingconstant, gA, equals 1. Recently Weinberg argued why constituent quarks should behave asDirac particles [1] in the limit of number of colors, Nc going to infinity. The analysis was basedon the Adler-Weisberger sum rule. We have reanalyzed [2] the axial vector coupling of theconstituent quark in the large-Nc limit and pointed out mechanisms which yield 1 - g^ ~ JV°.These mechanisms come from high-energy contributions to the sum rule. We have also pointedout that low-energy models (Nambu-Jona-Lasinio, Gell-Mann-Levy) also yield 1 - g^ ~ JVC° ifvector-meson couplings are present. The numerical value of gx is around 0.8, which is welcomeby phenomenology. A similar study has also been done for the magnetic moment [2].

References:

1. S. Weinberg, Phys. Rev. Lett. 65 (1990) 1181,

2. W. Broniowski, M. Lutz and A. Steiner, Phys. Rev. Lett. 71 (1993) 1787

Low-Energy Sum Rules and Large-Nc Consistency ConditionW. Broniowski

Recently, there has been a renewed interest in the large-iVc (number of colors) limit of QCD,which followed the derivation of the large-Nc consistency conditionsby Dashen and Manohar [1].These conditions reconcile the large-Nc limit of QCD with hadronic physics, and indicate thespecial role of the baryon decuplet states. We have discussed [2] in detail these issues startingfrom the point of view of the low-energy sum rules. We show that using the Adler-Weisbergeror the Drell-Hearn-Gerasimov sum rule one can very straightforwardly obtain the results ofRefs. [1]. The crucial point of this derivation is the special role of the A resonance, and thecorrect Nc counting of the remaining contributions to the cross sections which enter the sumrules.

References:

1. R. Dashen and A. V. Manohar, Phys. Lett. B315 (1993) 425, 438

2. W. Broniowski, Univ. of Regensburg preprint TPR-93-39 (1993)

Nuclear Collective Motionwithin O(N—1) Invariant Dynamics

M. Cerkaski and I.N. Mikhailov 1

1 Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Head Post Office,P.O.B.79, Moscow, Russia

Assuming an O(N — 1) symmetry for the interaction term in the iV-body Hamiltonian wefind a closed subsystem of equations describing the collective motion in a classical way. Whenstudying, in the group geometric way, the mutual correspondency of the O(N-l) invariant

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approach with the Sp(6,R) collective model we find that the nucleons move along trajectoriesdetermined by an effective one-body time-dependent harmonic potential being a function of thecollective variables. The relation between the equations for the collective motion and the systemof equations found elsewhere for the second order moments of the Wigner distribution functionis discussed. A class of stationary solutions to the collective equations of motion leads to thecranking model with the selfconsistency relations depending on the O(N-l) scalar part of thepotential.

Collective Modes in a Slab of Interacting Nuclear Matter:The Effects of Finite Range Interactions

W.M. Alberico l, P. Czerski, A. De Pace * and V.R. Manfredi 2

1 Dipartimento di Fisica Teorica deU'Universita-Torino, Italy and INFN, Sezione diTorino, Italy2 Dipartimento di Fisica delTUniversita-Padova, Italy and INFN, Sezione di Padova,Italy

We consider a slab of nuclear matter and investigate the collective excitations, which developin the response function of the system. We introduce a finite-range realistic interaction amongthe nucleons, which reproduces the full G-matrix by a linear combination of gaussian potentialsin the various spin-isospin channels. We then analyze the collective modes of the slab in the5 = T = 1 channel: for moderate momenta hard and soft zero—sound modes are found, whichexhaust most of the excitation strength. At variance with the results obtained with a zero rangeforce, new "massive" excitations are found for the vector-isovector channel [1].

Reference:

1. W.M. Alberico, P. Czerski, A. De Pace and V.R. Manfredi, Collective Modes in a Slab of InteractingNuclear Matter: The Effects of Finite Range Interactions, to be published in Z. Physik A

Spatial Dependence of Meson CorrelationFunctions at High Temperature

W. Florkowski 1 2 and B.L. Friman 1 3

1 GSI Darmstadt, Germany2 INP Krakow, Poland3 Institut fur Kernphysik, TH Darmstadt, Germany

The spatial dependence of meson correlation functions at high temperature is studied inperturbative QCD, keeping only the lowest order term. We obtain analytic results for thestatic correlation function in this approximation. Problems connected with the regularizationof the divergent expressions are discussed in detail. The meson screening mass is determinedfrom the form of the correlation function at large distances. We obtain mJcr = 2\Ar2T2 + M2,which agrees with the results of Eletskii and Ioffe for massless quarks (M = 0). Finally, thecorrelation function in the temporal direction is briefly discussed. For massless quarks we findthe corresponding screening mass macr = 2vT.

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Soft Photon Production in the Boost-InvariantColor-Flux Tube Model

W. Czyz x and W. Florkowski

1 Institute of Physics, Jagellonian University and INP Krakow, Poland

Starting from the classical expressions for emission of radiation we calculate soft photon pro-duction in the boost-invariant color-flux tube model. In the center-of-mass system of the initialtube we find that for large energies {yfs ~ 20 GeV) the production of photons with frequencies:20MeV < u> < 50MeV, and emitted perpendicularly to the collision axis is strongly enhanced;it exceeds considerably production of photons given by the Low limit. For the emission morecollinear with the collision axis and for decreasing u> the effect becomes weaker and, eventu-ally, in the limit u> = 0 we recover precisely the Low formula. We also find that for smallerenergies (y/s ~ 5 GeV) the emission of photons is well reproduced by the Low formula. Gener-ally speaking, the observed enhancement is related to the existence of a large, i.e. extended intime, region of photon emission. This, in turn, results from the time dilation accompanying thespace-time evolution of tubes. Strong time dilation effects follow from the boost-invariance ofour model and, for large s, considerably enhance radiation of soft photons. By the same token,this enhancement decreases with decreasing s, because dilation decreases.

Polarization of Incident Electron Beamand e-p Scattering Cross Sections

K. Golec-Biernat

The influence of the polarization of an incident electron beam on certain e-p scattering crosssections is studied. It is shown that photoproduction and bremsstrahlung cross sections are notaffected by the initial electron polarization in the Born approximation. The DIS case is alsoconsidered [1].

Reference:

1. K.Golec-Biernat, Polarization of Incident Electron Beam and e-p Scattering Cross Sections, HINote, DESY Hamburg, Hl-06/93-302 (1993)

Gluons from Logarithmic Slopesin the NLL Approximation

K. Golec-Biernat

We make a critical, next-to-leading order, study of the accuracy of the "Prytz" relation,which is frequently used to extract the'gluon distribution at small x from the logarithmic slopesof the structure function Ft. We find that the simple relation is not genarally valid in the HERAregime, but show that it is aleasonable approximation for gluons which are sufficiently singularat small x.

Reference:

1. K.Golej^iernat, Gluons from Logarithmic Slopes of F2 in the NLL Approximation, HI Note,DESY Hamburg, Hl-10/93-313 (1993), submitted for publication in Phys.Lett. B

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Small-a? Data Analysis by the Global Fit MethodK. Golec-Biernat, M.W. Krasny 1 and S. Riess 2

1 IFJ and LPNHE, University Paris VI and VII, Paris, France,2 Institute of Experimental Physics, University of Hamburg, Germany

The possibility of tracing shadowing corrections with hot spot scenario in the proton structurefunctions in deep-inelastic scattering is studied. The small x region of HERA is analyzed withreference to the experimental setup of the HERA colider. The global fit method is used.

Reference:

1. K. Golec-Biernat, M.W. Krasny and S. Riess, Small-x Data Analysis by the Global Fit Method,in preparation

Implications of Scaling Violations of F2 at HERAfor Peturbative QCD

A.J. Askew 2, K. Golec-Biernat, J. Kwiecidski, A.D. Martin a, and P.J. Sutton 2

1 Department of Physics, University of Durham, England,2 Department of Physics, University of Manchester, England

We critically examine the QCD predictions for the Q2 dependence of the electron-protondeep-inelastic structure function i ^ x , Q2) in the small x region, which is being probed at HERA.The standard results based on next-to-leading order Altarelli-Parisi evolution equations arecompared with those that follow from the BFKL equation, which corresponds to the ressumationof the leading log(l/a;) terms. The effects of parton screening are also quantified. The theoreticalpredictions axe confronted with each other, and with existing data from HERA.

Reference:

1. A.J. Askew, K. Golec-Biernat, J. Kwieciiiski, A.D. Martin and P.J. Sutton, Implications of ScalingViolations of F2 at HERA for Peturbative QCD, report INP 1653/PH (1993), submitted forpublication in Phys. Lett. B

Galilean Covariance in Classical and Quantum MechanicsP. Bochnacki, A. Horzela, E. Kapuscik \ J. Kempczyriski 2 and A. Radosz 3

1 INP and Krakow Pedagogical University2 Institute of Theoretical Physics, Warsaw University, Warsaw, Poland3 Institute of Physics, Wroclaw Technical University, Wroclaw, Poland

We have continued to study the properties of the Galilean covariant formulation of classicalmechanics as well as its consequences for Galilean covariant formalism of quantum mechanics.The fundamental concept of Galilean covariant single particle dynamics is based on the rejectionof the notion of force laws which, as non-covariant expressions of the forces in terms of a particleposition and velocity, can not describe acting forces (except of the constant one) in a covariantway. In our approach acting forces are considered as physical objects possessing their own timeevolution and they may be expressed in terms of force laws in only one, chosen reference frame.It means that for a complete and consistent description of a physical system a new degree of

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freedom has to be introduced and that we are to describe a particle always together with itsenvironment. The formalism admits Lagrangean and Hamiltonian formulations with technicalaspects which are similar to that of one dimensional field theory, but its interpretation needsnew ideas. In particular many physical quantities, identified within standard, non-covariantapproach, must be distinguished in the new formalism. The differences between covariant andnon-covariant formalisms are seen in the easiest way in the framework of the covariant canonicalformalism which gives unexpected results. The most important of them is a different shapeof the uncertainty principle (caused by the fact that the canonical and mechanical momentamust be distinguished) and the different Galilean transformation rule for the total and kineticenergies. The connection between covariant and non-covariant formalisms can be analysed in theframework of Dirac's theory of constrained systems which shows how the covariant formalismreduces to the standard one in a reference frame in which the force law is satisfied.

Physical Theories in Discrete Space-TimeA. Horzela, E. Kapuscik 1 and Ch.A. Uzes 2

1 INP and Krakow Pedagogical University2 University of Georgia, Athens, 30602 Georgia, USA

The aim of the research is the formulation of quantum mechanics in the configuration spacegiven by the finite, discrete set of allowed positions. In such a space the quantization can notbe given by the standard canonical procedure and becomes canonical only in the limit in whichthe spacing of the allowed positions tends to zero. In contradistinction to any discretization ofthe physical theory defined primarily on a continuum our approach realize the concept of thephysical theory defined from the very beginning on a discrete set. Such an approach demandsnew mathematical methods to be used. The algorithms based on the theory of discrete Fouriertransforms allows to perform theoretical investigations as well as numerical calculations.

Scalar Meson Dynamics

R. Kaminski, L. Lesniak and J.P. Maillet 1

1 Division de Physique Theorique, IPN, Orsay, France

Coupled channel analysis of the -Kit and KK interactions in the IG(JPC) = 0 + (0 + + ) stateshas been performed using a separable potential formalism [1]. A system of the Lippmann-Schwinger equations with relativistic propagators has been solved. The decay parameters ofthree resonances found in the analysis have been evaluated and compared with experimentaldata. The /o(975) resonance can be interpreted as a KK bound state. The root mean squareradii of the corresponding KK wave functions have been calculated for the different data sets andcompared with radii evaluated in the nonrelativistic approach. Their values (about 0.7 fm) areroughly 10 % smaller than the values found in the nonrelativistic analysis [2]. The parametersof the 7T7T and KK threshold interactions have been calculated. The scattering lengths havebeen compared with experiments and other determinations. The real part of the KK scatteringlength is about -1.65 fm and the imaginary part about 0.6 fm. The irw scattering length (0.17m"1) is in agreement with the experimental value.

Analogous calculations have been performed in the / = 2 TTT channel where a nonresonantbehaviour of the scattering amplitude was found.

References:

1. R. Kaminski, L. Lesniak and J.-P. Maillet, Relativistic Effects in the Scalar Meson Dynamics,Orsay preprint IPNO/TH 93-31 (1993)

2. F. Cannata, J.-P. Dedonder and L. Lesniak, Z. Phys. A 343 (1992) 451

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Nuclear Symmetry Energy and Structure of Dense Matterin Neutron Stars

PL9601050 M - K u t s c h e r a

Consequences for neutron star matter of the behaviour of symmetry energy which results indisappearing of protons at high densities are explored. It is shown that interactions responsiblefor disappearance of protons tend to separate protons and neutrons at lower densities. Twoseparation mechanisms are considered: a bulk separation of protons and neutrons and formationof a neutron bubble around a single proton. The latter one corresponding to trapping of protonsin the neutron background bubbles is more likely to occur in neutron star matter. In this caseprotons form polarons which are localized.

High Density Behaviour of Nuclear Symmetry EnergyM. Kutschera

There exists profound discrepancy in the high density behaviour of the nuclear symmetryenergy obtained in realistic variational many-body (VMB) calculations and in relativistic mean-field (RMF) calculations. While the symmetry energy decreases to negative values in the formerapproach it increases monotonically in the latter one. The origin of this discrepancy is discussedand it is argued that VMB prediction is more reliable. It is shown that vanishing of the symmetryenergy implies proton-neutron separation instability in dense matter.

Polarized Neutron Matter with Skyrme ForcesM. Kutschera and W. Wojcik 1

1 Institute of Physics, Krakow University of Technology, ul. Podchorazych 1,30-084 Krakow, Poland

It is shown that Skyrme forces with a commonly used parameter t% < 0 lead to instabilityof polarized neutron matter. This instability has a form of the ferromagnetic spin ordering.There is, however, no ground state and the system displays a singular behaviour. Physicallyconsistent description of polarized neutron matter requires that the exchange parameter x2,which was neglected in spin-saturated systems, is in the range -5/4 < x2 < — 1. We find thatSkyrme forces with x2 in this range provide very good parameterization of realistic neutronmatter calculations.

QCD Expectations for Deep Inelastic Scattering at Small xJ. Kwiecinski

The QCD expectations concerning the small x limit of parton distributions where x is theBjorken scaling variable are reviewed [1,2]. This includes discussion of the evolution equationsin the small x region, the Lipatov equation which sums the leading powers of ln(l/x) and theshadowing effects. Phenomenological implications of the theoretical expectations for the deepinelastic lepton-hadron scattering in the small x region which will be accessible at the HERA e-pcollider are described. We give predictions for structure functions F2 and FL and discuss specificprocesses sensitive to the small x physics such as deep inelastic diffraction and jet productionin deep inelastic lepton scattering. A brief review of nuclear shadowing in the inelastic leptonnucleus scattering at small x is also presented [1].

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1. J. Kwiecinski, Small x Physics, in: Proc. of the 32nd Schladming Winter School "Substructuresof Matter as Revealed with Electroweak Probes", Schladming, Austria, 24-th February-5th March1993; Lecture Notes in Physics 426 (1993) 215, eds. L. Mathelitsch and W. Plessas (Springer-Verlag, 1993)

2. J. Kwiecinski, QCD Expectations for Deep-Inelastic Scattering at Small x, in: Proc. of the Work-shop: "HERA - the New Frontier for QCD", 21-26 March 1993, St. John's College, Durham,United Kingdom; J. Phys. G19 (1993) 1443

QCD Predictions for Deep Inelastic Structure Functions atHERA

A.J. Askew 1, A.D. Martin 1, J. Kwiecinski and P.J. Sutton 2

1 Department of Physics, University of Durham, Durham, England2 Department of Physics, University of Manchester, Manchester, England

In [1] the perturbative QCD is used to predict the deep-inelastic electron-proton structurefunctions FT,L(^,Q2) in the small x region (x ss 10~3) from an experimental knowledge ofthe behaviour at larger x. Theoretical calculations are based on the kx factorisation theoremtogether with the gluon distribution obtained from solving the BFKL equation. Shadowingcorrections are quantified. In refs. [2,3] we study the general properties of the BFKL equationwhich sums the leading log(l/a;) terms and propose modifications to the infrared region. Inparticular we study the theoretical uncertainties in the predictions and show, in the HERAregime, that the effective slope A, denned by F2(x,Q2) - Ffg(x,Q2) = Cx~x, is a remarkablestable prediction of perturbative QCD, where Ffg is a suitably denned background. Numericalpredictions for the deep inelastic electron-proton structure functions at small x are presentedand confronted with recent HERA measurements.

References:

1. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, Phys. Rev. D47 (1993) 3775

2. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, Properties of the BFKL Equation andStructure Function Predictions for HERA, Durham University preprint DTP/93/28 (1993)

3. A.J. Askew, A.D. Martin, J. Kwiecinski and P.J. Sutton, A Structure Function Test of the QCDLipatov Behaviour at HERA, Durham University preprint DTP/93/38 (1993) (to be publishedin Modern Physics Letters)

Report of the Working Group on Radiative Corrections atHERA

B. Badelek 1, S. Bentvelsen 2, P. Kooijman 2, J. Kwieciriski, H. Spiesberger 3 andW. von Schlippe 4

1 Institute of Experimental Physics, Warsaw University, Warsaw, Poland2 NIKHEF, Amsterdam, The Netherlands3 Institute of Physics, Bielefeld University, Bielefeld, Germany4 Queen Mary and Westfield College, London, England

In inclusive deep inelastic lepton nucleon scattering, the radiative "tails" originating fromprocesses at Q2 values from the interval Q^ea* > Q2 > 0 contribute to measurements at Q2 —

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t n e knowledge of the structure functions in this Q2 interval is necessary. We revise andcompare existing parametrizations of structure functions and their extrapolations into the yetunexplored very low Q2 regions and discusss the resulting uncertainties for leptonic radiativecorrections. The unfolding procedures to determine structure functions from observed crosssections by the experiments NMC, ZEUS and HI are confronted with each other.

Reference:

1. B. Badelek, S. Bentvelsen, P. Kooyman, J. Kwiecinski, H. Spiesberger and W. von Schlippe, Reportof the Working Group on Radiative Corrections at HERA; Proc. of the Workshop "HERA - theNew Frontier for QCD", 21-26 March 1993, St. John's College, Durham, United Kingdom, J. Phys.G19 (1993) 1671

ii Shadowing in Deuteron and the New F*/F% Measurements

B. Badelek 1 and J. Kwiecinski

1 Department of Physics, Uppsala University, Uppsala, Sweden and Institute ofExperimental Physics, Warsaw University, Warsaw, Poland

The quantity 2i*2i(a;, Q2)lF%(%,Q2) — 1 is calculated in the region of low x and low- andmoderate Q2 relevant for recent NMC and E665 measurements as well as for the expectedfinal results of the precise NMC analysis of their low x data. The calculations include nuclearshadowing effects and a suitable extrapolation of the structure functions of free nucleons tothe low Q2 region. The theoretical results are in a good agreement with the NMC data. Theshadowing correction to the experimental estimate of the Gottfried sum is quantified.

Reference:

1. B. Badelek and J. Kwiecinski, Shadowing in the Deuteron and the New F%jF\ Measurements,Uppsala preprint TSL/ISV-93-0090 (1993)

'\°\ J/H? Coherent Production on Nuclei by High Energy Mesonsor Photons

L. Lesniak

The distorted wave Born approximation has been used to describe an effective cc pair nuclearabsorption in the J / $ coherent meson or photoproduction reactions on nuclei [1]. This effect hasbeen neglected in earlier analyses of experimental data. The best fit value of the effective J / $ -nucleon total cross section is <r$jv = 6.4 ± 1.7 mb. This value has been obtained by comparisonof the model with the data [2].

References:

1. L. Lesniak, Phys. Lett. B302 (1993) 140

2. New Muon Collab., P. Amaudruz et al., Nucl. Phys. B371 (1992) 553

W KK Scattering Length and the Nature of the /0(975) MesonF. Cannata 1, J.-P. Dedonder 2 and L. Lesniak

1 Dipartimento di Fisica and INFN, Bologna, Italy2 Laboratoire de Physique Nucleaire, Universite Paris 7 and Division de Physique Theorique,IPN, Orsay, France

In extensive studies of coupled channel effects at the KK threshold we have explored

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the possibility that the KK attraction is due to the coupling to a channel different from the TTTchannel [1]. So this requires to study three channels: TTTT , KK and a so-called exotic channel. Wehave studied various possibilities including the one where the bare exotic state is at Eex = 975MeV or at Eex = 1950 MeV. We favour the solution at 1950 MeV which corresponds to a polestructure like the one of the molecular picture for the /o(975) [2].

In view of alternative findings [3], we also study the solution at 975 MeV for the bare exoticstate which leads for the /o(975) meson to a pole structure of a conventional Breit-Wignerresonance in the energy variable , We find that our solution corresponding to the molecularpicture leads to a rather large KK scattering length whereas the low mass exotic solution at975 MeV displays a large cancellation in the KK scattering amplitude at low energies. Thiscancellation arises because of the coalescence of poles and zeroes of the 5 matrix.

References:

1. F. Cannata, J.-P. Dedonder and L. Lesniak, Z. Phys. A - Atomic Nuclei 343 (1992) 451

2. J. Weinstein and N. Isgur, Phys. Rev. D41 (1990) 2236

3. D. Morgan and M.R. Pennington, Phys. Rev. D48 (1993) 1185

Weak Hyperon Decays -1

P. Zenczykowski :

1 INP Krakow and Guelph University, Guelph, Canada

A simple explanation of the difference in the values of the apparent f/d ratios for the S- andP- wave amplitudes of nonleptonic hyperon decays was proposed [1] (experimentally (f/d)s =-2.6, {f/d)p — -1.9). The argument was formulated in the framework of the standard polemodel with 56,0+ ground-state and 70,1~ excited baryons as intermediate states for the P-and S-waves respectively. Under the assumption that the dominant part of the deviation of(f/d)p from - 1 is due to large quark sea effects it was shown that the naively expected equalityof (f/d)s and {f/d)p is lifted by the SU(3) symmetry breaking in energy denominators of S-wave amplitudes. A new relationship between these two f/d ratios was derived: (f/d + l)s =(1 + x)/(l - x) * (f/d + l)p (x = i , /A B K 0.33; 6, - strange-nonstrange quark mass difference;A^ - mean spacing of (56,0+) and (70,1~) baryons), which is in excellent agreement withexperiment ( — 1.6 ss 2 * (-0.9)). It was also pointed out that for weak radiative hyperon decaysthe signs of the asymmetries calculated in the SU(3)-symmetric approach [2] are unchanged bythe consideration of the SU(3)-symmetry breaking in energy denominators.

Nonleptonic Decays of Charmed Baryons ?z

P. Zenczykowski *

1 INP Krakow and Guelph University, Guelph, Canada

Quark and pole models of nonleptonic decays of charmed baryons were analysed from thepoint of view of their symmetry properties.

In the first paper on the subject [3] symmetry properties of parity conserving amplitudeswere discussed at length. It was shown that the symmetry structure of the dominant (dueto ground-state intermediate baryons) contribution to the parity conserving amplitudes differsfrom the structure hitherto employed in the symmetry approach [5]. The structure given inref.[5] must therefore be considered incorrect. It was also pointed out that the "subtraction"of sea quark effects in hyperon decays leads to an estimate of W-exchange contributions in

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charmed baryon decays that is significantly smaller than naively expected on the basis of SU(4).Furthermore, an SU(2)w constraint questioning the reliability of the factorization techniquefor parity conserving amplitudes was exhibited. Differences of symmetry structures of currentalgebra and pole model predictions for the parity violating amplitudes were also analysed [4]. Asimple technique generalizing the expressions of current algebra to the case of flavour symmetrybreaking in the intermediate state was applied to sum the contributions from all intermediateexcited l /2~ baryons of given charm. The technique permits easy discussion of departuresfrom current algebra for any value of Ac/Ao; (Ac-charm-noncharm mass difference, Au - l /2~- l / 2 + mass difference). It was found that in the pole model the symmetry structure of parityviolating amplitudes of charmed baryon decays into an octet baryon and a pseudoscalar mesonconsists of two pieces: (i) a term proportional to the standard current algebra expression butmuch smaller and of opposite sign and (ii) a term proportional to the factorisation contribution,interfering with it destructively. The full pole model was aplied to the description of availabledata [4], and compared with the predictions of current algebra [3]. Decays whose measurementsshould provide good discrimination between the pole model and current algebra were singledout.

References:

1. P. Zenczykowski, Weak Hyperon Decays: Quark Sea and SU(3) Symmetry Breaking, Report INP1647/PH (1993)

2. P. Zenczykowski, Phys. Rev. D44 (1991) 1485

3. P. Zenczykowski, Quaik and Pole Models of Nonleptonic Decays of Charmed Baryons, Report INP1643/PH (1993)

4. P. Zenczykowski, Nonleptonic Charmed Baryon Decays: Symmetry Properties of Parity ViolatingAmplitudes, Report INP 1655/PH (1993)

5. J.G. Koerner, G. Kramer, J. Willrodt, Phys. Lett. 78B (1978) 492; Z. Phys. C2 (1979) 117;J.G. Koerner, M. Kramer, Z. Phys. C55 (1992) 659; J.G. Koerner, H.W. Siebert, Ann. Rev. Nucl.Part. Sci. 45 (1991) 511

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LIST OF PUBLICATIONS:I. Articles:

1. A.J. Askew, J. Kwieciriski, A.D. Martin, P.J. Sutton:QCD Predictions for Deep Inelastic Structure Functions at HERAPhys. Rev. D47 (1993) 3775

2. B. Badelek, S. Bentvelsen, P. Kooijman, J. Kwiecinski, H. Spiesberger, W. von Schlippe:Report of the Working Group on Radiative Corrections at HERAJ. Phys. G: Nucl. Part. Phys. 19 (1993) 1671

3. Bao-An Li, M. Ploszajczak:Energy Dependence of Intermittency in Nuclear Reactions at Intermediate EnergiesPhys. Lett. B317 (1993) 300

4. R. Botet, M. Ploszajczak:Patterns of Fluctuations in Disaggregatiming SystemsLecture Notes in Physics 415 (1993) 303

5. R. Botet, M. Ploszajczak:The Analysis of the Charged Fragment Correlations Using a Fragmentation-InactivationBinary ModelPhys. Lett. B312 (1993) 30

6. P. Bozek, M. Ploszajczak:Multiscaling in the Hadronization in High Energy CollisionsZ. Phys. C59 (1993) 585

7. W. Broniowski, T.D. Cohen:Response of Nucleons to External Probes in Hedgehog Models. I. Electromagnetic Pola-rizabilitiesPhys. Rev. D47 (1993) 299

8. W. Broniowski, T.D. Cohen:Response of Nucleons to External Probes in Hedgehog Models. II. General FormalismPhys. Rev. D47 (1993) 313

9. W. Broniowski, T.D. Cohen:The Structure of the Pion and Effective Electric Currents in Soliton Models of the NucleonPhys. Rev. D48 (1993) 2299

10. W. Broniowski, M. Lutz, A. Steiner:JVc-Counting Rules and the Axial Vector Coupling Constant of the Constituent QuarkPhys. Rev. Lett. 71 (1993) 1787

11. M. Cerkaski, I.N. Mikhailov:Nuclear Collective Motion within the 0(N - 1) Invariant DynamicsAnnals of Phys. 223 (1993) 151

12. W. Czyz:Interaction of a Quark with the Perturbative VacuumActa Phys. Pol. B24 (1993) 483

13. W. Czyz, J. Turnau:Quark in a Magnetic VacuumActa Phys. Pol. B24 (1993) 1501

14. A. Horzela, E. Kapuscik:Another Treatment of the Relation Between Classical and Quantum MechanicsAnnales de la Fondation Louis de Broglie, 18 (1993) 155

15. A. Horzela, E. Kapuscik, Ch.A. Uzes:Comment on the paper: "Introductory Gauge Invariance", by R. Barlow [Eur.J. Phys. 1145-46 (1990)]Eur. J. Phys. (1993) 190

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16. A. Horzela, E. Kapuscik, Ch.A. Uzes:Comment on the paper: "Magnetic Monopoles, Galilean Invariance, and Maxwell's Equa-tions", by F.S. Crawford [Am. J.Phys. 60, 109-114 (1992)]Am. J. Phys. 61 (1993) 471

17. P. Kaminski, S. Drozdz, M. Ploszajczak, E. Caurier:Even-Odd Anomalous Tunneling EffectPhys. Rev. C47 (1993) 1548

18. M. Kutschera, A. Kotlorz:Maximum Quark Core in a Neutron Star for Realistic Equations of StateAstrophys. J. 419 (1993)

19. M. Kutschera, W. Wojcik:Proton Impurity in the Neutron Matter: A Nuclear Polaron ProblemPhys. Rev. C47 (1993) 1077

20. J. Kwieciriski:QCD Expectation for Deep-Inelastic Scattering at Small xJ. Phys. G: Nucl. Phys. 19 (1993) 1443

21. L. Lesniak:J / $ Absorption Effects in the Coherent Production on NucleiPhys. Lett. B302 (1993) 140

22. A.J. Askew, J. Kwieciriski, A.D. Martin, P.J. Sutton:A Structure Function Test of the QCD Lipatov Behaviour at HERAModern Physics Letters A8 (1993) 3813.

II. Contributions to Conferences:

1. W. Florkowski: Emission of Soft Photons in the Boos-Invariant Color-Flux Tube Model,to be published in the Proc. of the Krakow Workshop on Multiparticle Production: SoftPhysics and Fluctuations, Krakow 1993, R.C. Hwa ed., World Scientific

2. W. Florkowski, B.L. Friman: Screening and Dynamic Masses of Mesons in the Nambu-Jona-Lasinio Model, to be published in the Proc. of the Conference on Many Body Physics,Coimbra 1993, World Scientific

3. W. Florkowski, B.L. Friman: Meson Screening Masses in the Nambu-Jona-Lasinio Model,to be published in the Proc. of the XXXIII Krakow Summer School of Theoretical Physics:QCD Vacuum, Non-Perturbative Methods and Correlation Functions, Zakopane 1993,W. Czyz ed., Acta Phys. Pol. B

4. J. Kwieciriski: Small x Physics (An Introductory Theoretical Review), Proc. of the XVInt. Warsaw Meeting on Elementary Particle Physics, Kazimierz, Poland, 25-29 May 1992,eds. Z. Ajduk, S. Pokorski, A.K. Wroblewski, World Scientific, 1993

5. J. Kwieciriski: Small x Physics, Proc. of the 32. Int. Universitatswochen fur Kern- undTeilchenphysik, Schladming, Austria, 24 Feb.-5 March 1993, "Substructures of Matter asRevealed with Electroweak Probes", eds. L. Mathelitsch, W. Plessas, Springer-Verlag,Lecture Notes in Physics 426 (1993) 215

6. L. Lesniak: J / * Coherent Production on Nuclei by High Energy Muons or Photons,Contribution to the XIII International Conference "Particles and Nuclei", Perugia, Italy,28 June - 2 July 1993, Books of Abstracts, vol.1, p.149

7. F.Cannata, J.P. Dedonder, L. Lesniak: KK Scattering Length and the Nature of thefo(975) Meson. Contributed paper No 118 to the Int. Europhysics Conf. on High EnergyPhysics, Marseille, July 22-28, 1993.

8. R. Kamiriski, L. Lesniak, J.P. Maillet: Coupled Channels Analysis of the f0 Mesons. Con-tributed paper No 119 to the Int. Europhysics Conf. on High Energy Physics, Marseille,July 22-28, 1993.

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III. Reports:

1. Y. Abe, B.G. Giraud, M. Ploszajczak, E. Suxaud:Atomic Nuclei: A Laboratory for the Study of ComplexityGANIL preprint P-93-06 (1993)

2. A.J. Askew, K. Golec-Biernat, J. Kwiecinski, A.D. Martin, P.J. Sutton:Implications of Scaling Violations of F2 at HERA for Perturbative QCDInstitute of Nuclear Physics preprint INP 1653/PH (1993)

3. A.J. Askew, J. Kwiecinski, A.D. Martin, P.J. Sutton:Properties of the BFKL Equation and Structure Function Predictions for HERAUniv. of Durham preprint DTP/93/28 (1993)

4. B. Badelek, J. Kwiecinski:Shadowing in the Deuteron and the New F£ /F% MeasurementsUniv. of Uppsala preprint TSL/ISV-93-0090 (1993)

5. R. Botet, M. Ploszajczak:Fragmentation-Inactivation Binary Model - A New Model of Kinetic Sequential Fragmen-tationGANIL preprint P-93-14 (1993)

6. P. Bozek, M. Ploszajczak:Fluctuations in the Heavy Ion CollisionsGANIL preprint P-93-20 (1993)

7. W. Broniowski:Low-Energy Sum Rules and the Large-iVc Consistency ConditionsTechnical Report Univ. of Regensburg TPR-93-39 (1993)

8. W. Czyz, W. Florkowski:Soft Photon Production in the Boost-Invariant Color-Flux Tube ModelInstitute of Nuclear Physics preprint INP 1640/PH (1993), to be published in Zeit.Phys. C

9. W. Florkowski, B.L. Friman:Spatial Dependence of the Finite-Temperature Meson Correlation FunctionInstitute of Nuclear Physics preprint INP 1618/PH (1993), to be published in Zeit.Phys. A

10. W. Florkowski, B.L. Friman:Screening of the Meson Fields in the Nambu-Jona-Lasinio ModelInstitute of Nuclear Physics preprint INP 1622/PH (1993)

11. R. Kaminski, L. Lesniak, J.-P. Maillet:Relativistic Effects in the Scalar Meson DynamicsIPN Orsay preprint IPNO/TH 93-31 (1993)

12. P. Kaminski, M. Ploszajczak, R. Arvieu:Quantum Tunneling in the Driven Lipkin N-Body ProblemGANIL preprint P-93-13 (1993)

13. M. Kutschera:Nuclear Symmetry Energy and Structure of Dense Matter in Neutron StarsInstitute of Nuclear Physics preprint INP 1641/PH (1993)

14. M. Kutschera:High Density Behaviour of Nuclear Symmetry EnergyInstitute of Nuclear Physics preprint INP 1642/PH (1993)

15. M. Kutschera, W. Wojcik:Polarized Neutron Matter with Skyrme ForcesInstitute of Nuclear Physics preprint INP 1654/PH (1993)

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16. J. Kwiecidski:Small x PhysicsInstitute of Nuclear Physics preprint INP 1620/PH (1993)

17. E.N. Nikolov, W. Broniowski, K. Goeke:Electric Polarizability of the Nucleon in the Nambu-Jona-Lasinio ModelRuhr-Univ. Bochum Technical Report RUB-TPII-55/93 (1993)

18. P. Zenczykowski:Quark and Pole Models of Nonleptonic Decays of Charmed BaryonsInstitute of Nuclear Physics preprint INP 1643/PH (1993)

19. P. Zenczykowski:Weak Hyperon Decays: Quark Sea and SU(3) Symmetry BreakingInstitute of Nuclear Physics preprint INP 1647/PH (1993)

PARTICIPATION IN CONFERENCES AND WORKSHOPS:P. Boiek:

1. Interdisciplinary Workshop on Statistical Description of Transport in Plasma, Astro- andNuclear Physics, Les Houches, France, February 1993.

W. Broniowski:

1. Electromagnetic Polarizabilities in Hedgehog Models, University of Regensburg, Regens-burg, Germany, January 1993,

2. Nc Counting Rules and g\ of the Constituent Quark, Institute of Physics, Ljubljana Uni-versity, Ljubljana, Slovenia, April 1993,

3. Nc Counting Rules and the Axial Vector Coupling Constant of the Constituent Quark,Institute of Theoretical Physics, Bochum University, Bochum, Germany, May 1993,

4. Low-Energy Sum Rules and the Large-iVc Limit, talk at the Session "Chiral Symmetry inHadrons and Nuclei" of ECT, Trento, Italy, Sept. 1993 and at the Institute of TheoreticalPhysics, Bochum University, Germany, October 1993,

5. Linear Response in Chiral Soliton Models, talk at the Session "Structure of Nucleons" ofECT, Trento, Italy, October 1993.

P. Czerski:

1. The Equation of State for Nuclear Matter , University of Padova, Padova, Italy, March1993,

2. Collective Modes in a Slab of Interacting Nuclear Matter, University of Padova, Padova,Italy, March 1993.

W. Czyi:

1. Theory and PHOBOS, Workshop on Heavy Ions Interactions at Brookhaven and the PHO-BOS Experiment, High Energy Physics Department, INP Krakow, November 1993.

W. Florkowski:

1. Screening Masses of Mesons in the Nambu-Jona-Lasinio Model, Institute of Physics, Jag-ellonian University, Krakow, March 1993,

2. Convective Stability of the Relativistic Hydrodynamic Flow, Institute of Physics, Jagel-lonian University, Krakow, March 1993,

3. Screening of the Meson Fields in the Nambu-Jona-Lasinio Model, High Energy PhysicsDepartment, INP Krakow, April 1993; XXXIII Summer School of Theoretical Physics,Zakopane, June 1993,

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4. Soft Photon Production in the Boost Invariant Color Flux Tube Model, Krakow Workshopon Multiparticle Production - Soft Physics and Fluctuations, Krakow, May 1993 - invitedtalk.

K. Golec-Biernat:

1. Shadowing at Small x, 32 Internationale Universitatswochen fur Kern - und Teilchen-physik: "Substructures of Matter as Revealed with Electroweak Probes", Karl-FranzensUniversitat Graz, Schladming, Austria, February 24 - March 5, 1993,

2. Small x Physics at HERA, High Energy Physics Department, INP Krakow, March 1993.

A. Horzela:

1. Galilean Covariance in Classical and Quantum Mechanics, Department of Physics, Uni-versity of Georgia, Athens, USA, March 1993,

2. On the Galilean Covariant Generalization of the Harmonic Oscillator Lie Algebra , IIIWigner Symposium, Oxford, UK, 5-11 Sept. 1993,

3. On the Connection Between Classical and Quantum Mechanics , Frontiers in FundamentalPhysics, Olimpia, Greece, 25-30 Sept. 1993.

E. Kapuscik:

1. Physics without Physical Constants , Frontiers in Fundamental Physics, Olimpia, Greece,25-30 Sept. 1993,

2. Galilean Covariance Revisited, Frontiers in Theoretical Physics, Edirne, Turkey, 15-21Dec. 1993.

M. Kutschera:

1. Maximum Quark Core Inside a Neutron Star for Realistic Equations of State, Institute ofPhysics, Jagellonian University, Krakow, April 1993,

2. Properties of Dense Hadronic Matter, Workshop on Research Programme of the Instituteof Nuclear Physics, Krakow, May 1993,

3. The Equation of State of Dense Nuclear Matter, Topical Workshop on Meson Productionin Nuclear Collisions, GSI Darmstadt, Germany, May 1993 - invited talk,

4. Galactic Physics I, Institute of Physics, Jagellonian University, Krakow, November 1993.

J. Kwieciiiski:

1. QCD Expectation for Deep Inelastic Scattering at Small x, Workshop on HERA - thefrontier for QCD, held at St. John's College, Durham, England, 21-26 March 1993 - focaltalk, discussion leader,

2. QCD Expectations for Deep Inelastic Scattering and their Phenomenological Explorationat HERA, LPTHE Orsay, France, July 1993,

3. International Europhysics Conference on High Energy Physics,Marseille, France, July 1993,

4. Structure Functions at Low x, DESY Theory Workshop: "Quantum Chromodynamics",Hamburg, Germany, 29.09 - 1.10.1993.

L. Lesniak:

1. Structure of the /o Mesons , Topical Workshop on Meson Production in Nuclear Collisions,GSI Darmstadt, Germany, May 1993 - invited talk,

2. Studies of the /o Mesons , Krakow Seminar of Nuclear Physics and its Applications,Institute of Physics, Jagellonian University, May 1993,

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3. «/y# Coherent Production on Nuclei by High Energy Mesons or Photons, XIII Int. Conf."Particles and Nuclei", Perugia, Italy, June 1993,

4. Aspects of /o Mesons, Int. Conf. on High Energy Physics, Marseille, France, July 1993,5. Interactions of the J / # Mesons in Atomic Nuclei at High Energies, High Energy Physics

Department, INP Krakow, November 1993.

M. Pioszajczak: - invited talks

1. Fluctuations in Nuclear Fragmentation, Krakow Workshop on Multiparticle Production -Soft Physics and Fluctuations, Krakow, May 1993,

2. Fluctuations in Multiparticle Dynamics , n TAPS Workshop, Guardamar, Spain, June1993,

3. Revue sur les outils nouveaux dans la recherche de la multifragmentation , ColloqueGANIL, Pradet (Var), France, June 1993,

4. Fluctuations in the Fragmentation Process, XXIII Mazurian Lakes Summer School onNuclear Physics, Piaski, Poland, August 18 - 28, 1993,

5. Fragmentation - Inactivation Binary Model - a New Model of Kinetic Sequential Fragmen-tation, Int. Workshop on Dynamical Features of Nuclei and Finite Fermi Systems, Sitges,Spain, September 13 - 17, 1993,

6. Quantum Tunneling in the Driven Lipkin N-Body Problem, Workshop on Large AmplitudeCollective Motion, Institute for Nuclear Theory, University of Washington, Seattle, USA,November 1993.

P. Zenczykowski:

1. Weak Radiative Hyperon Decays - Rare but Important Processes, invited talk at the JointTheoretical and Experimental Wine-and- Cheese Seminar, Fermilab, USA, April 2, 1993,

2. Weak Radiative Hyperon Decays and Hara Theorem, invited talk at the E761 meeting,St.Petersburg Nucl. Physics Institute, Gatchina, Russia, October 19, 1993,

3. The Neutrino Affair: the Position of MSW, Institute of Physics, Jagellonian University,Krakow, November 1993,

4. Weak Decays of Charmed Baryons, Institute of Physics, Jagellonian University, Krakow,November 1993.

LECTURES AND COURSES:W. Broniowski

1. How Stiff are Hadrons ?,lectures for physics students at the Institute of Physics, Regensburg University, Regens-burg, Germany, January 1993,

2. Electromagnetic Polarizabilities of Hadrons,lectures for graduate students at the Institute of Physics, Ljubljana University, Ljubljana,Slovenia, April 1993.

W. Czyi

1. Quantum Mechanics,lectures for graduate physics students at the Institute of Physics, Jagellonian Universityand Institute of Nuclear Physics.

130

E. Kapuscik

1. Introduction to Nuclear and Elementary Particle Physics ,lectures for physics students at the Krakow Pedagogical University, Krakow 1993,

2. Classical Electrodynamics,lectures for physics students at the Krakow Pedagogical University, Krakow 1993,

3. General Properties of Space-Time,lectures for teachers of physics at the Krakow Pedagogical University, Krakow 1993.

M. Kutschera

1. Introduction to Theoretical Astrophysics,lectures for students of physics at the Jagellonian University, Krakow, 1993,

2. Introduction to Physical Cosmology,lectures given at the 1993 European School of High Energy Physics, Zakopane, 12-25September 1993.

3. Are Protons in a Neutron Star Core Polarons ?lecture given at the Institute of Physics, Jagellonian University, Krakow, January 1993.

J. Kwieciriski

1. Recent Developments in Particle Physics ,advanced lectures for physics teachers at the Krakowy Pedagogical University,

2. Small x Physics,lectures given at the 23nd Schladtning Winter School: "Substructures of Matter as Re-vealed with Electroweak Probes", Schladming, Austria, 24th Feb. - 5th March 1993.

M. Pioszajczak

1. Fluctuations and Correlations in Heavy-Ion Collisions,Institute of Theoretical Physics, University of Catania, Catania, Italy, 27 February - 12March 1993.

INTERNAL SEMINARS:

1. A. Blin (University of Coimbra, Portugal):Temperature Effects in the Lipkin and the Dicke Models

2. P. Bozek :Subthreshold Meson Production

3. P. Bozek :The Effect of the Cut-Off on the Multiparticle Correlations

4. O. Boyarkin (University of Grodno, Byelorussia):Probing Physics Beyond the Standard Model

5. W. Broniowski:Low-Energy Sum Rules and Nc —> oo Limit

6. M. Cerkaski:Rotational Nuclear Bands within Unitary U(3) Model

7. Z. Chylinski:Passive and Active Interpretation of Space Time Symmetries

8. P. Czerskv.The Equation of State for Nuclear Matter

9. W. CzykInteractions of Light and Heavy Quarks with Paramagnetic Vacuum

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10. W. Florkowski:Screening Masses of Mesons in the Nambu-Jona-Lasinio Model

11. W. Florkowski:Convective Stability of the Relativistic Hydrodynamic Flow

12. 5. Giller (University of Lodz):The Meaning of Periodic Orbits in the Quantization of Hamilton Classical Systems

13. St. Glazek (University of Warsaw):Renormalization of Hamiltonians

14. A. Gorski:Chiral Soliton Model of the Nambu-Jona-Lasinio Type

15. B. Hiller (University of Coimbra, Portugal):Static and Dynamical Properties of Mesons in the Nambu-Jona-Lasinio Model

16. M. Jezabek:Is It Worth to Construct a New Accelerator e+e~ ?

17. R. Kamiriski:Relativistic TTTT Interactions in the s-State

18. E. Kapuscik:Another Look at Maxwell's Electrodynamics

19. M. Kutschera:Maximum Quark Core Inside a Neutron Star for Realistic Equations of State

20. J. Kwiecinski:Nuclear Shadowing in Inelastic Lepton-Deuteron Scattering

21. L. Lesniakr.Searches for t-Quark

22. A. Maiecki:Unitarity Constraints of Diffraction

23. A.D. Martin (University of Durham, U.K.):Deep Inelastic Scattering

24. H. Patka:The Search of Higgs Particles in Experiments at LEP

25. M. Ploszajczak.Fluctuation in Nuclear Fragmentation

26. Ch.A. Uzes (University of Georgia, Athens, USA):Quasi-Canonical Approach to Quantum Mechanics

27. B. Wosiek:A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Interactions

28. 5. Zubik:What is the Value of the Nuclear Incompressibility Coefficient ?

29. P. Zenczykowski:Weak Nonleptonic Decays of Charmed Baryons

VISITORS TO THE DEPARTMENT:

1. Prof. J.-P. Maillet - Division de Physique Theorique, Institut de Physique Nucleaire,Orsay, France, April 1993

2. Dr. 0. Boyarkin - Department of Theoretical Physics, University of Grodno, Byelorussia,June 1993

3. Prof. A.D. Martin - Department of Theoretical Physics, University of Durham, England,June, September, October - December 1993

4. Prof. Ch.A. Uzes - Department of Theoretical Physics, University of Georgia, Athens,USA, August/September 1993

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5. Dr. A. Blin and dr. B. Hiller- Department of Theoretical Physics, University of Coimbra,Portugal, September 1993

6. Dr. P.J. Sutton - Department of Theoretical Physics, University of Manchester, England,October - December 1993

7. Dr. A.J. Askew - Department of Theoretical Physics, University of Durham, England,October - December 1993

8. Dr. S. Riess - Department of Experimental Physics, University of Hamburg, Germany,November/December 1993

9. Dr. J. Kurzhoffer and dr. A. de Roeck- DESY, Hamburg, Germany, December 1993

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Department ofHigh Energy Physics

PL9601061

DEPARTMENT OF HIGH ENERGYPHYSICS

(High Energy Physics Laboratory)1

Head of the Department: Professor Tomir CoghenDeputy Heads: Professor Roman Hotyriski, Dr. Grzegorz PolokSecretaries: E. Bukala, D. Filipiak, D. Krzyszton and M. Mielniktelephone: (48) (12) 33-33-66e-mail: HEPSEC@VSK06.IFJ.EDU.PL

PERSONNEL:Sub-department of Electronic Particle Detectors (EPD)Research Staff (26):

Head: Professor Krzysztof Rybicki,Grazyna Bak-Zalewska, Ph.D.Andrzej Bozek, M.Sc. - research studentPawel Briickman, M.Sc. - research studentAlfred Budziak, M.Sc. - research studentMichal Dziadus, M.Sc.Eng.Szymon Gadomski, M.Sc. - research studentLidia Gorlich, Ph.D.Leszek Hajduk, M.Sc.Zbigniew Hajduk, Ph.D.Pawel Jalocha, M.Sc.Bartlomiej Kisielewski, Ph.D.Mieczyslaw Krasny, Assoc. ProfessorWojciech Krupiriski, M.Sc. - research studentTadeusz Lesiak, Ph.D.Janusz Martyniak, M.Sc. - research studentJerzy Michalowski, Eng.Stanislaw Mikocki, Ph.D.Ewelina Mroczko, M.Sc.Zbigniew Natkaniec, M.Sc. Eng.Grazyna Nowak, Ph.D.Henryk Palka, Ph.D.Grzegorz Polok, Ph.D.Maria Rozariska, Assoc. ProfessorMichal Turala, Professor (Deputy Director)Jacek Turnau, Assoc. ProfessorMariusz Witek, Ph.D

RYBICKI@CHOPIN.IFJ.EDU.PLZALEWSKA@CHOPIN.IFJ.EDU.PLBOZEK@CHOPIN.IFJ.EDU.PLBRUECKMAN@CHOPIN.IFJ.EDU.PLBUDZIAK@CHOPIN.IFJ.EDU.PLDZIADUS@CHOPIN.IFJ.EDU.PLGADOMSKI@CHOPIN.IFJ.EDU.PLGOERLICH@CHOPIN.rFJ.EDU.PLLEHAJ@CHOPIN.IFJ.EDU.PLHAJDUK@CHOPIN.IFJ.EDU.PLJALOCHA@CHOPIN.IFJ.EDU.PLKISIELEWSKI@CHOPIN.IFJ.EDU.PLKRASNY@CHOPIN .IFJ.EDU.PLKRUPINSKI@CHOPIN.IFJ.EDU.PLLESIAK@CHOPIN.IFJ.EDU.PLMARTYNIAK® CHOPIN.IFJ.EDU.PLMICHAL0WSKI@CH0PIN .IFJ.EDU.PLMIKOCKI@CHOPIN.IFJ.EDU.PLMROCZKO@CHOPIN.IFJ.EDU.PLZBIGNIEW@CHOPIN.IFJ.EDU.PLNOWAK@CHOPIN.IFJ.EDU.PLPALKA@CHOPIN.IFJ.EDU.PLP0L0K@CH0PIN.D?J.EDU.PLROZANSKA® CHOPIN.IFJ.EDU.PLTURALA@CH0PIN.D7J.EDU.PLTURNAU@CHOPIN .IFJ.EDU.PLWITEK@CHOPIN.IFJ.EDU.PL

Technical Staff (2):Andrzej FlorekBoguslaw Florek

'Address: ul.Kawiory 26 A, 30-055 Krakow, Telephone: 48 (12) 333366, Fax: 48 (12) 333884, Telex: 322294

135

Experiments and International Collaborations of EFD:

DELPHI (e+e- interaction at LEP Em « lQOGeV), CERN; GenevaHI {e~p interaction 30 GeV x 820 GeV at HERA), DESY, HamburgCRYSTAL BALL (e + e- interactions at DORIS, E^ ss lOGeV), DESY, HamburgNA32 (ir-Cu interactions at 200 GeV), CERN, Geneva,ATLAS (Preparation of the experiment at the LHC 7 TeV x 7 TeV), CERN, Geneva

Sub-department of Experimental Elementary Particle Physics (EEPP)Research Staff (20):

Head: Professor Andrzej EskreysJerzy Bartke, ProfessorPrzemysiaw Borzemski, M.Sc.Wojciech Burkot, Ph.D.Janusz Chwastowski, Ph.D.Tomir Coghen, ProfessorJan Figiel, Assoc. ProfessorEwa Gladysz-Dziadus, Ph.D.Jerzy Halik, M.Sc.Eng.Zbigniew Jakubowski, Ph.D.Marek Kowalski, Ph.D.Bronislaw Niziol, Ph.D.Krystyna Olkiewicz, Ph.D.Bogdan Pawlik, Ph.D.Krzysztof Piotrzkowski, M.Sc. - res. studentMaciej Przybycieii, M.Sc.Piotr Stefanski, Ph.D.Piotr Stopa, Ph.D.Maciej Zachara, Ph.D.Leszek Zawiejski, Ph.D.

ESKREYS@CHOPIN.IFJ.EDU.PLBARTKE@CHOPIN.IFJ.EDU.PLBORZEMSKI@CHOPIN.IFJ.EDU.PLBURKOT@CHOPIN.IFJ.EDU.PLCHWASTOWSKI@CHOPIN.IFJ.EDU.PLCOGHEN@CHOPIN.IFJ.EDU.PLFIGIEL@CHOPIN.IFJ.EDU.PLGLADYSZ@CHOPIN.IFJ.EDU.PLHALIK@CHOPIN.IFJ.EDU.PLJAKUBOWSKI@CHOPIN.IFJ.EDU.PLKOWALSKI@CHOPIN.IFJ.EDU.PL

OLKIEWICZ@CHOPIN.IFJ.EDU.PLPAWLIK@CHOPIN.IFJ.EDU.PLPIOTRZKOWSKI® CHOPIN.IFJ.EDU.PLPRZYBYCIEN@CHOPIN.IFJ.EDU.PLSTEFANSKI@CHOPIN.IFJ.EDU.PLSTOPA@CHOPIN .IFJ.EDU.PLZACHARA@CHOPIN.IFJ.EDU.PLZAWIEJSKI@CHOPIN.IFJ.EDU.PL

Technical Staff (6):

Lucyna AntosiewiczBogdan DabrowskiPiotr Jurkiewicz, M.Sc.Eng.Maria PieczoraAnna Stobierzanin-AleksandrowaWojciech Wierba, M.Sc.Eng.

DABROWSKI@CHOPIN.IFJ.EDU.PLJURKIEWICZ@CHOPIN.IFJ.EDU.PL

WIERBA@CHOPIN.IFJ.EDU.PL

Experiments and International Collaboration of EEPP:

ZEUS (e~p interactions 30 GeV x 820 GeV at HERA), DESY, HamburgE665 (/x+p interactions at 500 GeV, TEVATRON), Fermilab, Batavia, USANA35/NA49 (heavy ion interactions on nuclear targets at 60 and 200 GeV/nucleon, SPS),CERN, GenevaALICE (preparation of the experiment with ultrarelativistic heavy ions at the LHC 3 A TeV x3 A TeV), CERN, Geneva

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GenevaALICE (preparation of the experiment with ultrarelativistic heavy ions at the LHC 3 A TeV x3 A TeV) CERN, GenevaNA22-EHS (TT+, K+,p - p interactions at 250 GeV, SPS), CERN, GenevaWA59 (i/, v interaction at 10 - 200 GeV, SPS^ CERN, Geneva

Sub-department of High Energy Nuclear Interaction (HENI)Research Staff (12):

Head : Professor Roman Hoh/nskiAnna Dabrowska, M.Sc.Alina Jurak, Ph.D.Dariusz Kudzia, M.Sc. Eng.Andrzej Olszewski, Ph.DMonika Szarska, Ph.D.Adam Trzupek, Ph.D\Barbara Wilczynska, Ph.D.Henryk Wilczynski, Ph.D.Wladyslaw Wolter, Assoc.ProfessorBarbara Wosiek, Assoc.ProfessorKrzysztof Wozniak, Ph.D.

HOLYNSKI@CHOPIN.IFJ.EDU.PLDABROWSKA@CHOPIN.IFJ.EDU.PL

KUDZIA@CHOPIN.IFJ.EDU.PLOLSZEWSKI@CHOPIN.IFJ.EDU.PLSZARSKA@CHOPIN.IFJ.EDU.PLTRZUPEK@CHOPIN.IFJ.EDU.PLBWILCZYNSKA@CHOPIN.IFJ.EDU.PLWILCZYNSKI@CHOPIN.IFJ.EDU.PLWWOLTER@CHOPIN.IFJ.EDU.PLWOSIEK@CHOPIN.IFJ.EDUWOZNIAK@CHOPIN.IFJ.EDU.PL

Technical Staff (7):

Maria BrozynaKazimiera ChudobaJanina CzajkaWitold KitaMarianna KowalczykAnna LasaAnna Polarska

CZAJKA@CHOPIN .IFJ.EDU.PL

LASA@CHOPIN.IFJ.EDU.PL

Experiments and International Collaborations of HENI:

JACEE (Composition, energy spectra and nuclear interactions of cosmic rays in balloon-borneemulsion chambers)KLMM (16O,28 5i,32 5 - emulsion interactions at 15, 60 and 200 GeV/nucleon) BNL-Brookhaven,CERN - GenevaKLMT ( ir~ - emulsion interactions at 525 GeV) Fermilab, Batavia, USAPHOBOS (Preparation of the experiment at the Relativistic Heavy Ion Collider 100A GeV x100A GeV) Brookhaven, USA.

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Electronic and Computing GroupStaff (13):

Head: Assoc. Professor Piotr Malecki(Deputy Director)Jerzy Andruszków, M.Sc. Eng.Krzysztof Cetnar, M.Sc.Witold Daniluk, EngEdward Górnicki, Eng.Zofia KawulaAndrzej Kotarba, M.Sc.Eng.Bogdan Madeyski, Eng.Paweł MałotaArkadiusz Moszczyński, M.Sc. Eng.Krzysztof Oliwa, Eng.Andrzej Sóbala, M.Sc.Artur Wolak, M.Sc.

MALECKIOCHOPIN .IFJ.EDU.PL

ANDRUSZKOW@CHOPIN.IFJ.EDU.PLCETNAR@CHOPIN.IFJ.EDU.PL'DANILUK@CHOPIN.IFJ.EDU.PLGORNICKI@CHOPIN.IFJ.EDU.PLKAWULA@CHOPIN.IFJ.EDU.PLKOTARBA@CHOPIN.IFJ.EDU.PLMADEYSKI@CHOPIN.IFJ.EDU.PLMALOTA@CHOPIN.IFJ.EDU.PLMOSZCZYNSKI@CHOPIN.IFJ.EDU.PLOLIWA@CHOPIN.IFJ.EDU.PLSOBALA@CHOPIN.IFJ.EDU.PLWOLAK@CHOPIN.IFJ.EDU.PL

Participation in ZEUS, ATLAS and NA35/NA49 Collaborations.

Theory GroupResearch Staff (5):

Head: Professor Kacper ZalewskiPiotr Białas, Ph.D.Stanisław Jadach, Assoc. ProfessorMarek Jeżabek, ProfessorZbigniew Was, Assoc. Professor

ZALEWSKI@CHOPIN.IFJ.EDU.PLBIALAS@CHOPIN.IFJ.EDU.PLJADACH@CHOPIN.IFJ.EDU.PLJEŻABEK@CHOPIN.IFJ.EDU.PLWAS@CHOPIN.IFJ.EDU.PL

Participation in HI, ZEUS, ATLAS, DELPHI Collaborations.

Mechanical and Thermal Computing and Engineering GroupStaff (11):

Head: Dr. Krzysztof Pakoński(on leave of absence, the group is presently headedby M.Stodulski, M.Sc.Eng.)Jacek Błocki, Dr.Eng.Marian DespetKazimierz Gałuszka, M.Sc.Eng.Jan Godlewski, M.Sc.Eng.Marian Lender, M.Sc.Eng.Marek Stodulski, M.Sc.Eng.Zdzisław StopaAndrzej StrączekMieczysław StrękTadeusz Wojas

PAKONSKI@CHOPIN.IFJ.EDU.PL

BLOCKI@CHOPIN.IFJ.EDU.PL

GODLEWSKI@CHOPIN.IFJ.EDU.PLLEMLER@CHOPIN .IFJ.EDU.PLSTODULSKI@CHOPIN.IFJ.EDU.PL

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Participation in DELPHI, HI, ZEUS, ATLAS, PHOBOS and also in R&D of LHC accelera-tor.

Administration:Mrs. Ewa Bukala,Mrs. Danuta Filipiak,Mrs. Danuta Krzyszton,Ms. Maria'Mielnik, M.A.

GRANTS:A. From the State Committee for Scientific Research (KBN)

1. Prof. K. ZalewskiGrant No. 203809101, 1991-93" Predictions of Standard Model for new-generation accelerators ".

2. Prof. R. HolynskiGrant No. 203419101, 1991-94" Composition, energy spectra and nuclear interactions of cosmic rays ".

3. Prof. A. Eskreys and Prof. K. Rybicki, together with Prof. J. Zakrzewski of the WarsawUniversityGrant No. 204209101, 1991-93" Project HERA - experiments ZEUS and HI ".

4. Dr A. Zalewska, together with Prof. R. Sosnowski and Dr K. Doroba of the Institute ofNuclear Studies, WarsawGrant No. 209639101, 1991-93" Participation in DELPHI experiment ".

5. Prof. J. Bartke, together with Prof. E. Skrzypczak of the Warsaw UniversityGrant No. 204369101, 1991-94" Collisions of relativistic nuclei ".

6. Prof. R. HolyriskiGrant No. 203799101, 1991-94" Study of nucleus-nucleus interactions at highest accelerator energies ".

7. Prof. S. JadachGrant No. 223729102, 1992-94" Predictions of Standard Model for future colliders ".

8. Assoc. Prof. J. FigielGrant No. 2P30204104, 1993-94" Investigation of muon-nucleon and muon-nucleus interactions at the TEVATRON(experiment E665) ".

9. Prof. T. CoghenGrant No. 2P30215104, 1993-95" Participation in the PHOBOS experiment: study of correlations and fluctuations of low

pt particles produced in heavy ion interactions in the future RHIC collider at BNL ".10. Dr Eng. K. Pakonski

Grant No. 3P40700604, 1993-96" Technology of manufacturing extremely stiff thin shells made of carbon-carbon compo-sites ".

139

11. Prof. M. Turala, together with Prof. D. Kisielewska of the School of Mining and Metal-lurgy, Krakow, and Prof. J. Krolikowski of the Warsaw UniversitySpecial grant No. 115/E - 343/SPUB - 206/93, first part of the three-years' project" Preparation of the physics programme and detectors for studying proton-proton interac-tions at 16 TeVin the LHC collider ".

B. From the Polish-German Foundation

1. Prof. A. Eskreys and Prof. K. Rybicki, together with Prof. D. Kisielewska of the Schoolof Mining and Metallurgy, Krakow, and Prof. J. Zakrzewski of the Warsaw UniversityGrant No. 506/92, 1993-95" Experiments ZEUS and HI at the HERA collider in DESY ".

2. Prof. J. Bartke, together with Prof. E. Skrzypczak of Warsaw UniversityGrant No. 565/93/LN, 1993-95" Experiment NA49 with ultrarelativistic heavy ions at the CERN SPS ".

OVERVIEW:

The Department originated from a group of cosmic ray and high energy physicists createdby the late Prof. M. Mifsowicz in the early fifties. This group consisted of people originallyemployed and housed in the Academy of Mining and Metallurgy. In 1955 some of them weretransferred to the so-called Krakow Branch of the High Energy Physics Department of the In-stitute of Nuclear Studies in Warsaw, which rapidly increased in number and in 1970 becamea Department in the Institute of Nuclear Physics in Krakow. The Department is located in aseparate building in the campus of the Academy of Mining and Metallurgy, which facilitates theclose collaboration with research groups from the latter as well as with the theorists from theJagellonian University. Joint weekly seminars represent a more than 30-years old tradition ofthis high energy physics community, where theorists from the Department of Theoretical Physicsof our Institute also play an important role. On April 5, 1993 the first anniversary of the deceaseof Prof. Mi§sowicz, who for 37 years was the leader of the high energy physics community inKrakow, agreement was signed by representatives of the Academy of Mining and Metallurgy,the Jagellonian University and the Institute of Nuclear Physics to honour his name by formingthe M. Mifsowicz Centre for High Energy Physics in Krakow.

In 1993, the research in the Department continued to cover a variety of problems of expe-rimental and theoretical high energy elementary particle physics: hadronic and leptonic inte-raction with nucleons and nuclei, mainly characteristics of particle production, including heavyquark physics, e+e~ interactions and tests of the Standard Model (also evaluation of radiativecorrections), ultrarelativistic heavy ion interactions and search for the quark-gluon plasma, aswell as spectra, composition and interactions of high energy cosmic ray particles. Research anddevelopment of apparatus for high energy physics experiments at future accelerators such asLHC or RHIC were also carried out.

The experiments in which the Department participates are mainly carried out within theframework of large international collaborations formed at leading laboratories where large ac-celerators have been or will be constructed: the European Centre for Nuclear Research CERNin Geneva, DESY in Hamburg, Brookhaven National Laboratory and Fermilab, Batavia in theUSA, with relatively more engagement in European laboratories. In 1993 this work brought thepublication of further very interesting results from the e+e~ experiment DELPHI at CERN andgave first physics results from the e~p experiments HI and ZEUS at DESY. Important results

140

which the reader can find in the following pages have also been obtained by other experimentsand our theorists.

An important part of the activity of the Department was teaching and training of studentsboth from the University and the Academy of Mining and Metallurgy on the master's and PhDlevel. This is possible owing to the vicinity of the Department site to the university campus.

In addition to the staff listed above some task teams working on certain projects, e.g.DELPHI, ZEUS and the future ATLAS experiment also include people belonging to various de-partments of the Institute of Nuclear Physics and other institutions forming the M. Mie,sowiczCentre for High Energy Physics.

On December 31, 1993 the staff of the Department was 106, including 6 PhD students.

JProf. T. Coghen

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REPORTS ON RESEARCH: PL9601062

The DELPHI experiment at LEP 1

The DELPHI Collaboration 2

Kraków DELPHI group:P. Briickman, A. Budziak, Z. Hajduk, P. Jalocha, K. Korcyl, W. Krupiriski,

W. Kucewicz, T. Lesiak, J. Michałowski, B. Muryn, G. Polok, H. Pałka, K. Rybicki,M. Witek, A. Zalewska

physicists, engineers and technicians contributing to the project:A. Adamski, J. Błocki, M. Despet, A. Florek, B. Florek, K. Gałuszka, T. Gdański,

J. Godlewski, P. Gruszecki, W. Sosnowski, M. Stodulski, Z. Stopa, A. Strączek,M. Stręk, M. Turała

DELPHI (Detector for Electrons, Leptons, Photons and Hadrons Identification) is one offour multi-purpose detectors installed at the LEP accelerator at CERN. It serves to study e+e~interactions at the energies close to the mass of the Z° boson.

In 1993 LEP was working since May till November. During this time about- 800,000 Z° eventshave been collected by the DELPHI detector. Data corresponding to 16.3723 pb^1, 9.4294 pb'1

and 9.4753 pb—1 have been taken at the Z° peak, 2 GeV below the peak and 2 GeV above thepeak, respectively. It is expected that the Z° energy scan and high precision measurements ofthe beam energy performed this year should give a reduced error of 5 MeV for both the Z° massand the Z° width determinations. A total number of about 2,200,000 Z° particles has beencollected by DELPHI since the LEP startup in 1989 till the end of 1993.

The analysis of the data taken since 1990 till 1992 resulted in about 20 publications andin tens of conference contributions. They cover a wide range of physics: precise tests of theelectroweak interactions, search for new particles, e.g. Higgs bosons and excited quarks, tests

'work of Polish groups partially supported by the giant 2 09 63 91.01 of the State Committee for ScientificStudies

2Iowa State University, Ames, USA, Univ. Instelling Antwerpen, Wilrijk, Belgium, ULB-VUB, Brussels,Belgium, Univ. de l'Etat Mons, Mons, Belgium, University of Athens, Athens, Greece, University of Bergen,Bergen, Norway, Università di Bologna and INFN, Bologna, Italy, Collège de Prance, IN2P3-CNRS, Paris, France,CERN, CH-1211 Geneva 23, Switzerland, Centre de Recherche Nucléaire, IN2P3 - CNRS/ULP, Strasbourg,France, Institute of Nuclear Physics, N.C.S.R. Demokritos, Athens, Greece, Last, of Physics of the C.A.S.,Praha, Czechoslovakia, Università di Genova and INFN, Genova, Italy, Institut des Sciences Nucléaires, IN2P3-CNRS, Université de Grenoble 1, Grenoble, France, Research Institute for High Energy Physics, SEFT, Helsinki,Finland, Joint Institute for Nuclear Research, Dubna, Russian Federation, Universität Karlsruhe, Karlsruhe,Germany, Institute of Nuclear Physics, Krakow, Poland, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro,Brazil, Lab. de l'Accélérateur Linéaire, IN2P3-CNRS,Orsay, France, University of Lancaster, Lancaster, UK,LIP, Lisboa, Portugal, University of Liverpool, UK, LPNHE, IN2P3-CNRS, Universités Paris VI et VII, Paris,France, University of Lund, Lund, Sweden, Université Claude Bernard de Lyon, IPNL, IN2P3-CNRS, France,Universidad Complutense, Madrid, Spain, Univ. d'Aix - Marseille II - CPP, IN2P3-CNRS, Marseille, France,Università di Milano and INFN, Milan, Italy, Niels Bohr Institute, Copenhagen, Denmark, Charles University,Praha, Czechoslovakia, NIKHEF-H, Amsterdam, The Netherlands, National Technical University, Athens, Greece,University of Oslo, Oslo, Norway, University of Oxford, Oxford, UK, Università di Padova and INFN, Padua,Italy, Pontificia Univ. Católica, Rio de Janeiro, Brazil, Rutherford Appleton Laboratory, Chilton, UK, Universitàdi Roma II and INFN, Rome, Italy, Centre d'Etude de Saclay, France, Istituto Superiore di Sanità, INFN,Rome, Italy, Universidad de Santander, Santander, Spain, Inst, for High Energy Physics, Serpukow, RussianFederation, University of Ljubljana, Ljubljana, Slovenia, University of Stockholm, Stockholm, Sweden, Universitàdi Torino and INFN, Turin, Italy, Università di Trieste and INFN, Trieste, Italy, Università di Udine, Udine, Italy,University of Uppsala, Uppsala, Sweden, IFIC, U. de Valencia, Valencia, Spain, Institut für Hochenergiephysik,Österr. Akad. Wissensch., Vienna, Austria, Inst. Nuclear Studies and University of Warsaw, Warsaw, Poland,University of Wuppertal, Wuppertal, Germany.

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of quantum chromodynamics, studies of the quark hadronisation processes. A growing interestin heavy flavours physics could be observed. Almost a half of the DELPHI publications andconference contributions in 1993 concerned the latter topics. The Krakow group participated intwo studies of baryons containing the 6 quark, namely the Aj, and the H(>. They are discussedbelow as separate contributions.

Apart from the data analysis, the Krakow DELPHI group has helped during the data tak-ing period and was co-responsible for three subdetectors: the Microvertex Detector, the InnerDetector and the Ring Imaging Cherenkov detectors (RICH).

The data acquisition, the safety of the detector, the quality of the data and the data process-ing had to be controlled during runs. The Krakow group had more than 50 shifts, participatingin first three kinds of controls.

Last year was crucial for the Microvertex Detector. An almost completely rebuilt detectorshould be installed in the experiment in 1994. This is a part of an even bigger upgrade forseen in1995. The Krakow group has contributed to the Microvertex project by testing some of silicondetectors, building reinforcement bars for one of its layers, working on the data acquisition andthe online analysis programs and working on the detector simulation programs. The group tookalso part in running the actual Microvertex Detector and preparing it for the data taking. Adescription of.the detector upgrade and more informations concerning the work for it is givenbelow as a separate contribution.

The Inner Detector is a common responsibility of the DELPHI group from the NIKHEFInstitute in Amsterdam and of the Krakow DELPHI group. Our group was preparing both thedetector and the data acquisition programs for running, took shifts during runs and helped inthe calibration of the detector using collected data. The Inner Detector is very useful for studiesof the accelerator background. Results of these studies are described in a separate contribution.

In 1993 the Forward RICH detector has been completed and has been working with anefficiency of about 50 % averaged over the whole period of the data taking. The Krakow grouphas contributed by helping in preparations of the detector for runs, by working on the detectorprograms and the data and by building the special setup for tests of elements of the RICHdetectors outside the experiment. The Forward RICH detector is presented below in a separatecontribution.

Measurement of A& production and lifetime in Z° hadronicdecaysT. Lesiak

This analysis was devoted to a study of the production rate as well as of the lifetime of the A&baryon. Its results have been presented at the XXVII International Conference of High EnergyPhysics in Marseille [1] (August 1993) and are intended to be published in Physics Letters B.Part of the analysis was done in Krakow as the continuation of earlier study based on a smalleramount of data [2].

The A(, particle, made from the u, d and 6 quarks is believed to be the lightest of baryonscontaining the b quark. Better knowledge of its properties would provide deeper understandingof the quark fragmentation and of the weak decay of the b quark. The Aj, candidates weresearched for demanding two high-momentum particles from its semileptonic decay: the leptonitself (with p\ > 3 GeV) and the A0 (with p^ > 4 GeV), where the baryon number of thelatter was opposite to the charge of the former (the so called right-sign pairs; by wrong-signpairs we understand pairs with the same sign of the lepton charge and the baryon number of A0).Due to large mass of the b quark only leptons with high transverse momentum (pf > 0.6 GeV)with respect to the jet containing the lepton and A0 were selected.

143

This study needed tracking devices of the DELPHI detector (the microvertex, the innerdetector, the time projection chamber, the outer detector and the forward tracking chambers)and the RICH detectors used to identify protons from the A° decays.

The data taken between 1990 and 1992 amount to a total number of 1 134 000 hadronicevents. Lepton detection was based on the muon drift chambers and on the high-density projec-tion chamber. Muons and electrons were selected with the efficiences of (90±l) % and (80±3) %,respectively. A0 hyperons were tagged by their decay into proton and pion yielding secondaryvertices formed by pairs of oppositely charged particles. A sample of (2000 ±43) A0 —• pir decaysfor the A0 momentum greater than 4 GeV has been collected. The selection efficiency of A0 wasfound to be equal to (16 ± 3) %.

Selected leptons and A0 baryons were then coupled demanding that the invariant mass ofthe lepton-A0 pair was between 2.0 and 6 GeV. This was intended to get rid of the backgroundcoming from the semileptonic decays of B meson and of the Ac baryon as well as from accidentalcombinations.

The (pir) invariant mass distribution for the right- and wrong-sign combinations for muonand electron channels, respectively are shown in Fig. 1. We observe an excess of (92 ± 15(stat.) ±15(syst.)) entries in the right-sign combinations (after subtracting the corresponding entries inthe wrong-sign combinations) in the range 1.106 GeV < M^ < 1.126 GeV. Prom this value

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and from the total efficiency of (3.8±0.9) % and (2.4±0.5) % for the muon and electron channels,respectively, we determine the product of the probability of the fragmentation of the 6 quarkinto A{, baryon and the branching fraction for the decay A& —• \°lviX as:

f{b -* A*) x BR(Ab -> A % X ) = (0.32 ± 0.06 ± 0.08) %

(this result is obtained assuming lepton universality; the results in the muon and electron chan-

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nels are 0.30 db 0.06 ± 0.08 and 0.35 ± 0.09 ± 0.09, respectively).The measurement of the A;, lifetime was based on the reconstruction of the secondary vertices

formed by the lepton, the A0 and particle of the opposite charge to that of the lepton (this particlewas assumed to be a pion resulting from the A+ -* A°n+X decay). The A& momentum estimateneeded to compute the lifetime from the measured decay length was obtained by the 'residual-energy' technique described in ref. [3]. For the lifetime analysis only the muon sample has beenused and 44 decays have been reconstructed out of 147 right-sign A°/i events. A maximumlikelihood fit to the lifetime distribution of these 44 decays resulted in the lifetime value forthe At of

rAfc = (0.68±S;|S ± 0.13) ps.

Thus the A;, lifetime is shorter than that of B mesons, for which r « 1.6 ps. This indicates thepresence of the W exchange diagram in addition to the spectator one.

References

[1] F. Bianchi, U. Gasparini, T. Lesiak, P. Zalewski: "Measurement of beauty baryons produc-tion and lifetime in in Z° hadronic decays", DELPHI 93-88 PHYS 192, contribution to theXXVII International Conference of High Energy Physics, Marseille, August 1993.

[2] DELPHI collaboration, "Measurement of A& production and lifetime in Z° hadronic de-cays", Phys. Lett. 31 IB (1993) 379.

[3] DELPHI Collaboration, "A measurement of B mesons production and lifetime using D-lepton events in Z° decays". Zeit. Phys. C 57 (1993) 181.

Production of the S& hyperon at LEPB. Muryn

The search of "beauty" baryons seems to be very important since it provides a knowledgeon the hadronisation mechanism and extends spectrum of known hadrons containing "beauty"quark b.

An observation of the the A baryon via its semileptonic decay and A°-lepton correlationswas a stimulation for a similar analysis of Ef, hyperons using mainly their semi-inclusive decays[1],

Here muon fi was emitted in b —» cpv transition and the charge symmetric reactions with E+

production were also investigated.We have looked for E±s decaying both inside and outside of the Vertex Detector (VD). In the

first case only the S± decay products could be measured by VD. In the second case the S± trackitself was searched for in VD. Tracks having three VD hits not associated with measurementsdone by other tracking detectors were considered as 3* candidates. In both cases the trackingdetectors outside the Vertex Detector provided measurements of the E^ decay products.

In the next step only events with lepton originating from Sj, decay were selected. This waspossible due to standard cuts on the energy and transverse momentum of leptons calculatedwith respect to the flight line of the 3^ baryon. Such a sample has been analysed and dividedaccording to two types of S^-lepton correlations. Events with S and lepton having the same

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1PL9601065

signs of the electric charge (right combination) were taken as good H& candidates, whereas thosewith opposite signs ( wrong combination) were considered to be a background. The comparisonof both samples shows that they are different (see Fig. 1, a and b). For the right chargecombination one can see a peak at the E* mass position (see Fig. 1 a). The corresponding massdistribution for the wrong charge combination (background) does not show such a property (seeFig. 1 b). This difference can be explained by E& hyperon production.

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References

[1] S. Plaszczynski, P. Roudeau, A. Stocchi (LAL Orsay)( B. Muryn (Krakow), Search forStrange-B baryon production at LEP, DELPHI 93-92, contribution to the XXVII Interna-tional Conference on High Energy Physics, Marseille, August 1993.

Upgrade of the Microvertex Detector

J. Blocki, P. Bnickman, T. Gdanski, J. Godlewski, P. Jalocha, W. Kucewicz,J. Michalowski, B. Muryn, H. Palka, A. Zalewska

The DELPHI Microvertex detector provides high precision measurements of track positionin the plane transverse to the beam. It evolved from a two layered detector installed for theDelphi start-up in 1990, to the three layered set-up with a smaller diameter beam pipe, inoperation since 1991 till now. Its ability to measure three points on a track precisely and closeto the primary vertex, is of great benefit in the reconstruction of tracks and vertices and enablesdetailed studies of heavy quarks and a r lepton. The present Microvertex detector measurestracks with polar angles above 45° with respect to colliding beams. The DELPHI Collaborationdecided in 1992 to increase tracking capabilities of the whole detector and to extend them downto small polar angles. These changes are vital in order to meet requirements of physics programof high energy phase of LEP (LEP200). The main physics motivation is to improve the b quarktagging capabilities and to increase the efficiency of the searches for Higgs bosons.

The modifications concerning the silicon tracker include :

• rebuilding of the Microvertex detector by replacement of single sided silicon detectors bydouble sided detectors allowing track reconstruction in space and an extension of the layersto cover polar angles down to 25° (the Forward Microvertex Detector or FMD)

• the addition of three layers of silicon detectors covering the angles between 15° and 25°(the Very Forward Tracker or VFT)

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The Krakow DELPHI group participates in the FMD part of the upgrade. The FMD projectproceedes in two stages. In the first stage, which will be ready for 1994 runs, the outermostlayer and the closest layer are being equipped with double sided detectors and the length of theclosest layer is extended from 22 cm to 28 cm. A schematic view of the FMD'94 is shown in aFig. 1. In the second stage (to be operational in 1995) , the middle layer will be equipped withdouble sided detectors and the length of both outer and inner layers will be extended from 24cm to 48 cm .

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The use of double sided detectors arranged in long layers required thorough tests and strictselection criterias to be applied on the quality of the detectors used. The selected detectors hadto pass acceptance criteria based on parameters of the detector which are vital for a performanceof the set-up. The criteria included limits on the total leakage current from the active area, thedepletion voltage, the coupling capacitance, the resistivity of polysilicon resistors, the numberof pinholes in in the coupling oxide and the number of defective channels in the active area.More than 100 detectors have been tested in four collaborating laboratories, and 30 of them inKrakow.

A special attention has to be paid to the mechanical construction of the detector, to achievethe precision close to the intrinsic precision of the silicon. The detector modules should be rigidenough and the amount of the material introduced by the construction should be minimal. Thesecond constraint is especially important in the case of the closer layer support because thislayer measures the first point on the track. The supports for the closer layer modules have beendesigned and constructed in Krakow. The stiffening of the modules was achieved via V-shapedkevlar beams which ensure the module deflection of 2.2 /xm per a gramm of load, while theadditional material constitues 0.1% Xo .

The hardware contribution of the Krakow group to the upgrade includes also redesign andconstruction of voltage supplies as well as participation in the assembly of modules.

In parallel to hardware efforts, we were active in a software development needed for the newdetector for data taking in 1994. The Monte Carlo simulation program has been adapted tothe new set-up, the database for the detector has been coded and the on-line software has beenchanged accordingly.

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The Synchrotron Radiation measurementsin the Trigger Layers of the DELPHI Inner Detector

Z. Hajduk, M. Witek

Trigger Layers (TL's) axe 5 cylindrical, concentric MWPC with 192 sensitive wires per planeand the cathodes made of solid copper foil of 17.5 /zm. The electronics can measure chargecollected by wires using FADC (flash-analogue-to-digital-converter) which samples input pulseevery 75 ns. Thus the electronics has some crude time measuring properties. Studying the oldliterature [1] on proportional counters sensitivity to gamma rays, we find that TL's are ideallysuited to photon detection (in X-rays range) having walls of relatively heavy material whichserves as converting medium for photons and being thin enough to allow knocked electronsescape into the gas volume.

LEP synchrotron radiation has critical energy of 100 keV with mean energy around 60 keV.We have used TL's as synchrotron radiation monitor to set absolute scale for Monte Carloprograms used by machine people to estimate the synchrotron radiation background.

The data have been taken at the end of physics run with stable beam conditions. We havetaken runs with fully random trigger running synchronously with LEP BCO changing positionof 8 m horizontal collimators. Data have been written to tape using the standard DELPHIdata acquisition system. To make the Inner Detector less sensitive to possible minimun ionizingparticles accompanying photons we have risen the proper thresholds in electronics in such waythat efficiency for MIP's has dropped to 20-25%. The detectors have been run on full nominalvoltages. We believe this arrangement to have good efficiency for photons since the ionizationshould be an order of magnitude higher than for MIP's.

Later the data have been analysed by standard Inner Detector monitoring program modifiedto be sensitive to pointlike events. We have estimated that the efficiency of our detector to X-raysin LEP region is around 0.2 % per layer. Once again, the boosting factor quoted in literature [1]for multilayer photon counter is estimated to be around 4 for five layers counter. Recently wehave used an EGS [2] program to evaluate the efficiency of our setup to X-rays by Monte Carlomethod. We have obtained a value of 1.2 % which is slightly higher than the previous one.This difference can be easily explained by the fact that the Monte Carlo method has taken intoaccount the real spectrum emitted by LEP and different incident angles of incoming photons.Thus for further calculations we have taken the value of 1.2% as Trigger Layers efficiency forsynchrotron radiation photons seen at TL's radii.

Figure 1 shows a comparison between measured and simulated [3] frequencies. The characterof changes is very well reproduced. The higher values of measured frequencies (exceeding thoseof Monte Carlo) can be attributed to the fact that the MC program has been using idealizedorbit which crosses magnetic field of the quadrupoles at 'zero' angle. The real orbit hardly doesthat and so the passage through quadrupoles consists another source of synchrotron radiation.

The timing properties of the Trigger Layers have been used to estimate the contributionto the background from various places along the beam pipe where photons can be scatteredand reflected. The measurement has been done with a single positron beam. Figure 2 showsthe results. 'DIRECT ' line indicates time of the photons arriving together with the beam(drift time in th TL's is around 150 nsec). Another line shows expected arrival time of thephotons reflected from the collimators laying 'downstream?. We see that appearing maxima ofthe spectrum correspond to different position of the reflecting collimator.

From the presented results we see that Trigger Layers proved to be very useful tool for themonitoring, calibration and timing measurements of synchrotron radiation background.

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PL9601067References

[1] E. Fünfer, H. Neuert - Zahlrohre und Szintillationzahler, Verlag G. Braun, Karlruhe 1946.

[2] The EGS4 - code system - W.R. Nelson et al. SLAC - 265 Dec 1985

[3] Georg von Holtey - Monte Carlo simulations of synchrotron background at LEP ( privatecommunication).

The FRICH detectorA. Budziak, A. Florek, B. Florek, J. Michalowski, G. Polok

FRICH (Forward (Backward) Ring Imaging Cherenkov) is a part of the particle identificationsystem of the DELPHI detector [1], [2]. It is used for a hadron identification over most ofthe momentum range up to 40 GeV/c by Cherenkov angle reconstruction. The RICH systemcovers almost the full solid angle. It consists of two end-cap detectors (together reffered toas FRICH) and a detector of cylindrical geometry in the central region, the Barrel RICH.Forward RICH covers the polar angles 15° < 0 < 35° and 145° < 0 < 165°. Geometry ofForward RICH is totally different from the Barrel RICH but exploited principles are exactlythe same. Cherenkov photons in Ultra Violet (UV) range from both liquid and gaseus radiatorsare detected by Time Project Chamber sensitive to single photons. The RICH counters arenot stand-alone instruments. They rely on tracking detectors for the determination of particlemomenta, as well as for the measurement of track coordinates. In the case of Forward RICH thenecessary particle tracking information is obtained from the forward tracking chambers. Up to0 = 20°(160°) central tracking detectors are contributing significantly to particle information.From the photon coordinates measured in the TPC plane, emission angles with respect to particletracks are reconstructed. For a given particle momentum, various mass hypotheses are testedagainst the observed number of photons and the distribution of Cherenkov angles of individualphotons.

Geometrically both (forward and backward) detectors are placed ±1720 mm from interactionpoint (front faces) and extend 940 mm along beampipe. The full description of the design ofthe detector and of its readout system can be found in the references [1], [2].

The Kraków group has a substantial contribution to the construction of the FRICH. Photondetectors (drift boxes), main vessels and support tubes were designed, prototyped and producedby the Kraków group. Our group has also been involved in a prototype work for the singlephoton sensitive TPC and many solutions found in Kraków are now in general use. Detailsconcerning the construction of these parts of the FRICH can be found in [2].

In 1993 the main hardware effort of the Kraków group was the production of a test drift boxfor the RICH detectors. The test box has been contracted in Kraków and then equipped andtested at CERN. This device simulates in a smaller scale one sector of the RICH detector. Itconsists of a photon detector, a pocket for the multiwire proportional chamber, a high voltagedegrader-vessel and a calibration system. A drift volume of the photon detector has a lenghtof 170 mm. It is closed by quarc windows, 5 mm thick. They enable a penetration of the UVphotons starting from a wave length of 160 nm. Dimensions of the pocket for the chambers havebeen adjusted to enable tests of the multiwire proportional chambers used in the experimentwith a full access to their preamplifiers. The calibration system provides the UV photons of aknown wave length in a region of the photon detector. Apart from the tests of the chambers thetest box will serve for studing different gas mixtures, drift velocities and calibration systems.

150

In 1992 one quarter of the FBICH was installed and took first data. In 1993 FRICH wasfully operational and data for about 400k Z° events were taken. Some preliminary results havebeen presented on a few conferences and schools ( e.g. Dallas 92, BARI 93).

The fact that the magnetic field (1.2 Tesla) in the Forward RICH is not parallel to the electricfield responsible for drifting and a conciderable background due to the secondary processesin a material of the end-plates of the barrel detectors seriously complicate the FRICH dataanalysis. Measurements of the resolutions in Cherenkov angle based on high energy muons fromthe reaction e+e~ —v fi+fi~ indicate both for liquid and gas radiators that values close to thesimulated prediction will be obtained once alignment and calibration procedures become perfect.In each of the two radiators media the number of detectable photons is about 8 for tracks at/3 « 1. In analysing multi-track hadronic Z° events in real data, the true particle identificationis in general unknown. Fig.l from [2] shows preliminary results of the data analysis for hadronicZ° decays, obtained with the liquid radiator. A clean separation between pions, kaons andprotons is realized. Obtaining a better calibration of the Forward RICH, a better alignmentand a more efficient reconstruction of charged tracks in the forward regions of DELPHI requirefurther studies. Solving these problems will allow us to really use the 1993 Forward RICH datafor the particle identification.

mean Cerenkov angle - liquid

Figure 2: Liquid radiator data: mean Cherenkov angle as a function of particle momentum. Theangles shown are the unambiguous result of a set of robustified least squares estimates. The fitused photons in a 5 <r band around each mass hypothesis.

References

[1] W. Adam,..., A. Budziak, A. Florek, B. Florek, K. Gahiszka, J. Michalowski, K. Pakonski,G. Polok, M. Stodulski, Z. Stopa, M. Turala et al., Performance of the Forward RICHDetector System at DELPHI - IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL.40, NO.4 AUGUST 1993, 583-588

[2] W. Adam,..., A. Budziak, A. Florek, B. Florek, K. Gahiszka, J. Michalowski, K. Pakonski,G. Polok, M. Stodulski, Z. Stopa, M. Turala et al., The Forward Ring Imaging Cherenkovdetector of Delphi, CERN-PPE/93-154, Nucl. Instr. and Meth. ...

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PL9601068

The HI Experiment at HERA

The HI Collaboration 1

During 1993 the HI experiment collected about 530 nb'1 of high quality data at electron-proton collider HERA in DESY/Hamburg. The data from 1992 corresponding to an integratedluminosity of 22.5 nft"1 has been analysed and the results presented in eleven publications [1]-[11], three of which were restricted to detector performance. In the next entry of this report wepresent results of the HI collaboration on the first measurement of the proton structure functionand soft parton distributions [6],[11] in the low x region. Also the topic of multi-jet rates indeep-inelastic scattering (DIS) will be covered [10].

Members of the HI Krakow group have participated in the analysis of data and significantlycontributed to activities of the following physics working groups:

• DIS working group

• heavy quark group

• radiative corrections group

They have also participated in the HI run shifts.The Krakow contribution to physics analysis and the HI detector upgrade covers several

topics:

• Preliminary studies of local parton density fluctuations ("hot spots") at low x, based onthe ideas of Muller [12], have started with the data collected in 1993. The clear signatureof the "hot spot" process is the production of a high energy jet in the particular kinematicregion. The event topology with the associated jet very close to the beampipe in the protonbeam direction represents a real experimental challenge. Using the simulated data, detailedstudies of the selection and identification criteria for this process have been performed. Thecontribution of beam induced and photoproduction background has been estimated. In therestricted kinematic region we observe in the 1993 data more jets indicating the Lipatovbehaviour than in Monte Carlo simulation. Prospects for tests of Lipatov behaviour inDIS and (with more statistics) a direct search for "hot spots" are very promising. Thisproblem was vividly discussed during a workshop (1-6.12.1993) organized in our instituteby the Department of Theoretical Physics and the Hi Krakow group. This workshopwas generally devoted to theoretical and experimental aspects of low x physics at HERA.Physicists from Krakow, DESY, Durham and Warsaw, participated in this meeting.

• The gluon distribution in proton at small x can be extracted from DIS data using themeasurement of heavy flavour production. The possibility of charm particles detection

'Krakow HI group: L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. MikockiyE. Mroczko, G. Nowak,K. Rybicki and J. Turnau.engineers and technicians contributing to the project: E. Banas, A. Cyz, B. Dulny, M. Dziadus, J. Godlewski andW. Janczur.Participating institutions: Antwerpen Univ., Univ. of Birmingham, Brussels Univ., CEN Saclay, Davis Univ.,DESY, Dortmund Univ., Ecole Polytechnique (Palaiseau), ETH (Zurich), Glasgow Univ., Hamburg Univ. (1.and 2. Institute), Heidelberg Univ., Inst. of Nuclear Physics (Krakow), Institute of Physics (Prague), Instituteof Experimental Physics (Kosice), DESY - Institut fur HEP Zeuthen, INFN Roma, Kiel Univ., Lancaster Univ.,Liverpool Univ., Lund Univ., Manchester Univ., ITEP (Moscow), Lebedev Physics Institute (Moscow), MPI(Miinchen), LAL Orsay, P.& M. Curie Univ. (Paris), Queen Mary and Westfield College (London), RWTHAachen (1. and 2. Institute), Rutherford Appleton Lab., SLAC (Stanford Ca), Wuppertal Univ., Zurich Univ.

152

by tagging an electron from their semileptonic decay has been studied. Electron identi-fication method based on electromagnetic shower characteristics in the HI liquid argoncalorimeter and dE/dx information from tracking detectors has been developed. Furtheroptimalization of the detection technique and studies of b quark decays are foreseen.

• In 1993 the LAL-Krakow project of the topological second level trigger has been pur-sued. The contribution of the Krakow group included Monte Carlo tests of the triggerefficiency, the upgrade of the trigger simulation program to real, working conditions of theHI detector, as well as the design and preliminary programming of the trigger monitorsystem.

Deep Inelastic Scattering at Low x

The data collected with the HI detector in 1992 during the first year of HERA running corre-spond to an integrated luminosity of 22.5 nb~l . The HI detector description can be found inthe previous Annual Report. The analysis of the neutral current deep inelastic e-p scattering(NC-DIS) allows the first measurement of soft parton distributions in proton [6],[11] and studiesof the hadronic final states [10].

At HERA, where 26.7 GeV electrons collide with 820 GeV protons, one can study NC-DIS ofan electron off the proton constituents carrying a very small fraction x of the proton momentum.For the first time values of the x Bjorken in the range x % 10~4 — 10~2 can be measured in the

DIS regime (Q2 > bGeV2). The proton structure function can be probed at distances which areten times smaller than those previously accessible in the fixed target experiments.

The kinematics of the inclusive neutral current reaction ep —y eX at fixed centre of massenergy y/s is determined by two variables usually taken as x, the Bjorken scaling variable andQ2, the negative four-momentum squared from the electron to the proton. According to therelation Q2 = sxy both are related via the relative energy transfer y. In the NC-DIS eventsthe final state consists of the scattered electron and the hadronic final state . The HERAexperiments simultaneously measure the scattered electron and reconstruct the hadronic finalstate therefore the kinematic variables can be determined using either energy and angle of thescattered electron or of the hadronic system or a combination of both. In this analysis the eventkinematics is calculated by two methods which are very different with respect to systematicuncertainties and therefore allow an important cross-check of the final result. In method I weuse the electron variables ( the energy and the polar angle of the scattered electron ) and inmethod II the mixture of the hadron measurement of y and the electron measurement of Q2.These methods differ substantially not only in the dependence on systematic effects but also inthe size of radiative corrections, in the event selection and in the accessible kinematic range of

This analysis is restricted to the low x region and to 5eV2 < Q2 < 80eV2. In the Q2

region under consideration the scattered electrons are detected in the backward electromagneticcalorimeter (BEMC). The events were triggered by requiring an energy cluster with more than4 GeV deposited in the BEMC and no time of flight veto from the scintilator hodoscope TOFinstalled behind the BEMC. In total we have recorded ss 5 X 105 events which are dominated bybeam-induced background and photoproduction. A clean sample of DIS candidates is selectedoffline using more stringent criteria on the scattered electron candidates, the suppression ofbeam induced and photoproduction background. The final data sample comprises about 1000events.

In the region of low Q2 (Q2 << M2) the cross section for NC-DIS is expressed in termsof the structure function F^ and the photoabsorbtion cross section ratio of longitudinally and

153

transversely polarized photons, R =

d2a

The ratio R(x, Q2) has not yet been measured at HERA and we have chosen R values accordingto the QCD prescription [13]. In the quark-parton model the structure function F2 can beexpressed in terms of parton distribution in the proton. The F2 values measured with the help ofmethod I and II are presented in Fig.l for two Q2 values, together with data points from the N-MC[14] and BCDMS [15] fixed target muon proton scattering experiments. The global systematicerror of 8% is not shown in the figure. Both methods give consistent results. The high x pointsagree well with the available fixed target data, giving a cross check of the absolute normalizationwith an accuracy of about 20%. A unique F2 in the full range of x and Q2 is obtained by takingF2 values with smaller systematic error. The x dependence of F2 is shown in Fig.2 for four Q2

values. We observe a clear rise of F2 with decreasing x. The Q2 dependence of F2 is shown inFig.3 for Q2 > 10eF2. For constant values of x, F2 increases slowly with Q2 in agreement withscaling violation expected from perturbative QCD. Similar results have been obtained by theZEUS collaboration. The F2(x,Q2) evolution at small x reflects the assumptions made on theshape and the evolution of the gluon distribution as the sea quark distribution at low x is drivenby the gluon density. Since the small x region is unexplored experimentally, extrapolationsof presently proposed parton distributions in this range vary rapidly. The measured structurefunction F2(x,Q2) in Fig.2 and 3 is compared to several structure function parametrizationfitted to recent low energy data. Our data are consistent with the GRV [16] and the MRSD-[17] parametrizations. For the GRV parametrization small x partons are radiatively generatedaccording to the Altarelli-Parisi evolution equations, starting from the "valence like" quark andgluon distributions at Qo = 0.3eF2. For MRSD- parametrization the small x evolution of thegluon density ( at Qo = 4eF2) is assumed to be singular with a characteristic x~x, A ~ 0.5behaviour ( Lipatov behaviour). The range of validity in x for the Lipatov behaviour is unknown.Both ( GRV and Lipatov type) parametrizations predict large densities of gluons in the region ofsmall x. If F2(x, Q2) grows sufficiently fast at low x, HERA will allow to test QCD in the domainof high parton densities, where the new effects such as screening and saturation may becomedetectable. Assuming validity of Altarelli-Parisi evolution equations in our kinematic range andneglecting the quark contribution in this evolution, we have extracted a first estimate of thegluon distribution in the proton at small x (Fig.4). The experimental estimate of the gluondistribution G(x,Q0), at Qo = 20eF2, rises with decreasing x. The observed x dependence,with large experimental uncertainty, is consistent with the expectation based on the Lipatovevolution. The search for the new QCD effects, such as screening and saturation, damping thefast increase of the parton density may be possible with further accumulation of high qualitydata at low x. One could assume that the large gluon density increase does not develop uniformlyover the full transverse size of the proton, but is localized instead in small regions, the so called"hot spots". For the hot spots we expect large saturation effects that may become detectable atHERA. The search for hot spots of soft partons is a great experimental challenge with interestingtheoretical consequences and will be studied with the HI data.

The analysis of the hadronic final states for values of Q2 up to 500 GeV2 and in the rangeof the invariant mass W of the hadronic system between 70 and 230 GeV has been performed.The detailed description of the event selection and background suppression can be found in [10].Multi-jet production in this new kinematic region of DIS has been observed (Fig.5). The jetswere reconstructed using the JADE algorithm, requiring jet-jet masses above 10 GeV or more(depending on W). Between 10% and 20% of events contain 2+1 jets (2 high pt jets and protonremnant). The data are in good agreement with QCD expectations, especially with the MEPSmodel based on first order matrix elements and additional parton shower evolution describes

154

the jet characteristics in satisfactory way without any further adjustment of parameters.

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Figure 1: Measurement of F2(x,Q2) for two values of Q2. The full circles correspond to methodII (mixed variable measurement). The error bars show statistical and systematic errors inquadrature. In addition all points have a normalization uncertainly of 8%. Data points of thefixed target muon-proton scattering experiments NMC and BCDMS are shown for comparison.

9* = t.S CtV , «* = is c«v*

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Figure 2: The measured structure function F2(x,Q2) for different values of Q2, compared toseveral structure functions parametrizations which are fitted to recent low energy data. Theerror bars show statistical and total errors obtained by adding the statistical and systematicerrors in quadrature. In addition, all poits have a normalization uncertainty of 8%.

155

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156

Q* < SO GcV1.0

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MEPS recon.- - MEPS hadrons .

MEPS pertonj

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rTrnrrn. (1-1) ;cl»• (2-1) jets» (S3-1) jol$- MEPS recon.

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Figure 5: Functions of N + 1 jets (Rjv +1) vs the cut variable of the jet algorithm for 12<Q2 <80GeV2 (bd) compared in a), b) with simulation with MEPS at the detector level, at the hadronlevel and at the parton level, and in c), d) to predictions from the QCD based model.

References

[1] HI Collab., T. Ahmed et al., Phys. Lett. B298 (1993) 469-478[2] HI Collab., T. Ahmed et al., Phys. Lett. B299 (1993) 385-393[3] HI Collab., T. Ahmed et al., Phys. Lett. B299 (1993) 374-384[4] HI Collab., I. Abt et al., Phys. Lett. B314 (1993) 436-444[5] HI Collab., I. Abt et al., Nucl. Phys. B396 (1993) 3-26[6] HI Collab., I. Abt et al., Nucl. Phys. B407 (1993) 515-535[7] HI Calorimeter Group., B. Andrieu et al., DESY preprint 93-047 (1993)[8] HI Calorimeter Group., B. Andrieu et al., DESY preprint 93-078 (1993)[9] HI Collab., I. Abt et al., DESY preprint 93-103 (1993)

[10] HI Collab., I. Abt et al., DESY preprint 93-137 (1993)[11] HI Collab., I. Abt et al., DESY preprint 93-146 (1993)[12] A. H. Muller, Nucl. Phys. B (Proc. Suppl.) 18C (1990) 125[13] G. AltareUi, G. Martinelli, Phys. Lett. 76B (1978) 98[14] NMC Collab., P. Amandruz et al., Phys. Lett 295B (1992) 159[15] BCDMS Collab., T. Ahmed et al., Phys. Lett. 298B (1993) 485[16] M. Gliick, E. Reya and A. Vogt, Z. Phys. C53 (1992) 127

M. Gliick, E. Reya and A. Vogt, Phys. Lett. 306B (1993) 391[17] A.D. Martin, W.J. Stirling, R.G Roberts, Phys. Lett. 306B (1993) 145, ibid. 309B (1993)

492

157

f I

The HEGRA experiment PL9601069

The HEGRA (High Energy Gamma Ray Array) detector is a ground-based array for thedetection of ultra high energy cosmic radiation 2. It is located at Roque de los Muchachos (2240m altitude) at La Palma island (Canary Islands, Spain). During 1992-1993 the collaboration hasinstalled a novel type of air Cerenkov detector matrix, named AIROBICC. The matrix consistsof hemispherical, 20 cm diameter photomultipliers observing light disk from extended air showerswith angular acceptance of 1 sr. The incident shower direction is determined with high precisionfrom the individual timing signals due to very sharp time definition of the light front and thelarge diameter of the Cerenkov light disk. The radial light structure contains information ofthe shower developement as a function of altitude. In 1993 first performance results from a 7x 7 submatrix were obtained Data from the first run period have shown that the most of theexpected performance has been achieved 3 and confirmed basic predictions of Monte Carlo airshower simulations 4. Fig. 1 shows the time structure of the particle cloud and of the Cerenkovlight for the same shower. As predicted one observes for the light front a much more reducedtime spread.

The physicists from Institute of Nuclear Physics participated in Monte Carlo simulationsand in studying 7-hadron discrimination possibilities of AIROBICC detector 5.

1 1 2

§ 1 0

c

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Fig. 1: Time structure of the particle cloud and the Cerenkov light of an air shower 3.1M. Rozariska in the collaboration with Universities of Hamburg, Kiel, Madrit, Wuppertal, Max-Planck Insti-

tute for Physics and Astrophysics - Munich and Institute of Physics - Yerevan.2F. Aharonian et al., Status and upgrade of the HEGRA air shower experiment at La Palma, Proc. XXIII

ICRC 4 291 (1993).3A. Karle et al., First Running Experience with the Novel Wide Angle Air Cerenkov Matrix Detector AIRO-

BICC, Proc. XXIII ICRC 4 666 (1993).4S. Martinez et al., Monte Carlo simulation of the HEGRA array performance, Proc. XXIII ICRC 4 742

(1993).SF. Arqueros, S. Martinez and M. Rozariska, 7/proton discrimination in cosmic rays (1013 — 1016eVr) using

EAS information from electrons and air Cernkov light, Proc. XXIII ICRC 4 738 (1993).

158

The ACCMOR collaboration(NA32 experiment terminated in 1986)

PL9601070

A study of A+ decays into pK ?r+, pK 7r+7r° and pK 7r+7r°7r°Amsterdam-Bristol-CERN-Krak6w6-Munich-Rutherford-Valencia collaboration

The paper7 is based on the results of a high-precision charm experiment performed at theCERN SPS. The experiment used a negative 230 GeVjc beam and a 2.5mm Cu target. Charmdecays were reconstructed with a sophisticated silicon vertex detector and a large-acceptancespectrometer. We have collected a clean sample of 121 A+ —• pK~ir+ decay vertices8 and wehave studied the effective mass distribution of the subsystems pK~, pr+ and K~TT+ . A jointfit to these distributions yielded the subresonant structure of pK~ir+ state. The results areshown in Table 1, in which the subscript "nr" denotes the non-resonant i.e. the genuine three-body decay and the branching ratio for the second channel has been corrected for the unseenK*°(S92) -> K°K° decay mode.

In the same experiment we have observed some secondary pK~T+ vertices with a visiblemass mvia below the A+ mass m\. In order to separate statistically the channels with variousnumbers of neutral secondaries, we have used the neutral mass mo defined as:

where p"" is the visible transverse momentum with respect to the direction of the parent A+.A joint fit to mvi, and m0 distribution yielded fractions of events with one, two or even three7r°'s in the final state. The results are also listed in Table 1.

Table 1: Branching ratios with respect to the total A+ —» pK x+ channel

Final state(PK-T+)nT

PK*°(S92)A++(1230)iir-A ( 1 5 2 0 ) T T +

pK-ir+T0

pK-TT + TT0*0

ptf-Tr+TrW0

No of events70.5+?^

38.8±S"g14.0±|-»11 q+47

ii-y-3.866.6 ±6.415.0 ±6.98.4 ±4.6

Branching ratio0.56^;^ ± 0.050.351°•{£ ± 0.030.1212;°* ± 0.050.091°;^ ± 0.02

0.73 ±0.12 ±0.050.16 ±0.07 ±0.030.10 ±0.06 ±0.02

6A. Boiek (Ph.D thesis), Z. Hajduk, H. Palka, K. Rybicki and M. Witek7Physics Letters B 311 (1993) 2478A particle symbol stands for particle and antiparticle i.e. any reference to a specific state implies the charge-

conjugate state as well

159

1PL9601071

Spin Alignment of Z>*+(2010) Mesons Producedin 230 GeV/c TT'CU Interactions

K. Rybicki and R. Rylko9

The paper10 is also based on the results of the ACCMOR collaboration which collected aclean sample of 127 D*+(2010) -* D°ir+xi decays11 with a subsequent D° decay into K~w+ orK~ir+ir+ir~. The D° decay vertices were reconstructed in a sophisticated silicon vertex detectorand in a large-acceptance spectrometer with a good hadron identification.

The angular distribution of the D*+ decay has been fitted to the form:

where 0 is the angle between the D*+ momentum in the laboratory frame and the ir*xt momen-tum in the D*+ rest frame, while r\ is the D*+ alignment parameter. The fit to the angulardistribution yields for the whole sample:

± °-01

The spin alignment is consistent with zero for such Feynman x and transverse momentum cutsas were possible in our sample. This is the first result on the spin alignment of hadronicallyproduced charmed mesons. It has been used to test the statistical approach to spin countingsuggested by Donogue12. This approach gives a simple relation between the spin alignmentparameter and the production cross sections of vector and pseudoscalar mesons. The resultshown in Eq.(3) corresponds to:

,°}r+\n^ = 0.83+g-iJ ± 0.01<T{D*+) + <r{D+) ~° 10

while the direct measurement performed in the same experiment13 yields 0.47 ± 0.11. Thus thestatistical approach, shown to be successful in e+e~ interactions, appears to fail in hadronicproduction.

'Now at Queen Mary and Westfield College, University of London.10Acta Physica Polonica B 24 (1993) 1049.11A particle symbol stands for particle and antiparticle i.e. any reference to a specific state implies the charge-

conjugate state as well."Physical Review D 1£ (1979) 2806."ACCMOR collaboration, Z. Phys. C 5 (1991) 555.

160

PL9601072

ATLAS experiment at LHC1

FromlNP Krakow: J. Błocki, J. Chwastowski, A. Czermak, S. Gadomski, J. Godlewski,Z. Hajduk, W. Iwański, M. Kajetanowicz, J. Kapłon, K. Korcyl, P. Malecki, Z. Natkaniec,

A. Moszczyński, J. Olszowska, W. Ostrowicz, A. Sóbala, M. Tárala, A. Wolak

The ATLAS collaboration is a group of more than 80 institutes and universities2 preparing anexperimental programme and a large spectrometer for the studies of proton-proton interactionsat energy of 14 TeV (center of mass) at the LHC accelerator at CERN [1]. The Kraków groupsfrom the Institute of Nuclear Physics and the Faculty of Physics and Nuclear Techniques aretaking part in this programme. The preparatory works include:

• simulation studies of physics processes, designing of the spectrometer and simulation ofits performances, prototyping work on detectors, electronics and programing,

• participation at CERN R&D programme on development of detectors for LHC experi-ments, in particular in the following projects:- RD6 "Integrated high-rate transition radiation detector and tracking chamber for theLHC" [2],- RD11 "Embedded architecture for second level-triggering in LHC experiments (EAST)"[3],- RD20 "Development of high resolution Si strip detectors for experiments at high lumi-nosity at the LHC" [4],- RD28 "Development of gas micro-strip chambers for high radiation rate detection andtracking" [5].

References

[1] ATLAS Int. Note, GEN-NO-004, March 1993[2] CERN/DRDC/90-38, CERN/DRDC 91-55 (Oct. 1991), CERN/DRDC/93-46 (Nov. 1993)[3] CERN/DRuC/gO-oô, CERN/DRDC 92-11 (March 1992),[4] CERN/DRDC 91-11, CERN/DRDC 92-28 (May 1992), CERN/DRDC 93-30 (Aug. 1993)[5] CERN/DRDC 92-30 (1992), CERN/DRDC/93-34 (Aug. 1993)

'Work supported in part by Polish State Committee for Scientific Research, grants 2 0906 91 01 and 115/E-343/SPUB-206/93

2Univ. Alberta, Inst. Alma-Ata, NIKHEF Amsterdam, LAPP Annecy, ANTU Athens, Athens Univ., Univ.Barcelona, HEP Lab. Bern, Univ. Bermingham, Univ. Bratislava, Cambridge Univ., Univ. Clermont-Ferrand,NBI Copenhaghen, Univ. Calabria, INP Krakow, FPNT Krakow, INR Debrecen, Univ. Dortmund, Univ.Edinburgh, Florence Univ., INFN Frascati, Freiburg Univ., CERN Geneva, Univ. Geneva, Univ. Glasgow,IN2P3-CNRS Grenoble, IIT Haifa, Univ. Hamburg, Univ. Heidelberg, SEFT Helsinki, Innsbruck Univ., Univ.Jena, Kobe Univ., IEP Kosice, Univ. Lancaster, LIFEP Lisbon, Univ. Liverpool, QMWC Univ. London,RHBNC Univ. London, Univ. College London, Lund Univ., Univ. Madrid, Manchester Univ., Mannheim Univ.,CPPM Marseille, Meulbourn Univ., Milan Univ., Univ Montreal, ITEP Moscow, FLAN Moscow, MEPI Moscow,Moscow Univ., Univ. Munich, MPI Munich, Univ. Neijmegen, LAL Orsay, Oslo Univ., Oxford Univ., ParisVII Univ., Pavia Univ., Pisa Univ., Prague Univ., LHEP Protvino, Univ. Rio de Janeiro, Univ. 'La Sapienza'Rome, Univ.'Tor Vergata" Rome, RAL Lab., DAPNIA Saclay, CST Saratov, Univ. Sheffield, Siegen Univ., MSIStockholm, Stockholm Univ., IFMO St. Petersburg, NPI St. Petersburg, ANSTO Sydney, Tel-Aviv Univ., Univ.Tokyo, Univ. Uppsala, Univ. Valencia, Univ. Vancouver, Univ. Victoria, IHOAW Vienna, WIS Rehovot, Univ.Wuppertal.

161

B-physics in ATLAS

S. GadomskiPL9601073

Collider experiments at LHC will be able to see large numbers of bb events. Due to thehigher center of mass energy the signal-to-background ratio is more favorable then in fixedtarget experiments, <r(bb)/<r(tot) ~ 1/100. High cross-section for 66 production allows to study6-quark decays at luminosities of the order of 1033cm~2s -1 , during the initial period of the LHCoperation. One year (107 s) of such luminosity will give 1.7 X 1010 events including the triggerefficiency.

Thanks to the large number of registered events it will be possible to study interesting andrare 6-quark decays. One example is a B% —• TT+IT~ decay, which displays the violation of the CPsymmetry. This decay channel provides a good independent test of the theory which describesthis fundamental phenomenon. The efficiency of the ATLAS detector for recording B° —* TT+TT"

has been studied [1]. Using the ATLAS vertex detector it is possible to select charged particlepairs which come from the B-decay. Combinatorial background, very large without secondaryvertex reconstruction, is reduced to a negligible level. The remaining background comes mainlyfrom the other two-body B decays, such as Ba

d -> K+ir~, B° -> K+ir~ and B° -> K+K~.This background can not be reduced by means of secondary vertex reconstruction. One yearof operation at low luminosity should bring of the order of 3100 signal events. With a totalbackground of around 8200 events it is possible to measure the asymmetry in B-decays andprovide an independent measurement of CP-violation [2].

1

Figure 1: Reconstructed (TZ+T ) mass for signal (dark region) and signal plus background (whiteregion).

References

[1] S. Gadomski, P. Eerola, N. Ellis, D. Froidevaux, Workshop on B Physics on Hadron Accele-rators, Snowmass, Colorado, June 21-July 2, 1993

[2] The ATLAS Collaboration, CERN/LHCC/93-53, 15 October 1993.

162

PL9601074

A Vertex Detector for LHC Experiments

J. Blocki, S. Gadomski, J. Godlewski, M. Turala, A. Wolak

The prime goal of experiments at the LHC will be to search for Higgs particles and otherexotic phenomena, but this accelerator will produce also large quantities of particles containing6and i-quarks. Such processes will represent a substantial background for Higgs search however,on the other side, they are interesting on their own. Due to the finite lifetime of B mesons,b and <-jets will be characterised by the separation from primary interaction point and as suchcould be identified with the help of a precise vertex detector.

The ATLAS group has recognised the potential of heavy flavours tagging right from thebegining: a conceptual design of the central part of the ATLAS Inner Detector includes highprecision tracking layers made out of silicon microstrips and pixels - Fig. 1 [1]. On the otherhand it was also clear that severe operational conditions at the LHC (very high radiation levels)will require new detectors and electronics (special RfeD programme) and that, in addition, somecompromises will be necessary between performances and the lifetime of the detector.

400 800 BOO 1000

Figure 1: Conceptual design of the ATLAS vertex tracker.

Several simulation studies have been done to understand better the influence of the geometry,detector parameters and the amount of material on the impact parameter resolution of a vertexdetector - Fig. 2 [2]. From these studies as well as from the general analythical considerationsa few strong recommendations follow:- the first detector layer has to be very precise and it shall be placed as close as possible to theinteraction point (beam line),- the amount of material of the first detector layer (and a beam pipe) shall be kept at minimum,- the angular accuracy of the whole tracking system should be very high (of the order of hundredsmicroradians) to allow for high precision extrapolations.

Using such constrains the Krakow group has proposed a gas cooled silicon strip vertexdetector for LHC, which could replace pixel detectors - Fig. 3 [3]. The design is based on60 x 60 mm2 detector units with 50 /«n readout pitch assembled into self supporting "bridges".The power dissipated by the readout electronics (2 mW/channel) can be effectively cooled by thegasous helium (the temperature uniformity of the order of a few °C can be reached). Accordingto our judgement such solution minimises the mass of the detector.

163

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878 195

Figure 3: Conceptual design of gas cooled silicon strip vertex detector (a.) and a single detectormodule (b.).

Recently a new layout for barrel part of the ATLAS Inner Detector has been presented [4];it includes a vertexing layer at the radius of 6 cm from the beam pipe. The performance of suchsolution would be superior against the ones proposed up to now but the lifetime of detectorsand electronics will be limited to a few years. However that period of time will be sufficient toaccumulate a significant number of interesting physics events so the construction of this detectoris justified.

References

[1] The ATLAS Inner Detector, ATLAS Int. Note, GEN-NO-004, March 1993[2] J.-C. Chollet, S. Gadomski at al, ATLAS Int. Note, PHYS-NO-019, May 1993[3] J. Blocki, S. Gadomski, J. Godlewski, K. Pakonski, M. Turala; Presented at Int. Symposium

on Silicon Detectors, Hiroshima, May 1993[4] S. Gadomski, S. Roe and P. Weilhammer; ATLAS Int. Note, INDET-NO-035, Nov. 1993

164

PL9601075

Development of silicon detectors and VLSI electronicsRD20 Collaboration

From Krakow: A. Czermak, P. Grybos, W. Dabrowski, M. Idzik, J. Kaplon,M. Kajetanowicz, S. Moszczyriski, A. Skoczen, M. Turala

The Krakow group is involved in designing and testing of silicon microstrip detectors andVLSI electronics for RD20 collaboration [1]. Last year the Krakow group has continued inves-tigating of test structures designed within this project [1], [2], [3].

To be able to explain some of the experimental observations the ToSCA (Two-dimensionalSemiconductor Analysis) simulation program has been lernt and applied. Fig. 1 obtained bymeans of using ToSCA shows electron and hole densities near the Si/ SiOi interface of n-sidedetector (a simple model of one-strip detector was used). One can see accumulation layer ofelectrons interrupted in neighbourhood of strip edges by field plates potential and inversion layerof holes in the same region.

Elektronendichte Loecherdichte

Figure 1: Electron and hole densities.

Some of the n-side detector test structures (with field plate strip isolation) have been irra-diated with 7 rays from mCo source at the Institute of Oncology in Krakow. The electricalparameters of these test structures, before and after irradiations, have been measured with thehelp of an Alessi probe-station, HP4145B Semiconductor Parameter Analyser and HP4284ALCR Meter. Some unexpected results on leakage currents have been observeed. The ToSCAprogram was used to explain the observed behaviour of the detectors [3].

The contribution of Krakow group to development of RD20 electronics [4], [5] and coolingsystems [6] is reported elsewhere.

References

[1] RD20 Status Report , CERN/DRDC 93-30[2] S. Moszczynski, M. Turala, et al., CERN/PPE/93-137, Submitted to Nucl. Instr. and

Meths.S. Moszczynski, et al., RD20 Technical Note TN/25A. Czermak, M. Kajetanowicz, J. Kaplon, S. Moszczynski, et al., RD20 Technical NoteTN/23

[5] M. Kajetanowicz, J. Kaplon, RD20 Technical Note TN/24[6] J. Blocki, J. Godlewski, K. Pakonski, RD20 Technical Note TN/26

165

Transition radiation tracker

ATLAS, RD6 and R D l l CollaborationsPL9601076

From Krakow: K. Cetnar, G. Ciechanowska, Zb. Hajduk, St. Jagielski, P. Jurkiewicz,B. Kisielewski, A. Kotarba, P. Malecki, Zb. Natkaniec, J. Olszowska, W. Ostrowicz

A considerable activity of physicists and engineers from our Institute concerned the researchand development project of the transition radiation datector, the important part of the futureInner Detector of the ATLAS experiment. The work concentrated on three subjects: the designand construction of the test system for the readout electronics, the design and construction ofthe second level trigger model system and on the analysis of the data collected during the testrun of the TRT prototype.

SECOND LEVEL TRIGGER FOR TRT DETECTOR.We have contributed to the hardware design and construction of a level two trigger system

for Transition Radiation Tracker [1]. The system has been based on special commercial imageprocessor (Max-Video) [2] running feature extraction algorithm (feature - a physical variableon which a trigger decision is based). The algorithm [3] was based on histogramming techniquewhich was looking for an absolute maximum on the event image in the detector. In collaborationwith CERN and the Weizmann Institute we have designed and build two parts of the system.The general configuration is presented on the Fig. 1. We have constructed, debugged and finalyrun the HIPAD [4] interface and DATA COLLECTOR.

Tl

Daisfas fflPJL ROUTER DAQ

HIPP!

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Mix-Videoteotu*

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Figure 1: Structure of the second level trigger system for TRT

Presented structure has been sucessfully tested with the TRT prototype detector during '93autumn test run at the SPS accelerator.

TEST SYSTEM FOR FRONTEND TRT ELECTRONICS.We have built and run a test system for TRT frontend electronics, called 'daughter boards'

(ROB - on the Fig. 2). One board covers 32 channels of the detector. It contains the analoguepart, set of discriminators, the digital communication electronics and the slow control part usedfor card initialisation and control. All electronics is build with ASICs to minimise the space.

Our test system hardware was build in the VME standard. The control software (devicedrivers, application programs) has been written for the OS-9 environment. The test system iscomposed of following blocks (see Fig. 2):

• analogue switch and control ('analog card')

• read-out unit - the heart of the system ('readout card')

166

• slow control board (built by MPI-Munich; 'TRDS controller')

Figure 2: Test system for frontend electronics of TRT detector.

The system allows to test functionality of the cards and perform their calibration. Parame-ters, like pedestals, offsets, noise, crosstalks can be adjusted. A software based on pulled downmenus has been written to make the tester operational. The results are presented in tables orhistograms form.

TEST RUN OFF-LINE DATA ANALYSIS.

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167

PL9601077

The TRT detector prototype has been tested at the SPS electron and pion beams in the fall1993. The data collected during this run have been analysed by us and the preliminary resultspresented at the RD6 collaboration meeting in Dec. 93. The analysis allowed for the test of thereadout channels efficiency, overall DAQ functional test as well as for some analysis of the trackreconstruction and electron/pion identification efficiency.

The track reconstruction efficiency was satisfactory and the pion/electron rejection factor -due to the TR (transition radiation) effect - has been estimated at the value about 5.

References

[1] Status Report CERN/ DRDC/ 93-46.

[2] MaxVideo hardware reference manual - DATACUBE, Inc August, 1992.

[3] A. Gheorge, Z. Natkaniec et al, EAST note # 92-17 CERN May 92.

[4] fflMAX - User Manual L. Levinson, Z. Natkaniec et al, EAST note #93-04.

Modelling of local/global architectures for second leveltriggering at the LHC experiment

R D l l Collaboration

From Krakow: Z. Hajduk, W. Iwanski, K. Korcyl

A local/global architecture for a second level trigger has been chosen for modelling [1]. Theproposed architecture is based on a FEAST concept [2]. The basic building block of the proposedsystem contains one or two TMS320C40 processors serving as a feature-extractor (feature - aphysical variable on which a trigger decision is based) and a boards-manager. In case of oneprocessor both tasks are performed by single processor This particular piece of hardware hasbeen chosen due to its computing power and 6 communication links which can support highspeed data transfers between different processors. Former studies [3] shown that the data fromevents accepted by level-1 trigger should be stored on the FEAST board i.e. data are transferredfrom the front-end electronics to the T2-bufFer immediately after every positive Tl decision.

The boards can communicate and exchange the data via links provided by level-2 triggerprocessors. In such a way a 'sliding window' can be formed in order to cover fully the Re-gion_of_Interest i.e the detector part where level-1 trigger gave positive notation. The fullsystem will form a 'mesh' covering the surface of detector.

The other links of the processors serve as communication pathes with global part of thesystem, the read-out and connection to the third level.

We have used as modelling tool a MODSIM II [4] 'object oriented' language. The boardcomponents has been constructed as objects having some limited resources which could havebeen granted only to one event in a given time instant. In such a way a queing of events isrealised. Then within one object the resources have different priorities and demand for freeresource of higher priority can interrupt an action of the resource currently used, thus theinterrupt system was implemented.

From such a single block a more complicated system has been build containing a matrixof N * N boards. The system has been fed with randomly incoming events having averagefrequency of 100 kHz (Fig. la). The number of 'regions of interest' was also randomlygenerated according to the distribution from Fig. lb. Whole system was completed by adding

168

a simple switch conducting the data to the T2 global level processors having fixed (2msec)processing time. Described construction allowed for easy modification of the board configurationand simple changes in number of used components. Ex. one of the variable parameters was thesize of the 'farm' used as the feature extractor (one, two or more DSP's).

We have investigated the following issues:

• average and peak occupancy of the FIFO's, units, links, buffers and processors

• average and peak 'live time' of the event in the system i.e. time from positive Tl deci-sion until readiness of the event for global processing for one or two processors i.e boardmanagement and feature extraction in one processor or seperate CPU's (Fig. lc, Id)

• average and peak processing time for 1 or two processors on the board i.e board manage-ment and feature extraction in one processor or seperate CPU's (Fig. le, If).

The following conclusions can be drawn from our studies:

• processing units should be built as farms of several processors to decrease significantlylocal queues

• efficient management of T2 buffer is very important

• MODSIM II has proven to be very handy tool for behavioural simulations of quite com-plicated systems.

StnuMcnraauln • tocdtfoM wcNtocbra bwed on FWST gonafit

• n (ona/Locolfmcmmiguu-lDSP

Figure 1: MODSIM II simulation results

References

D. Crosetto et al: LHC Workshop, Aachen, 1990P. Clarke, Z. Hajduk, K. Korcyl, W. Iwanski et al: EAST note # 93-11 CERN August 93G. Appelquist, W. Iwanski: EAST note # 92-27, FERMI note # 13, CERN November1992

[4] CACI Products Company - MODSIM II Reference Manual

169

The ZEUS Experiment at HERA 1

HillnrTTo n 11 i . • 1 I ilium mil I I I mil III niiillllliin

ZEUS Collaboration z PL9601078

Group from the Institute of Nuclear Physics includes:P. Borzemski, J. Chwastowski, A. Eskreys, K. Piotrzkowski, M. Przybycien, M. Zachara,

L. Zawiejski (physicists)and

J. Andruszk6w, B. Da.browski, W. Daniluk, P. Jurkiewicz, A. Kotarba, K. Oliwa, W. Wierba(engineers and technicians)

HERA (Hadron Electron Ring Anlage , located at DESY in Hamburg, is the first andunique accelerator colliding proton and electron beams at very high energy {sfs = 314GeF). Itstarted operation in 1992. This year's running was very succesful, experiments have collectedabout 600nb~1 of integrated luminosity i.e. 20 times more than in 1992.

ZEUS Luminosity Monitor has been designed and built by the Krakow team which includesgroups from the INP and from the Nuclear Physics Faculty of the Academy of Mining andMetallurgy3. Thus, the main responsibility of the Krakow group is the maintenance of this de-tector and the luminosity measurement itself. The experience gathered during the first runningperiod allowed for some important improvements and modifications implemented during the1992/1993 winter shut down. The most important steps in the development of the luminositymeasurement are:

• Installation of the position detector for the electron calorimeter, which allows better un-derstanding of the systematic errors in the luminosity measurements and provides a veryimportant tool in the analysis of the photoproduction processes.

• Implementation of the new, more complete and relialable online display of the luminositymeasurement used by the ZEUS experiment and by the accelerator crew for optimizationof the electron beam orbit.

• Further development of software necessary for the precise offline luminosity calculation.1Polish ZEUS groups activity is partially supported by the State Committee for Scientific Researches (grant

No 204209101)2Participating institutions: Argonne National Laboratory, University and INFN (Bologna), Universitat Bonn,

Bristol University, Brookhaven National Laboratory, Calabria University and INFN (Cosenza), Columbia Univer-sity, Institute of Nuclear Physics (Krakow), Dept. of Physics and Nuclear Technology of the Academy of Miningand Metallurgy (Krakow), Jagellonian University (Krakow), DESY (Hamburg), DESY-Zeuthen (Zeuthen), Uni-versity and INFN (Florence), INFN (Frascati), Universitat Freiburg, University of Glasgow, Hamburg University(I. and II. Institutes of Physics), Imperial College London, University of Iowa (Iowa City), Institut fur Kern-physik (Jiilich), Korea University (Seoul), Louisiana State University (Baton Rouge), Univer. Autonoma Madrid,University of Manitoba, McGill University (Montreal), Moscow State University, NIKHEF (Amsterdam), OhioState University (Columbus), University of Oxford, University and INFN (Padova), Pennsylvania State University(University Park), Univ. 'La Sapienza' (Rome), Rutherford Appleton Laboratory (Chilton,Didcot), University ofCalifornia (Santa Cruz), Universitat-Gesamthochschule Siegen, Tel-Aviv University, University of Tokyo, TokyoMetropolitan University, University and INFN (Torino), University of Toronto, University College London, Vir-ginia Polytechnic Institute (Blacksburg), Warsaw University, Institute for Nuclear Studies (Warsaw), WeizmannInstitute (Rehovot), University of Wisconsin (Madison), York University (North York)

3s. INP Annual Reports 1991, 1992

170

• Design and construction of the new electronics for the photon position detector to beinstalled during the present shutdown.

• Design of the new, more reliable scheme for the calibration of the calorimeters, based onthe light pulser with laser diode; this system will be also implemented during this wintershutdown.

Members of the Krakow ENP group have been taking part in the ZEUS run shifts. They have alsocontributed to the development of the general ZEUS online and offline software. Our physicistshave actively participated in the physical analysis of the collected data and have significantlycontributed to that of the photoproduction processes.

Many aspects of the deep inelastic scattering, photoproduction processes and searches fornew particles have been studied by both HERA experiments: ZEUS and HI. Results of theZEUS physics analysis, based mainly on the data collected in 1992, have been published in7 papers. New interesting data concerns mainly the deep inelastic scttering processes (DIS)in the new kinematic range available at HERA collider. Results on the study of the protonstructure, similar for both experiments, are presented in this Report by group working for theHI Collaboration. Here we would like to review briefly on the analysis of a special subsampleof the ZEUS DIS events.

Observation of Events with a Large Rapidity Gap in DeepInelastic Scattering at HERA 4

ZEUS Collaboration

M. Derrick et al. 5

The dominant mechanism of DIS is the scattering of the incident lepton from a coloured quark(see Fig. la). The colour transfer between the struck quark and the proton remnant is respon-sible for populating the rapidity interval between them with final state hadrons. Such a picturepredicts that DIS events observed at HERA should have substantial energy deposits at anglesclose to the proton direction. Indeed, the energy flow distributions found for those events areconsistent with this prediction [1,2].

In this paper the ZEUS Collaboration reported on the first observation of a class of DIS eventsin which the hadronic energy deposit closest to the proton beam direction is observed at a largeangle. These events exhibit a sizeable difference between the pseudorapidity, r\ — —lntan(9/2),of the smallest detector angle/footnote In the ZEUS coordinate system the polar angle 6 ismeasured with respect to the z axis pointing along the proton beam direction. (9 = 1.5°, r\ — 4.3)and the pseudorapidity of the hadrons observed closest to the proton direction. These events arenot described by standard QCD based fragmentation models [3]. Theit general characteristicsare compatible with those expected from difractive dissociation with pomeron exchange.

The present understanding of the pomeron nature is poor despite a wealth of data [4]. It hasbeen suggested that the pomeron may have a partonic structure which could be probed in harddiffractive dissociation [5]. The concept of the pomeron structure function has been studied interms of perturbative QCD [6,7-13]. It has been suggested that the pomeron structure couldbe probed with a virtual photon at HERA [5,14,15] and that the experimental signature of a

*Phys. Lett. B315 (1993) 4815INP authors: P. Borzemski, J. Chwastowsld, A. Dwuraany, A. Eskreys, Z. Jakubowski, B. Niziol,

K. Piotrzkowski, M. Zachara, L. Zawiejski

171

pomeron exchange wotdd consist of a quasi-elastically scattered proton, well separated in rapidityfrom the remaining hadronic system as illustrated in Fig. lb. The events described here havesuch a rapidity gap.

Fig. 1: (a) Schematic diagram describing particle production in deep inelastic electron proton scattering, (b)Schematic diagram describingparticle production by diffractive dissociation in a deep inelastic ep interaction. Wis the center of mass energy of the y*p system and Mx is the invariant mass of the hadronic system measured inthe detector. N represents a proton or low-mass nuclear system, (c) Schematic view of the ZEUS calorimeter andcentral tracking. Overlaidis an event with a large rapidity gap. Tracks are detected in the central tracking chamberand energy deposits are obseved in the calorimeter. The electron is detected in the rear direction (RCAL).

The data were collected during fall 1992 and the sample used in this analysis corresponds toan integrated luminosity of 24.7 nb'1. The ZEUS detector has been described elsewhere [16].The hermetic uranium-scintillator calorimeter (CAL), the central tracking detector and thevertex detector were the main components used for this analysis. They are shown schematicallyin Fig. lc.

The kinematic variables used to describe DIS events are the following: Q2, the negative ofthe squared four-momentum transfer carried by the virtual photon, 7*,

172

Q> = -f = -(k - k')2,

where k and k' are the four-momentum vectors of the initial and final state electrons, respec-tively; y, the variable which describes the energy transfer to the hadronic final state,

y = (q.P)/(k.P),

where P is the four-momentum of the incoming proton; x, the Bjorken variable,

x = Q2/{2q.P) = Q2/ys,

where s is the center-of-mass energy squared of the ep system; and W, the center-of-mass energyof the 7*p system,

W2 = (q + Pf = Q2(l - x)/x + M2,

where Mp is the mass of the proton.The kinematic variables can be determined from either the leptonic or hadronic system. Studieshave shown [17] that it is sometimes advantageous to used a mixed set of variables. Here weuse the so called "double angle" method [18]. The relevant quantities will be denoted by thesubscript DA.

/

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o

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+++++ H,

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Fig. 2: (a) The fraction / of events for which 99% of the hadronic energy is contained within the pseudorapidity

interval -3 .8 < -r\ < rjc.t as a function of r/cut, for data and for MC events, (b) Distribution of J?mo*, the

maximum rapidity of a calorimeter cluster in an event, where a cluster is defined as an isolated set of adjacent

cells with summed energy higher than 400 MeV, for data and for MC events. The boundaries of the calorimeter

are indicated. Values of v-max > 4.3 may occur when particles are distributed in many contiguous cells around

the beam hole of the FCAL.

The data selection procedure used for the isolation of the DIS sample and the Monte Carlomethod used to determine the detector acceptance and the possible background are described in[18]. Final sample of the deep inelastic events consists of 1441 events. Most of the characteristicsof that sample are similar to those of the Monte Carlo (MC) neutral current DIS events generatedwith HERACLES [19] (the hadronic final state was simulated using ARIADNE [20] for the QCDcascade and JETSET [21] for the soft processes). In one importatnt aspect, however, the datadiffers from MC. In the data we observe a substantial number of events with low energy depositedin the forward calorimeter (FCAL) in contrast to the MC expectations.

173

Fig. 2a shows for both data and MC the fraction of events, for which 99% of the hadronicenergy measured in the calorimeter is contained within -3.8 < r\ < 77^, as a function of r ^ .The lower limit of of 77 = —3.8 is denned by the inner edge of the rear calorimeter (RCAL).In almost all MC events, the full calorimeter acceptance is required to measure 99% of thedeposited energy. However, in the data we observe a clear excess of events for which 99% of thedeposited energy is contained within a smaller angular range, corresponding to 77^ < 3.

To study these events further, we define r\rnax as the maximum pseudorapidity of all calorime-ter clusters in an event. The distribution of r)max is shown in Fig. 2b both for data and MC.A clear excess of events in the data sample is observed for rjmax < 1.5. We denote events withVmax < 1-5 as events with large rapidity gap. This corresponds to requiring a rapidity gap of atleast 2.8 units. After estimation of the number of backround events an excess of 78 ± 10 remains,corresponding to 5.4% of the DIS sample.

Deep inelastic interactions due to diffractive virtual photon-proton scattering (j*p) are ex-pected to produce events with a large rapidity gap in the final hadronic state. In the tripplepomeron exchange one expects a flat rapidity distribution of the recoiling diiFractive state. Forfully contained diffractive states the r)max variable is related to the rapidity distribution of thehadronic state. In the region of 77max < 1.5 in Fig. 2b, the measured distribution is indeed flat.We have then looked into inclusive properties of the large rapidity gap events.

We divide the DIS events into two samples, one with r)max < 1.5 and the other with r\max >1.5. In Fig. 3 we present for both samples the correlation between the invariant mass Mx ofthe observed hadronic system and the total available energy WDA in the ~f*p system. A featureof the events with a large rapidity gap is that Mx is small compared to WDA and is typicallysmaller than 10 GeV.

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50 100 150 200 250

Fig. 3: Correlation between the invariant mass Mx of the hadrons observed in the calorimeter and the invariant

mas, WDA, of the y'p system. Events with a large rapidity gap, r)max < 1.5, are shown as solid dots, and events

with r)ma* > 1.5 are shown as crosses.

There are also other inclusive distributions shown in the paper. Their shapes are suggestiveof a difltactive interaction between a highly virtual photon and the proton, mediated by theexchange of the pomeron. The selection criteria limit the acceptance for the diffractive-like

174

events. Since we have made no corrections for acceptance, the 5.4% for DIS events should beconsidered a lower limit for diffractively produced events.

References

[1] T. Ahmed et al., Phys. Lett. B298 (1993) 469.

[2] M. Derrick et al., Z. Phys. C59 (1993) 231.[3] B. Andersson et al., Phys. Lett. B94 (1980) 211;

B. Anderson et al., Phys. Rep. 97 (1983) 31;B.R. Weber, Nuci. Phys. B238 (1984) 492;Y.I. Azimov et al., Phys. Lett. B165 (1985) 147.

[4] K. Goulianos, Phys. Rep. 101 (1983) 169; Nuci. Phys. B,Pore. Suppl. 12 (1990) 110.

[5] G. Ingelman and P.E. Schlein, Phys. Lett. B152 (1985) 256.[6] E.L. Bergef et al., Nuci. Phys. B286 (1987) 704.[7] L.V. Gribov et al., Phys. Rep. 100 (1983) 1.[8] J. Bartels and G. Ingelman, Phys. Lett. B235 (1990) 175.[9] E.M. Levin and M. Wiisthoff, DESY 92-166, FERMELAB-Pub-92/334.

[10] M.G. Ryskin, Sov. J. Nucl. Phys. 53 (1991) 668.[11] G. Ingelman and K. Prytz, Z. Phys. C58 (1993) 285.[12] N.N. Nikolaev and B.G. Zakharov, Z. Phys. C53 (1992) 331.[13] J.C. Collins et al., Phys. Lett. B307 (1993) 161.[14] R. Donnachie and P.V. Landshoff, Phys. Lett. B191 (1987) 309.[15] K.H. Streng, Proc. HERA Workshop, Vol.1 (1987) p. 365; CERN-TH-4949 (1988).[16] M. Derrick et al., Phys. Lett. B293 (1992) 465.

[17] S. Bentvelsen et al., Proc. Workshop on Physics at HERA, Vol. 1 (1991) p. 23.[18] M. Derrick et al., Phys. Lett. B303 (1993) 183.

[19] A. Kwiatkowski et al., Proc. Workshop on Physics at HERA, Vol. 3 (1991) p. 1294.[20] L. Lonnblad, LU TP-89-10 (1989).[21] T. Sjostrand, Comput. Phys. Commun. 39 (1987) 347;

T. Sjostrand and M. Bengtson, Comput. Phys. Commun. 43 (1987) 367.

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FNAŁ £665 ExperimentThe inelastic fi+p and /x+-nucleus interactions

The E665 Collaboration6

The INP group: A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik, P. Stopa7

The group led by J. Figiel has been, continuing investigations of muon-nucleon (nucleus)interactions at 490 GeV. In 1993 the reduction process of the data of the 1990 run (fi+b,Cainteractions) was completed and of the 1991 run (/x+Z?2,J2 interactions) was well advanced.In particular our group was involved in software development and studies of systematic errors.Other activity of growing importance to which our group contributed significantly was the ana-lysis of various physical subjects using processed data. The following problems were studied :a) The Bose - Einstein Correlations in muon - nucleon interactions [1]b) Measurements of the ratio crnjav in inelastic muon - nucleon scattering

at very low x and Q2 [2]c) Perturbative QCD effects in deep — inelastic muon scattering and determination of strong

coupling constant a,(Q2) [3,4]d) Production of charged hadrons in muon - deuterium and muon - xenon interactions, nuclear

effects in lepto - production of hadrons [5,6]e) Production of neutral strange particles in muon - nucleon scattering [7]

In 1993 7 papers were prepared of which 2 have been already published and 4 have beenaccepted for publication.

Some of them are presented briefly below.

Q2 Dependence of the Average Squared Transverse Energy ofJets in Deep — Inelastic Muon — Nuclepn Scattering with

Comparison to QCD PredictionsThe E665 Collaboration

In the parton model of deep - inelastic muon - nucleon scattering, a virtual photoninteracts with a single quark within the nucleon. The experimental signature in the photon -nucleon centre of mass system is a forward jet of particles resulting from the struck quark anda backward jet coming from remnants of the nucleon. Perturbative Quantum Chromodynamics(PQCD) corrections introduce processes with two current partons with transverse energy rela-tive to the virtual photon direction. To the first order this energy is proportional to the strongcoupling constant a,. As it cannot be measured directly we measured instead the average trans-verse energy of jets as a function of four momentum transfer Q2 of the scattered muon.It turned out that, on average, this is a good measure of the parton final state. So it was possibleto deduce from the single process the dependence of a3 on Q2. As can be sean from Fig.l ourresults are compatible with PQCD predictions and the other measurements.

"Albert-Ludwigs -Universitat Freiburg i. Br.,Germany, Argonne National Laboratory, Argonne IL USA, Uni-versity of California, San Diego, CA USA, Fermi National Accelerator Laboratory, Batavia, IL USA, HarvardUniversity, Cambridge, MA USA, University of Illinois, Chicago, IL USA, Institute of Nuclear Physics, Kraków,Poland, Department of Nuclear Physics and Technique, Academy of Mining and Metallurgy, Kraków, Poland,University of Maryland, College Park, MD USA, Massachusetts Institute of Technology, Cambridge, MA USA,Max-Planck-Institut fur Physik Munich, Germany, Northwestern University, Evanston, IL USA, University ofWashington, Seattle, WA USA, University of Wuppertal, Wuppertal, Germany, Yale University, New Haven, CTUSA,

7work of Kraków group supported partly by the grant 2P30204104 of the State Committee for ScientificReseach

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• £655 JET <ZTl> ANALYSIS

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b) as(Q2), E665 data compared with other experiments

Production of charged hadrons by positive muons onDeuterium and Xenon at 490 GeV [5,6]

The E665 Collaboration

The hadrons produced in lepton - nucleon interaction originate mainly from partonfragmentation. This is non - perturbative strong process for which there is no satisfactorytheory. That is why it is important to study it experimentally. This experiment is speciallysuited for this purpouse because of nearly complete reconstruction of hadronic final state up toCMS energy W = 30 GeV. The results for (i D interaction may be summarised a following:a) The average charged multiplicity increases approximately linearly with In (W2), the width of

the distribution is proportional to its average.b) With increase of energy W the " plateau " in rapidity distribution develops.c) The positive, short range correlation between backward and forward multiplicities and two-

particle correlation are observed.For the ft+Xe interaction the distributions of hadrons are modified due to possible

reinteractions in the Xe nucleus.The most striking nuclear effect is the excess of hadrons (mainly positive) in the backward

hemisphere whereas no significant increase is found is the central region. This suggests presenceof the intranuclear cascade but very weak multiple projectile ( = photon dissociated into hadronicstate) scattering.

The collisions inside the nucleus produce the " knock out " protons some of which canbe observed as so called "gray" tracks. There is of course positive correalation between numberof collision and multiplicity of grey tracks, which enables more detailed study of nuclear effectsin hadron production. This is demonstrated in Fig.2, where the ratio of multiplicities in (i+Xe

177

and fi+D in function of rapidity is shown for events without and with grey tracks. Clearly thenuclear multiplication of hadrons is rather weak for no = 0.

Ratio CuXe) / )U | < i i i | i i u | i n i | u i i | i M I | i i i i | n 11 | r i r r j i j

10 = 0

charged• 1111111111111 u 111111111111 ii 1111111111111

2 ,JD 4

Fig.2 The ratio of charged particles densities as a function of CMS rapidity y* in / i + l e andinteractions for two subsamples of fi Xe interactions: without (TIG — 0) and with grey

tracks (na ^ 0).

We tried also to compare hadron production in two subsamples of fi+Xe interactions:one in which the shadowing of the per- nucleon cross- section is observed (see previous AnnualReport) (XBJ < 0.02) and second - where it is negligible (XBJ > 0.02). This comparison maygive insight into the mechanism of shadowing in lepton - nucleus interaction. Very preliminaryresults are presented in Fig.3. Surprisingly, the effect of nuclear cascading is weaker in thenon- shadowing sample then in the shadowing one. The investigation of this subject is beingcontinued.

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Fig.3. Difference of charged particles densities in n+Xe and fiD interactions as a functionof CMS rapidity y* in shadowing (black circles) and non - shadowing regions (open circles).

178

References PL9601083

[1] M.R. Adams et al., An Investigation of Bose-Einstein Correlations in Muon-Nucleon Inter-actions at 490 GeV, Phys. Lett. B308, 418 (1993).

[2] M.R. Adams et al., Measurement of the ratio <rnp in inelastic muon-nucleon scattering atvery low x and Q2, Phys. Lett. B309, 477 (1993).

[3] M.R. Adams et al., Perturbative QCD Effects Observed in 490 GeV Deep-Inelastic MuonScattering, FNAL Pub 93/169, accepted for publication in Physical Review D, June 1993.

[4] M.R. Adams et al., Q2 Dependence of the Average Squared Transverse Energy of Jets inDeep-Inelastic Muon-Nucleon Scattering with Comparison to QCD Predictions, FNAL Pub93/171, accepted for publication in Physical Review Letters, June 1993.

[5] M.R. Adams et al., Scaled Energy (z) Distributions of Charged Hadrons Observed in Deep-Inelastic Muon Scattering at 490 GeV from Xenon and Deuteriumm Targets, FNAL Pub93/245 submitted to Physical Review D, August 1993.

[6] M.R. Adams et al., Production of Charged Hadrons by Positive Muons on Deuteriumand Xenon at'490 GeV, MPI-PhE/93-17, FNAL Pub 93/246, accepted for publication inZeitschrift fur Physik C, August 1993.

[7] M.R. Adams et al., " Production of Neutral Strange Particles in Muon-Nucleon Scatteringat 490 GeV " accepted for publication in Z.Phys (1994).

Experiments with Ultrarelativistic Heavy Ions at CERN )<<>'•

Our participation in experiments with ultrarelativistic heavy ions at CERN can be described inthree points:

1. Continuation of data analysis from the experiment NA35 at the SPS

The NA35 Collaboration involves the following laboratories:Athens (Univ.) - Bari (INFN and Polit.) - Berkeley (LBL) - CERN - Kraków (INP) -Darmstadt (GSI) - Frankfurt (Univ.) - Freiburg (Univ.) - Marburg (Univ.) - Munich(MPI) - Warsaw (Univ. and INS) - Zagreb (IRB). This experiment, in which the 2 mlong streamer chamber placed in a magnetic field served as the main detector which wassupplemented with a set of calorimeters, took data with oxygen and sulphur beams of 60and 200 GeV/nucleon at the SPS in the years 1986-92. A time projection chamber (TPC)was added to the set up at the later stage, allowing to obtain significantly higher statisticsand precise momentum analysis also for particles emitted into the forward hemisphere.Data analysis from the streamer chamber and the TPC is still being continued, focussedon different aspects of nuclear collisions. In 1993 two papers were published by the Col-laboration, five presented at the Quark Matter Conference in Borlange, Sweden, and onesubmitted for publication. Below we present results of the investigation of intermittency.

2. Preparation of the experiment NA49 at the SPS

This experiment aims to study interactions of lead ions at 160 GeV/nucleon, which shouldbe accelerated in the SPS by the end of 1994. Approved in 1991, and using mostly newapparatus with large TPC 's as principal detectors, the NA49 experiment is being pre-pared by the collaboration with has evolved from NA35, with a few newcomers (KFKIBudapest, Univ. of Birmingham, Univ. of Washington in Seattle). Our contribution toNA49 is threefold :

a) development of electronics and programming for low-voltage power supply system forthe TPC 's ;

179

PL9601084

b) construction of the mechanical manipulator/extractor for handling the TPC readoutplates for the Main TPC ;c) computer simulation of the TPC performance.

Preparation of the heavy ion experiment ALICE at the LHCThe Letter of Intent for ALICE was submitted to the LHC Committee on March 1, 1993.In view of many questions from the referees, extensive simulation activities are still goingon. In particular, in Kraków the performance of the TPC is being studied by computersimulation within the RD-32 programme. A short account of a part of this work is givenbelow.

Our participation in the NA35/NA49 experiments is supported by the grant from the State Com-mittee for Scientific Studies (KBN), Nr. 204369101 (the grant manager is Prof. E. Skrzypczak ofWarsaw University), and since recently also by the allocation Nr. 565/93/LN from the Polish-German Foundation, granted to Prof. J. Bartke.

CERN Experiment NA35The NA35 Collaboration, from Krakow:

B. Wosiek, J. Bartke, E. Gładysz, M. Kowalski, P. Stefański

An Investigation of Intermittency in Proton-Gold, Oxygen-Gold,Sulphur-Gold and Sulphur-Sulphur Interactions at 200 GeV per

Nucleon8

The intermittency phenomenon is investigated in proton-gold, oxygen-gold, sulphur-goldand sulphur-sulphur collisions at 200 GeV per nucleon. The data were taken with the NA35streamer chamber detector at the CERN SPS. The data samples were carefully cleaned fromdouble-countings of tracks. Using the Fritiof event generator and the GEANT detector simula-tion package contaminations from photon conversions, particle decays and secondary interactionswere determined. Such contaminations are shown to have a sizable effect on the observed inter-mittency signal and the necessary corrections have been applied. Two methods are adopted tostudy intermittency. The first method uses factorial moments Fq, for which a modified definitionis employed to eliminate the effects from the non-uniform single particle distributions and fromcorrelations between the kinematical hadron variables. The second method uses correlation in-tegrals Fq

GHP. One of their advantages over the Fq moments is the fact that they have smallerstatistical errors what allows to extend the analysis to smaller cell sizes in phase space.

The correlation integral of the order q is denned as [1]

F?HP(v) = (Nq(v))/(N™m(v)}

where Nq(v) denotes the total number of g-tuples in an event within a cell of volume v. Fornormalization, JVJlorm, the number of q-tuples of uncorrelated particles is counted in fake eventswhich are constructed from the experimental data sample. For each fake event it was requiredthat all N particles are taken from N different randomly chosen real events. The averaging() is performed over the whole event (fake event) sample. The superscript GHP refers to thesymmetrized integral for which one requires that all q particles are within a cell of volume v.

J. Bachler et al., accepted for publication in Z. Phys. C

180

The analysis is carried out in three-dimensional (y,pr, <f>) phase space. For each reaction westart with the phase space volume V = Ay • Apr • A<f>, where Ay = 2.0, Apr = 1.995 GeV/c andA<f> = 2ir. The number of g-tuples is counted in movable phase space cells of size v in real andfake events and correlation integrals are calculated according to (1). The data are comparedwith the Monte Carlo (MC) simulations for which we have used the Pritiof event generator withthe additional incorporation of Bose-Einstein correlations [2].

Fig.l shows corrected FjfHP moments for negative particles for q = 2 and q = 3. Theyare plotted as a function of the total number of three-dimensional cells M3 — V/v. On theleft (right) hand side plots for the data (MC) are shown. A clear evidence for fluctuations canbe seen in all reactions. The moments differ from unity and increase with decreasing size ofthe cell (i.e. with increasing M3). A somewhat stronger and earlier rise is seen for pAu data.For nucleus-nucleus (AA) collisions the effect is weaker and long range correlations seem tobe suppressed. No significant differences are seen between OAu, SAu and SS collisions. Theobserved reduction of the correlations for AA collisions as compared to pAu data is however notas strong as expected in superposition models [3]. Thus, to explain AA results some collectiveeffects are required and BE interference is an obvious candidate.

10* 10"

Fig.l Log-log plots of FS>HP VS. Af3 for negative Fig.2 Log-log plots of F?HP vs. Jlf3 for ( - , - )

hadions. and (+, —) pairs.

To investigate the importance of BE correlations we compare (Fig.2) the correlation integralsfor like sign and unlike sign pairs (results for SAu reactions are not shown, since only negativelycharged particles were measured). A strong rise of F2HP for (—) pairs contrasts with almostflat moments for (H—) pairs and favours the explanation by BE interference effects.

From the data on the moments Fq and F^HF and their comparison with the MC simulation(which included Bose-Einstein correlations) the following main physics conclusions are drawn:

Basically, the analysis in terms of factorial moments lead to the same physics results as theanalysis of correlation integrals, however, the latter exhibit the observed effects more clearly.For negative hadrons the moments rise with decreasing cell size, thus showing nonstatisticalfluctuations. This rise is stronger for the third than for the second order moments. The corre-lations are weaker for AA collisions than in pAu data, however the effect decreases much moreslowly than (dN~/dy)'1 which would be expected in superposition models.

181

PL9601085We observe no significant effect of nonstatistical fluctuations for (H—) pairs.A Monte Carlo version of the Pritiof model, which approximately incorporates the BE cor-

relations describes the data reasonably well.From a comparison of the second correlation integral for (H—) and ( — ) pairs we con-

clude that the observed correlations are probably due mostly to the Bose-Einstein interference.Consistency between data and MC simulations supports the BE interpretation.

References:

1. P. Lipa et al., Phys. Lett. B285, 300 (1992)2. K. Kadija and P. Seyboth, Phys. Lett. B287, 363 (1992)3. A. Capella et al., Phys. Lett. B230, 271 (1989)

Calculation of Space Charge Distortions in ALICE TPC

Marek Kowalski

In Time Projection Chambers working in the environment of high particle densities ( largemultiplicities and/or high event rates ) one of the possible sources of the distortions of tracksis the build-up of positive charge from the primary ionization in the drift volume. The reasonis that the drift velocity of positive ions is by 3-4 orders of magnitude lower than for electronswhat leads to the permanent presence of the positive charge and thus to the extra electric field,affecting drift of the electron swarm to readout chambers. This can be particulary harmful forheavy ion collider experiments like STAR at RHIC or ALICE at LHC. The detailed calculationof the space charge effect is therefore very important.

In order to calculate the above distortions one has to solve the Poisson equation in cylindricalcoordinate system:

2 ) = p(R,z),

where $ is the potential, p is charge density and drift is along the z-axis.The charge density can be obtained from the y — pt distribution taken from Monte Carlo.

I I I50 100 150 200 250

z. cm100 150 200 250

z, cm

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PL9601086

The Figure shows radial (a) and azimuthal (b) distortions for ALICE TPC filled with theNe/CH4/CO2 88/10/2 mixture which is considered in ALICE Letter of Intent as the primarychoice. The calculations have been done for the highest luminosity L = 2*1027 cm"2 s"1

which corresponds to the event rate of 11.6 kHz. One should notice that these distortions scalelinearily with the luminosity, for event rate of 5 kHz they are smaller by a factor of ~2. In orderto reduce them one can also use gases with small Z and/or higher drift velocity of positive ions.

The validity of above calculations has been checked using data from the NA49 TPC 1993 testrun. The TPC has been irradiated with the muon beam. The space charge resulted as the effectof opened gate which allowed the leaking of positive ions from the gas multiplication processto the drift volume. Results of calculation reproduce the order of magnitude and the generalbehaviour of the data, better description requires more detailed knowledge of gas parameters.

BNL 868 Experiment9

The KLMM Collaboration10

from Kraków:A. Dąbrowska, R. Hołyński, A. Olszewski, M. Szarska, B. Wilczyńska and W. Wolter

Interactions of 10.6 GeV/n Gold Nuclei in Nuclear Emulsion

In 1992 the Brookhaven AGS accelerated for the first time a beam of gold ions, deliveringnuclei with kinetic energy of 10.6 GeV/n to the target areas. We exposed a number of stacks ofBR-2 nuclear emulsion to these nuclei.

Here we present the analysis of 461 interactions [1], for which the angles of emission of allcharged particles and charges of multicharged projectile fragments have been measured.

The number of released protons from the gold projectile is defined as n p = Zj^n — (2 • Na +Y^N %F)' The Np and Zp denote the number and charges of the projectile fragments with Z>3and N a is the number of alpha particles emitted from the projectile nucleus.

In order to test the dependence of the fragmentation of a projectile nucleus on the energy ofthe projectile we have compared our results with those obtained at lower energies, <1 GeV/n [2].The fractional yields of fragments with Z>3 at the two energies are compared in Fig. 1. At firstsight it appears that these yields are nearly identical. There is however a significant differenceat Np = 0, such that at the higher energy nearly 10% of the interactions have no fragments,whereas the low energy projectiles are essentially never completely disrupted. Also, the meancharge of the fragments from the high energy projectiles is 20.3±0.6, which is significantly lessthan 28.3±0.9 for the fragments at the low projectile energies. The fractional yields of alphaparticles are compared in Fig. 2. It is three times less likely to have no alpha particles athigh energy interactions than at lower energy, but twice as likely to produce between 3 and 6alphas. On the other hand, copious alpha particle emission, N a > 7, although relatively rare,appears to be independent of the projectile energy. As a consequence of the above differences inthe fragmentation of a projectile into multicharged fragments, the fractional yields of releasedprotons also show a significant energy dependence (see Fig. 3). At low energy 48% of all theinteractions have very few, np < 4, protons released, to compare with only 16% of such events

'This research has been partially supported in Poland by State Committee for Scientific Research, grant No203799101.

10Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Department of Physics and As-tronomy, Louisiana State University, Baton Rouge, LA, USA; University of Minnesota, Minneapolis, MN, USA;Institute of Theoretical and Experimental Physics, Moscow, Russia.

183

at the high energy. The high energy interactions have also consistently higher yields of eventswith rip > 30.

A special case of nucleus fragmentation is a fission of a nucleus, where just two heavyfragments are emitted. The fission of gold nuclei have been studied and the striking result is analmost complete suppression of fission of the gold nuclei in the high energy interactions [3]. InFig.4 we show the yields of a fission seen at lower energies compared to that observed for thehigh energy projectiles. It can be seen that there is a suppression of fission by more than anorder of magnitude.

Concluding, the breakup of the projectile gold nuclei at the energy of 10.6 GeV/n is appre-ciably more severe than that observed at the lower energies. Although on the average a similarnumber of fragments is produced, their mean charges are smaller at high energy interactions.Similarly, more alpha particles and released protons are observed in these energetic interactionsand, finally the fission of the gold nuclei, relatively frequent at lower energies, becomes largelysuppressed at the high energy.

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References

1.

2.

M.L. Cherry et al., Inst. of Nuci. Phys., Kraków, Poland, Report No.1637/PH, June 1993, in press in Z. Phys. C (1994).R. Hołyński, Proc. 10th Inter. Conf. on Ultra-Rel. Nucleus-NucleusCollisions, Borlange (1993), to be published in Nuclear Phys. A (1994).C.J. Waddington and P.S. Freier, Phys. Rev. C31 388 (1985).

3. C.J. Waddington et al., Proc. 23rd ICRC, Calgary, Vol.2;203 (1993).

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PL9601087

FNAŁ - experiment 667The KLMT Collaboration1

From Kraków:A. Dąbrowska, R. Hołyński, A. Jurak, M. Szarska, B. Wosiek and K. Woźniak

Measurements of 525 GeV pion interactions in emulsion2

Measurements have been made of inclusive T~ interactions in emulsion at 525 GeV, the high-est available fixed target energy. We present the 525 GeV results2 together with a comparisonwith the earlier pion and proton data. The ratio of the dispersion of multiplicity distribution ofshower particles n5 to its average value is constant at all energies for both protons and pions.The KNO scaling appears to hold for T~-emulsion collisions in the energy range 60-525 GeV.The shower particle pseudorapidity distributions are independent of the beam energy in thetarget fragmentation region and in the projectile fragmentation region. Both the multiplicityand pseudorapidity distributions of shower particles measured at 525 GeV agree well with theFRITIOF model predictions. The multiplicity distributions of heavily ionizing particles {Nh),mostly target fragments, do not vary significantly with the energy.

A/5

V 40

35

30

25

20

15

10

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I I I ł f I I I I I I I I I t

Av

4.5

10 20 30 40

3.5 -

2.5 -

2 -

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Fig.l The mean multiplicity {nt) of shower particlesas a function of Nh-

Fig.2 The dependence of the average pseudorapi-dity on Nh-

The dependence of the shower particle multiplicity (nt) on Nh approaches saturation asthe number of heavy tracks exceeds about 20 (see Fig.l). The shower particle pseudorapiditydistributions shift toward lower values with increasing Nh- In consequence the average pseudo-rapidity decreases with increasing Nh, as it is shown in Fig.2. For large Nh this dependence,however, seems to level off. Thus, one can conclude that for interactions characterized by thehigh values of N^ i.e. violent target nucleus disruption, the multiparticle production processbecomes independent of the target fragmentation.

1 Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Louisiana State University, BatonRouge , LA, USA; Lebedev Physical Institute, Moscow, Russia; Physical Technical Institute, Tashkent, Uzbeki-stan.

2M.L. Cherry et al., to be published in Phys. Rev. D.

185

\r.'

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CERN - EMU07 experiment1

The KŁM Collaboration 2

From Kraków:A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski, M. Szarska, A. Trzupek,

B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek and K. Woźniak

Particle production in interactions of 200 GeV/nucleon oxygen and sulfur nucleiin nuclear emulsion

Oxygen and sulfur nuclei with energies of 200 GeV/nucleon from CERN SPS interactedin nuclear emulsions and were scanned with minimum bias criteria so that essentially all theinteractions were detected. Approximately 1000 interactions of each projectile were analyzed [1].Results on the multiplicity distributions, the pseudorapidity distributions and the fragmentationof the projectile and target nuclei were presented. These results concentrated on obtaining aglobal description of the inelastic interactions by analyzing inclusive data sample. In additionthe subsamples of interactions characterized by different degrees of centrality were also studied.It is shown that the mean number of intranuclear nucleon-nucleon collisions, {Ncoii), calculatedfrom a superposition model, is a useful parameter to organize the data. We have found that thenormalized particle multiplicity is a function of the number of intranuclear collisions only anddepends neither on the mass of the projectile nor on its energy (see Fig.l).

A

20 40 60 80 100 120

Fig.l The dependance of the normalized meanmultiplicity {NT)/((Nr)pp) on (NcoU) for oxygen(open squares) and sulfur (solid squares) interac-tions in emulsion at 200 GeV/n. The published[2] data for oxygen interactions in emulsion at14.5, 60, and 200 GeV/n are shown by stars.

Fig. 2 The inclusive pseudorapidity distributionsof shower particles, produced in proton (stars),oxygen (open squares), and sulfur (solid squares)interaction in emulsion.

The inclusive pseudorapidity distributions of shower particles, N,, produced in proton, oxy-gen and sulfur interactions in nuclear emulsion are shown in Fig.2. The increase of particleproduction with increasing mass of the projectile is evident over the entire range of pseudora-pidity. However, a more detailed analysis of pseudorapidity distributions has shown that theangular distributions of shower particles from oxygen and sulfur projectiles are essentially thesame for groups of events characterized by similar values of (Ncou).

The universal dependence of the scaled multiplicity on the number of nucleon-nucleon colli-sions, observed in a wide range of (Ncou), together with other results presented in [1] stronglysupports the superposition models.

'This research has been partially supported in Poland by State Committee for Scientific Research,grant No 203799101.

2Participating institutions: Institute of Nuclear Physics, Kraków, Poland; Louisiana State University, BatonRouge, LA, USA; University of Minnesota, Minneapolis, MN, USA.

186

References:

1. A. Dąbrowska et al., Phys. Rev. D47, 1751 (1993).2. M.I. Adamovich et al., Raport LUIP 9103 (1991).

1PL9601Ó89

Comparison of particle production in nucleus-nucleuscollisions with predictions of the Venus Monte Carlo modelA comparative analysis of the particle production in 200 GeV/nucleon oxygen and sulfur

interactions in emulsion has been done [1,2] using the Venus 4.02 Monte Carlo model. Thedata samples contain about one thousand inclusive interactions for each projectile. For eachinteraction the forward charge flow, Qp, was determined from the measurements of angles andcharges of projectile fragments. The charge flow distributions can be directly compared tothe Monte Carlo predictions. To improve the agreement for large Qp values, the uncertaintiesin charge measurements of heavy projectile fragments were taken into account in the modelcalculations of Qp [2]. The uncertainties were assumed to have a gaussian shape with thewidths of 0.3-0.5 and 0*3-0.7 for oxygen and sulfur interactions respectively. A resulting goodagreement is shown in Fig.l.

0.28 i r 0.28

/1

4 8 12charge flow, Qf

8 16 24charge flow, Q,

Fig.l Charge flow distributions for a) 1 6O and b) 3 2S - interactions in emulsion. Solidline - experimental data, dotted line - Venus model predictions with uncertainties of chargemeasurements included.The relation between the forward charge flow and the number of intranuclear nucleon-nucleon

collisions was calculated from the Venus model for both oxygen and sulfur interactions in emul-sion. Using this relation we compared the measured multiplicity of produced charged particlesin interactions characterized by different degrees of centrality with the model predictions. Theresults are presented in Fig.2.

400

V

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300

200

100

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1

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Fig.2 Comparison of the Monte Carlo predictions (open circles) and the experimental data(solid circles) of the dependence of (Nx) on (Ncoii).

187

PL9601090

Prom Fig. 2 we see that the relation between the mean multiplicity and the correspondingnumber of intranuclear collisions is well reproduced by the Monte Carlo simulations, except forthe largest values of (Ncon) where multiplicities predicted by the model are slightly larger thanthe measured ones.

References:

1. A. Dąbrowska et al., Phys. Rev. D47, 1751 (1993).2. R. Holyński et al., 23rd ICRC, vol.4, 9 (1993).

Multifractal analysis of nucleus-nucleus interactions

We have performed a multifractal (G-moment) analysis of 14.6-200 GeV/nucleon nucleus-nucleus and 200-800 GeV proton-nucleus interactions from KLM and Fermilab E-90 and E-508emulsion data, including explicit corrections for the finite statistical sample [1]. The correctedslopes of the G-moments for protons, 1 6O, 28Si, and 32S nuclei show only slight evidence fordepartures from random behaviour. The case of 32S - AgBr, the heaviest system that has beeninvestigated, is the most interesting from the point of view of having the smallest statisticaluncertainty in the derived slope parameters. Only this system shows convincing evidence fornonrandom behaviour. Given the size of the uncertainties for all investigated systems, theresults of the fractal analysis are not inconsistent either with results of intermittency analysesfor nucleus-nucleus collisions [2,3] or with the nonrandom behaviour previously reported forleptonic and hadronic collisions.

It should be emphasized that for central nucleus-nucleus collisions, the fluctuations are smalland are dominated by statistical background. It is therefore a crucial and rather difficult task,often dependent on the detailed analysis method, to disentangle dynamical and statistical fluc-tuations. We have shown that because of the effects of statistical noise, the fractal analysis isnot as sensitive as the intermittency analysis for detecting non-statistical fluctuations.

References:

1. K. Sengupta et al., Phys. Rev. D48, 3174 (1993).

2. R. Hołyński et al., Phys. Rev. Lett. 62, 733 (1989); Phys. Rev. C40, R2449 (1989).

3. B. Wosiek, INP Preprint 1553/PH (1991).

188

PL9601091

BNL - Experiment PROBOS at RHIC 1

The PHOBOS Collaboration2

From Krakow:A. Białas, A. Budzanowski, T. Coghen, W. Czyż, J. Godlewski, R. Hołyński, J. Kotuła,

H. Lemler, P. Malecki, A. Olszewski, K. Pakoński, H. Palarczyk, M. Stodulski,A. Trzupek, H. Wilczyński, B. Wosiek, K. Woźniak and K. Zalewski

The PHOBOS experiment [1,2,3] will explore the rich physics program for the collisions ofthe beams of gold nuclei at Relativistic Heavy Ion Collider (RHIC) in Brookhaven. This willbe the first accelerator, where the beams of heavy ions will collide at relativistic energy (100GeV/nucleon each). It will open a new area of research - the physics of strongly interactingmatter at extreme energy densities. In such conditions the creation of the Quark Gluon Plasma(QGP) is expected. There are several sensitive observables to probe the existence of the QGP.The PHOBOS detector is designed to study a number of this specific signatures like e.g. struc-tures in the pt distributions, multiparticle correlations, abundant production of some species ofparticles and other. Some of these observables can be investigated on an event-by-event basis,the other will be obtained from the inclusive high statistics measurements.

Multiparticlespectrometers

PaddleTrigger counters

Time of flightarray

High 7j triggercounters

Ring multiplicitydetector

Vertex detectorsPole pieceand coil

Magnet yoke

Fig.l The overall view of the PHOBOS detector (upper part of the magnet is not drawn to showthe details of the multiparticle spectrometer).

The PHOBOS experiment will focus on the precise measurements of the particles producedin the central region, where the search for QGP should be most promissing. These measurements

'Supported in part in Poland by State Committee for Scientific Reasearch, grant No 2P302 151 042Participating institutions: From USA: Brookhaven National Laboratory, Massachusetts Institute of Tech-

nology, University of Illinois at Chicago, University of Maryland, Yale University; From Danmark: Niels BohrInstitute, University of Copenhagen; From Poland: Institute of Nuclear Physics, Jagellonian University.

189

with the limited phase space acceptance will be complemented with information about the globalevent features.

The multiplicity and the emission angles of the particles will be measured in a very widepseudorapidity interval (-5.5 to 5.5) by the vertex and multiplicity detectors. In the central regionof rapidity (between 0 and 1.5) the charged and decaying neutral particles will be identified andtheir momenta will be precisely measured in the two-arm spectrometer placed in the magneticfield. We have chosen the conventional magnet with 2 Tesla magnetic field, since it can producemore uniform field in a wide area. The planes of silicon with pads or strips will be used as theactive elements everywhere except the TOF and trigger counters.

Mechanical structure and cooling system

The PHOBOS detector can be divided into three groups: multiparticle two arm spectrometer,vertex detector and ring multiplicity detectors. Each type of detectors requires a rigid mechanicalstructure ensuring precise and stable location of silicon planes and an efficient cooling systemwhich will keep front-end electronics and detectors at constant temperature. The Krakow groupof the PHOBOS collaboration is responsible, among others, for designing and manufacturingof both mechanical structures and cooling systems. Intensive studies have been performed toprepare the documentation of the design. The present design of mechanical structures andcooling systems is presented in Conceptual Design Report [3] (see also Fig.l). Finite ElementMethod has been used to calculate the rigidity of supporting structures and the efficiency ofcooling systems. Bending stiffness of the spectrometer base plate is the most crucial amongthe mechanical issues. Acceptable deflection of 0.5 mm over the distance of 1500 mm requiresextremely high concern in the design and the selection of the material of the plate. From variouslight materials considered for a spectrometer base plate, carbon-epoxy composite has the bestmechanical properties and is planned to be used.

PHOBOS PAD DETECTORStemperatures in stagnant air

Q.I- (10 w/m. v - ZZ 1/min

PHOBOS STRIP DETECTORStempera I u re i in stagnant air

Ql- lOfl W/m.v-ZOI/mln

« M M A M N IN iii lit IM IM

position across deUctor position across detector

Fig.2 Comparison of the measured and calculated temperatures for two kinds of the PHOBOSsilicon detectors.

The front-end electronics of spectrometer and vertex detectors is cooled with water whilethat of ring multiplicity detectors with moving air. The water cooling system consists of twoclosed circuits. The circuit cooling front-end electronics is working at pressure lower than theatmospheric one to avoid water leakage. The cooling system is designed to absorb heat emittedfrom electronics and magnet as well, and to keep the silicon detector temperature at about20°C. The results of the heat flow calculations have been compared with the experimental dataobtained for specially built models of cooling frames with pad and strip detectors (Fig.2). The

190

presented diagrams indicate, that the special attention has to be payed to the pad detectordesign.

The Monte Carlo simulations

In the central collisions of two Au nuclei at RHIC energies we expect very large numberof particles produced in the primary interaction. As they traverse the material surroundingthe interaction point a number of secondary interactions occurs in which several times morebackground particles is produced - most of them in the magnet yoke and coil. The MonteCarlo simulations using the GEANT simulation package were performed in order to check thecapability of track recognition and identification of the particles in the spectrometer. We haveused the central events produced by HIJET Monte Carlo event generator and normalized allresults to a "standard" event with dnch/dy=1000 at y=0, what corresponds to about 14000primary particles.

First we have studied the occupancy (i.e. the number of the particles hitting a detectorplane divided by the number of channels in this plane). In most planes we have managed tokeep the occupancy close to 3% - the value that should ensure an efficient and reliable patternrecognition. Only in some planes in their parts closest to the beam pipe occupancy was muchhigher - up to maximum of 12%. Those parts of the spectrometer will be still usefull for theevents with lower multiplicity.

The results of the analysis of the trajectories of particles with different momenta and ra-pidities, produced at three positions of the interaction point (-10, 0, 10 cm) (Fig.3), were usedto optimize the geometry of the spectrometer. The final positions and dimensions of the siliconplanes in the spectrometer were chosen to obtain the highest acceptance and best momentumresolution, without exceeding the planned cost.

Fig.3 Examples of the trajectories of particles with different momenta produced at vertex posi-tion = 0 cm.

For the optimized spectrometer layout we have determined the geometrical acceptance formeasuring and identification of different particle species. Our results (Table 1) were scaled to 106

"standard" events (such that dnch/dy=l000 at y=0). We assume, that a particle is measuredwhen it traverses sufficient number of planes to accuratelly determine its momentum. Using themeasured values of dE/dx we can identify pions and kaons with momenta up to 550 MeV/c,protons up to 950 MeV/c. The TOF measurements can increase those limits to 1200 MeV/cand 2000 MeV/c respectively.

191

ParticleTT*

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2.4X106

2.2xlO6

8.2xlO3

3.7xlO3

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0.9X108

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Table 1. Numbers of various particles measured and identified, for 106 standard events.

The measured and identified particles will have rapidity in the range 0-1 (pions up to 1.8).The lowest pt that can be observed are: 20 MeV/c for T±, 60 MeV/c for K± and 80 MeV/c forp and p. The phase space regions, where PHOBOS spectrometer will identify particles can beseen in Fig. 4.

u

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References:1. "A Letter of Intent to Study Very Low pt Phenomena at RHIC" - PHOBOS Collaboration,19922. "Proposal to Study Very Low pt Phenomena at RHIC" - PHOBOS Collaboration, 19923. "PHOBOS Conceptual Design Report", PHOBOS Collaboration, 1993.

192

JACEE Experiment" PL9601092From Kraków:

R. Hołyński, B. Wilczyńska, H. Wilczyński and W. Wolter

Cosmic ray composition, energy spectra and nuclear interactions are studied by the JACEECollaboration with emulsion chambers exposed to cosmic radiation in balloon flights at highaltitude. Both primary cosmic ray particle and products of its interaction are recorded in thechamber. Primary particle charge and energy are measured, thus elemental composition andspectra can be obtained at energies in the 1-100 TeV/nucleon energy range.

1 Cosmic ray spectrum

Cosmic ray energy spectrum spans many orders of magnitude: from MeV region to 1O20 eV.The intensity of cosmic radiation falls with energy according to E~21 power law below 1015 eVand E~32 above 1016 eV. The break in the energy spectrum around 1015 - 1016 eV is calledthe 'knee'. While at low energies the cosmic ray flux is large enough for use of small detectors(spectrometers, calorimeters, etc.) to collect data, spectra of individual elements cannot bedetermined at energies above about 1014 eV due to insufficient data statistics which can beaccumulated during lifetime of an apparatus.

It has long been expected that the knee in cosmic ray spectrum may be due to some importantchange in cosmic ray acceleration mechanisms and/or propagation conditions in the Galaxy,when one mechanism becomes less effective and the other takes over. Therefore detailed cosmicray study at energies 1012 -10 1 5 eV is of critical importance to our understanding of accelerationand propagation of cosmic ray particles.

Presently available experimental data on spectra of individual elements cover only the regionwell below the knee. The highest energy data on composition and spectra presently availableare those provided by JACEE [1]. Summary of JACEE data on proton spectrum [2] is shownin Fig.l. JACEE-1 to JACEE-6 denote the emulsion chambers exposed to cosmic radiationin balloon flights in the U.S.A., while JACEE-7 and JACEE-8 are the chambers from longduration balloon flights Australia - South America. As the statistics increased, the steepeningof the spectrum was increasingly evident at energy above 4-1013 eV. Spectra of heavier elements[3] tend to flatten in this energy region, as shown in Fig.2. This is in a rough agreement withexpectations for cosmic ray acceleration in supernova remnants: as proton spectrum gets cut off,the fraction of heavier nuclei should increase with energy before the heavier nuclei consecutivelyreach their limiting energies. However, present data show no sign of spectral cutoff of Heliumnuclei up to 1014 eV/nucleon. Clearly, the data is not sufficient to draw definite conclusions.

In December 93/January 94 new JACEE emulsion chambers were exposed to cosmic radiationin long duration balloon flights in Antarctica. New data from these chambers will significantlyincrease our statistics, and will extend the experimental spectra to higher energies.

2 High energy interactions

A special effort was devoted to heavy particle decay study. Among the interactions detected sofar two events were found which contain secondary vertices with almost identical, characteristictopology: a singly charged particle track undergoes a kink, with four photons apparently emitted

'Participating institutions: Institute for Cosmic Ray Research - University of Tokyo, Hiroshima University,Kobe University, Kobe Women's Junior College, Kochi University, Okayama University of Science, Waseda Uni-versity, University of Alabama in Huntsville, Louisiana State University, NASA Marshall Space Flight Center,Universitu of Washington, Institute of Nuclear Physics - Kraków.

This research was partially supported by Polish State Committee for Scientific Research, grant No. 203419101.

193

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rT-r ..

10* W* W«Energy (GcV)

Figure 1: Differential energy spectrum of protons

from the kink and converting into electron pairs near the emission point. Interpretation of thesevertices as nuclear interactions is very unlikely; most probably they are due to bottom particledecays [4]. The two decay vertices are shown schematically in Fig.3. In both events one ofsecondary particles, denoted particle 1 in each event, decays into neutrals and one chargedparticle, which in turn undergoes another apparent decay within the detector. The four photonswhich convert into electron pairs were undoubtedly emitted from decay vertex of particle 1 ineach event, not from primary interaction vertex.

A virtually complete transverse momentum balance among the decay products is observedin both decay vertices. Analysis of the decays indicates that the decaying particles are mostprobably bottom particles in both events. The photons convert into electron pairs very early,within 0.38 and 0.59 conversion length, respectively in the two events. In case there werejust four photons emitted in each decay, the observed conversion distances would be unusuallysmall. More photons emitted from the decay vertices would make it difficult to explain apossible (weak) decay mode of a heavy particle into one charged particle and many photons.The decays obviously proceed via the weak interaction, since particle 1 decaying via strongor electromagnetic interaction would not leave a visible track, while particles 1 are observed

10 3

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194

E o - 50T«y/n

-120-83 -40 40 80 120 X(pm) 200X(pm)

Figure 3: Projection of decays of particle 1 in the two events

to travel before decay 23.4 ram and 7.9 mm, respectively in the two events. The two decaysdiscussed were found in a sample of 15 high energy interaction events, so they appear to berelatively common. On the other hand, all known decay modes of heavy particles [5] withtopologies resembling the observed one have small branching ratios. Thus the events discussedmay be examples of a new decay channel of a bottom particle.

References

[1] S. Swordy, Rapporteur talk at the 23rd International Cosmic Ray Conference, Calgary, July1993.

[2] K. Asakimori et al., Proc. 23rd ICRC, Calgary 1993, vol.2, p.21.[3] K. Asakimori et al., Proc. 23rd ICRC, Calgary 1993, vol.2, p.25.[4] H. Wilczyński et al., Proc. 23rd ICRC, Calgary 1993, Vol.4, p.29.[5] Particle Data Group, Review of Particle Properties, Phys. Rev. D45 Part 2 (June 1992).

195

1Theory G r o u p PL96Ó1093

In the year 1993 research activity of the particle physics theory group was continuationof the projects already performed in 1992. Altogether twenty seven papers and conferencecontributions were published or prepared for publication in this year (thirteen were published ininternational journals). Main subjects which were discussed are: (a) effects of the photon andgluon emission in electron-positron, electron-proton and proton-proton collisions, (b) productionand decay mechanism of heavy quarks and heavy leptons (c) comparison of the new experimentaldata with the predictions of Standard Model and its extensions.

Below, we shall present the most important results grouped by subjects. The correspondingpapers were often quoted, in particular at the international conferences and in the publica-tions presenting new experimental data, proposals for forthcoming accelerators or experiments(asymmetric B-factory, ATLAS, 500 GeV e+e~ collider).

A general reveiw of heavy flavour physics has been given in the plenary talk "Heavy flavours(theory)" on International Europhysics Conference on High Energy Physics by K. Zalewski.

In the papers (Z. Phys. C57 (1993) 115 and Z. Phys. C59 (1993) 117) the problem of finidingthe most general, consistent with conservation laws, distributions in complicated particle decaysis solved. The paper (Z. Phys. C59 (1993) 399) suggests, that when an atomic nuclues is struckby a very energetic projectile the energy absorbed by the nucleus is limitted. When this limit isapproached a kind of phase transition occurs: the nucleus gets rid immediately of all the surplusenergy. The paper (Z. Phys. C59 (1993) 677) shows that an Isgur-Wise function, in very goodagreement with experiment can be simply obtained from the MIT bag model. The paper (Phys.Lett. B314 (1993) 74) clarifies the relation of intermittency to finite size scaling in the Isingmodel. The repport (CERN-TH 7058/93) exposes the origin of the discreappancy between twomethods of calculating the decay constants of heavy mesons.

Quantum theory of quarks and leptons predicts existence of the t quark of the mass mt =110 - 200 GeV. This is more than masses of W and Z bosons of weak interactions. One expectsthat this mass, the biggest dimensional parameter of presently most fundamental theory ofinteractions, may play exceptionally important role in future theory explaining numerical valueof all quark and lepton masses. Precise measurement of this parameter will form one of themain goals of planned 500 GeV e+e~ collider. The lifetime of t quark is probably shorterthan time necessary for formation of the bound states it. That is why methods designed formeasurement of b and c quark masses cannot be used. This problem as well as measurementof the QCD running coupling constant as(Q2) was discussed in articles by M. Jeżabek Phys.Rev. D48 (1993) R1910 and Z. Physik C59 (1993) 669 as well as in other six publications andcontributions to conferences.It has been also pointed out (Phys. Lett. B301 (1993) 121) that running of as(Q2) may indicateexistence of supersymmetric particles.QCD corrections to semileptonic decays of polarised quarks have been calculated. Some resultsof this work (preprint TTP 93-32) are presented in fig. 1. These results can be used for processesinvolving polarised top quarks as well as polarised charmed and beautiful A baryons from Z°decays.

One of important aspects of LEP I scientific program are precision tests of the StandardModel. The idea is to measure and calculate certain observables to such a precision that effectsof radiative corrections can be tested. This seemingly uninteresting name covers very deep testof the Standard Model. In calculation of radiative corrections one has to take into account effectsdue to quantum structure of theory and also renormalization. Papers, Phys. Rev. D47 (1993)2682 and Phys. Rev. D47 (1993) 3733 include study of matrix elements for Bhabha scattering.In Comp. Phys. Commun. 76 (1993) 361, new version of the T decay library was published.

196

It is now being implemented together with PHOTOS into the Monte Carlo program KORALZ(see not yet published reports CERN-TH.7033, CERN-TH.7075) which is widely used by LEPexperiments. These papers form final steps in developing Monte Carlo algorithms used by theLEP I experiments for high precision tests of the Standard Model. This long term project wasstarted by S. Jadach nearly ten years ago.

0.2 0.4 0.6 0.8-0.4

0 0.2 0.4 0.6 0.8Fig. 1 The asymmetry functions for bottom quark, a,=0.2, e=0 and 0.35 : a) QCD corrected(Xb(x) - solid - and Born cc°\x) - dashed lines; b) ab(x)^\x) for the transitions b -* c (e = 0.35)- solid - and b —> u (e = 0.0) - dashed line.

This abstract does not have ambitions to present all papers published in the year 1993 intheoretical physics group. We refer the interested reader to the complete list of publications.

In the year 1993 Marek Jeżabek received the scientific title of Professor. Two Ph. D. thesis,by P. Biatas (superviser K. ZaleWski) and W. Płaczek (superviser S. Jadach) were defended.Z. Was gave lectures on the European School of High Energy Physics in Zakopane, Poland.

197

PL9601094

Engineering and Technical Support of High Energy PhysicsExperiments

J. Blocki, M. Despet, A. Florek, B. Florek, K. Gałuszka, J. Godlewski, J. Kotuta,M. Lemler, J. Michałowski, K. Pakoński, M. Stodulski, Z. Stopa, A. Strączek, M. Strck

The ATLAS ExperimentDesign study of the supporting structure and rail systems for suspension of the inner detector

inside the cryostat of the barrel calorimeter were performed. In addition, a method of suspensionof the polyethylene moderator from the cryostat wall was proposed. Thanks to a fellowship fromCommission of the European Communities this work was carried out at NIKHEF in Amsterdam.

The DELPHI ExperimentSilicon detector modules of the upgraded DELPHI microvertex tracker had to be stiffened.

After carrying out numerical calculations, V-shaped kevlar beams which are directly glued tomicrostrip detector modules were proposed. Two dummy models of the module were made.Their stiffness was checked experimentaly. Thirty of such kevlar beams were manufactured.

The PHOBOS ExperimentA conceptual design of the mechanical structures positioning and fixing the PHOBOS silicon

detectors was continued. Numerical simulations of both the spectrometer base plate deflectionand heat transmission from the front-end electronics to the cooling water were carried out.Calculated deflection of a carbon-epoxy composite plate of 5 mm thick reinforced with webingis presented in Fig.l. Prototypes of the spectrometer cooling frames as well as the pad and stripdetectors were made and tested to verify calculated temperature distribution in the detectors.

RD20 - Gas Cooling for Silicon Strip DetectorsA gas cooling method of silicon strip detectors has been developed. Based on it, a concept

of a silicon vertex detector has been proposed. The calculations of temperature distributionsand mechanical deformations of a detector module have been performed using Finite ElementsAnalysis. Thermal measurements with air and helium as a cooling agents have been performed.A temperature distribution throughout a detector module (Fig.2) and the results of mechanicalmeasurements and simulations show that it is possible to cool a specially designed Silicon VertexTracker by a gas flow.

Carbon/Carbon Composites for Special Applications

The main aim of the project is to develop a method of manufacturing thin shell elementsmade of a special carbon material. Such elements should have high stiffness, good reproducibilityof mechanical properties, high radiation hardness and, in addition, low coefficient of thermal ex-pansion. With the help of researchers from School of Mining and Metallurgy some carbon/carboncomposite samples in the form of thin plates were produced. Different types of carbon fibresand fabrics were used. The elastic properties of these samples were tested using a simple bend-ing method and ultrasonic method which connects wave propagation velocity with the materialelasticity. This work is supported by the State Committee for Scientific Research (grant no. 3P407 006 04).

198

Design Study of the Large Hadron Collider (LHC)

In the framework of the LHC project led by the Mechanical Technology Division at CERNmechanical properties of superconducting wires have been studied. Basing on the unidirectionalfibre composite material theory a method which allows to establish all the elastic properties ofa superconducting wire was proposed. For a Ti-Nb/Cu wire some numerical calculations usingthe ANSYS code were carried out.

PBOBOS - ba»a,c-£, 1*9.0 M, vobafjoxl) x*0(frartt,« y-o.b(p«reio

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Fig.2 Comparison of air and helium cooling efficiency

199

LIST OF PUBLICATIONS:

I. Articles:

1. ACCMOR Collab., S. Barlag, (A. Bożek, Z. Hajduk, H. Pałka, K. Rybicki, M. Witek) etal., Charmed Pair Correlations in it~ - Cu Interactions at 230 GeV/c, Phys. Lett. B302(1993) 112;

2. ACCMOR Collab., A. Bożek, (Z. Hajduk, H. Pałka, K. Rybicki, M. Witek) et al.,A Study of A+ Decays into pK~ir+, pK'n+ir0 and pK-ir+Tr°w°, Phys. Lett. B312(1993) 247;

3. W. Adam, (A. Budziak, W. Duliński, A. Florek, B. Florek, K. Gałuszka, J. Michałowski,K. Pakoński, G. Polok, M. Stodulski, Z. Stopa, M. Turala) et al., Performance of theForward RICH Detector System at DELPHI, IEEE Trans. Nucl. Sci. 40 No 4 (1993)583-588;

4. J. Bartke, Wspomnienie o Profesorze Marianie Mięsowiczu (1907-1992), Postępy Fizyki44 (1993) 515-521;

5. P. Białas, J.G. Korner, M. Kramer, K. Zalewski, Joint Angular Distribution in ExclusiveWeak Decays of Heavy Mesons and Baryons, Z. Phys. C57 (1993) 115;

6. P. Białas, J.G. Korner, K. Zalewski, Complete Angular Analysis of the Decay CascadeB_>D**(->D*(->D7r)+7r) + W(->h/), Z. Phys. C59 (1993) 117;

7. Big Bubble Chamber Neutrino Collab., A.E. Arsratyan, (W. Burkot, T. Coghen) et al.,Diffractive Production of Charmed Strange Mesons by Neutrinos and Antineutrinos,Z. Phys. C58 (1993) 55-60;

8. Big Bubble Chamber Neutrino Collab., V.A. Korotkov, (T. Coghen) et al., Bose-EinsteinCorrelations in Neutrino and Antineutrino Interactions with Nucleons,MPI-PhE/93-11 (1993); Z. Phys. C60 (1993) 37-51;

9. N. Bingefors, (P. Briickman, P. Jałocha, P. Kapusta, M. Turala, A. Zalewska) et al., TheDELPHI Microvertex Detector, CERN-PPE/92-173 (1992); Nucl. Instr. and Meth.A328 (1993) 447-471;

10. R. Brenner, (A. Czermak, S. Gadomski, M. Turala) et al., Measurements of the SpatialResolution of Double-Sided Double-Metal AC-Coupled Silicon Microstrip, Nucl. Instr.and Meth. A326 (1993) 189-197;

11. R. Brenner, (A. Czermak, S. Gadomski, P. Jałocha, M. Turala) et al., Results fromDouble-Sided Silicon Microstrip Detector with Field Plate Separation, Nucl. Instr. andMeth. A326 (1993) 198-203;

12. Z. Burda, K. Zalewski, R. Peschanski, B. Wosiek, Finite Size Scaling Analysis ofIntermittency Moments in the Two-dimensional Ising Model, Phys. Lett. B314 (1993)74;

13. W. Czyż, J. Turnau, Quark in a Magnetic Vacuum, Acta Phys. Pol. B24 (1993) 1501;14. R. Decker, (Z. Was) et al., Tau Decays Into Three Pseudoscalar Mesons, Preprint

TTP-92-25; Z. Phys. C58 (1993) 445-452;15. D.B. DeLaney, (S. Jadach) et al., Multiple Photon Effects in Fermion-(anti)-Fermion

Scattering at SSC Energies, Univ. of Tennessee preprint UTHEP-92-0101, Phys. Rev.Lett. D47 (1993) 853;

16. DELPHI Collab., P. Abreu, (P. Jałocha, K. Korcyl, W. Krupiński, T. Lesiak, B. Muryn,G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Measurement of BMeson Production and Lifetime Using Dl~ Events in Z° Decays, CERN-PPE/92-174(1992); Z. Phys. C57 (1993) 181;

200

17. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,G. Polok, M. Witek, A. Zalewska) et al., Measurement of Inclusive Production of LightMeson Resonances in Hadronic Decays of the Z°, CERN-PPE/92-183; Phys. Lett.B298 (1993) 236;

18. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,G. Polok, M. Witek, A. Zalewska) et al., A Search for Lepton Flavour Violation in Z°Decays, CERN-PPE/92-190 (1992); Phys. Lett. B298 (1993) 247;

19. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka,G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Determination of a, forb Quarks at the Z° Resonance, Phys. Lett. B307 (1993) 221;

20. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,G. Polok, M. Witek, A. Zalewska) et al., A Measurement of the Tau Lifetime,CERN-PPE/93-12; Phys. Lett. B302 (1993) 356;

21. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, G. Polok,K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Measurement of the Triple-GluonVertex from 4-Jet Events at LEP, CERN-PPE/93-29; Z. Phys. C59 (1993) 357;

22. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Measurement of Aj, Production andLifetime in Z° Hadronic Decays, CERN-PPE/93-32; Phys. Lett. B311 (1993) 379;

23. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Determination of a,Next-to-Leading-Log Approximation of QCD, CERN-PPE/93-43; Z. Phys. C59(1993) 21;

24. DELPHI Collab., P. Abreu, (A. Budziak, P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn,H. Pałka, G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska et al., Limits on theProduction of Scalar Leptocpiarks from Z° Decays at LEP, CERN preprintCERN-PPE/93-161; Phys. Lett. B316 (1993) 620;

25. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, G. Polok,K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Study of B° - B° Mixing UsingSemileptonic Decays of B Hadrons produced from Z°, Phys. Lett. B301 (1993) 145;

26. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka,G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Determination of a,from the Scaling Violation in the Fragmentation Functions in e+e~ Anihilation, Phys.Lett. B311 (1993) 408;

27. DELPHI Collab., P. Abreu, (Z. Hajduk, P. Jałocha, K. Korcyl, W. Kucewicz, T. Lesiak,H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., A Measurement of D MesonProduction in Z° Hadronic Decays, Z. Phys. C59 (1993) 533;

28. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka,G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., Search for Z° Decays totwo Leptons and a Charged Particle-Antiparticle Pair, Nuci. Phys. B403 (1993) 3;

29. DELPHI Collab., P. Abreu, (P. Jałocha, W. Krupiński, T. Lesiak, B. Muryn, H. Pałka,G. Polok, K. Rybicki, M. Turała, M. Witek, A. Zalewska) et al., A Measurement of theMean Lifetimes of Charged and Neutral B-Hadrons, Phys. Lett. B312 (1993) 253;

30. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., An Investigation of Bose Einstein Correlations in Muon-Nucleon, Phys.Lett. B308 (1993) 418;

31. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., Perturbative QCD Effects Observed in 490 GeV Deep-Inelastic MuonScattering, FERMILAB-PUB-93-169-E; accepted to Phys. Rev. D;

201

32. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., Q2 Dependence of the Average Sqared Transverse Energy of Jets inDeep-Inelastic Muon Scattering with Comparison to QCD Predictions, FERMILABpreprint FNAL-PUB-93-171-E; submitted to Phys. Rev. Lett. ;

33. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel, P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., Measurement of the Ratio a(N)/<r(P) in Inelastic Muon-NucleonScattering at Very Low x and Q2, FERMILAB preprint FNAL-PUB-93-065-E, March(1993) 12; Phys. Lett. B309 (1993) ;

34. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel. P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., Production of Charged Hadrons by Positive Muons on Deuterian andXenon at 490 GeV, MPI-PhE/93-17; FNAL-PUB-93/246; submitted toZ. Phys. C ;

35. E665 Collab., M.R. Adams, (A. Eskreys, J. Figiel. P. Malecki, K. Olkiewicz, B. Pawlik,P. Stopa) et al., Scaled Energy (Z) Distributions of Charged Hadrons Observed inDeep-Inelastic Muon Scattering at 490 GeV from Xenon and Deuterium Targets,FNAL-PUB-93/245; submitted to Phys. Rev. D;

36. E730 Collab., M. Szarska, (H. Wilczyński, W. Wolter, K. Woźniak) et al., E~ - NucleusInteractions in Emulsion at 350 GeV, Phys. Rev. D47 (1993) 784;

37. S. Gadomski, M. Turala et al., Pulse Shapes of Silicon Strip Detectors as a DiagnosticTool, Nucl. Instr. and Meth. A326 (1993) 239-242;

38. HI Collab., T. Ahmed, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Total Photoproduction Cross-SectionMeasurement at HERA Energies, DESY-92-160, Phys. Lett. B299 (1993) 374-384;

39. HI Collab., T. Ahmed, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Observation of Deep Inelastic Scattering atLow x, DESY-92-164 (1992); Phys. Lett. B299 (1993) 385-393;

40. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., A Search for Leptoquarks, Leptogluons andExcited Leptons in HI at Hera, DESY-93-029, Nuci. Phys. B396 (1993) 3-23;

41. HI Collab., T. Ahmed, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Measurement of the Hadronic Final State inDeep Inelastic Scattering at Hera, DESY-92-162, Phys. Lett. B298 (1993) 469-478;

42. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Measurement of Inclusive Jet Cross-Sections inPhotoproduction at HERA, DESY-93-100, Phys. Lett. B314 (1993) 436-444;

43. HI Collab., T. Ahmed, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Hard Scattering in 7 p Interactions,DESY-92-142, Phys. Lett. B297 (1993) 205-213;

44. R. Hołyński, Particle Production and Fragmentation Processes in Heavy Ion Interactionsin Emulsion, INP Report 1650/PH; The Conf. "Quark Matter'93", to be published in:Nucl. Phys. A;

45. S. Jadach, Z. Was et al., The r Decay Library TAUOLA, Version 2.4,CERN-TH/93-67 (1993); Comp. Phys. Commun. 76 (1993) 361-380;

46. M. Jeżabek, J.H. Kuhn, Light Gluinos in Z° Decays?, Phys. Lett. B301 (1993) 121;47. M. Jeżabek, J.H. Kuhn, The Top Width - Theoretical Update, Karlsruhe Univ. preprint

TTP 93-4; Phys. Rev. D48 (1993) 1910;48. M. Jeżabek, J.H. Kuhn, Higgs Effects in Top Production, Karlsruhe Univ. preprint TTP

93-22; Phys. Lett. B316 (1993) 360;

202

49. M. Jeżabek, T. Teubner, Momentum Distributions in tt Production and Decay nearTreshold (II): Momentum Dependent Width, Z. Phys. C59 (1993) 669;

50. KLM Collab., A. Dąbrowska, (R. Hołyński, A. Jurak, A. Olszewski, M. Szarska,A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woźniak) et al.,Particle Production in Interactions of 200 GeV/nucleon Oxygen and Sulfur Nuclei inNuclear Emulsion, INP Report 1595/PH (1992); Phys. Rev. D47 (1993) 1751;

51. KLM Collab., A. Dąbrowska, (R. Hołyński, A. Olszewski, M. Szarska, A. Trzupek,B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woźniak, K. Zalewski) et al.,Evidence for a Nuclear Phase Transition in Target Nuclei after Relativistic NuclearInteractions, INP Report 1617/PH; Z. Phys. C59 (1993) 399;

52. KLM Collab., K. Sengupta, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski,M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek,K. Woźniak) et al., Multifractal Analysis of Nucleus-Nucleus Interactions, Phys. Rev.D48 (1993) 3174;

53. M.W. Krasny, E.M. Levin, M.G. Ryskin, Semilocal Evolution of Singlet StructureFunction for GLAP and GLR Equation, Z. Phys. C57 (1993) 273;

54. LEP Collab.: ALEPH, DELPHI, L3, OPAL, Measurement of the Mass of the Z Bosonand the Energy Calibration of LEP, Phys. Lett. B307 (1993) 187;

55. NA22 Collab., LV. Ajinenko, (K. Olkiewicz) et al., Two Particle Azimuthal and RapidityCorrelations in Intervals of Momentum in 7r+p Interactions at 250 GeV/c, Z. Phys. C58(1993) 357;

56. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Pomeron-Pomeron Cross Sectionfrom Inclusive Production of a Central in Quasielastic p and K p Scattering at 250GeV/c, Nijmegen preprint HEN-360; Z. Phys. C60 (1993) 229;

57. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Factorial Moments, Cumulants andCorrelation Integrals in x+p and K+p Interactions at 250 GeV/c, Z. Phys. C59 (1993)405;

58. NA22 Collab., N. Agababyan, (K. Olkiewicz) et al., Influence of Multiplicity andKinematical Cuts on Bose-Einstein Correlations in 7r+p Interactions at 250 GeV/c,Z. Phys. C59 (1993) 195;

59. NA35 Collab., J. Bachler, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek)et al., Multiplicity Distributions in Small Phase-Space Domains in CentralNucleus-Nucleus Collisions, Raport MPI-PhE/92-21 (1992); Z. Phys. C57 (1993)541-550;

60. NA35 Collab., J. Bachler, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al.,Production of Charged Kaons in Proton-Nucleus and Nucleus-Nucleus Collisions at200 GeV/nucleon, Raport MPI-PhE/92-21 (1992); Z. Phys. C58 (1993) 367-375;

61. NA35 Collab., D. Rohrich, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al.,Hadron Production in S+Ag, S+Au Collisions at 200 GeV/nucleon, The Conf. "QuarkMatter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys A ;

62. NA35 Collab., M. Gaździcki, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański,B. Wosiek) et al., New Data on Strangeness Enhancement in Central Nucleus-NucleusCollision at 200 GeV, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June,to be published in: Nucl. Phys. A ;

63. NA35 Collab., J.T. Mitchell, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański,B. Wosiek) et al., Charged Hadron Distribution in 200 GeV/n S+Au Collisions: A Lookat Stopping, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to bepublished in: Nucl Phys. A ;

203

64. NA35 Collab., G. Roland, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek)et al., Systematic Study of the Target-Rapidity- and Transverse Momentum Dependenceof the 2II~ Correlation Function in 200 GeV/nucleon S+A Collisions, The Conf. "QuarkMatter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ;

65. NA35 Collab., B. Wosiek, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al.,A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Collisions, TheConf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl.Phys. A ;

66. J. Pluta, (P. Stefański, H. Dąbrowski) et al., Possible Observation of Medium EffectsUsing a Pion Correlation Technique, Nucl. Phys. A562 (1993) 365-388;

67. RD11 Collab., J. Badier, (P. Malecki, Z. Natkaniec, A. Sobala) et al., Evaluating ParallelArchitectures for Two Real-Time Applications with 100 kHz Repetition Rate, IEEETrans. Nucl. Sci. 40 No 1 (1993) ;

68. RD20 Collab., N. Bingefors, (S. Gadomski, P. Jalocha) et al., A Novel Technique for FastPulse-Shaping Using a Slow Amplifier at LHC, Nucl. Instr. and Meth. A326 (1993)112-119;

69. K. Rybicki, R. Rylko, Spin Alignment of Z>*+(2010) Produced in 230 GeV/c II-CuInteractions, Acta Phys. Pol. B24 (1993) 1049;

70. M. Sadzikowski, K. Zalewski, Isgur-Wise Functions from the MIT Bag Model, Z. Phys.C59 (1993) 677;

71. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Observation of Two-JetProduction in Deep Inelastic Scattering at HERA, Phys. Lett. B306 (1993) 158-172;

72. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Search for Leptoquarks withthe ZEUS Detector, Phys. Lett. B306 (1993) 173-186;

73. ZEUS Collab., M. Derrick, (W. Burkot, A. Eskreys, K. Piotrzkowski, M. Zachara,L. Zawiejski) et al., Initial Study of Deep Inelastic Scattering with ZEUS at HERA,Phys. Lett. B303 (1993) 183-197;

74. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Search for Excited ElectronsUsing the ZEUS Detector, DESY 93-075, June 1993; Phys. Lett. B316 (1993) 207;

75. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Hadronic EnergyDistributions in Deep-Inelastic Scattering Electron-Proton Scattering, DESY 93-068,May 1993; Z. Phys. C59 (1993) 237;

76. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,B. Nizioł, K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Observation of Events with aLarge Rapidity Gap in Deep Inelastic Scattering at HERA, Phys. Lett. B315 (1993) 481;

77. ZEUS Collab., M. Derrick, (J. Chwastowski, A. Dwuraźny, A. Eskreys, Z. Jakubowski,K. Piotrzkowski, M. Zachara, L. Zawiejski) et al., Measurements of the Proton StructureFunction F2 in ep Scattering at HERA, Phys. Lett. B316 (1993) 412;

78. S. Jadach, Z. Was, R. Decker and J.H. Ktihn, "The tau decay library TAUOLA: Version2.4", Comput. Phys. Commun. 76 (1993) 361;

79. R. Decker, E. Mirkes, R. Sauer and Z. Was, "Tau decays into three pseudoscalarmesons", Z. Phys. C58 (1993) 445;

80. S. Jadach, B.F.L. Ward and S.A. Yost, " Exact results on e+e~ -* e+e~27 at SLC /LEP energies" Phys. Rev. D47 (1993) 2682;

204

81. S. Jadach, M. Skrzypek and B.F.L. Ward, "Analytical results for low angle Bhabhascattering with pair production", Phys. Rev. D47 (1993) 3733;

82. M. Jeżabek and C. Junger, Energy of W distribution in top quark decays, Acta Phys.Polonica B (1993) in print, preprint TTP 93-20, Karlsruhe 1993.

II. Contributions to Conferences:

1. F. Arqueros, S. Martinez, M. Różańska, 7/proton Discrimination in Cosmic Rays (1013 -1015 eV) Using EAS Information from Electrons and Air Cerenkov Light, Proc. of the23rd ICRC, Calgary 4 (1993) 738;

2. S. Gadomski, P. Erola, N. Ellis, Reconstruction of B% -> T + T " Decays in the ATLASExperiment at LHC, B-Physics Workshop, Snowmass, May (1993) ;

3. I. Holi, ( M. Różańska) et al., A Matrix of Wide Angle Air Cerenkov Counters as anAlternative Air Cerenkov Teleskopes, Proc. "Towards a Major Atmospheric CerenkovDetector for TeV Astro/particle Physics", eds. P. Fleury, G. Vacanti (1993) 287;

4. JACEE Collab., H. Wilczyński, (R. Hołyński, A. Jurak, B. Wilczyńska, W. Wolter,B. Wosiek) et al., Multiple Photon Emission in Decays of Particles Produced in CosmicRay Interactions, Proc. 23rd ICRC, Calgary 4 (1993) 29;

5. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński,W. Wolter, B. Wosiek) et al., Tickling the Knee with JACEE, Proc. 23rd ICRC, Calgary4 (1993) 708;

6. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński,W. Wolter, B. Wosiek) et al., Cosmic Ray Composition and Spectra: (I) Protons, Proc.23rd Int. Cosmic Ray Conf., Calgary 2 (1993) 21;

7. JACEE Collab., K. Asakimori, (R. Hołyński, A. Jurak, B. Wilczyńska, H. Wilczyński,W. Wolter, B. Wosiek) et al. f Cosmic Ray Composition and Spectra: (II) Helium andZ>2, Proc. 23rd Int. Cosmic Ray Conf., Calgary 2 (1993) 25;

8. M. Jeżabek, J.H. Kuhn, T. Teubner, Radiative Corrections to the Top Quark Width,Proc: Workshop on Physics and Experiments at Linear e+e~ Colliders, Waikoloa,Hawaii, April 1993, Karlsruhe Univ. preprint TTP 93-21 (1993) ;

9. M. Jeżabek, J.H. Kuhn, T. Teubner, Production and Decay of tt Pairs in the TresholdRegion, Proc. of II Workshop on e+e~ Collisions at 500 GeV, Munich, Annecy, Hamburg(1993);

10. M. Jeżabek, J.H. Kuhn, T. Teubner, Comment on the Average Momentum of TopQuarks in the Treshold Region, Proc. of II Workshop on e+e~ Collisions at 500 GeV,Munich, Annecy, Hamburg (1993);

11. A. Karle, (M. Różańska) et al., First Running Experience with the Novel Wide Angle AirCerenkov Matrix Detektor AIROBICC, Proc. of the 23rd ICRC, Calgary 4 (1993) 666;

12. KLM Collab., R. Hołyński, (A. Dąbrowska, A. Olszewski, M. Szarska, A. Trzupek,B. Wilczyńska, H. Wilczyński, W. Wolter, B. Wosiek, K. Woiniak) et al., Comparison ofParticle Production in Nucleus-Nucleus Collisions with Prediction of the Venus MonteCarlo Model, Proc. 23rd ICRC, Calgary 4 (1993) 9;

13. KLM Collab., C.J. Waddington, (A. Dąbrowska, R. Hołyński, A. Jurak, M. Szarska,B. Wilczyńska, W. Wolter) et al., Fragmentation of High Energy UH Nuclei, Proc. 23rdInt. Cosmic Ray Conf., Calgary 2 (1993) 203;

14. KLM Collab., W. Wolter, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski,M. Szarska, A. Trzupek, B. Wilczyńska, H. Wilczyński, B. Wosiek, K. Woźniak,K. Zalewski) et al., Evidence for a Critical Temperature in Excited Nuclei Due to HighEnergy Nuclear Interactions, Proc. 23rd Int. Cosmic Ray Conf., Calgary 4 (1993) 5;

205

15. F. Krennrich, (M. Różańska) et al., Observation of VHE 7-Emission from the CrabNebula with the Prototype of the HEGRA Air Cerenkov Telescope Array, Proc. of 23rdICRC, Calgary 1 (1993) 251;

16. M. Merck, (M. Różańska) et al., Search for the UHE 7 Sources with the HEGRA EASScintillator Array, Proc. of the 23rd ICRC, Calgary 1 (1993) 361;

17. M. Merck, (M. Różańska) et al., Search for the UHE 7's from the Direction of the CrabNebula and Mrk 421 with the HEGRA Scintillator Array, Proc. of the 23rd ICRC,Calgary 1 (1993) 290;

18. NA35 Collab., D. Rohrich, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański) et al.,Hadron Production in S+Ag, S+Au Collisions at 200 GeV/nucleon, The Conf. "QuarkMatter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys A ;

19. NA35 Collab., M. Gaździcki, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański,B. Wosiek) et al., New Data on Strangeness Enhancement in Central Nucleus-NucleusCollision at 200 GeV, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, tobe published in: Nucl. Phys. A ;

20. NA35 Collab., J.T. Mitchell, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański,B. Wosiek) et al., Charged Hadron Distribution in 200 GeV/n S+Au Collisions: A Lookat Stopping, The Conf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to bepublished in: Nucl Phys. A ;

21. NA35 Collab., G. Roland, (J. Bartke, E. Gładysz, M. Kowalski, P. Stefański, B. Wosiek)et al., Systematic Study of the Target-Rapidity- and Transverse Momentum Dependenceof the 211- Correlation Function in 200 GeV/nucleon S+A Collisions, The Conf. "QuarkMatter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl. Phys. A ;

22. NA35 Collab., B. Wosiek, (J. Bartke, E. Gladysz, M. Kowalski, P. Stefański) et al.,A Study of Correlation Integrals in Proton-Nucleus and Nucleus-Nucleus Collisions, TheConf. "Quark Matter'93", Borlange, Sweden, 20-23 June, to be published in: Nucl.Phys. A ;

23. K. Rybicki, High Energy Physics in Poland, Proc. of European School of ParticlePhysics, Zakopane, September 12-25 (1993) ;

24. A. Trzupek, Y. Lu, J. Poirier, The Energy Scale of Extensive Air Showers, Proc. of 23rdICRC, Calgary 4 (1993) 359;

25. A. Trzupek, Y. Lu, J. Poirier, Is there a Moon Shadow in Single Muon Data, Proc. of23rd ICRC, Calgary 4 (1993) 422;

26. A. Zalewska, B-Hadrons at LEP, Proc. of the XV Int. Warsaw Meeting on ElementaryParticle Physics "Quest for Links to New Physics", Kazimierz 1992, (World Scientific)(1993) 105;

27. S. Jadach, B.F.L. Ward and Z. Was, "KORALZ: Physics Monte Carlo for high statisticsLEP I: toward the ultimate version" Talk on International Europhysics Conference onHigh Energy Physics, Marseille, France, 22-28 July 1993;

28. K. Zalewski, "Heavy flavors (theory)", Plenary talk International EurophysicsConference on High Energy Physics, Marseille, France, 22-28 July 1993;

206

III. Reports:

1. W. Adam, (A. Budziak, W. Duliński, A. Florek, B. Florek, K. Gałuszka, J. Michałowski,K. Pakoński, G. Polok, M. Stodulski, Z. Stopa, M. Turała) et al., The Forward RingImaging Cherenkov Detector of DELPHI, CERN preprint CERN-PPE/93-154 (1993);

2. ALICE Collab., N. Antoniou, (J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefariski)et al., Letter of Intent for a Large Ion Collider Experiment, CERN/LHCC/93-16,March 1 (1993);

3. ALICE Collab., N. Antoniou, (J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefański)et al., Answers to LHCC Questions, CERN/LHCC/93-59 November 10, 1993; ALICEInternal Note /GEN/93-33 (1993);

4. J. Bartke, E. Gładysz-Dziaduś, M. Kowalski, P. Stefański, A.D. Panagiotou, InterestingPhysics Beyond Midrapidity, ALICE Internal Note PHY/93-12, January 19 (1993);

5. J. Blocki, Mechanical Properties of Superconducting Wires Treated as UnidirectionalComposits, CERN, MT Report, February (1993);

6. J. Blocki, Moderator and Support Structure with Rail System for the ATLASExperiment, NIKHEF, Technical Report, December (1993);

7. J. Blocki, J. Godlewski, K. Pakoński, Gas Cooling for Silicon Strip Detectors, CERNReport RD20-TN26 (1993);

8. J. Blocki, M. Stodulski, ANSYS Study of the Effects of Friction in the CERN LHC "Onein One" Dipole Magnet Model, Technical Note, CERN/MT-ESH/93-02 (Part 1,Part 2) (1993);

9. J. Carter, Z. Hajduk, K. Korcyl, J. Strong, A Second Level Calorimeter TriggerAlgorithm, ATLAS Internal Note, January 12 (1993);

10. J.C. Chollet, D. Froidevaux, S. Gadomski, L. Serin, Update on Latest Particle LevelSimulations for H -> ZZ* -> 4/, ATLAS note PHYS-No-019 (1993);

11. A. Czarnecki, M. Jeżabek et al., QCD Corrections to Decays of Polarised Charm andBottom Quarks, Preprint MZ-TH/93-35; HEP-PH 93-12249; TTP 93-32 (1993);

12. R. Decker, (Z. Was) et al., Tau Decays Into Three Pseudoscalar Mesons, PreprintTTP-92-25; Z. Phys. C58 (1993) 445-452;

13. D.B. DeLaney, S. Jadach et al., Renormalization Group Improved Exponentation of SoftGluons in QCD, Preprint UTHEP-93-0401 (1993);

14. DELPHI Collab., P. Abreu, (A. Budziak, Z. Hajduk, P. Jałocha, K. Korcyl,W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., Production ofA and A A Correlations in the Hadronic Decays of the Z°, CERN preprintCERN-PPE/93-171 (1993);

15. DELPHI Collab., P. Abreu, (A. Budziak, Z. Hajduk, P. Jałocha, K. Korcyl,W. Kucewicz, T. Lesiak, H. Pałka, G. Polok, M. Witek, A. Zalewska) et al., ProductionRate and Decay Lifetime Measurements of B° Mesons at LEP Using D, and <f> Mesons,CERN preprint CERN-PPE/93-176 (1993);

16. S. Gadomski, Studies of Pattern Recognition in SiTV, ATLAS note INDET-No-025(1993);

17. HI Collab., B.Andrieu, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, K. Rybicki,J. Turnau) et al., Results from Pion Calibration Runs for the HI Liquid ArgonCalorimeter and Comparison with Simulations, DESY Report 93-047 (1993);

18. HI Collab., I. Abt, (E. Banaś, J. Godlewski, L. Gorlich, L. Hajduk, M.W. Krasny,M. Lender, J. Martyniak, S. Mikocki, G. Nowak, J. Olszowska, K. Rybicki, J. Turnau) etal., The HI Detector at Hera, DESY Report DESY-93-103 (1993);

207

19. HI Collab., B. Andrieu, (E. Banaś, J. Godlewski, L. Gorlich, L. Hajduk, M.W. Krasny,M. Lender, J. Martyniak, S. Mikocki, G. Nowak, K. Rybicki, J. Turnau) et al., The HILiquid Argon Calorimeter System, DESY Report DESY-93-078 (1993);

20. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., A Measurement of Multi-Jet Rates in DeepInelastic Scattering at HERA, DESY Report DESY-93-137 (1993);

21. HI Collab., I. Abt, (L. Gorlich, L. Hajduk, M.W. Krasny, J. Martyniak, S. Mikocki,G. Nowak, K. Rybicki, J. Turnau) et al., Measurement of the Proton Structure FunctionF2 (x, Q2) in the Low x Region at HERA, DESY Report DESY-93-117 (1993);

22. S. Jadach, B.F.L. Ward, Role of A(LR) in High Precision Z Physics, PreprintUTHEP-93-0101 (1993);

23. S. Jadach, M. Skrzypek, B.F.L. Ward, Soft Pairs Real and Virtual Infrared Functions inQED, Preprint UTHEP-93-0301 (1993);

24. S. Jadach, Z. Was, B.F.L. Ward, The Monte Carlo Program KORALZ, Version 4.0, forthe Lepton or Quark Pair Production at LEP/SLC Energies, CERN ReportCERN-TH/7075/93 (1993);

25. KLM Collab., M.L. Cherry, (A. Dąbrowska, R. Hołyński, A. Jurak, A. Olszewski,M. Szarska, B. Wilczyńska, W. Wolter) et al., Interactions of 10.6 GeV/nucleon GoldNuclei in Nuclear Emulsion, INP Report 1637/PH (1993);

26. PHOBOS Collab., D. Barton, (A. Budzanowski, T. Coghen, R. Hołyński, J. Kotula,K. Pakoński, M. Stodulski, A. Trzupek, H. Wilczyński, B. Wosiek, K. Woźniak,K. Zalewski) et al., PHOBOS Conceptual Design Report, PHOBOS Report, July (1993);

27. RD-11 Collab., Z. Hajduk, W. Iwański, K. Korcyl, MODSIM II Simulations ofArchitectures for LHC Triggering Systems, Nota Wewnętrzna, Kraków, czerwiec (1993);

28. RD-11 Collab., Z. Natkaniec et al., HIMAX - HLPPI to MaxVideo Interface, EAST Note,CERN 93-04 (1993);

29. RD-11 Collab., K. Cetnar, (Z. Hajduk, W. Iwański, K. Korcyl, P. Malecki, A. Sobala)et al., Status Report - Embedded Architectures for second level Triggering, EAST Note,CERN 93-08 (1993);

30. RD-11 Collab., Z. Hajduk, (K. Korcyl, W. Iwański) et al., The FEAST Project, EASTNote, CERN 93-11 (1993);

31. RD-6 Collab., K. Cetnar, (J. Chwastowski, S. Jagielski, P. Malecki, Z. Natkaniec) et al.,Integrated Transition Radiation and Tracking Detector for LHC, RD-6 Status Report,Cem November 9 (1993);

32. RD20 Collab., A. Holmes-Siedle, (A. Moszczyński, M. Turała) et al., Radiation Toleranceof Single-Sided Silicon Microstrips, CERN preprint CERN-PPE/93-137 (1993);

33. RD20 Collab., (J. Blocki, A. Czermak, S. Gadomski, J. Godlewski, P. Jalocha,J. Kapłon, K. Pakoński, A. Moszczyński, M. Turała) et al., RD20 Status Report to theDRDC. Development of High Resolution Silicon Strip Detectors for Experiments at HighLuminocity at LHC, CERN Report CERN/DRDC 93-30 (1993);

34. S. Narison and K. Zalewski, "The Ratio of decay constants f(B) / f(D)", preprint CERNTH 7058/93;

35. E. Barberio and Z. Was, "PHOTOS- A universal Monte Carlo for QED radiativecorrections: version 2.0", CERN-TH.7033, October 1993;

36. A.H. Hoang, M. Jeżabek , J.H. Kuhnand T. Teubner, Hadron radiation in leptonic Zdecays, preprint TTP 93-34, Karlsruhe, Dec.1993.

208

SCIENTIFIC DEGREES:M.Sc. degrees

Maciej PrzybycieńArtur Wolak

Ph.D. degrees

Piotr Białas (supervisor: K. Zalewski)Wiesław Płaczek (supervisor: S. Jadach)Wojciech Burkot (supervisor: T. Coghen)Andrzej Olszewski (supervisor: W. Wolter)

LECTURES AND COURSES:The HEPD staff participates in the education process of physics at the Jagellonian Universityin Kraków. The following staff members participated in this activity in 1993:

• "Selected topics of the experimental techniques of high energy physics"undergraduate course led by P. Malecki and M. Turała

• "Experimental high energy physics"undergraduate course led by K. Rybicki

• "Experimental high energy physics"undergraduate course led by J. Bartke

• Students' seminar on experimental high energy physicsled by J. Figiel, J. Turnau, B. Wosiek and B. Pawlik

SEMINARS:

Joint seminars with the Theoretical Physics Departmentof the Jagellonian University

(the list for the autumn period is not complete)

08.01.1993 W. Busza (MIT): " The PHOBOS project at RHIC "15.01.1993 J. Szwed (Univ.): " Spin effects in deep inelastic scattering "22.01.1993 M. Różańska (INP): " Point-like galactic sources of photons

(the HEGRA experiment)"19.02.1993 W. Wolter (INP): " Evidence for a critical temperature in

high energy heavy ion collisions "26.02.1993 A. Dyrek (Univ.): " New experiment on electron scattering on nuclei

(the ELFE project) "05.03.1993 A. Sitarz (Univ.): " Non- comutative geometry "12.03.1993 M. Nowak (Univ.): " The Berry phase "19.03.1993 T. Lesiak (INP): " The Ab production in LEP experiments "26.03.1993 W. Florkowski (INP): " Screening masses of mesons "16.04.1993 E. Leader (London): " The EMC effect "

209

23.04.1993 G. Wonnser (LAL, Orsay): " Recent physics results from DELPHI usingits particle identification "

30.04.1993 A. Białas (Univ.): " Meaning of intennittency "14.05.1993 K. Fiałkowski (Univ.): " Power growth of cumulants in 3-d bins "21.05.1993 R.J. Peterson (Colorado): " Interactions of mesons with nuclei "28 05 1993 "*' r ^ u r n a u (INP): " First physics results from the HI experiment at

" ' HERA "08.10.1993 R. Hołyński (INP ): " Interactions of 10 A GeV gold ions with emulsion

nuclei "19.11.1993 J- Bartke (INP): " New results on Bose-Einstein correlations in collisions

of relativistic heavy ions "

Internal seminars

06.01.1993 A. Sobala: " New computer technology - hardware and software "

13.01.1993 A. Budziak: " Hadron identification in the DELPHI experiment (detec-tors FRICH and BRICH) "

20.01.1993 G. Wilk (Institute for Nuclear Studies, Warsaw): " Coherence and chaosin the interacting gluon model for hadronic and nuclear collisions "

24.02.1993 K. Korcyl: " Microprocessors in high energy physics - application to theDELPHI experiment "

10.03.1993 M. Krawczyk (Warsaw University): " Investigating the photon structurewith the HERA collider "

17.03.1993 A.. Filipkowski (Institute for Nuclear Studies, Warsaw): " What can westill learn from hypernuclei ? "

24.03.1993 M. Kowalski: " Project of the heavy ion experiment "ALICE" at theLHC machine "

31.03.1993 K. Golec-Biernat: " Small x physics with HERA - expectations" - part 107.04.1993 K Golec-Biernat: " Small x physics with HERA - expectations" - part 2

14.04.1993 E. Kryś (University of Łódź): " Investigation of the gamma- ray bunchesfrom point-like cosmic sources "

21.04.1993 S. Ratti (Univ. Pavia): " Photoproduction of charm at Fermilab "12.05.1993 B- Badelek ( Warsaw University): " New information on structure func-

tions at small x measured by the NMC Collaboration in CERN "19.05.1993 H. Pałka: " Searches for the Higgs particles in LEP experiments "07 06 1993 D - T r e i U e (DELPHI - CERN): " Physics for the future e+e" accelera-

tors"16.09.1993 Ch. Fabjan (CERN): " LHC physics with ATLAS"29.09.1993 Y. Arnoud (CEN Saclay): " All you wanted to know about B, but were

afraid to ask "06.10.1993 A. Górski: " Formfactor of the nucleon from the chiral soliton model of

Nambu-Jona and Lasinio "13.10.1993 H. Bialkowska (Institute for Nuclear Studies, Warsaw): " The conference

QUARK MATTER '93 in Borlange, 20-24 June 1993"

210

20.10.1993 H. Pałka : " The EPS Conference on High Energy Physics in Marseille,22-28 July 1993 "

27.10.1993 B. Pietrzyk (LAPP Annecy): " Does LEP test the standard model ? "03.11.1993 M. Różańska: " The TRISTAN II project at KEK "10.11.1993 Z. Hajduk: " Computer as a necessary aid for an engineer "17.11.1993 L. Leśniak: " Interaction of the J / * mesons with atomic nuclei at high

energies "24.11.1993 F. Kapusta (LPNHE Paris): " The photon structure function "01.12.1993 A.D. Martin (Durham,UK & ESTP): " Deep inelastic scattering " - part 108.12.1993 A.D. Martin (Durham,UK & LNP): " Deep inelastic scattering " - part 215.12.1993 A.D. Martin (Durham,UK & LNP): " Deep inelastic scattering " - part 322.12.1993 S. Jadach: " QED corrections to the precise measurements of luminosity

at LEP"

SHORT TERM VISITORS TO THE DEPARTMENT:Dr G. Wonnser - LAL, FrancjaDr D. Treille - CERNDr 0. Ullaland - CERNDr E. Dahl-Jensen - Niels Bohr Inst., KopenhagaDr F. Kapusta - Univ. Paris VI-VIIDr A. Elliot-Peisert - CERNProf. A. Wagner - DESYProf. G. Fliige - RWTH Aachen - CERNDr C. Fabjan - CERNDr P. Faugeras - CERNDr P. Rohmig - CERNProf. R. Sosnowski - INP WarszawaProf. J.A. Zakrzewski - LEP WarszawaDr G. Feofilow - Inst. of Physics, St.PetersburgDr 0. Godisov, Meson Scientific Association, St.PetersburgDr H. Kristiansen - SI OsloDr K. Ratz - CERNProf. S. Rati - Univ. PaviaDr Y. Arnound - CEN SaclayProf. A. Martin - Univ. DurhamDr B. Pietrzyk - LAPP AnnecyDr G. Wilk - LNP WarszawaDr M. Krawczyk - LEP ŁódźDr B. Badelek - IEP U WDr H. Białkowska - INP WarszawaProf. W. Busza - Massachusetts Institute of TechnologyDr B. Wyslouch - Massachusetts Institute of Technology (2 times)Dr J. Ryan - Massachusetts Institute of Technology

211

Department ofEnvironmental

andRadiation Transport

Physics

PL9601095

DEPARTMENT OF ENVIRONMENTALAND RADIATION TRANSPORT PHYSICS

Head of Department: Prof. J. ŁoskiewiczSecretary: E. Lipkatelephone: (48) (12) 37-02-22 ext.: 345e-mail: mazur@bron.ifj.edu.pl

PERSONNEL:Research staff:

Jerzy Łoskiewicz, Professor - Head of the DepartmentJan A. Czubek, ProfessorAndrzej Zuber, ProfessorJan Lasa, ProfessorPiotr Małoszewski, Assoc.ProfessorUrszula Woźnicka, Assoc.ProfessorKrzysztof Drozdowicz, Ph.D.Jan M. Zazula, Ph.D.Ireneusz Śliwka, Ph.D.Joanna Bogacz, M.Sc.Teresa Cywicka-Jakiel, M.Sc.Bogdan Drozdowicz, M.Sc.Dominik Dworak, M.Sc.Joanna Dąbrowska, M.Sc.Barbara Gabańska, M.Sc.Andrzej Igielski, M.Sc.Ewa Krynicka, M.Sc.Jadwiga Mazur, M.Sc.Eugeniusz Mnich, M.Sc, E.Eng.Janusz Swakoń, M.Sc. - postgraduate studentGrzegorz Tracz, M.Sc.Jarosław Płaszczyca, M.Sc.

Technical staff:Jacek Burda, Eng.Jerzy DysiekWładysław KowalikRyszard HaberAntoni RościszewskiJanina WanicTadeusz Z dziarski

Administration:Ewa Lipka

213

GRANTS:Grants from the State Committee for Scientific Research:

1. Prof. A. Zubergrant No 0 9602 030 04,"Investigations of noble gases in some mineral waters of southern Poland"

2. Prof. J. Lasagrant No 6-040591-01,"Measurements of atmospheric trace gases - greenhouse effect"

3. Prof. J.A. Czubekgrants No 6-631891-02 and 9-060691-01,"Physics of radiation transport in nuclear well logging"

4. Prof. J. Łoskiewiczgrant No 2-026091-01,"Determination of the influence of the humidity and ash content changes on neutron mea-surement of coal calorific value"

5. Assoc.Prof. U. Woźnickagrant No 2-019991-01,"Thermal neutron diffusion in small heterogenous media"

6. Dr. K. Drozdowiczgrant No 2 P302 074 05,"Implementation of a new model of the synthetic neutron-scattering function for calcula-tion of the diffusion parameters in finite hydrogenous media"

7. A. Igielski,grant No 2 P302 021 05,"System for an effective measurement of the decay constant of non-stationary neutronfields".

Grants from the International Atomic Energy Agency, Vienna (Austria):

1. Prof. A. ZuberCoordinated Research Programme on "Mathematical Models for Quantitative Evaluationof Isotope Data in Hydrology", (completed in June 1993).

2. Prof. J. ŁoskiewiczCoordinated Research Programme on "Nuclear Techniques in Exploration and Exploita-tion of Coal: On Line and Bulk Analysis and Evaluation of Potential EnvironmentalPollutants in Coal and Coke".

OVERVIEW:The research activity in the Department is carried out by the three Laboratories:

1. Laboratory of Environmental Physics (head: Professor Andrzej Zuber)

2. Laboratory of Neutron Transport Physics (head: Assoc.Prof. Urszula Woźnicka)

3. Laboratory of Radiation Transport Physics and Modelling (head: Professor Jerzy Łoskiewicz)

The Department employs: 4 professors, 2 associated professors (docent), 3 doctors , 11research physicists, 2 electronic engineers and 7 technicians of different specialities. The De-partment is engaged in theoretical and experimental research in the following areas:

214

1. The physics of tracer transport in porous (geological) media.2. The physics of molecular phenomena in chromatographic detectors.3. The physics of nuclear radiation transport in solids.4. The physics of neutron interactions with nuclei (low energy region).5. The physics of nuclear well loggings.

Basic research is carried out in order to apply the results to the following problems:

1. Development of a theory of solute transport in porous and fractured media for the im-provement of the interpretation of artificial and environmental tracer data. Studies related todetermining the origin of formation waters from environmental isotope and radioisotope data.Both directions of studies are related to the management and protection of ground water reser-voirs, mineral and thermal waters used for therapeutical purposes (in close cooperation withthe Faculty of Nuclear Physics and Techniques of the Academy of Mining and Metallurgy inKraków and the Institute fur Hydrologie, GSF, Neuherberg, Germany).

2. Environmental physics problems using gas chromatographic methods: measurements of freonsin the atmosphere, extraction of methane from the atmosphere for mass spectrography of carbonisotope ratio, methods of CO, CH4 and CO2 measurements in the atmosphere, the physics ofthe electron capture detectors in gas chromatography, measurements of trace concentration ofother gases in the atmosphere in connection with the greenhouse effect (in close cooperationwith the Faculty of Nuclear Physics and Techniques of the Academy of Mining and Metallurgyin Kraków).

3. Research into the physics of neutron transport in solids. The evaluation of neutron materialcross sections needed in the calculations of radiation fields in matter (in collaboration withthe Centro Atomico Bariloche, Argentina and with the Dept. of Reactor Physics of ChalmersUniversity of Technology, Gothenborg, Sweden).

4. Development of theoretical and experimental determines of the neutron and radioactiveparameters of geological formations and the technological parameters of some raw materials(mainly coals and coke). The methodology of the measurement of the decay constant of thethermal neutron fields in bounded heterogenous media using the pulsed neutron generator.

5. Establishing the calibration procedures for neutron well logging methods (in collaborationwith the Laboratory of Geophysics of the Academy of Mining and Metallurgy in Kraków).

6. Consulting in: radon and its decay products determination in air; application of geostatisticsin mining.

The results of basic research are published in open literature, whereas the results of appliedresearch carried out on the requirements of industry or other research institutes are included inthe internal reports.

Prof. J. Łoskiewicz

215

PL9601096 PL9601097 PL9601098

REPORTS ON RESEARCH:;f\. Theory of a semi-empirical way of neutron tool calibration;

further developmentJan A. Czubek

The true and apparent neutron parameters have been calculated for basic sedimentary rocksrepresented by SiO2, CaCO3 , CaMg(CO3)2 of variable porosity saturated with fresh water andbrines. The apparent parameters have been calculated for geometry requirements correspondingto the dual detector Western Atlas No 2435 tool situated inside boreholes of variable diameter.Using the semi-empirical approach the whole set of interpretation correction charts have beenestablished for this tool for the following conditions: variable borehole diameter, variable bore-hole and formation fluid salinity, variable tool stand-off inside the borehole, variable lithology,variable rock matrix absorption cross section. The agreement of interpretation charts obtainedby the semi-empirical method with those published by the Western Atlas was very good. Ina few cases the inadequacy of some of the Western Atlas results have been found. The trueneutron parameters have been calculated for the calibration pits at Zielona Góra. Then theapparent neutron parameters have been calculated for the DSN-102 tool (Polish design) andfor the tool, dead times 20 and 40 /is, the semi-empirical porosity calibration curves have beencalculated. For the 40 fis dead time a full set of interpretation charts have been designed.

Paper prepared:"Neutron tool calibration by scaling procedure" (submitted to Nucl. Geophys).

,, f Critical review of methods used in Poland for the radon andf its decay products determination

Jan A. Czubek

At the beginning of 1993 several laboratories involved in the monitoring of radiation hazardsin the atmosphere (underground mines, buildings, dwellings, etc.) reported serious discrepanciesobserved between the assay results obtained by different labs at the same spots. The review wasperformed on the demand of the President of the Polish Atomic Authority. It contains a shortreview of techniques used by different laboratories and very detailed analysis of all availableexperimental data. Several possible origins of observed discrepancies have been found and thelack of proper data treatment has been shown. Several recommendations to the Polish AtomicAuthority have been made in order to improve the reliability of assays.

Paper prepared:"Critical review of the routine measurements of radon and its decay products performed in themine conditions in Poland" (submitted to the Progress in Nuclear Technique, in Polish).

r? The use of a hydrogen signal in correcting the carbonconcentration from 12C(n,n'7)12C reaction in coal

T. Cywicka-Jakiel, J. Loskiewicz and G. Tracz

The idea to use the 2.22 MeV proton-neutron capture 7-ray as the correcting signal forcarbon content measurements has been shown in our earlier papers [1,2].

The range of change of the 4.43 MeV carbon 7-ray intensity from 12C(n,n'7)12C reactionwith changing water content of coal was investigated for different coal samples.

The decrease in carbon 7-ray intensity is significant and results in l-f3 % per one percent ofadditional water. We do think that the use of 2.22 MeV hydrogen 7-ray correcting signal will

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PL9601099 PL9601100 PL9601101

make the use of the inelastic neutron scattering gauges more precise in the measurement of thecalorific value of coal and its carbon content using inexpensive Nal(Tl) scintillation detectors.

References:

1. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, Nuci. Geophys. (1993) 7, 529-537.2. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, The Journal of Coal Quality (in press).

Development of natural radioactivity measurements / / J. Bogacz, T. Cywicka-Jakiel, J. Łoskiewicz, J. Mazur, J. Swakoń and G. Tracz

In 1993 the Laboratory of Physics of Radiation Transport and Modelling obtained fromthe State Committee of Nuclear Security and Radiological Protection the ability to certificatethe value of concentration of natural radionuclides in building and waste materials. The naturalradioactivity measurements are carried out for samples from different industrial places. The newcomputer programme KONGAM for gamma-ray spectra analysing was prepared and tested.

Numerical calculations of doses at high energy accelerators ) fjfJ

D. Dworak and J.M. Zazula

A new field of activity was opened with radiation transport numerical calculations of doses athigh energy accelerators. We have taken part in calculations performed for the future LHC ac-celerator and ATLAS detector at CERN Geneva. More substantial collaboration was developedwith the DESY Radiation Protection Group (Dr Klaus Tesch), which resulted in the modifiedversion of the FLUKA code, calculations of neutron transport in labyrinths, estimations of theneutron dose equivalent attenuation coefficient for concrete shielding at high energy proton ac-celerators (HERA ring). 13 common reports and papers were published during 1989-1993. Wehave now entered into official collaboration between our groups.

M e t h o d o l o g y of m e a s u r e m e n t of t h e t h e r m a l n e u t r o n t i m e jff

d e c a y c o n s t a n t o n p u l s e d n e u t r o n g e n e r a t o rK. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka

A pulsed beam of fast neutrons produced by a pulsed neutron generator is the source ofthe decaying thermal neutron flux which can be observed in a medium of interest. Knowledgeof the decay constant of the thermal neutron flux in a bounded medium gives information onthe thermal neutron transport and diffusion parameters of the medium. The high values of thedecay constant (which correspond to the thermal neutron life time in the range of 20 /xs to 50 /xs)have been of interest in the present research. These values characterize the decay of the thermalneutron fields in small volumes of the investigated materials having a high absorption crosssection and/or characterized by a high heterogenity. Theories which describe the behavior ofthe time dependent thermal neutron field in bounded media can be verified by a measurementof the fundamental mode of the time decay constant in the medium of interest. The valuesof the decay constants should be measured with an accuracy better than 0.5 per cent and themeasurement time should be reduced to a minimum. This requires a proper experimental systemwith precisely defined parameters.

The method of measurement of the thermal neutron time decay constant has been directedto the measuring and recording system which consists of a thermal neutron 3He detector, pulseforming and amplifying electronics, and the multichannel time analyzer Canberra 35 + [2]. The

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main item of the system is a fast multiscaler (MCS 7880) and the accuracy of the measurementis strongly influenced by its performance and possibilities.

The methodology of the measurement has to be adjusted to the equipment used. An experi-mental verification of a dead time of the instrumentation system has to be done and a count-losscorrection has to be introduced to the data collected by the time analyzer. Optimum parametersfor the measurement and for the determination of the decay constant have to be adjusted to theinstrumentation system being used. The operation system of the registration part of the Can-berra 35+ analyzer and the multiscaler have forced us to develop an unconventional procedureof the die-away curve collection and of the determination of the decay constant. The procedureis presented in [2] including a detailed statistical description and results of test measurements.

An application of a fitting procedure to experimental data which can be represented by a sumof decaying exponentials is presented in [1]. The method can be used for a general case when anynumber of the exponentials with a constant component is taken into account. Attention is paidto the problem of separation of the fundamental mode decay constant in the presence of highermodes and background. For this purpose a computer program has been written that within aset of experimental data performs a "fit" to one and two exponentials with a constant term.The "fit" interval can be moved along the time axis and in this way the found estimators of thedecay constants can be observed as a function of the initial delay time. This offers a possibilityto separate the fundamental term with high precision. A detailed discussion of statistical errorsis given, utilizing the variance method.

The methodology can be applied to instrumentation systems developed for a thermal neutrontime decay constant measurement different from the particular one used in the INP.

References:[1] K. Drozdowicz, B. Gabańska and E. Krynicka, INP Report No 1635/PM (1993),

Institute of Nuclear Physics, Kraków.[2] K. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka, INP Report No

1651/AP (1993), Institute of Nuclear Physics, Krakow.

Statistical analysis of the calibration method of the thermalneutron absorption cross section determination

E. Krynicka

A calibration method for the determination of the thermal neutron macroscopic mass ab-sorption cross section S f for rock samples has been derived. The cross section is determinedon the basis of only one measurement of the time decay constant A of thermal neutrons in aparticular cylindrical system where the investigated sample is surrounded by a moderator offixed size H^g- A big advantage of the method is that the calibration lines t>S(A) | H.tg (therelationship between the absorption rate t>£ of the sample and the measured decay constant A)have been obtained using real rock samples [1,2]. The total number of the investigated samplesis 85. Individual calibration lines for different sizes K^g of the moderator have been obtainedusing / (equal from 20 to 60) independent experimental points {A,, t;St} | H2g-

A computer simulation method has been utilized for an estimation of the standard deviation<r(t>£ ) of the absorption rate vE of the measured composed sample [3]. The standard devia-tion 0-(t;£ ) is influenced by both the standard deviation <r(\N) of the decay constant measuredfor the investigated sample and the statistical uncertainty of the relevant calibration line. Theuncertainty of the calibration line follows the statistical uncertainty of each experimental point(Xi, viii) | H"ig which results from an existence of the standard deviations (r(\i) of the measureddecay constant A; and <r(v%i) of the corresponding absorption rate vE; of the sample.

218

Then, a simple calculation is performed to achieve the corresponding macroscopic massabsorption cross section S*f of the investigated rock matrix itself and its standard deviation

References:[1] E. Krynicka, INP Report No 1541/AP(1991), Institute of Nuclear Physics, Kraków.[2] E. Krynicka, Nucl.Geophys. (1994) — in print.[3] E. Krynicka, INP Report No 1627/AP(1993), Institute of Nuclear Physics, Kraków.

LIST OF PUBLICATIONS:I. Articles:

1. T. Cywicka-Jakiel, J. Łoskiewicz and G. Tracz, "The use of hydrogen signal in correctingthe carbon concentrations from 12C(n,n*7)12C reaction in coal", Nucl. Geophys. 7 (1993)529.

2. J.A. Czubek, "Neutron parameters of brines", Nucl. Geophys. 7 (1993) 1-34.3. J.A. Czubek, "Neutron tool calibration by scaling procedure", (submitted to Nucl.

Geophys.).4. J.A. Czubek, "Critical rewiev of the routine measurements of radon and its decay products

performed in the mine atmosphere in Poland", (submitted to the Progress in NuclearTechnique, in Polish).

5. P. Małoszewski and A. Zuber, "Principles and practice of calibration and validation ofmathematical models for the interpretation of environmental tracer data in aquifers",Adv. Water Resour. 16 (1993) 173-190.

6. P. Małoszewski and A. Zuber, "Tracer experiments in fractured rocks: matrix diffusion andthe validity of models", Water Resour. Res. 29 (1993) 2723-2735.

7. A. Fasso, A. Ferrari, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "Comparison ofFLUKA simulations with measurements of fluence and dose in calorimeter structures",CERN/TIS-RP/93-2/PP, Geneve, Dec.1992, accepted for publ. in Nucl. Instr. Meth.

8. J. Łasa, B. Drozdowicz and I. Śliwka, "Physical model of the electron capture detector",Chromatographia, (in press).

9. H. Dinter, D. Dworak and K. Tesch, "Attenuation of the neutron dose equivalent inlabyrinths through an accelerator shield", DESY Report D3-74, and Nucl. Instr. Meth.A333 (1993) 507.

10. J. Lasa, I. Śliwka, B. Drozdowicz and J. Rosiek, "Measurements of trace atmosphericgases active in greenhouse effect", Environment of Poland and Global Change, PANKrakow (in Polish, in press).

11. J. Lasa, "Influence of trace gases on the climate of Earth", Problemy EkologiczneKrakowa, No 16. Edited by AGH for Polski Klub Ekologiczny, Kraków 1993 (in Polish).

12. A. Zuber, "Calculation of hydraulic conductivity from grain-size distribution curve",Współczesne Problemy Hydrogeologii, Oficyna Wyd. Sudety, Wrocław 1993, pp. 415-419(in Polish).

13. J. Motyka and A. Zuber, "Parameters of fissures and the hydraulic conductivity of rocks",as above, pp. 421-425 (in Polish).

14. A. Zuber, K. Osenbrueck, S.M. Weise, J. Grab czak and W. Ciężkowski, "Noble gases andtheir isotope ratio in thermal waters of Lądek Zdrój and Cieplice Śląskie", as above, pp.151-156 (in Polish).

219

15. I. Pluta, A. Zuber, J. Grabczak, R. Śląski and M. Bebek, "Origin of brines in the southernpart of the Upper Silesian Coal Basin (GZW) as determined in the Morcinek coal mine",as above, pp. 95-100 (in Polish).

16. S. Geyer, J. Grabczak, I. Śliwka and A. Zuber, "Application of C-14 in DOC and chlorinecompounds to age identification of inflows to the Wieliczka salt mine", as above, pp.353-357 (in Polish).

II. Contributions to Conferences:

1. A. Fasso, A. Ferrari, J. Ranft, P. Sala, G.R. Stevenson and J.M. Zazula, "FLUKA 92",presented at the Workshop on Simulation of Accelerator Radiation Environments, SantaFe, USA, Jan. 1993.

2. P. Aarnio, A. Fasso, A. Ferrari, J-H. Mohring, J. Ranft, P. Sala, G.R. Stevenson and J.M.Zazula, "Electron-photon transport: always as good as we think? Experience withFLUKA", presented at the Int. Conference on Monte Carlo Simulation in High Energyand Nuclear Physics, Tallahassee, USA, Feb. 1993.

3. P. Aarnio, A. Fasso, A. Ferrari, J-H. Mohring, J. Ranft, P. Sala, G.R. Stevenson andJ.M. Zazula, "FLUKA: hadronic benchmarks and applications", presented at the Int.Conference on Monte Carlo Simulation in High Energy and Nuclear Physics, Tallahassee,USA, Febr. 1993.

4. J. Lasa, "The Earth ozon layer", presented at the Commission of Health Protection, PolishAcademy of Science (PAN), 17 June 1993, Kraków.

5. A. Korus and J. Lasa, "Estimation of the applicability of the photo-ionization detector(PID) to analyse stable gases " (poster), VI National Chromatography Seminar "Science- industry; modern analytical methods", Lublin, 15-17 Sept. 1993.

6. B. Drozdowicz and J. Lasa, "Measurements of CO, methane and carbon dioxide introposphere" (poster), as above.

7. I. Śliwka, B. Drozdowicz, J. Lasa and J. Rosiek, "A method of measurements of chlorinecompounds in the air with enrichment" (poster), as above.

8. T. Cywicka-Jakiel, J. Loskiewicz and G. Tracz, "The hydrogen signal use in correcting theneutron measurements of the calorific value of coal", presented at The 1993 Int.Symposium of Int. Atomic Energy Agency "On-line Analysis of Coal", Vienna, Oct.1993.

9. T. Cywicka-Jakiel, "Ecological aspect of the determination of coal calorific value using theinelastic neutron scattering method", presented at the International Workshop,"Ecological aspects of underground mining of usable mineral deposits", Szczyrk, Poland,23-25 Nov. 1993.

10. J. Lasa, "Applications of gas chromatography in investigations of environmentalpollution", invited talk for the 2-nd Conference on "Geochemical, hydrochemical andbiochemical changes in the environment in the areas of anthropogenic pression", Krakow,9-10 Dec. 1993.

III. Reports:

1. E. Krynicka, "Determination of the thermal neutron absorption cross section for rocksamples by a single measurement of the time decay constant", INP Report No 1627/AP,Kraków 1993.

2. K. Drozdowicz, B. Gabańska and E. Krynicka, "Fitting the decaying experimental curve bya sum of exponentials", INP Report No 1635/PM, Krakow 1993.

220

3. K. Drozdowicz, B. Gabańska, A. Igielski, E. Krynicka and U. Woźnicka, "Methodology ofmeasurement of thermal neutron time decay constant in Canberra 35+MCA system",INP Report No 1651/AP, Kraków 1993.

4. G.R. Stevenson and J.M. Zazula, "Estimates of dose in the LHC Tunnel due to beam-gasscattering", CERN/TIS-RP/TM/93-6, Geneve Dec. 1992.

5. J.A. Czubek, T. Kuc and P. Olko, "Report of the Committee for verification of methodsused in Poland to the radon and its decay products determinations", (in Polish), June1993, pp. 173.

6. J.A. Czubek, "Calculation of general neutron parameter for porosity, lithology and salinitydetermination", report to the Polish Scientific Committee for the grant No 9 9047 9102-P02, Nov. 1993, pp. 66 (in Polish).

7. J.A. Czubek, "Check of semi-empirical method of calibration for the tools DSN-102 andPKNN-3", report to the Polish Scientific Committee for the grant No 9 9211 93C, Nov.1993, pp. 10 + programs: NEWCROSS, SLOWN22A, NEROTH22, REPRNT22 andLMBIRN22 (in Polish).

8. J.A. Czubek, "Catalogue of neutron parameters for Zielona Góra calibration blocks", reportto the Polish Scientific Committee for the grant No 6 6318 91 02, Dec. 1993, pp. 17 (inPolish).

9. J. Łasa, I. Śliwka, B. Drozdowicz and J. Piotrowski, "Methodology of applications ofelectron negative tracers in investigations of gastightness of industrial vessels andexchange of air in buildings", INP Report No 1636/AP, Krakow 1993.

PARTICIPATION IN CONFERENCES AND WORKSHOPS:J. Dąbrowska, "Seminar on advanced Monte Carlo computer programs for radiationtransport", 27-29 April 1993, Centre d'Etudies Saclay, France.

LECTURES AND COURSES:K. Drozdowicz:Lecture: "Research activities at the Institute of Nuclear Physics in Kraków. Applications ofnuclear radiation interactions in matter", Centro Atomico Bariloche, CNEA, Argentina, March1993.

K. Drozdowicz:Lecture: "Thermal neutron macroscopic absorption cross section measurement and relatedneutron diffusion problems", Centro Atomico Bariloche, CNEA Argentina, March 1993.

K. Drozdowicz:"Physics of a measurement of the thermal neutron absorption cross section of rock materials",a course for students of Universidad Nacional de Cuyo, Instituto Balseiro, Bariloche,Argentina, March 1993.

K. Drozdowicz:Lecture: "Experiment for water-flow measurement by the pulsed-neutron activation",Chalmers University of Technology, Dept. of Reactor Physics, Goeteborg, Sweden, Oct. 1993.

/. Lasa:Lectures and practicals on "Chromatographic analytical methods" for Ph.D. students of theFaculty of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Kraków.

221

U. Woźnicka, A. Igielski and B. Gabańska:"14 MeV pulsed neutron generator - geophysical application", a course for students of theFaculty of Geology, Geophysics and Environmental Protection, Academy of Mining andMetallurgy, June 1993.

A. Zvber:"Tracer methods in hydrology", 12-hours course for students of the Faculty of Geology,Geophysics and Environmental Protection, Academy of Mining and Metallurgy, Kraków.

INTERNAL SEMINARS:

1. J. Łoskiewicz, "Estimation of the Ea value from K,TJ,Th concentrations and rock lithologydata", 2 Feb. 1993.

2. T. Cywicka-Jakiel, "News on a determination of the calorific value of coal using neutroninelastic scattering method", 3 March 1993.

3. D. Dworak, "Calculation of gamma doses outside shields of the high energy protonaccelerators", 6 April 1993.

4. J. Swakoń, "Analysis of complex gamma-ray spectra using the method of the standardgamma-ray spectra", 18 May 1993.

5. J. Dąbrowska, "A new method to asses Monte Carlo convergence", 1 June 1993.6. J. Łoskiewicz, "Use of the hydrogen signal for a correction of results of measurements of the

neutron inelastic scattering on carbon in coal", 5 Oct. 1993.7. J.A. Czubek, "Radon measurements in Poland", 16 Nov. 1993.8. K. Drozdowicz, "Water-flow measurement by the neutron activation", 23 Nov. 1993.9. G. Tracz, "Analysis of the coal composition using a pair spectrometer", 21 Dec. 1993.

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Dr S.M. Weise - Institute for Hydrology, Neuherberg, Germany.2. Dr K. Osenbrueck - University of Heidelberg, Germany.3. Mr Wang Zhiming - Deputy Director of Res. Dept., China National Nuclear Industry

Corporation, Beijing, China.4. Dr Hu Shaokang - China National Nuclear Industry Corporation, Beijing, China.

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Department of

andEnvironmental

Biology

PL9601103

DEPARTMENT OF RADIATIONAND ENVIRONMENTAL BIOLOGY

Head of Department: Assoc. Prof. Antonina Cebuhka-WasilewskaSecretary: Ewa Barteltelephone: (48) (12) 37-02-22 ext.: 322e-mail: WASILEWSKA@VSB01.IFJ.EDU.PL

PERSONNEL:

Research StaffAntonina CEBULSKA-WASILEWSKA Assoc.Prof.,Janusz GAJEWSKI M.Sc,Jerzy HUCZKOWSKI Ph.D.,Małgorzata KAJTA M.Sc.,Beata KSIAŻKIEWICZ M.Sc.,Bogusława KRZYKWA M.Sc.,Małgorzata LITWINISZYN M.Sc.,Barbara ŁAZARSKA Ph.D.,Barbara PAŁKA Ph.D.,Igor PAWŁYK M.Sc.

Technical StaffJolanta ADAMCZYK,Ewa BARTEL,Barbara JANISZEWSKA M.Sc., Eng.,Tomasz JANISZEWSKI,Ewa KASPER M.Sc.,Stanisław KRASNOWOLSKI M.Sc,Krystyna KULCZYKOWSKA M.Sc, Eng.,Monika MOSZCZYŃSKA M.Sc, Eng.,Bożena POŁCZYŃSKA,Janusz SMAGAŁA Eng.,Anna WIERZEWSKA M.Sc,Joanna WILTOWSKA.

GRANTS:

1. Assoc. Prof. A. Cebulska-WasilewskaEnvironmental Studies:a) PECO 10964 CIPDCT 925100 (Joint Research CEC Project)b) PECO 6943 East/West CEC grant No - ERB 3510 PL920811

223

Radiobiology:a) PECO 2992 CIPDCT 925008 (Joint Research CEC Project)b) PECO 2981 East/West CEC grant No - ERP 3510 PL922981c) BMH-CT 92-0859 PL1012, PL93-1013 (Joint Research Project)2. Dr B. ŁazarskaJoint grant No 550079102 (the State Committee for Scientific Research) with the Academy ofAgriculture, Kraków, Poland.

OVERVIEW:

This year, our research programme was particularly exciting as the new group structureswere established and newly denned projects were appearing in the Department of Radiation andEnvironmental Biology:1. Laboratory of Radiation and Environmental Cytogenetics,2. Laboratory of Radiation and Environmental Mutagenesis,3. Neutron Therapy and Preclinical Studies Group.

This year we reorganized our laboratory for cytogenetics studies while continuing our basicresearch into the genotoxic effects of ionizing and nonionizing radiation, chemicals mutagenicin the environment and their interaction with radiation. In two types of eucariotic cells wecontinued the studies begun last year on the relationship between the amount of energy depositedand the various types of damage that result from the exposure to fast neutrons and X-rays. Weextended our studies to look at the effects of low radiation doses in human blood lymphocytesand we are now looking at possible increased levels of mutation in TSH system resulting fromlow radiation doses of X-rays and 5.6 MeV neutrons. Finally, we started the new radiobiologyprojects concerning comparisons between relative biological effectiveness of high LET radiation,particularly neutrons from HFR JRC in Petten and fast neutrons from U-120 in Cracow inthe induction of various genetic end-points. Our proposals won grants to join the ongoing CECproject CLLNCT aimed at the application of fission neutrons for cancer therapy. In co-operationwith the Radiobiology Group from the National Radiological Protection Board, Chilton, UKand the Radiobiology Group from ECNICE in Petten, using our two best assays ( TSH andCA in lymphocytes), we made our first attempt to compare experimentally the effectiveness offission neutrons and fast neutrons in the induction of gene and lethal mutations in Iradescantiaand chromosome aberrations in human blood lymphocytes. The studies of cytogenetic damageinduced by fast neutrons are almost finished, while fission neutrons are still under study.

Our environmental studies were also going exceedingly well. With an application of genemutations in Tradescantia assay (TSH) we continued studies into the genotoxic effects of organicchemicals related to pesticides. We were looking for the results of both types of treatment:individual and combined with radiation. In the field applications of TSH assay for in situstudies of genotoxicity of ambient air pollution, we repeated monitoring at site of the primaryschool No 12 in Cracow. At this site a new shield against traffic noise and pollution had justbeen constructed, and our data showed a great improvement in air quality. Our studies insitu with the TSH as a bio-indicator also demonstrated that a high genotoxic effect was to beobserved at the tested sites along the main traffic routes in Cracow. In some places the averagemutagenic effect observed was higher than that observed in the vicinity of the petroleum plantin Płock. Due to our long term studies into the genotoxic effects of benzene related compounds,two European Community grants (training + research) were given to join the ongoing projectin the field of environmental studies aimed at finding the cause or early markers and indicatorsof the process involved in cancer and genetic damage induction. These grants will allow us to

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PL9601104

broaden further our research field, and to develop Unking programs between the Department ofRadiation Genetics and Chemical Mutagenesis at the Faculty of Medicine at Leiden University,the Department of Genetic BIBRA, Carshalton and our Department. The studies on cytogeneticdamage in blood lymphocytes of persons occupationally exposed to benzene related compoundshave already been started, following parallel studies at BIBRA into the checking of the presenceof oncoproteins.

The third line of research in our Department is more linked to the possible improvementthat might be achieved in clinical cancer therapy. A. Cebulska-Wasilewska was successful witha grant application to Gray Laboratory, Mount Vernon Hospital for participation in ESTROAdvanced Radiobiology Course for Radiotherapists in late April 1993, which was followed bya 2-day workshop devoted to techniques commonly used at Gray Laboratory. These includedcell culture, animal studies and molecular biology. Our own preclinical studies on early and latehealth tissue response performed on C3H mice have been going on intensively this year. Theyconcerned various dose fractionation systems, and aimed at replacing the classical fractionationsystem with a new shorter one that would give good clinical results. It should also be noted,that besides our research goals we continued our duties connected with therapy treatment (oneweek per month cycle), performing irradiation of patients of the Oncological Centre in Cracowusing the fast neutron beam from 9Be + d reaction at our U-120 cyclotron.

, \

Assoc. Prof. Antonina Cebulska-Wasilewska

REPORTS ON RESEARCH:

Comparison between ambient air genotoxicity in urban areaswith genotixicity of known mutagens

A. Cebulska-Wasilewska

The aim of the studies begun in 1991 was to compare the genotoxicity of ambient air intwo urban areas affected by benzene and petrol associated compounds. Various sites have beentested in the Cracow area and in the vicinity of a petroleum plant in central Poland.

Iradescantia clone 4430 plants grown according to the conditions described elsewhere [1,2],were exposed on sites potentially in danger of chemical pollution. In somatic cells of Tradescantiagene, lethal mutations rates as well as disturbance of cell cycle were measured, beginning onthe 11th day of exposure, the biological effect of exposure being expressed as the number ofmutations per 100 hairs.

Studies performed in Cracow resulted in the highest value of mutation frequency, which wasobserved in the year 1991, at the site situated about 30 meters from the heavy traffic road-crossing near primary school No 12. The biological effect observed in plants exposed at thatplace was significantly higher than at the site which was not affected by traffic pollution from thecrossroads (Table 1). In 1992 biological monitoring with TSH assay was performed in Cracowat the sites situated along traffic routes. Differences between the levels of mutation observedat those sites ranged from 0.25 to 0.33 mutations per 100 hairs. Chemical monitoring datareported for the time of plants exposition showed that the levels of pollutant contents in the airwere much below permissible levels. In spite of that fact, the biological effects measured at sites

225

affected by traffic pollution were significantly higher than those observed at the site situatedat the Institute. In 1993 biological monitoring was repeated when a screen shielding primaryschool No 12 had been constructed. A significant decrease in the biological effects induced inplants exposed at site of the school was observed (Fig.l). There was no significant differencebetween the effects measured at the same sites as were tested in 1991. Biological monitoringwith TSH-assay confirmed that the screen protection from traffic pollution works effectively.

Biological monitoring in the city of Płock area revealed the average mutation rate detectedwas comparable or lower than that observed in Cracow. There was also a variation between thelevels of mutation observed at various sites tested. Mutation frequencies appeared to be weaklydependent on the distance from the Petroleum Work (MZPiR) center (Fig.2). The correlationsbetween mutation frequencies induced and chemical concentrations in the air were stronger thanbetween mutations and the distance from the petroleum plant. It means that traffic in the citycenter significantly contributes to both pollution and the final biological effect. It can also playan important role in physiological cellular processes [5]. The average mutation rate detected inthe Płock area in 1993 achieved the lowest value, 0.24 mutations per 100 hairs, since the studiesbegan in 1991.

Many mutagens and carcinogens including radiation, the well known mutagen like EMS andsuch carcinogenic agents, classified as self pollution, like cigarette smoke and filter residue, werealso tested by the bio-assay based on gene mutations in somatic cells of Tradescantia (Table2)[3-5]. The last columns in Table 1 present X-ray doses which would induce quantitativelythe same effects in TSH as the biological effects observed after the exposures under study. Gy-equivalents calculated for biological effects in TSH caused by in situ exposures greatly extendthe permissible annual effective dose. The data presented above allow us to conclude that themutagenic effects of chemical pollutants present every day in the ambient air of the urban areas ofCracow and Płock, particularly at the places affected by benzene or traffic associated pollution,are comparable to the biological effect which was caused by the fallout from the serious nuclearaccident in Chernobyl [6] or with known strong mutagens and carcinogens.

Mutation frequently detected•t Public School No IS

I - 1991 av. mirt. rat* 0.40

[~|- 1993 au. mut raU 0.25

to 11I ri I rl

12 13 14 1513 14 15 IB 17

Days of exposureIB 19 20

Fig.l. Mutation values induced in TSH atpublic school No 12 before and after theshield construction.

BIOLOGICAL MONITORING

PŁOCK 1993

0.203 5 B 10 13 15 IB 20 23 25 28 30 33

Distance from Petroleum. Plant 1 1cm 1

Fig.2. Relationship between mutation ra-tes induced in plants exposed and distancefrom the work center.

226

TABLE 1.

MEAN VALUE OP MUTATION FREQUENCIES DETECTED in situ BY TSH ASSAY IN DIFFERENT

PERIODS AND PLACES AND in vitro AFTER MUTAGENIC TREATMENT

1 SiteKrakow:(IFJ) May 1991(1)**

(2)(3)(IFJ) May 1992

(1)(2)(3)(IFJ) May 1993(1)**

(2)(3)Płock:(Z) June 1991

(1)(2)(3)

(Z) September 1991

(1)(2)(3)(Z) September 1992

(1)(2)(3)(Z) June 1993

(1)(2)(3)cigarette smoke 6hfilter deposit 10 fAEMS 20 //I (0.045%)

NOH

226154747330316

14002714265013815246056

700830164693141758105960541210

-98550

105400768150

1176791567043144

631118133253041636080

19019227952

136380120090

1113808

[7][7][2]

PF+SE

0.20 +0.0100.40 +0.0250.28 +0.026

0.350.19 +0.0090.33 +0.0160.25 +0.010

0.290.24 +0.0250.26 +0.0230.22 +0.010

0.24

-0.33 +0.0230.25 +0.016

0.30

0.36 +0.0070.41 +0.0230.29 +0.016

0.320.39 +0.0250.37 +0.0230.27 +0.023

0.330.28 +0.0150.25 +0.0130.21 +0.015

0.23

0.08 + 0.0040.19 + 0.0100.60 + 0.003

STF

0.370.290.310.360.151.380.151.000.550.930.840.89

-0.200.120.15

0.783.291.341.600.601.950.510.941.930.820.520.90

---

Gy-equiv. [Gy] ||

0.0020.050.02

0.036*

0.030.0130.0220.0160.0160.0070.011

-0.0240.0130.024

0.0380.0490.0220.0290.0440.0400.0180.0290.0200.0130.0040.009

0.0180.0420.133

NOH - number of analyzed hairs, PP - gene, STF - lethal mutation frequency, (*) - level taken as acontrol value, (**) - public school No 12. Mutation's rates detected in the city: (1) - the highest, (2) -the lowest, (3) - an average

References:

1. Underbrink A.G., Schairer L.A., Spparrow A.H., (1973) in: Chemical mutagens: Principles andMethods for their detection. Ed. A. Hollaender Plenum Press, New York-London, Vol.3, 171-207.

2. Cebulska-Wasilewska A., IFJ Raport, No 1335/B (1986).3. Cebulska-Wasilewska A., Nukleonika, Vol.33, No 4-6 (1988) 91-105.4. Cebulska-Wasilewska A., Kuternozińska, Applied Biology 1993 (in press).5. Cebulska-Wasilewska A., Pawłowski J., Raport IFJ, No 1587/B (1992).6. Cebulska-Wasilewska A., (1992), Mut. Res. (in press).

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PL9601105

Induction of chromosomal aberrations in human lymphocytesby X-rays and fast neutrons

A. Cebulska-Wasilewska, A. Wierzewska E. Kasper and B. Krzykwa

The most developed and efficient way in which irradiation caused damage can be checkedis the lymphocyte model system based on the in vitro culture of human lymphocytes deliveredby the basal blood vessels. After irradiation culturing is terminated at the first mitosis, somechromosomal aberrations become visible in the cytogenetics samples slides. The method basedon the screening aberrations known as the ring and dicentric chromosomes has been acceptedall over the world as the basic for the measurement of the absorbed dose [1].

This paper presents some results of studies investigating the ability of different amountof energy and different types of radiation to induce chromosomal aberrations. The efficiencyof neutrons as well as X-rays to induce such abnormalities (rings and dicentrics) in humanlymphocytes was assessed. A comparison between these efficiencies was used to establish therelative biological efficiency (RBE) for 5.6 MeV average energy neutrons.

Blood samples were irradiated with neutron doses of 0.07 - 2.5 Gy produced by the U-120 cyclotron. X-radiation ranged from 0.1 to 5.0 Gy and was generated by a source with thefollowing parameters: 250kV, llOR/min, 0.5mm Cu filter. Blood samples collected from middle-aged volunteer donors, was placed into sterile and hemiparesis glass tubes and then irradiatedat room temperature. Lymphocytes were cultured in new, sterile reseals poured with mediacontaining Eagle medium with antibiotics (80%) and fatal calf serum (20%). Cell divisions werestimulated for 46 hr (previously 52 hr) with the LF-7. After that time colcemid was added intothe media and 2 hr later culturing was stopped. The collected samples were then stained withGiemsa solution and analyzed for the presence of chromosomal aberrations.

It was assumed that the measure of biological effect would be the number of ring and dicentricchromosomes per cell and the number of cells with chromosomal aberrations. Depending on thedose 200 to 700 metaphases were analyzed. For several doses of X-rays and neutrons, the yieldhas been measured. Fig. 1 demonstrates the results as regards the influence of irradiation onthe number of chromosomal aberrations induced in human lymphocytes by different doses offast neutrons and X-rays. Fig. 2 oversteps curves which show the number of aberrations percell depending on the neutrons dose.

Comparison between the X-ray and neutrons dose response curves shows that neutron doses,which induce the same arbitrarily chosen level of chromosome aberration, are much more efficientthan X-rays. Relative biological effectiveness depends on dose and in a range of investigateddoses the RBE changes from 3.7 at low doses to 2.7 for high doses region. The data in Fig.1 shows the number of aberrations induced depending on the X-ray doses in a linar-quadraticfunction. Generaly, the number of rings as well as dicentric chromosomes depends on the doseof irradiation and should be described by the following function [2]:

Y = C + aD + f3D2

where:Y - yield of chromosome aberrationsa - the linear coefficient(3 - the dose-squared coefficientD - dose of irradiation.For fast neutrons quadratic relation is rather bad and this dependence should be linear. The

best fit for our data results in the following equations:for X-rays,Y = C + 0, 05148Z? + 3,66910-2£2

for neutrons:a) Y = 0,508-D and

228

PL9601106b)Y = 1,25-D.Equation "a" describes the best fit for the data achieved in different dosimetry and culture

conditions [3], with a slightly longer time of culturing (52h), equation "b" emerged from the dataobtained in a new conditions of culture [1]. The comparison between alpha parameters derivedfrom the best fit for neutrons and X-rays dose response curves results in two RBE values for5.6 MeV neutrons [(a)-9.9 and (b)-24.3]. It seems that the first value was a little lower than thevalue expected from Lloyds estimation [2], on the base of which, RBE should be in the range of14 for 14.7 MeV neutrons and 59 for 0.7 MeV neutrons. The RBE value 24.3 resulting from therecent data obtained after modification in the method and new dosimetry gives a much betterestimation, however the studies of the reason for the observed difference should be continued.

&.

»0.M

•OOJO

iM i'io Vii'Dose ( Gy )

Fig.l. Dose respouse relationship for the in-duction of dicentrics and rings aberrations byX-rays and fast neutrons.

O.Ó0 i.4» IM *M' Hi"Neutron dose 1 Gy 1

Fig.2. The influence of experimental condi-tions on efficiency of detection of dicentricsand rings.

AcknowledgmentThis work is partly supported by CEC contract number PECO 2992 CIPDCT 925008

References:

1. Biological Dosimetry: Chromosomal Aberration Analysis for Dose Assessment, IAEA, TechnicalReports No.260, Vienna, 1986.

2. D.C. Lloyd, Biological dosimetry by cytogenetic methods, RIS Dosimetria Biologica, 1990 Madrid.3. A. Cebulska-Wasilewska, A. Wierzewska, E. Kasper, B. Krzykwa, H. Phiciennik, J. Occup. Med.

(in press).

An evaluation of genotoxic activity of pesticides and itsinteraction with X rays using TSH assay

M. Litwiniszyn, B. Pałka and A. Cebulska-Wasilewska

Extensive use of pesticides in modern agriculture has led to a dramatic increase in the numberof synthetic chemical compounds to which man is exposed directly or indirectly. Pesticides are ofpotential hazard not only to farmers but also to the general public, because pesticide residues arepresent in food [1], groundwater and soil [2], Pesticides are highly reactive and toxic compoundsand their harmful impact upon the environment and public health has to be evaluated.

In assessing genotoxic effects of pesticides different short-term bio-assays can be employed,based on: mutation induction, chromosomal aberrations or micronuclei induction in different

229

systems [3]. In our studies we applied a TSH (Tradescantia Stamen Hair) assay [4] to eva-luate the genotoxic activity of seven pesticides, i.e. Benomyl, Carbofuran, 2,4-D, Heptachlor,Methoxychlor, Parathion-methyl and Propachlor.1

All tested compounds are produced by well-known chemical companies (Bayer AG, du Pontde Nemours & Co., Ciba-Geigy AG), and are widely used in agriculture. All these compoundshave benzene rings.

Concentrations of pesticides employed for TSH assay were within the range of those used inagriculture. To test possible interaction with any other agent in the environment a combinedtreatment using small doses of X-rays was applied. All tested pesticides were screened for mu-tagenicity and lethality in TSH assay using Tradescantia clone 4430, and the data are presentedin Table 1.

Our findings shown in Table 1 revealed that only one of the pesticides tested, i.e. 2,4-D,was positive for mutagenicity in TSH assay. 2,4-D is an active compound of "Aminopielik" (apesticide widely used in Poland), which was found to be mutagenic in our earlier studies [5].The majority of the screened chemicals (five of seven) showed positive response for lethality.Synergistic effect of radiation and pesticides was not observed in our studies. These data areonly preliminary ones and the use of higher concentrations of the tested agents is recommendedin further studies. With the wide use of pesticides in modern agriculture, prudence requires theuse of different systems in assessing the mutagenic properties of these agents. For example, somepesticides require plant or animal activation to be genotoxic [6]. Furthermore, some chemicalsmay interact with small doses of radiation present in the environment and an enhancement ofthe effect can be observed. So, the use of TSH assay which is very sensitive to both: chemicalsand radiation seems to be appropriate and such studies should be continued.

TABLE 1. DATA OF GENOTOXIC ACTIVITY OF PESTICIDES IN TSH ASSAY

Pesticidecommon nameBenomyl

Carbofuran

2,4-D

Heptachlor

Methoxychlor

Parathion-methyl

Propachlor

Treatment

10/d-0.004%20/xl-0.004%10/il-0.004%20/d-0.004%10^1-0.004%20/d-0.004%10/xl + lGy10/xl-0.004%20^1-0.004%10/d + lGy10/d-0.004%20^1-0.004%10/d + lGy10/d-0.004%20/d-0.004%10/xl + lGy10/d-0.004%20/d-0.004%10/d + lGy

Mutagenicity

:

+

-

-

-

-

Lethality

—

:

++

++

++

++

+

Synergisticeffect

nt

nt

"-" - negative response, "+" - positive response, nt - not tested

'Chemically pure pesticides were kindly provided by Prof. J.M. Gentile from Department of Biology, HopeCollege, Holland, MI 49423, U.S.A.

230

n . PL9601107References:

1. Pesticide residues in food - 1991: Evaluations, Part II - Toxicology, Report of the FAO /WHO JointMeeting on Pesticide Residues, Geneva, 16-25 Sept., (1991).

2. N.W.H. Houx, W.J. Aben: Report - DLO Staring Centre, Wageningen, No. 60, (1992).3. I.S. Grover, A.K. Dhingra, N. Adhikari, S.S. Ladhar: Nucleus, 31, 69-77, (1988).4. A. Cebulska-Wasilewska: Raport No. 1434/B, IFJ Kraków, (1990).5. A. Cebulska-Wasilewska: Raport No. 1511/B, IFJ Kraków, (1990).6. M.J. Plewa, E.D. Wagner, G.J. Gentile, J.M. Gentile: Mutat. Res., 136, 233-245, (1984).

Biological effects of electromagnetic fields estimatedby TSH assay

A. Cebulska-Wasilewska, I. Pawłyk, S. Szmigielski1, G. Sokolska1 and R. Kubacki2

department of Biological Effects of Electromagnetic Fields, Military Institute of Health andEpidemiology, 00-950 Warszawa, ul. Szaferów 128

2Department of Microwaves, Military Institute of Health and Epidemiology, 00-950 Warszawa,ul. Szaferów 128

Much technology used nowadays is based on or is in itself a source of various types ofmagnetic, electromagnetic and sound fields which may disturb the biological process [1]. Studieson the influence of microwave radiation and symmetric stripe field on living organisms were basedon a biological test (TSH-assay) in which the bio-indicator Iradescaniia, clone 4430 was used.Gene mutations are visible as change of cell color from blue to pink, while lethal mutations - as adecrease of the cell number in a hair to below 16 cells. The pink gene mutations occur as a changeof color of a single cell or group of cells situated next to one another. The relationship betweenthe number of single pink cells and the number of all pink cells informs the observer of thepossible cell cycle perturbations. Frequency of mutations expressed as the number of mutationsper 100 hairs has been accepted as the measure of mutagenic effectiveness of a checked factoror group of factors [2].

Exposures were carried out in the Military Medical Academy in Warsaw, where it was pos-sible to generate different types of fields with the desired power. During the experiment thegrouped inflorescens were exposed for 1 or 2 hr to microwave field or to stripe line field in ananti-echoed chamber.

The generated fields had the following parameters:- microwave field: frequency f=2850 [MHz]- stripe line field: frequency f=332 [MHz].

For each field two different powers were generated. The characteristics of the exposures arepresented in Table 1. In the exposures in anti-echo chamber two controls were introduced. Inthe first of them, control plants were placed in the chamber where only a small effect of thefield was expected (code 2). This checking point was included to detect the potential mutagenicimpact of synthetic resin in the chamber induced by specially prepared glystyrene. The secondcontrol (code 9) plants were situated near the chamber which generated the microwave field. Inthis case plants were exposed to sounds of high intensity; some of these sounds were also of highfrequency which was typical for the interior of the chamber.

During the investigations devoted to the stripe line field plants were exposed for differentperiods of time to the field in the central part of the chamber, where the most uniform field was

231

expected. The control plants were kept in the same room as the chamber (code 6). During theexperiment some fluctuations in temperature occurred.

On the 11th day, after the plants have been under the influence of the field, the measurementof frequency of mutations started. Table 2 presents the average biological effects observed. Theseeffects of exposures were set in order of density of the fields. The first column (I) shows boththe densities of the field and its codes. The second column (II) shows the numbor of analyzedhairs for each code. The third (III) column presents the average frequency of pink mutations instamens of hair cells in the exposed flowers. Column IV in Table 2 demonstrates the frequencyof single pink mutations and column V in the same table - frequency of mutations of hairs withless than 16 cells. Column VI shows the value of the cell cycle index, which was counted asthe ratio of the number of single pink mutations to the number of all pink mutations. ColumnsVHI-X present values of t Student function in comparison with proper codes.

Our data revealed that the plants of codes 1 and 4, which were exposed to the field of thelowest density and for the shortest period of time are the only ones in which differences in genemutation frequency from control values are of statistical importance (with level of confidence of5%). The remaining groups of plants differ one from another as well as from the control groupstatistically insignificantly, and no correlation between mutation rate and the type of exposurewas found. There is a visible variation in the cell cycle factor, however alterations of cell cyclefactor are also observed in the plants controlling exposure conditions. It should be taken intoaccount that it is known that temperature affects the mutation level in TSH, so, it is possiblethat variation in temperature can be a strong factor affecting the results of exposure.

Therefore, our data demonstrate that the investigations of those fields did not result in clearlyvisible effects which could explain our previous findings with 250 kHz electromagnetic field [3].Considering the previous data, where the influence of electromagnetic field was established, anew experiment should be carried out using field parameters similar to those from the previousstudies and with an intensity similar to 353 V/m, and in conditions with better temperaturecontrol.

TABLE 1. CHARACTERISTICS

Code1

234

56789

10

Fieldstripe line

amicrowavemicrowavestripe line

cmicrowavestripe line

b

d

Power20F/ro

-

100W/m2

20W/m2

80 V/m-

100W/m2

80 V/m-

-

OF EXPOSURE.

Time1 hrs2 hrs1 hrs1 hrs2 hrs3 hrs2 hrs1 hrs3 hrs

-

Temp.[°C]28.5-32.0

35-30no data

28-3532-27

28.5-21.035-30

no data28-21

-

a - control plant in microwave chamber; b - control plant near microwave chamber; c - controlplant near stripe line field; d - control of the trip.

232

PL9601108

TABLE 2. AVERAGE BIOLOGICAL EFFECTS CAUSED BY EXPOSING TO THE MICROWAVE ANDSTRIPE LINE FIELDS.

ICode

nNOH

inPF +SE

IVSPF

VSTF

VICC

vnCodes

vnit

IXFD

X 1Signif.% 1

MICRO WAVE FIELD [W/m2]4372910

191881532217621178222248937027

0.30 + 0.0900.19 + 0.0830.24 + 0.1410.26 + 0.0880.31 + 0.0950.17 + 0.066

0.0880.0790.0920.1030.7430.068

0.500.440.510,510.760.71

0.350.410.410.400.240.45

4:104:11

2.6632.686

88

97.1397.23

STRIPE LINE FIELD[V/m]185610

1447514403191161623037027

0.30 + 0.1070.24 + 0.0990.19 + 0.0720.22 + 0.0900.17 + 0.066

0.1140.0760.0720.0620.068

1.070.700.640.710.71

0.380.290.400.310.45

1:101:11

2.3092.329

88

95.0395.18

NOH - number of hairs; PF, SPF, STF - pink, single pink, lethal mutation frequency; CC - cell cyclefactor; FD - degrees of freedom.

References:

1. Indulski A.J., "Environmental Health Criteria" PZWL, Warsaw (1987) in Polish.2. Cebulska-Wasilewska A., Raport IFJ 1434/B (1990) in Polish.3. Cebulska-Wasilewska A., Raport IFJ 1587/B (1992) in Polish.

Acute Reaction of Mouse Skin to Fractionated X -rayIrradiation Performed with the Use of Various SchedulesJ. Huczkowski, B. Janiszewska, T. Janiszewski, S. Krasnowolski, K. Kulczykowska,

B. Lazarska, J. Skołyszewski1, V. Svoboda2, K. Trott 3 and B. Wilczyńska1

ICentre of Oncology Maria Skłodowska-Curie Memorial Institute, Kraków2St. Mary Hospital, Portsmouth, England3Department of Radiobiology, University of London, London, England.

The results shown in this paper are the continuation of our previous investigation (Annual Report1992) of the reaction of normal tissues to a fractionated irradiation. The mouse skin system was usedto compare the results of various fractionated schedules. The reactions in groups of 4 C3H mice, eachexposed to a given 250 kV X-rays dose, were scored on an arbitrary scale (1) and the average dailyreaction was plotted against time. To compare the total doses needed to produce a given biologicalresponse dose response curves were used.

The preliminary results of the first part of out investigation showed that there was no difference inthe acute skin reaction between groups of mice irradiated with 20 fractions, twice a day with 3 and 6hours interfraction intervals. The short half-time for the sublethal damage repair (T 1/2 ) could be theprincipal cause of this observation. To get more information about the recovery kinetic a new experimentwas performed. Mice were irradiated over 2 weeks, twice a day with 0.5, 1, 3 and 6 hour intervals betweenfractions. The results are showed in the Fig.l.

The data obtained allowed us to calculate T 1/2 at the 3 different levels of skin damage. According tothe first order of kinetics we assumed the exponential repair curve. The values of Tl/2 are: 1.27, 1.2 and1.16 hours for a level of skin damage of 1.3, 1.65 and 2 respectively. These values agree with the repair

233

half-time (1.3 h) found for skin by Henkelman et al (2). Howevei T l /2 does not explain the absence ofdifference in skin reaction in mice irradiated with 3 and 6 hours interfraction intervals. If T l /2 is 1.2h and the full recovery dose is about 14 Gy there is 2.5 Gy still available for the repair when the timeinterval between fractions increases from 3 to 6 hours.

Nevertheless such a 2.5 Gy "gap" between series with 3 and 6 hours interfraction intervals wasnot observed in all our experiments. Even more, the results obtained showed, that there is a slight,nonsignificant tendency to a more pronounced skin reaction after irradiation with split doses with a 6hours time interval between fraction. The data about the kinetics of the split-dose recovery showed thatthe longer intervals between fractions might produce a decrease in the survival, which could be attributedto the progression of survivors to more sensitive phases of the cell cycle. If the increase in the time intervalbetween fractions from 3 to 6 h is sufficient to start the cell cycle progression this mechanism could be apossible explanation of the effect observed.

The second part of our present work presents estimation of the a/f3 value, which is a sensitive, quanti-tative index, convenient for predicting the radiation response of different normal and malignant tissues.The a/0 value was calculated using the data of 3 series of experiment and the Linear-Quadratic Modelas a reciprocal of the total doses plotted against the dose per fraction in the two different regimens offractionation.

This gave a straight line and the a/0 ratio was read off as a negative dose per fraction intercept, i.e.9.5 Gy ( Fig.2 ). This value is comparable with the a/0 values for the mouse skin 8.6 - 12.5 Gy found inthe literature [1,3].

The investigation of the response of late reacting tissues ( lung, kidney ) is in progress.

0.2 -

0.15-

0.05-

it asTllll II! [ (Gy)

Fig.l Dose -response curves for mouse skin reaction.

References:

•5 - 1 0 1 2 3 4 5 6 7 d ( G y )

Fig.2. Estimation of the a/0 ratio.

1. Douglas B.G. and Fowler J.F., Radiation Research, (1976), 4012. Henkelman R.M. et al., Radiation Research, (1980), 2763. Joiner M.C. et al., International Journal of Radiation Biology, (1986), 565.

LIST OF PUBLICATIONS:I. Articles:

1. A. Cebulska-Wasilewska, Correlation between physico-chemical monitoring and pollutiongenoticity detected by bio-indicators, (in polish), Proc. of Geochemical, Hydrochemical andBiochemical Changes of Natural Environment Cracow, 10-15, 1993;

2. J. Gajewski, E.B. Ramsay, L.E. Reinstein, Refinement of Monte Carlo Calculations for BNCT atthe Brookhaven Medical Reactor, Progress in Neutron Capture Therapy for Cancer eds R.F.Barth, A.H. Solovay (Plenum Press, New York) (1993) 1;

3. L.E. Reinstein (J. Gajewski) et al., SBNCT-PLAN: A 3-Dimensional Treatment Planning Systemfor Boron Neutron Capture Therapy, Progress in Neutron Capture Therapy for Cancer eds R.F.Barth, A.H. Solovay (Plenum Press, New York) (1993) 10;

234

4. A. Cebulska-Wasilewska, W. Flakiewicz, In situ studies of biological effects of electromagneticfield, J. Occup. Med. (in press);

5. A. Cebulska-Wasilewska, H. Pruciennik, Estimation of the mutagenic effectiveness of somepesticides, J. Occup. Med. (in press);

6. A. Cebulska-Wasilewska, Effectiveness of TSH assay for in situ biological monitoring of ambientair pollutants mixtures (in press);

7. A. Cebulska-Wasilewska, H. Pruciennik, A. Wierzewska, E. Kasper, B. Krzykwa, Comparisonbetween genotoxic effects of pesticides with genotoxicity of known mutagens and radiation (inpress).

II. Contributions to Conferences:

1. A. Cebulska-Wasilewska, Comparison between ambient air genotoxicity in two urban areas inPoland, Proc. of 23rd Annual Meeting of the European Environmental Mutagen Society,Barcelona, September 1993;

2. A. Wierzewska, E. Kasper, B. Krzykwa, A. Cebulska-Wasilewska, Chromosome aberrations inhuman blood lymphocytes in studies of fast neutrons biological effectiveness (in polish),Proc. VIII Annual Conference of Cytogenetics, Wroclaw, September 1993.

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. A. Cebulska-Wasilewska:VIII Annual Conference of Cytogenetics, Wrocław, September 1993,Seminar "Young People and Ecology", Cracow, October 1993,23rd Annual Meeting of the European Environmental Mutagen Society, Barcelona, September1993,Geochemical, Hydrochemical and Biochemical Changes of Natural Environment. Cracow,December 1993,

2. J. Huczkowski:XVIII Proton Therapy Group Meeting, Orsay April 1993,

3. E. Kasper:VIII Annual Conference of Cytogenetics, Wroclaw, September 1993,

4. B. Krzykwa:VIII Annual Conference of Cytogenetics, Wrocław, September 1993,

5. A. Wierzewska:VIII Annual Conference of Cytogenetics, Wroclaw, September 1993.

LECTURES AND COURSES:

1. A. Cebulska-Wasilewska:"Radiobiology, environmental mutagenesis, comparative environmental genotoxic risk analysis",Lecturing in a course for undergraduate students of Medical Physics and Dosimetry, at thePhysics and Technology Department at AGH, Kraków, Winter semester 1993,

2. A. Cebulska-Wasilewska,

Participation in Fourth Advanced Radiobiology Course, ESTRO April 1993. Mount VernonHospital, Northwood, Cancer Research Center, Gray Laboratory,

3. B. Księżkiewicz,

Participation in a Course of Health Risk Estimation, Łódź, April 1993.

235

INTERNAL SEMINARS:

1. J. Huczkowski, February 1993"Early and late effects in mice as a model system foi fractionation studies".

2. A. Cebulska-Wasilewska, Match 1993" Tradescantia assay (TSH) as a bio-indicator in environmental studies".

3. I. Pawłyk, April 1993"Biological methods in wastes control".

4. B. Łazarska, April 1993"Measurements and methods of absorbed dose estimation in neutron cancer therapy".

5. A. Wierzewska, May 1993"Chromosome aberration and sister chromatid exchange: application in radiobiology andenvironmental studies".

6. B. Krzykwa, May 1993"Development of cytogenetic methods for environmental studies".

7. B. Ksiażkiewicz, May 1993"Epidemiological methods in health risk analysis".

8. B. Pałka, June 1993"Biochemical methods in studies of environmental hazards".

9. H. Płuciennik, June 1993"Biological effects of incorporated radionuclides".

10. M. Plewa (USA), October 1993" Characterization of stable high molecular weight mutagenic products of plant-activated aromaticamine promutagens".

11. J. Gajewski, November 1993" Refinement of Monte Carlo Calculations for BNCT at the Brookhaven Medical Reactor".

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. R.M. CORTES- University UTAD, Vila Real, July 1993.

2. Drs P. CHAUVEL and N. BRASS ART- Department of Medical Application Center, Antoine - Luacassagne Nicaea, France, August1993.

3. Prof .dr M. PLEWA- Eksperimental Botany Institute, Praga, October 1993.

4. Dr E. WAGNER- University of Ilinois, Urbana-Champain, USA, October 1993.

5. E. RADETSKI (from Prof, dr J.F. FERARA)- Institut Ecology, Metz, France, October 1993.

236

Department ofNuclear

Radiosp ectroscopy

PL9601109

DEPARTMENTOF NUCLEAR RADIOSPECTROSCOPY

Head of Department: Prof. Jacek W. HennelSecretary: M. Zychtelephone: (48) (12) 37-02-22 ext.: 253e-mail: jhennel@bron.ifj.edu.pl

PERSONNEL:Magnetic Resonance Laboratory

Research Staff:Artur Birczyński, Ph.D.Jerzy Blicharski, ProfessorJacek W. Hennel, Professor, Head of Department and LaboratoryZdzisław T. Lalowicz, Ph.D.Zbigniew Olejniczak, Ph.D.Stanisław Sagnowski, Ph.D.Robert Serafin, M.Sc.

Administration:Secretary: Magdalena Zych

Magnetic Resonance Imaging LaboratoryResearch Staff:

Franciszek Hennel, Ph.D.Andrzej Jasiński, Assoc. Professor, Head of LaboratoryJacek Kibiński, Ph.D.Stanisław Kwieciński, M.Sc.Artur Krzyżak, M.Sc.Tomasz Skórka, M.Sc.Zenon Sułek, Ph.D.Krzysztof Szybiński, M.Sc.Eng.Bogusław Tomanek, M.Sc.Piotr Kulinowski, Technician

Laboratory of Solid State Physics and Computer Simulations

Research Staff:Krzysztof Parliński, Professor, Head of Laboratory,Małgorzata Sternik, Ph.D.

GRANTS:

1. Dr Z. T. Lalovnczgrant No 2 033649 91 01, (the State Committee for Scientific Research),Studies of quantum and classical reorientation of ND% ions by means of NMR spectroscopy.

237

2. Assoc. Prof. A. Jasiński,grant No 2 2442 91 02, (The State Committee for Scientific Research),Nuclear Magnetic Resonance Microscopy.

3. Prof. K. Parliński and Dr M. Sternik,grant No 2 2377 92 01, (The State Committee for Scientific Research),The mechanisms of structural phase transitions.

OVERVIEW:Research at the Department of Nuclear Radiospectroscopy of the H. Niewodniczański In-

stitute of Nuclear Physics is concerned with various problems of nuclear magnetic resonance(NMR) and their application in different areas of science with molecular dynamics in the firstplace. The Department is equipped with a 1.5T, 6cm gap electromagnet, 6.4T superconductingmagnet, a XP4-100 Bruker spectrometer, a laboratory developed 25.5MHz microimaging sys-tem and a laboratory developed Zero-Field NMR spectrometer of unique design allowing workat helium temperatures. The Department closely cooperates with the NMR group of Prof. J.S.Blicharski at the Department of Physics of the Jagellonian University in Cracow.

The current research program covers three areas: magnetic resonance, magnetic resonanceimaging and solid state physics by computer simulations.

MAGNETIC RESONANCE LABORATORY.There are in principle two mechanisms of molecular reorientations in solids: tunnelling

through the potential barriers and random jumps between distinct reorientations. The formeris responsible for orientational delocalisation at liquid helium temperatures, causing so-calledtunnelling splitting of the ground torsional energy level and therefore strongly influencing theNMR spectrum. Random jumps are possible at higher temperatures since the molecule needsa sufficient amount of energy to overcome the potential barrier. This type of motion can betreated classically. This also influences the NMR spectrum but in a manner quite different fromthat of tunnelling. In particular the deuteron NMR spectra exhibit the explicit evidence of thetype of motion, moreover measurements of the tunnelling frequency and the reorientation rateare possible. Both supply data on height and symmetry of the potential. Cases of multiaxialreorientation at low symmetry potentials are particulary challenging. Ammonium tetrachloro-platinate can be given as an example of complex mobility. Combined analysis of proton anddeuteron spectra of powder and single crystal samples, proton and deuteron relaxation, guidedus among several feasible motional models. It was also shown that the use of partially deuteratedcompounds containing NH3D+ ions may supply evidence of a substructure at the bottom of apotential well due to the observation of limited jumps and tunnelling. In order to find whethersome of the classical jump motion is present even at helium temperature, T\ was measured atlow magnetic field using the laboratory developed Zero-Field NMR spectrometer.

Another problem studied in 1993 by deuteron NMR in solids was the behaviour of hydrogensof crystallisation water in crystalline oxalic acide (COOD)22D2O. It was found that there isexchange of hydrogen nuclei between the water molecules and carboxylic groups.

Work on writing the book "Fundamentals of Nuclear Magnetic Resonance" by J.W. Hennelof this Laboratory and J. Klinowski from Cambridge University has been completed, and it waspublished by Longman Publ. Company in England early in 1993. "Fundamentals of NuclearMagnetic Resonance" explains simply and precisely the physical and mathematical foundationsof nuclear magnetic recsonance (NMR). The fundamental concepts are comprehensively pre-sented to enable the reader to achieve a full understanding of the phenomenon, the reasons forand the significance of the various spectral effects and to enable him or her to read originalresearch papers. The mathematical basis of the subject is fully explored and explained. There

238

are nine chapters covering different aspects of NMR. The initial chapter includes a condensedaccount of quantum mechanics at a level suitable for readers unfamiliar with the subject, thebackground to which is necessary to understand NMR fully. The remaining chapters discussthe areas of magnetic properties of the nucleus: nuclear paramagnetism, motion of magnetiza-tion, continuous wave NMR, pulsed NMR, NMR of liquids, the dipolar interaction and nuclearmagnetic relaxation. The five appendices are a valuable addition, with information on complexnumbers, scalar and vector products, calculation of traces, Dirac's delta function and sinusoidaloperators. Undergraduate and postgraduate students, chemists, physicists, earth scientists,mineralogists, anyone seriously interested in NMR will find this text easily accessible, and adependable reference source.

MAGNETIC RESONANCE IMAGING LABORATORY.Work on MR microscopy supported by a grant from the Polish State Committee for Scientific

Research involved the construction of a MR microscope based on a 6.3T superconducting magnet.This work was brought to its final stage.

Other work concerned the design of a local actively shielded coil for the human head. Per-formance of this coil was optimized using a purpose written software for direct Biot-Savart fieldcalculation. A surface gradient coil for the human chest was also developed.

In collaboration with the Institute for Biodiagnostics of the NRC of Canada in WinnipegMR functional images of the brain active visual centers were recorded.

LABORATORY OF SOLID STATE PHYSICS AND COMPUTER SIMULATIONS.In the Laboratory of Solid State Physics and Computer Simulations the work has been

concentrated around two topics:The tweed microstructure, experimentally observed in the high Tc superconducting material

YBa2Cu3O7_i, has been extensively studied on the model of molecular-dynamics simulation.The model has been supplemented by a term of external field which could be coupled to theoxygen concentration. This allows one to establish the temperature-oxygen concentration phasediagram with the tetragonal-orthorhombic phase boundary. Analytical mean field theory derivedfor this model, agrees with the MD findings. Special attention has been devoted to the oxygendistribution in the tweed microstructure. It has been shown that oxygen vacancies gathermainly within the domain walls arising as a result of the elastic tetragonal-orthorhombic phasetransition. Also, the microstructure changes with the oxygen concentration.

The ground state of our hexagonal model contains one-dimensional lq and two-dimensional3q modulations. This model has been extensively simulated by the MD method in order toelucidate the phase transition mechanisms between different types of modulated phases. Thefolowing phase transition mechanisms have been found: (i) Stripple mechanism occurs in thephase transition from commensurate to incommensurate one-dimensional phase. The stripplestructure is uniquely defined by the domain structure of the commensurate phase, (ii) Forthe first time it has been shown by simulation that the column phase 3q exists. The phasetransition from column 3q phase to a stripe lq phase relies on column merging, (iii) The phasetransition from column phase 3q, characterized by one wave vector, to another column phasewith a different wave vector is driven by the nucleation of the dislocation loop defined by thediscommensuration lattice. Correlations between stripple appearence on the vast system (176000particles) has confirmed the serial mechanism of nucleation.

/ ¥ fProf. J.W. Hennel

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REPORTS ON RESEARCH: PL9601110

Single-Shot Fourier Velocity ImagingF. Hennel, Z. Sułek and A. Jasiński

This paper describes a two-dimensional Fourier velocity experiment based on the concept ofecho-planar imaging (EPI), in which a flow profile can be determined in a subsecond time.

The measured signal s is a function of six dimensions of reciprocal space (k,q) and is connectedto the spin density p by the following formula

s(kq) — I p(rv)exp[-i(k • r + q • v)]d?rd3v

where r is the position in space, v - velocity and

*(*) = 7 /* G(t')dt', q(t) = 7 f t'G{t')dt'Jo Jo

G is the (switched on and off) gradient of the magnetic field. The demanded quantityproportional to the amount of spins in the position r having velocity v is P(T\). It can beobtained by Fourier transformation of the measured function s(kq) or s(ka!qz) if we confine theproblem to two dimensions.

To sample the signal s over the two-dimensional reciprocal space (k^qj) a special pulse andgradient sequence has been developed. A repeated pair of gradient pulses of duration T amplitudeg, separated by a time T causes the following changes: kx —• -kx and q^ —• -q2+ 7 Gz r T. Inresult the (kj-qj) space is sampled along a trajectory shown in Fig.l.

Fourier transformation of the 2D data in kx and qz gives a projection of the spin density onthe xvz plane as shown in Fig.2.

A full account of this paper is to be found in the Journal of Magnetic Resonance, SeriesA102, 95-97 (1993).

Fig.l Trajectory in the reciprocal space cor- Fig.2 Image obtained by the reported EPI-responding to the reperted sequence. like Fourier velocity imaging method showing

velocity distribution of water flowing througha tube. Horizontal axis: dimension across thetube x, vertical axis: velocity vz, brightness:density of spins.

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PL9601111 PL9601112

NMR and NQR Spin-Lattice Relaxation in PartiallyDeuterated (NH4)2SnCl6

C. Dimitropoulos* and Z.T. Lalowicz* Institut de Physique Experimentale, Ecole Polytechnique Federale de Lausanne, Ch-1015 Lausanne,

Switzerland

The chlorine-NQR and the deuteron NMR relaxation have been investigated in large "cross-relaxation" maximum of relaxation rate observed in both natural and partially deuterated com-pound at about 55K. The 35C1 NQR relaxation rate shows two smaller maxima at 20K and30 K in the deuterated salt only. These maxima are shifted to a higher temperature for 37C1isotope. The peak at 30K has a corresponding tunneling channel in the 2D-NMR relaxationrate. Deuteron spin-lattice relaxation rates, measured at 13.86 MHz and 52.37 MHz, besidesthe level-crossing maxima, show also classical maxima related to molecular motions against abarrier about 15 % of the full potential. All these effects are explained by jumps in a substructureat the bottom of the potential.

The nonabridged version of this work has been accepted for publication in Phys. Rev. B.

Fig.l The possible orientations of theion in the crystal lattice. The ion (repre-sented by the tetrahedron) is shown in amean position, but according to the con-clusion of this work there are three possi-ble, slightly different, orientations so that adeuteron on the apex may occupy any of thethree sites marked by the black dots. Bet-ween these positions jumps and tunnelingtake place.

M

ND

Local and Nonlocal Hydrogen Dynamics in a-Oxalic AcidDihydrate. A ID and 2D Single Crystal Deuteron NMR

StudyA. Birczyński, Z. Sułek, A. Muller * and U. Haeberlen *

* Max-Planck-Institut fur Med. Forschung, AG Molekulkristalle, Heidelberg, Germany

The aim of this work is to investigate the hydrogen dynamics in crystals of a-oxalic aciddihydrate by 2H-NMR line shape analysis and 2H 2D-exchange spectroscopy. We identify andcharacterize three types of hydrogen motions: (1) flips of water molecules, (2) exchange of acarboxylic deuteron with the deuterons of the nearest, hydrogen bonded water molecule, and (3)exchange of a carboxylic deuteron with the deuterons of a distant, non-hydrogen bonded watermolecule. In addition, we observe hydrogen diffusion over macroscopic distances.

The work was done at the Max-Planck-Institut, Heidelberg. It has been published inZeitschrift fur Physikalische Chemie, 178,133 (1992).

ibo

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N

-r so-

Fig.l Two dimensional spectrum of a single crystal of deuterized oxalic acid(C00D)2 2D2O. The appearance of the offdiagonal peaks labelled CW and C'W demon-strates the existence of an exchange process between carbolic and water deuterons.

Computer Simulation of the Tweed Microstructure inYBa2Cu3O7_*

K. Parlinski and M. Sternik

The tweed microstructure in the stoichiometric crystal of YBa2Cu2O7 has been already stu-died by computer simulation [1,2]. A two-dimensional model of 99 X 99 unit cells represents alayer of this crystal with an oxygen deficit and shows the ferroelastic tetragonal-orthorhombicphase transition. Recently, we applied this model to the case of non-stoichiometric oxygenconcentration [3]. The simulation allows us to determine the temperature-oxygen concentrationphase diagram. Below the transition temperature the strain fluctuations form a grid of needle-shaped areas, the density of which increases with the increasing degree of non-stoichiometry.On quenching, the tweed texture orders through the intermediate stripe phase, to a singleorthorhombic area. Changes of the microstructure of the system while increasing the annealingtime are shown for three oxygen concentrations in Fig.l. Oxygen vacancies, appearing due tonon-stoichiometric oxygen concentration, gather along the domain walls, and hence slow downthe kinetics of the annealing process.References:

1. K. Parlinski, V. Heine and E.H. Salje, J.Phys: Condensed Matter 5, 497 (1993)2. K. ParMski, E.K. Salje and V. Heine, Ada Metali. A41, 839 (1993)3. K. Parlinski and M. Sternik, J.Phys: Condensed Matter (to be published)

242

Fig.l. Maps of the strain order parameterobtained during annealing at temperatureTa=0.63Tc after quenching from tempe-rature T-1.24TC, for three values of off-stoichiometry parameters (a-d) 8 = 0.0,(e-h) 8 = 0.24, (i-j) 8 = 0.40. Maps (aei),(bfj), (cgk) and (dhl) correspond to an-nealing time t = 0.3, 0.9, 3.0 and 20.0 r0,respectively. The maps show 99 x 99 unitcells. The bright and dark shading corre-sponds to two different orthorhombic are-

as.

LIST OF PUBLICATIONS:Books:

1. J.W. Hennel and J. Klinowski, Fundamentals of Nuclear Magnetic Resonance, LongmanScientific and Technical, Harlow, England (1993)

I. Articles:

1. Y. Wu, Z-Y. Peng, Z. Olejniczak, B.Q. Sun and A. Pines, Effects of double rotation onhomonuclear spin systems, J. Mag. Res., A102, 29 (1993)

2. F. Hennel, Z. Sułek and A. Jasiński, Single shot Fourier velocity imaging, J. Magn.Resonance, A102, 95 (1993)

3. G. Bacić, K.J. Liu, J.A. O'Hara, R.D. Harris, K. Szybiński, F. Goda and H.M. Swartz,Oxygen tension in a murine tumor: a combined EPR and MRI study, Magn. Reson.Med., 30, 568 (1993)

4. A. Birczyński, Z. Sułek, A. Muller and U. Haeberlen, Local and nonlocal hydrogendynamics in a-oxalic acid dihydrate. A ID and 2D single crystal deuteron NMR study,Zeitschrift fur Physikalische Chemie, 178, 133 (1993)

5. C. Dimitropoulos and Z.T. Lalowicz, Deuterium NMR and chlorine NQR relaxation inpartially deuterated (NH4)2SnCl6, Phys. Rev. B (in print)

243

6. K. Parliński, Effect of hysteresis on the phase transition between high-ordercommensurate phases, Ferroelectrics, 141, 7 (1993)

7. K. Parliński, Phase diagram of the square-lattice model with lq and 2q incommensuratemodulations, Phys. Rev., B48, 3016 (1993)

8. K. Parliński, E.K.H. Salje and V. Heine, Annealing of tweed microstrucure in high Tc

superconductors studied by a computer simulation, Acta Metali. Mater., 41, 839 (1993)9. K. Parliński and G. Chapuis, Mechanisms of phase transitions in a hexagonal model with

lq and 3q incommensurate phases, Phys. Rev. B47, 13983 (1993)10. K. Parliński, V. Heine and E.H.H. Salje, Origin of tweed texture in the simulation of a

cuprate superconductor, J.Phys.: Condens. Matter, 5, 497 (1993)11. K. Parliński and M. Sternik, Computer simulation of tweed microstructure in high T c

superconductors, Journal of Physics: Condensed Matter (in print)12. K. Parliński and G. Chapuis, Phase transitions mechanisms between hexagonal

commensurate and incommensurate structures, Phys. Rev. B (in print)

II. Contributions to Conferences:

1. K. Parliński, Two dimensional modulated phases in tetragonal and hexagonal models,The 3-rd Meeting on Disorder in Molecular Solids, Gachy, France (1993) (Invited talk)

2. K. Parliński, Discommensuration Patterns and Phase Transition Mechanisms inHexagonal Incommensurate System, RAMIS (1993) (Invited talk)

3. K. Parliński and M. Sternik, Microstructure of YBa2Cu3O7_$ studied by moleculardynamics technique, RAMIS (1993)

4. K. Parliński and M. Sternik, Computer-simulation of the tweed-microstructure inYBaCuO, IV Workshop on Hightemperature Superconductors, Poznań, Poland (1993)

5. K. Parliński, Two-dimensional modulated phases in tetragonal and hexagonal models,Proceedings of "The 3-rd Meeting on Disorder in Molecular Solids", Gachy, June 14-17,1993

6. K. Parliński, Models with multi-q IC phases, European Research Conference onDynamical Properties of Solids, Lunteren, Netherland (1993)

7. C. Dimitropoulos and Z.T. Lalowicz, Deuterium NMR and chlorine NQR relaxation inpartially deuterated (NH4)2SnCl6, Conference on Quantum Molecular Tunnelling inSolids, Windsor, England, July 1993

8. Z.T. Lalowicz, E.E. Ylinen, M. Punkkinen and A.M. Vuorimaki, Ammonium iontunnelling and reorientation study in ammonium tetrachloroplatinate by proton anddeuteron NMR, Conference: as above

9. J.W. Hennel, Zero-Field NMR (Invited talk), Jagellonian University Spring School onNMR, Zakopane, Poland, May 1993

10. Z.T. Lalowicz, Tunnelling Rotation and Classical Jumps of Ammonium Ions at LowTemperatures, Conference RAMIS-93, 29-30.04.1993, Poznań, Poland

11. Z.T. Lalowicz, Z. Olejniczak, R. Serafin, Low Field lK NMR Ti Relaxation in NH4C1O4

at 4.2K, Conference: see above12. Z. Olejniczak, A. Llor, Multipolar Analysis in Zero-Field NMR, Conference: see above13. Z.T. Lalowicz, Z. Olejniczak, R. Serafin, Low field proton NMR spin-lattice relaxation in

NH4CIO4 at low temperatures, AMPERE Summer Institute on Advanced Techniques inExperimental Magnetic Resonance, Portotoz, Slovenia, 12-18.09.1993

14. Z. Olejniczak, A. Llor, Multipolar Analysis of Zero-Field NMR, Conference: see above

244

15. B. Tomanek, A. Jasiński, E. Staszków, Magnetic Resonance Imaging of Carbon Imolantsin the Rabbit Achilles Tendon in vivo, Proceedings of the Society of Magnetic Resonancein Medicine, XII Annual Scientific Meeting, New York, USA (1993), p. 885

16. P. Rapley, A. Jasiński, P. Kozlowski and J.K. Saunders, A Design for Semi-cylindricalSurface Gradient Coils, Proceedings of the Society of Magnetic Resonance on Medicine,XII Annual Scientific Meeting, New York, USA (1993), p. 315

17. M. Szayna, P. Kozlowski, J.K. Saunders, A. Jasiński, XH and 3 1 P Spectroscopic ImagingStudy of 9 L Brain Tumor, 2nd International Conference in Magnetic ResonanceMicroscopy, Heidelberg 1993, p. 50 (invited lecture)

18. Z. Sułek, A. Jasiński, B. Tomanek, F. Hennel, J. Kibiński, T. Skórka, A. Krzyżak,P. Kulinowski and J. Muszyńska, MR Microscopy Study of Honey Bee in vivo, 2 n d

International Conference on Magnetic Resonance Microscopy Heidelberg 1993, p. 5419. M. Rydzy, T. Jakubowski, F. Hennel, A. Jasiński, Z. Sułek, B. Tomanek, MARIS -

Software Pachage for Spectroscopy and Imaging, Conference: see above, p. 8320. Z. Sułek, A. Jasiński, B. Tomanek, J. Kibiński, T. Skórka, S. Kwieciński, Modular

System for MR Microimaging, Conference: see above, p. 8421. M. Szayna, P. Kozlowski, A. Jasiński and J.K. Saunders, *H, 3 1 P Spectroscopic Imaging

Study of Tumor Implanted in Rat Brain, Conference RAMIS-93, Poznań, Poland, 29-30April 1993

SCIENTIFIC DEGREES:

1. Małgorzata Szayna - Ph.D. degreeLocalized magnetic resonance spectroscopy. Study of the tumor implanted in the ratbrain, Supervisor: Assoc. Professor Andrzej Jasiński.

LECTURES AND COURSES:

1. J.W. Hennel"Introduction to the theory of NMR", a set of lectures given at the A. MickiewiczUniversity in Poznań, 5-10th July, 1993.

2. J. W. Hennel"A short course of the theory of NMR ", Set of 6 lectures given in theH. Niewodniczański Institute of Nuclear Physics, Krakow, October 1993.

3. Z. Olejniczak"Multiple-Quantum NMR spectroscopy ", A set of lectures given at the JagellonianUniversity Spring School on NMR, Zakopane, May, 1993.

4. K. Parliński"Molecular-dynamic simulation of phase transitions in hexagonal model and in high T c

superconductor", University of Antwerp, Belgium.5. K. Parliński

"Computer simulation of incommensurate phase transitions in hexagonal model".Institut fur Festkroperforschung, KFA, Julich, Germany.

6. K. Parliński"MD simulation of phase transitions between phases in hexagonal model", Laboratoirede Physique des Solides, Orsay, France.

245

7. K. Parliński"Simulation of phase transitions in hexagonal model and high T c superconductors",Max-Planck-Institut fur Medizinische Forschung, Heidelberg, Germany.

8. K. Parliński"Phase transitions between incommensurate phases", Laboratoire InstrumentationNucleaire, Sacley, France.

9. K. ParUński"MD simulation of elastic phase transition in high T c superconductor YBaCuO", Institutde Cristallographie, Universite de Lausanne, Switzerland.

10. K. Parliński"Simulation of phase transitions between incommensurate phases in hexagonal model",Institute of Physics, Academy of Sciences of the Czech Republic, Prague.

11. Z. Olejniczak"NMR spectroscopy in solids", Set of two lectures at the Institute of Catalysis andPhysical Chemistry of Surfaces, March, Kraków.

ORGANIZED CONFERENCES:26th National Seminar on NMR and its Applications Krakow, 1st and 2nd December 1993(130 participants). The Department organize these conferences each year in the first days ofDecember.

INTERNAL SEMINARS:

1. R. Serafin"Low field measurements of Ti for NH4C1O4 at 4.2K"

2. Z. Olejniczak"SIN-NMR"

3. A. Birczyński"Chemical exchange in hydrated oxalic acid investigated with 2D spectroscopy"

4. A. Birczyński"Tunnelling of CD3 group in potential of sixfold symmetry"

5. J.K. Saunders, Institute for Biodiagnostics, NRC, Ottawa, Canada"Magnetic resonance imaging and spectroscopy investigation of brain on animal modelsand human volountiers at NRC"

6. B. Sulikowski, Institute of Catalysis and Physical Chemistry of Surfaces, Krakow"Application of NMR in chemistry of zeolites"

7. M. Szayna' ł l H and 3 1 P SI in brain cancer investigations"

8. R. Serafin"Low-field dipole-dipole driven NMR"

9. S. Clough, University of Nottingham, England"Magnetic manipulation of methyl group tunneling at low temperatures"

10. P. Kamiński"Tunnelling in fermion groups of Su(2) symmetry"

11. P. Focke, Max-Planck-Institute, Heidelberg, Germany"Tunnelling of CD3 groups in aspirin"

246

12. B. Tomanek"Annual SMRM meeting in New York - report"

13. A. Jasiński"Conference on microimaging in Heidelberg - report"

14. K. Szybiński"Quantitative analisis of MR images of knee joint"

15. F. Hennel"Interference effects in NMR tomography"

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. S. Clough, University of Nottingham, Nottingham, UK2. Dr J.K. Saunders, National Research Council of Canada, Winnipeg, Man3. Dr W. Kuhn, Fraunhofer Institute for Biomedical Engineering (EBMT), St. Ingbert,

Germany4. Dr P. Kozlowski, National Research Council of Canada, Winnipeg, Man5. P. Focke, Max-Planck-Institut fur Medizinische Forschung, Heidelberg, Germany6. Prof. U. Haeberlen, Max-Planck-Institut fur Medizinische Forschung, Heidelberg,

Germany7. Eng. K. Bartusek, Institute of Scientific Instruments, Czech Republic8. Eng. P. Gran, MVT Kooperativ-Zavod Tesla Elektronika, Czech Republik9. Eng. B. Jilek, Institute of Scientific Instruments, Czech Republik

10. Dr P. Jonsen, Chemagnetics, 7, Claro Court Bussiness Centre, England11. Dr M. Kiral'varga, Department of Physics, Technical University, Kosice, Slovakia12. Dr J. Klinowski, Dept. of Chemistry, University of Cambridge, England13. Dr L. Mucha, Department of Physics, Technical University, Kosice, Slovakia14. Dr P. Tekely, Groupe de Nancy I, France15. Dr M. Tureckowa, MTV Kooperativ-Zavod, TESLA Elektronika, Brno, Czech Republik16. V. Zeman, STELAR CS, Spol. S.R.O., Brno, Czech. Republik

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Department ofNuclear

Physical Chemistry

uPL9601114

DEPARTMENTOF NUCLEAR PHYSICAL CHEMISTRY

Head of Department: Prof.dr Jan MikulskiDeputy Head of Department: dr Barbara Petelenztelephone: (48) (12) 37-02-22 ext.: 390 to 399e-mail: petelenz@vsb01.ifj.edu.pl

PERSONNELLaboratory of Nuclear Physical Chemistry

Research staffJan Mikulski, Professor,Barbara Petelenz, Ph.D., Head of LaboratoryEwa Ochab, Ph.D., Deputy Head of Laboratory,General Inspector of the Occupational Health and Safety,Paweł Zagrodzki, Chem.E., M.Sc.Technical staffPaweł Grychowski, M.Sc.Ryszard Misiak, M.Sc.Mirosław Szałkowski, Chem.E., M.Sc.Bogdan Was, Chem.E., M.Sc.

Laboratory of Chemistry and RadiochemistryResearch staffZdzisław Szeglowski, Assoc.Prof., Head of LaboratoryBarbara Kubica, Ph.D., Deputy Head of LaboratoryTechnical staffMaria Tuteja-Krysa, M.Sc.Roman Fiałkowski

Environmental Radioactivity LaboratoryResearch staffMirosława Jasińska, M.Sc, Head of LaboratoryKrzysztof Kozak, Nucl.E., M.Sc.Piotr Macharski, M.Sc.Jerzy Wojciech Mietelski, M.Sc.

249

GRANTS

The following grants have been received from the State Committee for Scientific Research(KBN):

1. Head: Professor Jan Mikulski.

Research Grant no. 202599101 Neutron - deficient isotopes for medicine. Optimization ofradiometrie and analytical methods.

2. Head: dr habil. Zdzisław Szeglowski;

Research Grant no. 226129102 Studies on the chemical properties of transactinium ele-ments (Z>104) in aqueous solutions in model systems with their homologues (Zr, Hf, Nb,Ta, W).

3. Two investment grants (INP symbols: A02 and A09) for the upgrading of the gammaspectrometric measurements, 1993.

OVERVIEW:The Department consists of three laboratories working on various projects of pure and applied

nuclear, analytical and physical chemistry.

Laboratory of Physical Chemistry of Separation ProcessesThe main interest of this research group is the production and separation of neutron-deficient

isotopes for medical diagnosis (SPECT). Recently, the main interest was in m I n which is apromising tracer for cancer diagnosis. To increase the effectiveness of production of indiumm I n , the reaction with deuterons on the enriched cadmium target was carried out instead ofthe previously used one with alpha particles on natural silver. The change of in the way ofproduction required switching from thermal separation of the radioactivity to the extractionmethod.

The separation processes were controlled by means of gamma spectrometry. Owing to theinvestment and research grants from KBN, the measurement equipment has been recently up-graded by purchasing two HPGe detectors from the detector laboratory of the Institute and twogamma spectrometry tracts from SILENA.

Non-radioactive contaminats in the samples were detected by means of atomic absorptionspectroscopy (AAS). The AAS laboratory is also involved in programs to determine of traceelements in evironmental and biological samples. The main cooperation in this respect has beenwith the Environmetal Radioactivity Laboratory of this Department, with the Medical School ofthe Jagellonian University and with the Institute of Nuclear Research in Reź (Czech Republic).

Another project in the group is the preparation of thin layers using the Langmuir-Blodgettmethod. The method turned out excellent for the preparation of sources for alpha and electronspectroscopy.

Finally, a project on the sulphide-sulphite method of flue gases desulphurization was alsocarried out in the Laboratory.

Laboratory of Chemistry and Radio chemistryThe studies of physicochemical properties of transactinide elements 104,105 and 106 in model

systems with their homologues Hf, Ta (Pa) and W were continued in collaboration with the JINRin Dubna as well as the IPN Orsay, and were partially supported by the Polish State Committeefor Scientific Research (Grant No. 226129102). In the scientific program investigations havebeen carried out on the following subjects:

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1. Rapid methods of isolation of the short-lived (>5 sec) isotopes of Hf, Ta and W from thenuclear reaction products obtained in the targets bombarded by heavy ions from the U-400Cyclotron of JINR Dubna.

2. Studies of Hf sorption on ion exchange resins from acetic acid media as well as frommixtures of acetic and nitric acid.

3. A method for deep decontamination of the 178m2Hf isomer from microquantities of Sc, Te,Co, Ni, Sb and Ag.

Environmental Radioactivity LaboratoryAs a part of the National Network for the Early Warning of Radioactive Contamination

in the Air, the Laboratory conducts continuous monitoring of radioactive contamination ofthe atmosphere at ground level, using a field station ASS-500 situated at the premises of theInstitute. Weekly reports are submitted to the National Atomic Agency (PAA) and to theCentral Laboratory for Radiation Protection (CLOR).

The Laboratory is also involved in the research programme on radioactive contamination inforests. During 1993 nearly 300 samples of mushrooms (34 species), plant (blueberry) and twolayers of forest litter, collected in the autumn of 1991 from all over Poland, were analysed withthe low-background HPGe gamma-spectrometer. This work was carried out as the continuationof investigations which were started in 1991. Altogether 800 samples were analysed. Besidesthe gamma-spectrometric measurements, in 1993, several alpha-spectrometric measurements ofthe activity of plutonium isotopes in forest litter samples were carried out. For this purpose aradiochemical procedure for plutonium determination was developed and tested.

In collaboration with the Institute of Geography of the Jagellonian University, studies onlocal (vertical and spacial) variation of radiocaesium content in various kinds of soil were carriedout for various landforms.

Prof. J. Mikulski

REPORTS ON RESEARCH:

Langmuir-Blodgett Films Used for Mono-Molecular ^Alpha-Spectroscopic Source Preparation

B. Was

A modified Langmuir-Blogdett technique which had been developed previously1 for thepreparation of mono-molecular sources for low-energy beta spectroscopy was applied to thepreparation of 241Am source for alpha-spectroscopy. High efficiency of the americium ions sorp-tion has been achieved. The obtained energetic resolution was limited by the alpha spectrometerbut it seems to be better than 30 keV. A further investigation with other alpha-emitters willbe performed next year. The improvement of the spectrometer resolution is planned, and theactual value for the FWHM will be determined. The method seems of great promise.

1B. Was, Nucl. lustrum. Meth. Phys. Research A332 (1993) 334-331.

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Flour Characteristics by Means of Pattern RecognitionMethods

P. Zagrodzki 1 | 2 , M. Schlegel-Zawadzka2, P. Malec3, E. Dutkiewicz1, M. Krośniak2 andA. Bichoński4

1H. Niewodniczański Institute of Nuclear Physics, Kraków; 3Department of Food Chemistryand Nutrition, Collegium Medicum, Jagellonian University, Kraków; 8Department of Phy-siology and Biochemistry of Plants, J. Zurzycki Institute of Molecular Biology JagellonianUniversity, Kraków; 4Institute of Cultivation and Acclimatization of Plants, Kraków.

Samples of twenty various brands of flour which originated from the fields of the PlantExperimental Stations in Smolice and Oleśnica Mała were examined for the content of selectedtoxic elements (Pb, Cd) and some macro- and microelements (Mg, Cu, Fe, Mn, Zn). Thechemical composition of flour and its baking characteristics determined through the routineanalysis were also included as parameters into the statistical analysis.

Metal levels were measured independently by the atomic absorption spectrometry (AAS),and anodic/cathodic stripping voltammetry (ASV/CSV). The CEM Corporation's MicrowaveDigestion System MDS-2000 was used for the mineralization of samples prior to the analysis.The atomic absorption analyses of Cd, Cu, Fe, Mn, Pb were performed with the Perkin-Elmer5100 PC atomic absorption spectrometer equipped with the 5100 ZL Zeeman Furnace Module.In Mg and Zn measurements the flame device of the Perkin-Elmer 5100 PC atomic absorptionspectrometer was used. In the ASV/CSV methods (Cd, Cu, Mn, Pb) the UPE-3 electrochemicalanalyser (Radius Cooperative, Gdańsk, Poland) was used.

Methods of advanced statistics were applied to achieve an exhaustive interpretation of theresults. An attempt was made to recognize patterns and isolate clusters on the basis of theselection of relevant variables. The applicability of the asumptions of the linear discriminanttechnique for this case was tested.

Vi Forest Litter Accumulation of Cesium and Radiocesium inSelected Regions of Poland

P. Zagrodzki12, J.W. Mietelski1, M. Krośniak2 and B. Petelenz1

1H. Niewodniczański Institute of Nuclear Physics, Kraków; 2Department of Food Chemistryand Nutrition, Collegium Medicum Jagellonian University, Kraków.

The study was a continuation of investigations into the forest ecosystems samples collectedin 1991 from woods all over Poland. In 20 samples (out of 345) of the two upper layers ofthe forest litter, which revealed the highest radioactivities (Cs-137, Cs-134), the stable cesiumwas assayed by the AAS preceded by microwave digestion. The samples originated from UpperSilesia and from North Eastern Poland.

An attempt was made to find any significant correlation between the contents of stable andradioactive cesium in the litter samples. The results were compared with those obtained formushrooms from the same sites. The influence of the stable cesium content on the radioce-sium transfer factor Tf (from litter to mushroom) was studied and no simple correlation wasfound. More complex relations provided very high correlation coefficients but the validity of theproposed models needs further checking.

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Determination of the half-life of 165HfD. Schumann1, R. Dressier1, S. Fischer1, S. Taut1, R. Binder2, Z. Szeglowski3,

B. Kubica3, L.I. Gusieva4, G.S. Tikhomirova4, V.P. Domanov5, O. Constantinescu5,G.V. Buklanov5, M. Constantinescu5, Dinh Thi Lien5, A. Jakushev5,

Yu.Ts. Oganessian5, V. Brudanin5, A.F. Novgorodov6 and H. Bruchertseifer7

XFG Radiochemie, Institut für Analytische Chemie, Technische Universität Dresden, FRG;2Kern- und Radiochemie Leipzig, FRG; 3 H. Niewodniczański Institute of Nuclear Physics,Kraków, Poland; 4 Institute of Geochemistry and Analytical Chemistry RAN, Moscow, Russia;BLaboratory of Nuclear Reactions, JINR, Dubna, Russia; 6Laboratory of Nuclear Problems,JINR, Dubna, Russia; 7PSI Villigen, Switzerland.

Many neutron-deficient isotopes are produced in heavy ion reactions. The nuclear propertiesof these nuclei have been not well-known till now. For instance, the half life of 1 6 5 Hf wasdetermined by several authors, the values differing from 75 s to 108 s. We re-examineded thishalf Ufe using a multichannel analyzer system (ACCUSPEC-A) which was previously tested bydetermining the half-life of 8 1 m K r .

ExperimentalShort lived isotopes of hafnium were produced via the following heavy ion reaction:

147,149Sm + 2 0 N e _> 165 H f (95.9g M e y )

at the U-400 cyclotron. The recoiled atoms were transported from the target chamber using aKCl/Ar gas jet (1 1/min). The equipment for the separation experiments has been describedearlier.

Columns (20X3mm) were filled with Dowex 50X8 or Dowex 1X8 (240 mesh) and preequili-brated for 12 hours. 0.2 M HF solution was used to adsorb hafnium completely on Dowex 1X8.Flow rates of 1-3 ml/min were used.

The activity was collected on the anion column for three minutes, then the column wasmeasured off-line 30 times for 15 s, using a high resolution HPGeX detection system. Duringthe whole time the column was washed with 0.2 M HF. This experiment was repeated 40 times.

Results and DiscusiónThe gamma peak at 179.9 keV was used for the half-life calculation (Fig.l). We obtained a

value of 78.6±1 s for the half-life of 165Hf. This result shows that the multichannel system usedin this experiment is suitable for the determination of the half-life of short-lived isotopes andcan probably be applied to investigations of short lived W isotopes (i64/165"W).

ICO 300 300 400 SOO

Figure 1: Calculation of165 Hf half-life, E 7 =179.9 keV.

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Physics of the Long-Lived High-Spin 1 6 5 Hf IsomerCh. Briançon1, M. Aiche1, D. Ledu1, R. Meunier1, P. Quentin1, Ch. Vieu1,

M. Hussonnois2, J.B. Kim2, D. Trubert2, F. Le Blanc2, M.D. Lunney2,Yu. Ts. Oganessian3, 0 . Constantinescu3, S.A. Karamian3, Z. Szeglowski4 and

R. Kulessa5

^SNSM-Orsay, IN2P3-CNRS, Orsay, Prance; 2Institut de Physique Nucléaire Orsay, France;3Joint Institute for Nuclear Research, Dubna, Russia; 4H. Niewodniczański Institute ofNuclear Physics, Kraków, Poland; 5Jagellonian University, Kraków, Poland.

Nowadays a large interest is attached to the production of exotic beams and targets fornuclear structure and reaction studies. The nucleus 178Hf, with its long-lived {T1/2 = 31 years)high-spin isomeric state V = 16+ at a relatively low-excitation energy (2.45 MeV), is indeed aunique probe to study nuclear phenomena in a new way.

For a few years a Dubna-Orsay collaboration has been established to produce this isomerusing the 1 7 6 Yb(a,2n) reaction and to obtain microweight quantities of it which are sufficientfor target preparation. Up to now 1.3 X 101 5 atoms of the isomer have been produced. Methodsof irradiations with high-intensity beams, of high-purity chemistry, of isotopic separations withyields as high as 25% have been developed. Various targets have been prepared and adapted todifferent types of experiments.

A wide research program is underway in the framework of the "Hafnium Collaboration"which now covers around 80 scientists from 16 Institutes. A series of experiments are beingcarried out or are in preparation. This report gives the results of the recent experiments of thiscollaboration.

On-Line Study of Neutron Deficient Hafnium Isotopes asHomologues of Element 104

D. Trubert1, M. Hussonnois1, J.F. Ledu1, L. Brillard1, V. Barci2, G. Ardisson2,Z. Szeglowski3, 0 . Constantinescu4 and Y.T. Oganessian4

institute of Nuclear Physics, Orsay, France; laboratory of Radiochemistry, Nice, France;3H. Niewodniczański Institute of Nuclear Physics, Kraków, Poland; 4Joint Institute forNuclear Research, Dubna, Russia.

A rapid method of continuous production, separation and purification has been developedat the tandem accelerator of Orsay (FRANCE). This device, developed in Dubna for transac-tinide chemistry, was tested in producing different neutron-deficient hafnium isotopes. Mostof the spectroscopic properties of the isotopes produced were unknown. We have developed aspecial device for the study of these isotopes. Throughout irradiations of mono-isotopic targetsI54,I55,156Q¿ ^y I 6 Q i o n s w j t]j appropriate energy, and with the help of the continuous purifi-cation through Chromatographie ion exchange, we are able to obtain practically pure X and7 spectra of the selected isotope. Coincidence measurements have also been carried out andthe analysis is now in progress. For example, for 168Hf, more than 100 new gamma transitionshave been identified. Thus, spectroscopy of hafnium isomers from 164 to 169, with half-livesranging from 76 seconds to 26 minutes has been investigated. We present here merely some ofthe preliminary results obtained.

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High-Spin Nuclear Target of 178m2Hf: Creation and NuclearReaction Studies

Yu. Ts. Oganesian1, S.A. Karamian1, Yu. P. Gangrsky1, B. Górski1, B.N. Markov1,Z. Szeglowski2, Ch. Briancon3, O. Constantinescu3, M. Hussonnois3, J. Pinard3,

R. Kulessa4, H.J. Wollersheim4, G. Graw5, J. de Boer5, G. Huber6 and H.V. Muradian7

XFLNR, JINR Dubna, Russia; 2H. Niewodniczański Institute Nuclear Physics, Kraków,Poland; 3CSNSM, IPN, Orsay, France; 4GSI, Darmstadt, Germany; 6Miinchen University,Germany; 6Mainz University, Germany; 7Kurchatov Institute, Moscow, Russia.

Investigations of the hafnium-178 isomers are a new scientific direction promising the devel-opment of a fundamental knowledge both in the field of the nuclear structure and of nuclearreactions. The completed experiments give grounds for hope of obtaining data on the electro-magnetic moments, on the mean radius and the deformation of the 178Hf nucleus in the state16+, on the wave function structure of this state, as well as to study the influence of the targethigh spin on the differential cross sections of nuclear reactions, to find and investigate neutronresonances with a high spin, to obtain direct information on the density of the levels in the earlierinaccessible region of the spin and of the excitation energy, to measure directly the parametersof a giant dipole resonance based on the high spin state and to clarify in detail the role of thestructure hindrances in nuclear reactions.

Sorption Behaviour of Short-Lived W and Hf Isotopes on IonExchangers from HC1/HF Solutions in Fast On-Line

ExperimentsD. Schumann1, R. Dressier1, S. Fischer1, St. Taut1, R. Binder2, Z. Szeglowski3,

B. Kubica3, L.I. Gusieva4, G.S. Tikhomirova4, 0 . Constantinescu5, G.I. Buklanov5, V.P.Domanov5, M. Constantinescu5, Dinh Thi Lien5, A. Jakushev5, Yu.Ts. Oganessian5,

I. B. Brudanin6, A.F. Novgorodov 6 and H. Bruchertseifer7

*FG Radiochemie, Institut fur Analytische Chemie, Technische Universitat, FRG; 2Kern-und Radiochemie Leipzig, FRG; 3H. Niewodniczański Institute of Nuclear Physics, Kraków,Poland; institute of Geochemistry and Analytical Chemistry RAN, Moscow, Russia; laboratoryof Nuclear Reactions, JINR Dubna, Russia; 8Laboratory of Nuclear Problems, JINR Dubna,Russia; 7PSI Villigen, Switzerland.

IntroductionThe 4-6 subgroups of elements are suitable tracers to investigate the chemical properties

of the heavy elements 104-106. The main problem in this field is the fast separation of theseelements from all other nuclides produced in heavy ion reactions. Previous works showed that theseparation of W from Hf and lanthanides in mixed solutions of HC1 and HF at low concentrationscan be carried out using the ion exchange method. It was shown that W can be completelyseparated from Hf by adsorbing the latter on Dowex 50X8 using 0.05 M HC1 / 10"3M HFsolution. First on-line experiments at the TRIGA reactor in Mainz showed that Mo can becompletely separated from the lanthanides, Zr and Nb by using the degasser from the SISAKsystem and separation columns filled with cation exchanger. In the present work we testedthese conditions in fast one-line separations using heavy ion reactions at the U-400 cyclotron(Laboratory of Nuclear Reactions JINR Dubna, Russia).

ExperimentalShort lived isotopes of tungsten and hafnium were produced via the following heavy ion

reactions:

255

i47,i49Sm + 2oNe __> Hf (95-98 MeV)152,154,158Qd + 20N e _^ W ( 9 6 M e V )

at the U-400 cyclotron. The recoiled atoms were transported from the target chamber using aKCl/Ar gas jet (1 1/min). The equipment for the separation experiments has been describedearlier. Columns (20 X 3 mm) were filled with Dowex 50X8 or Dowex 1X8 (240 mesh) andpreequilibrated for 12 hours. All separation experiments were performed with the mixture of0.05 M HC1 and 10 ~3M HF using flow rates of 1-3 ml/min. The measurements were performedusing a high resolution HPGeX detector (ORTEC) and a HPGe-PT detector (ORTEC).

Results and Discussion1. TungstenThe main products of the nuclear reaction were m W (2.38 min), 170W (2.42 min), 169W

(1.27 min) and 168W (53.2 s) produced in the 3n and 4n reaction channel, respectively. l 7 4W(29 min.) and m W (34 min.) could not be detected due to their relatively long half-life. Theresults of the separation using the 0.05 M HC1 / 10"3M HF solution are shown in Fig.l. It canbe seen that all four W isotopes are found on Dowex 1X8 (171W: 294,8 keV, 170W: 316.2 keV,124.7 keV, 169W: 136.8 keV, 168W: 178.8 keV). These peaks cannot be found after the separationson Dowex 50X8. Some peaks from these W isotopes can be observed on the cation exchangertoo, but they are overlapped with those of other nuclides for example: m W / 1 6 8 H f - 183.7 keV.Therefore, the conclusion can be drawn that W can be completely separated in the describedway, as had already been expected from previous studies.

100 150 200 250 300 350 400 450 500

2500-

2000-

1300-

1000-

500-

DOUEN 1X8

f 9

"' ' a ?

100 150 200 250 300 350 400 450 500

trwrgy | k«V ]

Figure 1: 7-Spectra of the Dowex 50X8 and Dowex 1X8 columns: nuclear reaction: i52,i54,i58Gd

+ 20Ne -* W; solution: 0.05 M HC1 / 10"3 M HF.

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PL9601123

200 2SO 300anwgy (kav ]

Figure 2: 7-Spectra of the Dowex 50X8 and Dowex 1X8 columns: nuclear reaction: 147-149Sm +20Ne -» Hf solution: 0.05 M HC1 / 10~3 M HF.

2. HafniumAs can be seen from Fig.2 the main reaction products 166Hf (1.25 min.) and 186Hf (6.77 min.)

can be found on Dowex 50X8. Only small peaks of 165Hf (179.9 keV) and 166Hf (228.0 keV) areobserved on the anion exchange column. The calculation shows that 99% of Hf is adsorbed onthe cation exchanger while Lu is completely adsorbed on this column.

SummaryThe results show that in the described system of cation and anion exchange columns with

0.05 M HC1 / 10~3M HF solution tungsten can be separated from nearly all other elementsproduced in heavy ion reactions, mainly from lanthanides and hafnium. Consequently, thedeveloped system should be applicable for fast on-line separations of the element 106.

Ion Exchange Behaviour of Zirconium and Hafnium asHomologues of 104 Element in Phosphoric Acid SolutionsZ. Szeglowski1, L.I. Guseva2, Din Thi Lien3, V.P. Domanov3, O. Constantinescu3,

G.S. Tikhomirova2 and M. Hussonnois4

XH. Niewodniczański Institute of Nuclear Physics, Krakow, Poland; institute of Geoche-mistry and Analitycal Chemistry RAN, Moscow, Russia; 3Laboratory of Nucleai Reactions,JINR, Dubna, Russia; 4IPN, Orsay, France.

The distribution coefficient of Zr, Hf, Sr and some actinide and lanthanide elements betweenion exchange resins and phosphoric acid solutions were determined.

The optimum conditions for the concentration and separation of Zr(Hf) from the trivalentactinides in H3PO4 - ion exchange resins systems have been found.

The high decontamination factor (>106) of hafnium from europium was obtained using theDowex 50 resin in 0.5 M H3PO4 solution. In the conditions imitating the isolation of element 104

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a model experiment was performed on the short lived hafnium isotopes isolated from a naturalgadolinium target bombarded with the 1 8 0 ions on the U-400 cyclotron at JINR.

Aerosols Radioactivity Measurements in the Ground Level Airin the Institute of Nuclear Physics - Kraków

K. Kozak, M. Jasińska, P. Macharski and W. Kwiatek

An air sampling station ASS-500 (located in the Institute of Nuclear Physics) is used for theconstant monitoring of radioactive contamination in the atmospheric air. The station is a freestanding, all-weather instrument for the continuous collection of air aerosols. The high air-flowrate of 400-500 m3/h through a polypropylene filter (Petrianov type FPP 15-1.5) allows forrepresentative sample taking. The efficiency of this filter for aerosols of diameters between 0.3and 1.25 /mi, at linear air velocities through the filter varying from 0.25 to 4 m/s with a pressuredrop through the filter from 500 - 9300 Pa, is between 95 and 99%. Collection of aerosols fromair volume of 30000 to 60000 m 3 enables accurate spectrometric measurements (HPGe detector,low-background gamma spectrometer, SILENA) of natural and human-made radionuclides ina wide range of their concentration, starting from 0.5 /iBq/m3. The Aerosol Sampling StationASS-500 is equipped with an on-line radioactivity control system i.e. G-M counters and a URLtype ratemeter.

As a result of aerosols radioactivity measurements in the ground level air, weekly reportsproviding data for 7Be, 40K, 1 3 7Cs, 2 2 6Ra and 2 2 8Ra are issued. Any anomalies of any human-made radionuclides are also presented. These weekly reports are sent to the Central Laboratoryfor Radiological Protection and to the National Atomic Agency. In 1993 our Station became apart of the National Network for the Early Warning of Radioactive Contamination in Air. During1993 we have detected no emergency situations. Computer software (AFASS) for automataticcalculation of the activity level in air (for normal and emergency situation), including a libraryof isotopes was elaborated. This program evaluates the sample activity, specific air activity, LowLimit Detection, Minimum Detecable Level, and produces a complete filter analysis protocol.

By the end of 1993, more than 30 additional samples of air niters from the network stationof PIOS were analyzed using low-background gamma spectroscopy. The samples were collectedin winter 1992 and spring 1993 in different places in Krakow. Collaboration with PIOS will beused in the case of a nuclear emergency situation.

Additionally, concentrations of selected heavy metals in 22 samples of the air filters fromASS-500 were analysed by means of the PIXE method in the INP PIXE Laboratory.

Distribution of Radioactive Contaminaton in PolandJ.W. Mietelski, P. Macharski, M. Jasińska and R. Broda

An investigation of radioactive contamination in forest litter of A0 and Al layers from all overPoland was used to obtain an inventory of geographical distribution of the contamination withseveral artificial radioisotopes. Among them, 1 3 7Cs and 1 3 4Cs as well as 1 0 6Ru, 125Sb and 1 4 4Cewere analysed. The method of sampling and measuring has been described in separate papers[1,2]. The distribution of 1 3 7Cs and 1 3 4Cs (Fig.l and 2, respectively) obtained now confirmedbasically the results of investigation on the upper 10 cm of soil [3], presented by the Warsawgroup previously, with the highest contamination activity observed in the region of Silesia. Thecomplete maps showing the distribution of other radioisotopes are given for the first time. Thedistribution of 125Sb (Fig.3) and 1 0 6Ru (Fig.4) isotopes shows a similar pattern to that of 1 3 7Cs,although in some samples from Eastern Poland 1 0 6Ru relative to cesium abundance is muchhigher. Quite different is the distribution obtained for 1 4 4Ce (Fig.5) which was found almost

258

solely in the North-East corner of Poland. The distribution of europium isotopes (1 8 4Eu and15BEu) shows the same pattern, with initial activities smaller by the factor of 1000. They arelikely to be accompanied by the actinide isotopes of Chernobyl origin [2]. The traces of 6 0Coare present mainly in the North-East regions of Poland (Fig.6).

It is important to note that all maps are based on the measurements of samples originatingfrom 125 sites distributed semi-randomly all over Poland, so they could be regarded only as arough estimate of radioactive contamination distribution in Poland.

References

1. J.W. Mietelski, M. Jasińska, B. Kubica, K. Kozak, P. Macharski - Proceedings of the ThirdInternational Conference on Nuclear and Radiochemistry, Sept. 7-11, 1992, Vienna (to bepublished in J. Radioanal. Nucl. Chem.)

2. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Proceedings of the Conference"Nuclear and Analytical Methods in the Life Sciences", Prague, September 13-17, 1993(to be published in Biol. Trace Elem. Res.)

3. M. Biernacka, J. Henschke, J. Jagielak, A. Korczyński - Proceedings of the Interna-tional Symposium on Post-Chernobyl Environmental Radioactivity Studies in East Eu-ropean Countries, Kazimierz, September 17-19, 1990, UMCS Press, Lublin, (1991) pp.26-33.

259

Maps of radioactive contamination with selected radionuclides in forest litter ( AO and Allayers) from Poland in autumn 1991. All activities are decay corrected for September 1st, 1991.

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Plutonium from Chernobyl in PolandJ.W. Mietelski and B. Was

According to the UNSCEAR Report [1], the deposition of 2 3 9 . 2 4 0 p u from global fallout inPoland should be about 58 Bq/m2, and that for 2 3 8 Pu about 2.3 Bq/m2. There were no mea-surements of Pu in pre-Chemobyl Poland. The values estimated from Pu activities in BalticSea sediments are from 30 to 98 Bq/m2 for 2 3 9 . 2 4 0 p u [2]. Plutonium from the Chernobyl falloutappears in Poland mainly in a large diameter aerosole form -"Hot Particles" (HP) [3]. Such largeaerosols are not too dangerous from the dosimetric point of view, as they are not respirable.The activity of Chernobyl plutonium in the so called continous fraction of the contaminated airover Warsaw [4] in April-May 1986 was equal to 5.7xlO~"6 of the 1 3 7Cs activity, and activities ofboth radionuclides were well correlated. Thus, the expected maximum activity of Pu depositedfrom the Chernobyl cloud in Poland, in other a HP form was smaller than 1 Bq/m2. Large-scalegamma-spectrometry measurements of forest litter from all over Poland [5] established the pre-sence of 1 4 4Ce, 1 6 5Eu and 1 5 4Eu in some samples from the North-East and East of the country.The cerium and europium activity seems to be distributed evenly throughout each sample, sothey did not originate from typical HP. As the decay corrected activity ratio of Chernobyl Puto cerium 1 4 4Ce is known to be practically constant, the expected level of Chernobyl Pu was10 Bq/m2. The measurements of the initial batch of 20 samples confirmed this expectation. Theradiochemical procedure developed at the IAEA Laboratories, Seibersdorf [6] has been appliedin our work. Sources for alpha-spectrometry have been prepared using the NdF3 co-precipitationmethod. The 238pu 239,24Opu a ctj vity ratio in some samples reaches 0.60, which is a hallmarkof Chernobyl plutonium. The project is still in progress, but our preliminary results indicateclearly that Chernobyl Pu is present in the environment of Poland not only in the large HPform.

AcknowledgmentDr Rolph Zeisler, Head of the Chemistry Unit of the IAEA Laboratories Seibersdorf, is

warmly acknowledged for the long-term loan of the Canberra 7401 Alpha-Spectrometer. Wewould also like to express many thanks to Dr Jerrome J. La Rosa, of the IAEA LaboratoriesSeibersdorf, for his great support, help and the stimulation he gave our work.

References:

1. UNSCEAR Report to the General Assembly with Annexes, (1982), New York p. 238;2. B. Skwarzec, R. Bojanowski - J. Environmental Radioactivity 15 (1992) 249-263;3. R. Broda, B. Kubica, Z. Szeglowski, K. Zuber - Radiochimica Ada 48 (1989) 89-96;4. A. Pietruszewski, R. Bojanowski - Proceedings of the International Symposium on Post-

Chernobyl Environmental Radioactivity Studies in East European Countries, Kazimierznad Wisła, 17-19 September 1990, pp. 118-126, Lublin, UMCS Press 1991;

5. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Proceedings of the Conference"Nuclear Analytical Methods in the Life Sciences", Prague, 13-17 September 1993 (to bepublished in Biological Trace Elements Research);

6. J.J. La Rosa, E.L. Cooper, A. Ghods - Esphahani, V. Jansta, M. Makarewicz, N. Vajada- /. Environ. Radioactivity 17 (1992) 183-209.

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Local Variations in Distribution of Radio caesium in Soils ofthe Carpathian Foothills

W. Chełmicki1, J. Swicchowicz1, J.W. Mietelski, M. Jasińska, K. Kozakand P. Macharski

1 Jagellonian University, Institute of Geography, 31-044 Kraków, PolandThe research on natural factors of radioactive caesium distribution in soils of the Carpathian

Foothills was a part of the project entitled "Circulation and Transformation of AntropogenicContaminants in Geoecosystems of the Edge Zone of the Carpathian Foothills" carried out atthe Jagellonian University, Institute of Geography Research Field Station in Łazy (Grant: PB0389/P2/93/04).

While the study done in 1992 was focused on caesium distribution along the forested slopeprofile [1], the idea behind the measurements made in 1993 was to determine the spatial distri-bution of caesium in the valley bottom sediments of the elementary drainage basin (A), as wellas along the downslope profile of the active landslide (B). In the first case (A) the soil samplesfor 1 3 7Cs and 1 3 4Cs measurements were collected at 3 sites from 50 cm deep soil profiles, withdepth increments of 5 cm. In the second case (B) the samples were taken from 4 sites situated atvarious parts of the active landslide, and 1 site situated above the upper crest of this landform.The activities for caesium isotopes, as well as those for natural radionuclides were determinedwith low-background gamma-spectrometers. The obtained inventories for the caesium isotopesin whole profiles for each site of case (A) or (B), are presented in Fig.l. In both cases the resultsare being elaborated and should lead to a better understanding of the role of different landformsand soil properties (infiltration capacity, grain-size distribution, acidity and humus content) inthe redistribution of radioactive contaminants in the geoecosystems of the Carpathian Foothills.Up to date results show, that slope processes (overland flow and soil-wash) along with soil pro-perties are important factors in radioactive caesium redistribution. The 1 3 7Cs content on slopesis much lower than in valley bottom deposits. Thus the valley bottoms can be recognized asareas of accumulation of radioactive contaminants.

mlddte bottom

Elementary Drainage Baain

Above

Edg« Active Landslide 8itea

Figure 1: Inventories of 1 3 7Cs and 1 3 4Cs in soils profiles from various landforms. Activitiesare decay corrected for the 1 May 1986, the Chernobyl fallout date, to reveal global-falloutcomponent (137Cs to 1 3 4Cs activity ratio in Chernobyl fallout was equal 2±0.2). Cases A and Bas in text.

References

1. W. Chełmicki, J.W. Mietelski, P. Macharski, J. Święchowicz - Report INP no. 1615/D(1993).

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LIST OF PUBLICATIONS:I. Articles

1. B. Was, A. KovaKk, A.F. Novgorodov, J. Rak - A new Technique for the Preparation ofSmall-Size Radioactive Samples Based on the Langmuir-Blodgett Method - Nucl. Instr.Meth. Phys. Research A332 (1993) 334-341;

2. Z. Szeglowski, L. Gusiewa, et al. - Studies of the ion-exchange properties of zirconiumand hafnium as homologues of the element 104 in phosphoric acid solutions -Radiokhimiya 35 (1993) 59-65; (in Russian);

3. D. Trubert, M. Hussonnois, Z. Szeglowski et al. - On Line Study of Neutron DeficientHafnium Isotopes as Homologues of Element 104 - Radiochim. Acta (1993), in press;

4. Z. Szeglowski, Dinh Thi Lien, M. Hussonnois, O. Constantinescu, B. Kubica,S.A. Karamian - Hafnium Decontamination from Microquantities of Some Elements ofGroups I, II and HI - submitted to J. Radioanal. Nucl. Chem., Letters (1993), in press;

5. Z. Szeglowski, Dinh Thi Lien - Ion-exchange isolation of short-lived isotopes of Hf, Taand W, as homologues of trans-actinide elements in the solutions of H2C22O4 andH2C22O4 - HC1 (in Russian) - Radiokhimiya, in press;

6. D. Trubert, M. Hussonnois, J. Ledu, L. Brillard, V. Barci, G. Ardisson, Z. Szeglowski,0 . Constantinescu, V.P. Domanov, Yu. Ts. Oganessian - On-Line Study of NeutronDeficient Hafnium Isotopes as Homologues of 104 Element - submitted in 1993 toRadiochim. Acta;

7. J.W. Mietelski, J. La Rosa, A. Ghods - Results of 9 0Sr, 239+240pU) 238pu a n d 2 4 i A m

Measurenients in Some Samples of Mushrooms and Forest Soil from Poland - J.Radioanal. Nucl. Chem., Articles 170 (1993);

II. Contributions to Conferences:

1. Z. Zachwieją, J. Chłopicka, M. Schlegel-Zawadzka, P. Zagrodzki, J. Wypchlo,M. Krośniak - Evaluation of Zinc Content in Childrens Hair - Proceedings of the 4thInternational Congress on Trace Elements in Medicine and Biology. Trace Elements andFree Radicals in Oxidative Diseases, Chamonix, 5-9 April 1993;

2. M. Krośniak, P. Zagrodzki - Mineralization of biological samples in the microwave ovenand muffle furnace: comparison of methods - Proceedings of the 2nd Poznań AnalyticalSeminar: Modern Methods of Sample Preparation and Determination of Trace Elements,Poznań, 27-28 April 1993, (in Polish);

3. Z. Zachwieją, M. Schlegel-Zawadzka, J. Wypchlo, J. Chłopicka, M. Krośniak,P. Zagrodzki - The comparison of the copper content in the hair of children living inseveral towns in Southern Poland - Proceedings of the 8th International Symposium onTrace Elements in Man and Animals, TEMA-8, Dresden, 16-21 May 1993;

4. P. Zagrodzki, J.W. Mietelski, M. Krośniak, B. Petelenz - Forest littter accumulation ofcaesium and radioceasium in selected regions of Poland and its influence onlitter-to-mushroom transfer factor - Proceedings of the Conference "Nuclear AnalyticalMethods in Life Sciences", Prague, 13-17 September 1993;

5. Z. Zachwieją, M. Krośniak, P. Zagrodzki, M. Folta, M. Schlegel-Zawadzka - Microwavetechnique in the minotoring of metal contamination in the environment - Proceedings ofthe 6th Conference "Analytics for Geology and for Environment Protection",Krasnobrod, Poland, 11-15 October 1993, (in Polish)-

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6. Z. Zachwieją, P. Zagrodzki, M. Krośniak, J. Chłopicka, M. Folta, J.J. Pietrzyk,A. Nowak, Z. Mitkowska, A. Glińska, W. Wrzosek, T. Strzelecki, P. Dobosz - Heavymetals content (Pb, Cd, Ni) in maternal scalp and pubic hair from selected cities insouthern Poland - Proceedings of the First Global and European Conference -Environment and Public Health. Antwerpen, 25-30 November 1993;

7. Z. Szeglowski, H. Bruchertseifer, V.B. Brudanin, G.V. Buklanov, 0 . Constantinescu,Dinh Thi Lien, V.P. Domanov, L.I. Guseva, M. Hussonnois, G.S. Tikhomirova, I. Zvara,Yu. Ts. Oganessian - Possibilities of Chemical Isolation of Element 106 from AqueousSolutions According to The Model Experiments with Short Lived Tungsten Isotopes -Proceedings of the 2nd Workshop "Chemie Schwerster Elemente", Solothurn,Switzerland, May 1993, submitted to J.Radioanal. Nucl. Chem., Letters;

8. Yu. Ts. Oganessian, S.A. Karamian, Yu. P. Gangrsky, B.N. Markov, Z. Szeglowski -High-Spin Nuclear Target of Hf: Creation and Nuclear Reaction Studies - Proceedings ofthe International Conference "Nuclear Physics of Our Times", Florida, USA; Proceedingsof the International School-Seminar "Heavy Ion Physics", Dubna, Russia, 10-15 May1993; Report JINR Dubna E15-93-96 (1993); submitted to J. Radioanal. Nucl. Chem.,Letters;

9. Z. Szeglowski, M. Hussonnois, Yu. Ts. Oganessian et al. - Physics with the Long-LivedHigh-Spin 178m2Hf Isomer - Proceedings of the Eighth International Symposium on"Capture Gamma-Ray Spectroscopy", Fribourg, 20-24 September 1993;

10. K. Skarżyńska, E. Zawisza, M. Jasińska, M. Waligórski - Investigation of Radioactivity ofCoal Mining Wastes Przezchlebie Stockpile - Proceedings of the Ą-th InternationalSymposium on the Reclamation, Treatment and Utilization of Coal Mining Wastes,Kraków, 6-10 September 1993;

11. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Radioactive Contamination ofForests in Poland - Proceedings of the Nuclear and Analytical Methods in the LifeSciences, Prague, September 13-17 1993 (submitted to Biological Trace ElementsResearch);

12. J.W. Mietelski, P. Macharski, M. Jasińska, R. Broda - Distribution of RadioactiveContamination in Poland - International Symposium on Remediation and Restoration ofRadioactive-contaminated Sites in Europe, 11-15.10.1993 Antwerpen (a poster, withoutfurther publication);

13. K. Kozak - AFASS program: a proposal for standardization of the procedures, processingand presentation of data from the gamma-spectrometric measurements of the ASS-500stations filters - Seminar on the monitoring of the radioactive contamination in air inPoland, CLOR (Central Laboratory of Radiation Protection), Warsaw, 9-10 December1993.

III. Reports:

1. Z. Mazgaj - "WIDMO" - a program for the automatic interactive analysis of gammaemission spectra - Report INP no. 1628/C (1993), (in Polish);

2. M. Szalkowski, J. Kulawik, J. Mikulski - Wasteless method of SO2 removal from thecombustion products of sulphur-containing solid fuels - Report INP no. 1629/C (1993);

3. R. Misiak, A. F. Novgorodov, A. Kolaczkowski, J. Mikulski - A simple method ofthermal separation of gallium, indium and thallium isotopes from thick targets -

4. P. Zagrodzki, E.M. Dutkiewicz, P. Malec, M. Krośniak, W. Knap, A. Bichoński -Instrumental methods for analysis of some elements in flour - Report INP no. 1648/CA(1993);

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5. W. Chełmicki, J.W. Mietelski, P. Macharski, J. Świfchowicz - Natural Factors of 137-CsRedistribution in Soil (Case Study from the Carpathian Foothills), Report INPNo1615/D (1993).

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. M. Jasińska, contribution to the 4-th International Symposium on the Reclamation,Treatment and Utilization of Coal Mining Wastes, Kraków, 6-10 September 1993;

2. J.W. Mietelski - participation in the Conference "Nuclear and Analytical Methods in theLife Sciences", Prague, 13-17 September 1993;

3. P. Zagrodzki - participation in the Conference "Nuclear and Analytical Methods in theLife Sciences", Prague, 13-17 September 1993;

4. J.W. Mietelski - participation in the International Symposium on Remediation andRestoration of Radioactive-contaminated Sites in Europe, 11-15 October 1993Antwerp en;

5. K. Kozak and B. Kubica - as observers on the conference "Radium and radon as sourcesof the radiological risk", National Atomic Agency (PAA), Warsaw, 25-26 February 1993;

6. K. Kozak - participation in the Seminar on the monitoring of the radioactivecontamination in air in Poland, CLOR (Central Laboratory of Radiation Protection),Warsaw, 9-10 December 1993;

7. K. Kozak - followed the practical course "Off-Site Emergency Response to NuclearAccidents", Belgian Nuclear Research Center, Mol, 21-25 June 1993.

LECTURES AND COURSES:

1. J.W. Mietelski - Radioactive contamination in the environment - a popular lecture forthe secondary school teachers and students, 12 May 1993, Institute of Physics of theJagellonian University, 1 hour;

2. B. Petelenz - Applications of nuclear chemistry in medicine - a popular lecture for thesecondary school teachers and students, Institute of Physics of the JagellonianUniversity, 24 November 1993, 1 hour;

3. J.W. Mietelski - Natural and artificial radioactivty in the environment - lecture for thestudents of the Graduate School of the Environment Protection Agricultural Academy inKraków, 27 October 1993, 2 hours;

4. Environmetal Radioactivity Laboratory, two lectures on the radiological situation in theKraków region and in Poland, invited by the Consumers Federation in Kraków,8 February 1993;

5. Environmetal Radioactivity Laboratory, co-organization (with the Museum of NaturalScience) of the "Mycological Exhibition" and presentation of the materials about theradioactive contaminations in mushrooms in Poland, Kraków, 1-5 October 1993;

6. Environmetal Radioactivity Laboratory, popular presentations in the "Krater" TVstation and radio interviews;

7. Environmetal Radioactivity Laboratory, a cycle of popular articles about theradioactivity in the environment in the "Forest Echoes" journal.

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INTERNAL SEMINARS:

1. R. Misiak - Simple method of the high-temperature separation of Ga-67 from the massivegermanium target;

2. P. Zagrodzki - Report from the 4th International Congress on Trace Elements inMedicine and Biology, Chamonix, 5-9 April 1993;

3. K. Kozak - OfF-site emergency response to nuclear accidents, report from the training;4. J.W. Mietelski and P. Zagrodzki - Nuclear analytical methods in life sciences, Praque,

13-17 September 1993, report from the conference;5. M. Vilgis (KfK, Karlsruhe) - New glass dosimetry in KfK Karlsruhe - jointly with the

Radiation Protection Laboratory;6. V.P. Domanov (JINR, Dubna) - The formation of volatile compounds by radioisotopes of

platinum metals with O2, H 2 0, S and Se;7. K. Kozak and J.W. Mietelski - International Symposium on Remediation and Restoration

of Radioactive-Contaminated Sites in Europe, Antwerpen, 11-15 October 1993, a report;8. P. Zagrodzki - Enviroment and Public Health, Antwerpen, 25-30 October 1993, Report

from the conference;9. J.W. Mietelski - Isotopes of plutonium in the forest litter in Poland.

SHORT TERM VISITORS TO THE DEPARTMENT:

1. participants of the Conference "Geochemical, Hydrochemical and Biochemical Changesof the Environment in the Antropopression Areas" and the aldermen from theEnvironment Protection Commission of the Kraków Municipal Council, 11 March 1993,in the Environmental Radioactivity Laboratory;

2. dr Miloś Beran, Head of the Central Analytical Laboratory of the Nuclear ResearchInstitute in Reź, Czech Republic, 21-23 April 1993;

3. dr Jerrome J. La Rosa, Head of the IAEA Radiochemical Laboratory in Seibersdorf,Austria, in the Environmental Radioactivity Laboratory;

4. dr H. Vera-Ruiz (IAEA, Vienna) - 12-13 August 1993, in the Laboratory of PhysicalChemistry of Separation Processes;

5. dr V.P. Domanov (Flerov Laboratory of Nuclear Reactions JINR, Dubna, Russia),October 1993, in the Laboratory of Chemistry and Radiochemistry;

6. high school and university students (28 groups, 600 people altogether during the schoolyear), in the Environmental Radioactivity Laboratory;

7. physics teachers participating in Methodical Conferences (200 people), in theEnvironmental Radioactivity Laboratory;

8. participants of the Physicists Congress (60 people), September 1993, in theEnvironmental Radioactivity Laboratory.

OTHER:International agreementAn agreement between the Institute of Nuclear Research in Reź (Czech Republic) and theInstitute of Nuclear Physics has been signed. The subject of the agreement is the preparationand standardization of the reference material for determinations of radioactive cesium and ofselected heavy metals in mushroom samples. Preparation of 500 certified samples is expectedto be the result of the cooperation.

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Health PhysicsLaboratory

HEALTH PHYSICS LABORATORY

Head of Laboratory: Assoc. Prof. Michał P.R. WałigórskiDeputy Head: Dr Paweł OlkoSecretary: Irena Lipeńskatelephone: (48) (12) 37-02-22 ext.: 411, 415e-mail: olko@bron.ifj.edu.pl

PERSONNEL:Research Staff:

1. Paweł BILSKI, M. Sc. (Technical Physics) - Assistant, Radiation Safety Inspector2. Maciej BUDZANOWSKI, E. Eng. (Nucl. Eng.) - Assistant, Radiation Safety Inspector3. Tadeusz NIEWIADOMSKI, Ph. D. Assoc. Prof. (Physics) - Consultant4. Małgorzata NOWINA-KONOPKA, M. Sc. (Physics) - Assistant5. Paweł OLKO, Ph. D. (Physics), E. Eng. (Nucl. Eng) - Adjoint, Deputy-Head of Labora-

tory6. Maryla OLSZEWSKA-WASIOŁEK, Ph. D., E. Eng. (Nucl.Eng) - on leave of absence

to New Mexico Institute of Mining and Technology, Socorro, NM, USA)7. Michał WAŁIGÓRSKI, Ph. D., Assoc. Prof. (Physics) - Head of Laboratory8. Piotr WASIOŁEK, Ph. D. (Physics) - on leave of absence to New Mexico Institute of

Mining and Technology, Socorro, NM, USA

Technical Staff:

1. Józef DYBEŁ - Technician2. Jerzy IBKOWSKI - Technician, Radiation Safety Officer3. Irena LIPEŃSKA - Laboratory Assistant, Secretary4. Bronisław MOTYKA - Technician, Radiation Protection Officer5. Elżbieta RYBA, E. Eng. - Chief Specialist, Chief Radiation Safety Officer, INP6. Marta W0ŹNIAK, M. Sc. (Chemistry) - Chemist

GRANTS:

1. M.P.R. Wałigórski,grant No 607359101, (The State Committee for Scientific Research),"Analysis of microdeposition of energy for determination of radiation hazard, includingthat from radon"

2. M.P.R. Wałigórski,grant No 224309203, (The State Committee for Scientific Research),"Modelling of interaction of nuclear radiation in nanometre volumes"

3. T. Niewiadomski,grant No 607379101, (The State Committee for Scientific Research),"Investigation of the concentration of radon in dwellings over southern Poland"

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Dl QROIINTERNATIONAL COLLABORATION PROGRAMMES:

1. Polish-German Collaboration: Quantitative Assessment of Radiation Hazard,with Prof. Muller-Gartner/Dr. Th. Schmitz, Institute of Medicine, KFA Julich

2. Polish-German Collaboration: Neutron Dosimetry with TL Detectors,with Dr. Piesch, HSD, KfK Karlsruhe

OVERVIEW:The activities of the Health Physics Laboratory at the Institute of Nuclear Physics in Kraków

are principally research in the general area of radiation physics, and radiation protection of theemployees of the Institute of Nuclear Physics. Theoretical research concerns radiation detectors,radiation protection (modelling of radiation effects in biological and physical systems) and stu-dies of concepts in radiation protection. Experimental research concerns solid state dosimetry,mainly thermoluminescence (TL) dosimetry (present thrust: development of thin TL detectorsfor beta-ray and mixed neutron field dosimetry, development of ultra-sensitive LiF;Mg,Cu,Pphosphors) and environmental radiation measurements (radon in dwellings, low-level naturalradiation). The Laboratory provides expert advice on radiation protection regulations at na-tional and international levels. Routine work of the Health Physics Laboratory involves designand maintenance of an in-house developed TL-based personnel dosimetry system for over 200radiation workers at the INP, monitoring and supervision of radiation safety on INP premises,and advising other INP laboratories on all matters pertaining to radiation safety. Over the years,under the leadership of Prof. Tadeusz Niewiadomski, considerable expertise in TL dosimetry hasbeen gained at the Laboratory: TL detectors, based on LiF (Mg,Ti- doped, equivalent to HAR-SHAW TLD-100, TLD-600 and TLD-700, and Mg,Cu,P- doped, equivalent to ultra-sensitive"Chinese" phosphors) are produced, as well as TLD readers, gamma-irradiators and annealingovens. The Laboratory is able to accept not only commercial orders for production of largequantities of TL detectors and of TL laboratory equipment, but also to produce on requestnon-typical TL detectors according to specification, and to train and advise in the applicationsof TL dosimetry.

1993 was a busy but perhaps less spectacular year for the Laboratory than 1992, whenwe participated in two important international conferences in our field in the United States:the 10th Solid State Dosimetry Conference at Washington DC, and the 11th Symposium onMicrodosimetry at Gatlinburg, Tennessee, and several other meetings in Europe. Some of ourpapers presented at these meetings, reviewed in the 1992 edition of the INP Yearly Report, haveby now appeared in print (see List of Publications). This year we took part in several meetingsin Poland and in Europe.

In the beginning of 1993 our group was invited to the national meeting Radium and Radonas Sources of Radiological Hazard (Warsaw, February 25-26) organized by the President of thePolish National Atomic Energy Agency (NAEA). We have been active in formulating the scien-tific outline of the future Polish National Radon Programme Dr Paweł Olko had been selectedas a member of a national committee (headed by Prof. Jan Czubek) to report to the Presi-dent of the NAEA on the state-of- art of measurements of radon and daughter concentrationsin Polish mines. Measurements of radon and radon daughter concentrations in dwellings ofSouthern Poland were continued by Prof. Niewiadomski under a grant from the Polish StateCommittee for Scientific Research. We are also preparing a general report on the propertiesof radon in dwellings and on ways to measure and reduce its concentration, intended for thelocal administration and for the Regional Sanitary Inspection Office in Kraków, in view of radonconcentration limits to be introduced in Poland in 1995.

In our TLD research, we have succeeded in developing a technology of producing thin-layerTL (so-called sandwich) detectors for measuring the skin dose of low-penetrating radiation (beta-

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and X-rays) and for dosimetry in mixed neutron- gamma fields, to comply with recent recom-mendation of the ICRU. This work is carried out in close collaboration with the Radiation SafetyDepartment of KfK Karlsruhe, under a Polish-German scientific collaboration programme, andis partly sponsored by another grant from the Polish State Committee for Scientific Research.

We have also, in collaboration with KfK Karlsruhe, investigated the calibration and theTL background signal of ultra-sensitive LiF;Mg,Cu,P detectors developed in our laboratory,for environmental measurements. A set of these and other detectors was exposed for about18 months at a depth of 600 m underground (Asse salt-mine, Germany) and at the surfaceof the Bagersee lake in the Karlsruhe area. We found that calibration coefficients applied toevaluate cosmic-ray doses, typically obtained using Cs-137 sources, may have to be re-evaluatedto account for the anomalous response of LiF:Mg,Cu,P to low-energy photons.

The book Thermoluminescent materials, edited by D.R. Vij in which Prof. Niewiadomskicontributed the chapter Lithium Fluoride, has been published by PTR New Jersey in 1993. Thethird edition of a comprehensive book Natural Medicine (in Polish) in which Prof. Niewiadomskicontributed a chapter on ionizing radiation, will appear early in 1994.

Our work on applying phenomenological models (microdosimetry and track structure) tointerpret radiation effects in physical and biological detectors has been continued under yetanother grant from the Polish State Committee for Scientific Research, and under a Polish-German collaboration agreement with the Institute of Medicine of the KFA Julich. We havesubmitted for publication a model evaluation of the risk factor for radon exposure.

Within our routine personnel monitoring service, we have upgraded our automatic readerwith a computer interface and are presently developing the software to transfer readout data toa personnel dosimetry data base.

Since the beginning of 1993 Dr Waligórski has, apart from leading the Health PhysicsLaboratory, taken on the duties of Head of the Medical Physics Department of the KrakówDivision of the Maria Skłodowska-Curie Centre of Oncology. This will bring some of the researchactivities of the Health Physics Laboratory closer to physics in radiotherapy. In particular, weenvisage work on applying TL and alaninę dosimetry to clinical measurements in vivo and oncontinuing and further developing medical applications of the INP accelerators.

Assoc. Prof. Michał P.R. Waligórski

REPORTS ON RESEARCH:A. Environmental Radiation Protection:

Investigation of radioactivity of coal mining wastes-thePrzezchlebie Stockpile

K. Skarżyńska1, E. Zawisza1, M. Jasińska and M. Waligórski1 University of Agriculture, Kraków, Poland

(presented at the 4th International Symposium on the Reclamation, Treatment and Utiliza-tion of Coal Mining Wastes, Kraków, Poland 6-10 September 1993)

A complex investigation of background gamma-ray dose rate and radioactivity of wastes inthe Przezchlebie stockpile near Gliwice has been performed. The gamma- ray dose rate was mea-sured 1 m above the minestone dumping ground and above the ash lagoon using ultra-sensitiveLiF:Mg,Cu,P thermoluminescent detectors produced at the INP. The activity of radioactive ele-ments in the wastes taken from the dumping ground, from the transport vehicles, from the ash

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lagoon, as well as in surface samples of infiltrating water from the lagoon, was measured bygamma-ray spectrometry. The gamma-ray dose rates above ground correlated with the gamma-activity of the natural elements of uranium and thorium series in the waste materials. Thestockpile was found not to be radioactively hazardous to the environment, suitable for reculti-vation and for use in other economic activities. The described measurement technique in whichfield exposures of TL detectors can be completed within two weeks rather than after 3 months,is readily applicable to large-area waste stockpiles.

A Regional Survey of Indoor Radon Concentration inSouth-Eastern Poland

T. Niewiadomski(submitted to Nukleonika)

The Central Laboratory for Radiological Protection and the Institute of Nuclear Physicsbegan in 1991 a country-wide study of radon concentration in dwellings in which CR-39 track-etch detectors located in diffusion cups were used. South-Eastern Poland (a geo-morphologicallydiversified area constituting 17% of Poland's territory) was assigned to the INP and two surveyswere performed between November 1991 and November 1993. A total of 350 cups were randomlyplaced on the territory of 10 voivodships and about 300 cups were returned to the laboratoryfor chemical etching of plastics and optical track density counting. A computer data base wasset up to store and process the results. Using the calibration factor of 4.2 tracks*cm~2 per(kBq*h*m~3) it was found that the radon concentration over the investigated area exhibits anapproximately log-normal distribution with an arithmetic mean of 70 Bq m~3 in the first and 80Bq m~3 in the second measurement series (which was longer by a few autumn-winter months).In about 3% of housing stock which were monitored (i.e. 60 000 households with about 250 000inhabitants) the radon concentration exceeded 200 Bq m~3. If these results are extrapolated tothe population, the mean annual effective dose due to radon inhalation is equal to 1.5 mSv whilethe above-mentioned 3% of population receive from this source doses higher than 5 mSv peryear. Houses with higher radon concentration indoors have been found mainly in the southern,mountainous part of the area surveyed by the INP. Analysis of two measurement series allowsone to assess the sources of uncertainty in these measurements, which originate both in thelaboratory and in the field. (This research is partly supported by grant No 607379101 from theState Committee for Scientific Research).

Long - Term Measurements of Gamma Background RadiationUsing TŁ and Phosphate-Glass Detectors

B. Burghkardt1, M. Budzanowski2, P.Olko2, W. Pessara3 and K. Gmuer4

1 Karlsruhe Nuclear Research Centre, Germany,2Institute of Nuclear Physics, Kraków,3PTB Braunschweig, Germany, 4Paul Scherer Institut, Villigen, Switzerland

(work in progress)

The cosmic component of background gamma radiation, the intrinsic background or "self-dose" and the fading of TL (TLD-600, TLD-700, and TLD-200, all from HARSHAW, andMCP-N, i.e. LiF:Mg,Cu,P, produced at the INP Krakow) and Phosphate-Glass (SC-1) detectors(Toshiba) were measured over a period of c. 1.5 y (557 days) in the Asse salt-mine (Braunschweig,Germany) at a depth of c. 775 m, on a buoy placed on the surface of an artificial lake (Baggersee,

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Karlsruhe, Germany), at the top of Jungfraujoch (3576 m ) in the Alp mountains and in a steelcastle at the KfK laboratory. The "self-dose" for TL detectors in Asse salt mine was 0.07fiGy/y for TLD600/700, 29 fiGy/y for TLD200, 7.3 /*Gy/y for MCP-N and 9.4 juGy/y for SC-1. The average values of cosmic-ray gamma background dose rate estimated from readings ofTL and glass detectors were (250±2) //Gy/y, (140±1.7) /xGy/y, (1040±7) fiGy/y at the lakesurface, laboratory and Jungfraujoch peak, respectively. Based on measurements in the Assemine (constant temperature of 33 C, relative humidity below 25%) the fading of all types ofdetectors did not exceed 5%/y.

B. Developmeijit of new TL materials and model analyses of the responseof TL detectors:

6LiF Sandwich-Type Detectors For Low-Dose IndividualMonitoring in Mixed Neutron-Photon Fields

P. Olko1, M. Budzanowski1, P. Bilski1, B.Burgkhardt2, and E. Piesch2

1 Institute of Nuclear Physics, Kraków, 2Kernforschungszentrum Karlsruhe, Germany

(presented at the International Workshop on Individual Monitorun of Ionizing Radiation;the Impact of Recent ICRP and ICRU Publications, Villigen, Switzerland, May 5-7 1993)

ICRP publication 60 recommends the reduction of the annual dose limit for occupationalexposure from 50 mSv to 20 mSv and to double the quality factor for medium energy neutrons.If occupational doses are evaluated every month (which is obligatory e.g. in Germany and inPoland), the individual neutron dosimeter will have to measure neutron doses in the range of100 /xSv. No commercially available, automatic individual dosimetry monitoring system existswhich fulfils this requirement.

We studied some of the parameters which influence evaluation the neutron dose from read-ings of TL dosimeters in order to decrease the variance of the measured neutron signal. Inmixed neutron-photon fields, clear separation of the neutron component from the total readingdepends also on the uncertainty of the gamma dose measurements. While the thermal albedoneutrons are absorbed mostly at the surface of the 6LiF detector, the reduction of the detectorthickness results in decresing its photon sensitivity keeping neutron sensitivity almost constant.In concequence, uncertainty of gamma dose contributes with lower weight to the variance of theevaluated neutron signal. First tests of an optimised 200 /xm sandwich detector and 0.9 mmthick standart LiF chips were made at low neutron and photon dose ranges using different read-ers, in order to find out the uncertainty versus dose for different neutron/photon combinations.We demonstrate conditions under which the new sandwich-type detectors may improve albedoneutron dosimetry.

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Thermoluminescent Efficiency of LiF:Me,Cu,P (MCP-N)Detectors to Photons, Beta-Electrons, Alpha Particles and

Thermal NeutronsP. Bilski1, P. Olko1, B. Burgkhardt2, E. Piesch2 and M.P.R. Waligórski1'3

1Institute of Nuclear Physics, Kraków, 2Nuclear Research Centre Karlsruhe, Ger-many, 3 Centre of Oncology, Kraków

(submitted to Radiation Protection Dosimetry)

The thermoluminescent efficiency, 77, of LiF:Mg,Cu,P (MCP-N detectors, commercially pro-duced at the INP, Kraków, Poland), relative to 662 keV Cs-137 gamma rays, has been measuredfor (i) 1250 keV Co-60 gamma-rays, (ii) filtered X- ray beams of average energies in the range 15- 300 kVp , (iii) Pm-147 beta-electrons, (iv) thermal neutrons and (v) stopping alpha-particlesof initial energies in the range 0.5 - 5 MeV. A rapid decrease of TL efficiency with decreasingmean photon energy from 77=1.04 ± 0.02 for Co-60, 77=0.93 ± 0.02 for 300 kVp X-rays to 77=0.59± 0.016 for 15 kVp X-rays was observed. The measured value of relative efficiency for Pm-147beta-electrons was 77=0.90 ± 0.02. The relative efficiency for alpha particles decreased fromT7=O.O6 ± 0.004 to 77=0.03 ± 0.007 for particles of initial energies of 5 MeV and 1 MeV, respec-tively. The measured response of MCP-N detectors after doses of thermal neutrons was equal to0.72 1010 Gy n^cm2 , which corresponds to 77 =0.104 ± 0.012. The efficiency for 2.73 MeV3Htritons was found to be 77 = 0.155 ± 0.02. The rapid decrease of sensitivity of LiF:Mg,Cu,P withincreasing ionization density is a microdosimetric effect, resulting from the saturation of the TLsignal from high energy deposits. An empirical relationship between the mean lineal energy, yp,and 77 has been found which can be used to predict the TL efficiency of MCP detectors for pho-tons and electrons. However, TL efficiency 77 is not a unique function of yp, so this relationshipcannot be used to predict the value of 77 over the whole range of ionization densities (LET) ofheavy charged particles stopping in the detector. (This research is partly supported by grantNo 224309203 from The State Committee for Scientific Research, and by the Polish-Germancooperation programme).

C. Theoretical Radiobiology, Microdosimetry and Radiation Protection:

On Model-Based Assessment of Risk from Radon Daughters-the Microdosimetric Approach

P. Olko1 and M.P.R. Waligórski12

1Institute of Nuclear Physics, Krakow, 2Centre of Oncology, Kraków

(Nukleonika, in print)

Inhalation of radon daughters is considered to be the major source of radiation exposureto man. The quantitative estimate of risk of radon-induced lung cancer is presently based ontwo complementary methods. In the first method risk coefficients are derived directly fromepidemiological studies on radon-exposed uranium miners. In the second, dosimetric approach,a lung model is used to estimate doses to the bronchial epithelium. To express the dose fromthe radon daughter a-particles absorbed in the epithelium in terms of dose equivalent a quality

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factor, Q, is applied the value of which is recommended by international bodies (ICRP). Thepresently used value of Q appears to be of limited relevance for evaluating the risk of lung cancer.

We analyze the results of radiobiological experiments in order to derive a more realisticvalue of Q for radon exposure, basing our investigations on the microdosimetric analysis ofmeasurements of oncogenic transformation per surviving C3H10T1/2 cells after doses of protons,deuterons, helium-3. We argue that the probability relevant to radiation protection is that of celltransformation per exposed cell, therefore probability of cell transformation must be consideredin conjunction with that of cell survival. The RBE for cell transformation following irradiationof these cells by alpha particles should therefore decrease because some of the cells are killed andcannot undergo consecutive transformation. This conditional probability of cell transformationleads to a decrease of the value of Q for alpha particles, especially at the stopping end of theparticle track. We therefore suggest that the value of Q applied presently in the dosimetricapproach may be overestimated. (This research is partly supported by grant No 607359101from The State Committee for Scientific Research).

Microdosimetry of TritiumK. Morstin1, M. Kopeć1, P. Olko, T. Schmitz2 and L.E. Feinendegen2

1 Institute of Physics and Nuclear Techniques, The Mining Academy, Kraków, Poland2 Institute of Medicine, Research Centre Julich, Julich, Germany.

Microdosimetric aspects of tritium radiotoxicity are discussed. The level of coincidence oftritium locations and of radiation-sensitive sites doses not appear to be decisive for relativeeffectiveness of tritium exposures. The actual target structure and dimensions seem to be ofmore importance. Particularly efficient germ cell destruction by chronic exposures to tritiatedwater is unlikely to be explainable on the basis of classical principles of microdosimetry. Thephenomenological approach of investigating biological response functions may be a useful al-ternative for the interpretation of unexpected experimental results, especially when combinedwith bidimensional microdosimetry. The latter allows for clustering of nanometer sites within atarget of cellular dimensions.

D. Studies of Concepts in Radiation Protection:

Will it be possible to Implement the Limitation of RadonConcentration in Polish Dwellings from January 1995

Onwards?

T. Niewiadomski

(Nulcieoniia, in print)

The requirement in the current national regulation that the equivalent radon concentrationin houses constructed in Poland after January 1st 1995 must not exceed 100 Bq/m3 appearspresently to be impossible to implement from that date onwards. The extensive range of ope-rations required to realize this implementation is outlined. Despite the present difficulties andelays in this matter, it would be inhuman not to undertake every effort to decrease the numnerof lung cancers due to exposure to radon in Poland. A national programme for reducing radonexposure in Poland which would resemble those realized in other countries should therefore beginas soon as possible.

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What Should the National Programme of Reducing theIncidence of Lung Cancer due to Radon Inhalation Contain?

T. Niewiadomski1 and M. Waligórski1'2

1Institute of Nuclear Physics, Krakow, 2Centre of Oncology, Kraków

(INP Report No. 1619/D and Postępy Techniki Jądrowej, in print - in Polish)Radon and its daughters, prevalent in the atmosphere in dwellings, are one of the known

causes of lung cancer. This is one of the few environmental factors which can be controlled, i.e.the radon and daughter concentration decreased, in order to decrease the incidence of lung cancerin the population. For these reasons several countries have undertaken complex measures in theareas of research and preventive measures, on a national scale. We present an outline of such aprogramme and of research and administrative activities which should be undertaken in Polandin the next few years. Our aim is to demonstrate that instead of a number of uncoordinatedand fragmentary efforts now under way in Poland, a complex, comprehensive and well-designednational programme of reducing the incidence of lung cancer due to inhalation of radon and itsdaughters should be proposed and implemented as soon as possible.

LIST OF PUBLICATIONS:I. Books:

1. T. Niewiadomski, Lithium Fluoride, in: Thermoluminescent Materials, D.R. Vij, Ed.,PTR, New Jersey, 1993, pp. 142-180

II. Articles:

1. P. Olko, P. Bilski, E. Ryba and T. Niewiadomski, Microdosimetric Interpretation of theAnomalous Photon Energy Response of Ultra-Sensitive LiF:Mg,Cu,P TL Detectors,Radiat. Prot. Dosimetry 47, 31-36 (1993)

2. M.P.R. Waligórski, P. Olko, P. Bilski, M. Budzanowski and T. Niewiadomski, DosimetricCharacteristics of LiF:Mg,Cu,P Phosphors - A Track Structure Interpretation, Radiat.Prot. Dosimetry 47, 53-58 (1993)

3. M. Budzanowski, P. Bilski, P. Olko, T. Niewiadomski, B. Burghardt and E. Piesch, NewTL Detectors for Personal Neutron Dosimetry, Radiat. Prot. Dosimetry 47, 419- 423(1993)

4. K. Morstin, P. Olko and L. E. Feinendegen, Micro dosimetry of Tritium, Health Phys. 65,648-656 (1993)

«5. T. Niewiadomski, Will it be Possible to Implement the Limitation of Radon

Concentration in Polish Dwellings from January 1st 1995 Onwards? (Nukleonika, inprint)

6. M. Nowina-Konopka, On the Interpretation of Results of a National Survey of IndoorRadon Concentration (Nukleonika, in print)

7. P. Olko, P. Bilski and V.M. Michalik, Microdosimetric Analysis of the Response of LiFThermoluminescent Detectors for Radiations of Different Qualities (Radiat. Prot.Dosimetry, in print)

8. M.P.R. Waligórski, Track Structure Analysis of Two Mouse Lymphoma L5178Y CellStrains of Different Radiation Sensitivity (Radiat. Prot. Dosimetry, in print)

274

9. K. Morstin and P. Olko, Calculation of Neutron Energy Deposition in Nanometric Sites(Radiat. Prot. Dosimetry, in print)

10. R. Kat z and M.P.R. Waligórski, On the Linear Extrapolation to Low Doses (Radiat.Prot. Dosimetry, in print)

11. P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, 6-LiF Sandwich- typeDetectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields (Radiat.Prot. Dosimetry, in print)

12. P. Olko and M. Waligórski, On Model-Based Assessment of Risk from Radon Daughters -The Microdosimetric Approach (Nukleonika, in print)

13. P. Bilski, P. Olko, B. Burghardt, E. Piesch and M.P.R. Waligórski, ThermoluminescentEfficiency of LiF:Mg,Cu,P (MCP-N) Detectors to Photons, Beta- Electrons,Alpha-Particles and Thermal Neutrons (submitted to Radiat. Prot. Dosimetry)

III. Contributions to Conferences:

1. B. Skarżyńska, E. Zawisza, M. Jasińska and M.P.R. Waligórski, Investigation ofRadioactivity of Coal Mining Wastes - the Przezchlebie Stockpile, Proc. of the 4thInternational Symposium on the Reclamation, Treatment and Utilization of Coal MiningWastes, Kraków, 6-10 Sept. 1993

2. P. Olko and M.P.R. Waligórski, Radiobiological Assessment of the Quality Factor ofRadon Alpha Particles, Proc. of the 25th Annual Meeting of the European Society forRadiation Biology, Stokhohn, 10-14 June 1993 (abstract)

3. B. Rozwadowska, J. Lesiak, E. Byrski and M. Waligórski, Quality Assurance Programmefor the SELECTRON LDR/MDR, Programme and Abstracts of the Second BiennialMeeting on Physics in Clinical Radiotherapy, Prague, Czech Republic, 28-30 May 1993,p. 46 (abstract)

4. B. Burghardt, M. Budzanowski, P. Olko, W. Pessara and K. Gmur, Langzertexperimentzur Ermittlung des Egennulleffekts und des Kosmischen Anschprechvermoegeus vonFeskoerperdosimetem - in press, 110 Physikalisch Technische Bundesanstalt Seminar,Braunschweig, 30 Nov. - 1 Dec. 1993, Ortosisleistungmessungen Ionisierender Strahlunginn Bereich (1993)

IV. Reports:

1. T. Niewiadomski and M. Waligórski, Co powinien zawierać ogólnopolski projektobniżenia zachorowalności na nowotwory phic w wyniku wdychania radonu? (Whatshould the national programme of reducing the incidence of radon-induced lung cancercontain?), INP Report No. 1619/D, Kraków 1993, and to be published in PostępyTechniki Jądrowej (in Polish)

PARTICIPATION IN CONFERENCES AND WORKSHOPS:

1. M.P.R. Waligórski,(Member of the International Scientific Advisory Board of the 11th InternationalConference on Solid State Dosimetry, Budapest 1995)(Member of the Subcommittee on Radiation Protection of the National Board for AtomicEnergy)

275

(Member of the Subcommittee on Medical Applications of Ionizing Radiation of theNational Board for Atomic Energy)(Member of the INP Scientific Council)(President of the Kraków Division of the Polish Medical Physics Society)National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26February 1993; keynote adress: "Radon - Physics, Environment, Society"Annual Brachytherapy Meeting GEC-ESTRO, Venice (Italy), 12-14 May 1993International Symposium on Measurement Assurance in Dosimetry, Vienna, 24-27 May1993Second Biennial Meeting on Physics in Clinical Radiotherapy, Prague, 28-30 May 1993;presentation: B. Rozwadowska, J. Lesiak, E. Byrski, M. Waligorski - Quality AssuranceProgramme for the SELECTRON LDR/MDRMeeting of the Scientific Advisory Committee of the 11th International Conference onSolid State Dosimetry, Budapest, Hungary, 11-13 July 1993The Second International Summer School "Physics in Radiotherapy", Centre ofOncology Warsaw (Ursynów) 26 August - 3 September 19934th International Symposium on the Reclamation, Treatment and Utilization of CoalMining Wastes, Kraków, 6-10 September 1993, presentation:: B. Skarżyńska, E. Zawisza,M. Jasińska, M. Waligorski - Investigation of Radioactivity of Coal Mining Wastes - ThePrzezchlebie Stockpile3rd Central European Nucletron Brachytherapy Working Conference, Zakopane, Poland,6-8 October 1993International Workshop on Proton Therapy, Bonn, Germany, 15-17 November 1993

2. P. Olko,(Member of EURADOS WG 10 Group)(Member of the NAEA President's Committe for Assessment of the State-of-Art ofRadon Measurement in Mines in Poland)National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26February 1993; presentation: "Controversies on the Value of Risk actors for Exposure toRadon and Progeny, Based on Radiobiological Models"25th Annual Meeting of the European Society for Radiation Biology, Stokholm, Sweden,10-14 June 1993; presentation (poster sesssion): P. Olko, M. Waligrski - RadiobiologicalAssesment of the Quality Factor of Radon Alpha ParticlesWorking Meeting of EURADOS WG 10, Kraków, 5-6 November 1993: Host andorganizerInternational Workshop on Proton Therapy, Bonn, Germany, 15-17 November 1993

3. T. Niewiadomski,National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26February 1993; presentation:"Will it be Possible to Implement the Limitation of RadonConcentration in Polish Dwellings from January 1st 1995 Onwards?"

4. M. Budzanowski,International Workshop on Individual Monitorun of Ionizing Radiation; the Impact ofRecent ICRP and ICRU Publications, Villigen, Switzerland, 5-7 May 1993; presentation:P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, "6-LiF Sandwich-typeDetectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields"

5. P. Bilski,International Workshop on Individual Monitorun of Ionizing Radiation; the Impact ofRecent ICRP and ICRU Publications, Villigen, Switzerland, 5-7 May 1993; presentation:P. Olko, M. Budzanowski, P. Bilski, B. Burghardt and E. Piesch, "6-LiF Sandwich-typeDetectors for Low-Dose Individual Monitoring in Mixed Neutron-Photon Fields"

276

6. M. Nowina-Konopka,National Seminar "Radium and Radon as sources of Radiation Hazard", Warsaw, 25-26February 1993; presentation: "On the Interpretation of Results of a National Survey ofIndoor Radon Concentration"

SCIENTIFIC DEGREES:M. Sc. Theses:

1. B. Mysliwa-Kurdziel (Medical Physics, Jagiellonian University)Optimization of a Method of Measuring Radon Concentration in Dwellings(advisor: Prof. M. Waligórski)

2. T. Ho diak (Technical Physics, Academy of Mining fe Metallurgy)Investigation of Selected Dosimetric Properties of the Ultra-Sensitive LiF:Mg,Cu,P TLDetector on the Conditions of its Thermal Treatment (advisor: Prof. M. Waligórski)

LECTURES AND COURSES:

1. M. Waligórski, lecture: Track Structure Modelling of the Response of Solid StateDetectors, at the International School on ESR Dosimetry, Marciana Marina, Italy,2-11 June 1993

2. M. Waligórski, invited lecture: Radiation-Induced Effects and Track Structure, at theInternational Training Course on Problems of Radiation Safety and Radiobiology,Dubna, Russia, 28 July - 7 August 1993

INTERNAL SEMINARS:

1. Dr. L. Kalmykov (Institute of Medical Radiology, Kharkov, Ukraine) "Dosimetricproblems in the Chernobyl Area", 12.01.1993

2. Prof. T. Niewiadomski, "Comparison of basic dosmetric units wi ICRP-26 and ICRP-60", 28.04.1993

3. Dr. M. Vilgis (KfK Karlsruhe) "Modern Glass Dosimetry in KfK", 5.10.19934. EURADOS (European Dosmietry Group) "WG 10 Working Meeting", 4-7.11.1993

SHORT TERM VISITORS TO THE DEPARTMENT:

1. Prof. N. Pilipenko, Institute of Medical Radiology, Kharkov, Ukraine2. Dr L. Kalmykov, Institute of Medical Radiology, Kharkov, Ukraine3. Dr. Hlawacz-Martinez, University of Caracas, Venezuela4. Dr. M. Vilgis, KfK Karlsruhe, Germany5. Dr. P. Segur, University of Tulouse, France6. Dr. P. Colautti, Lab. Nazionale di Legnaro, Italy7. Dr. P. Pihet, IPSN, Fontenay-aux-Roses, France8. Dr. A. Waker, Chalk River Laboratory, Canada9. Dr. Th. Schmitz, KfA Julich, Germany

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Cyclotron Laboratory

Cyclic Accelerator R & DLaboratory

Electronics Laboratory

Computing and Networks

Division ofMechanical Constructions

Energy Efficiency Center

PL9601138

CYCLOTRON LABORATORY

Head of Division: Edmund Bakewicz, M.Sc.E.E.telephone: (48) (12) 37-02-22 ext.: 365e-mail: lazarska@bron.ifj.edu.pl

PERSONNEL:

Head of Division: Edmund Bakewicz, M.Sc.E.E.

U-120 Cyclotron Section:

Head of the Section: Bronisław Wojniak, M.Sc.Józef CoraTadeusz FrancuzMieczysław KubicaMaria MirekStanisław PapierzZbigniew PazdalskiBogusław SałachBogdan SułekJacek Sulikowski, M.Sc.Marek Talach, M.Sc.E.E.Ryszard TarczońLucyna Włodek

AIC-144 Cyclotron Section:

Head of the Section: Henryk Doruch, M.Sc.E.E.Krzysztof Daniel, M.Sc.E.E.Leszek DzieżaJerzy Korecki, M.Sc.E.E.Janusz ŁagiszTadeusz NorysWojciech PyziołMarek RuszelJerzy Starzewski, M.Sc.E.E.Ryszard Taraszkiewicz, Ph.D.

279

Acceleration techniques have been development in our Institute from the very beginning ofits existence. The first cyclotron we had was a "small" cyclotron C-48, built in Cracow.

In 1992 the "small" C-48 was decomissioned. At the same time we had finished building theAIC-144 cyclotron.

In June 1993, the Division of Cyclotron was created in our Institute. It consists of twosections: U-120 Cyclotron Section and AIC-144 Cyclotron Section.1. U-120 Cyclotron Section

The U-120 cyclotron has been exploited in our Institute since 1958.Its parameters are as follows:

Magnet pole diameter: 120 cmMagnetic field:Number of dees:R-F system:Dee voltage:Extraction radius:Ion sources:Extraction system:

ParticlesdeuteronsH2-ions3H-ionsalphaEmittance:

13-15 kGs2 (a = 180°)8-16 MHz/120 kW150 kV52,5cmPIG, internalelectrostatical, XJj - 60 kV(+magnetic channel)Energy Intensity12-14 MeV 60 /iA12-14 MeV 40 /iA29-32 MeV 3 /xA24-28 MeV 20 /zAe, = 50 mm-mrad ez = 35 mm-mrad

The equipment of U-120 consists of five beam transport lines with many facilities and apparatus'for nuclear research. We have a stand for radionuclides production, the radiobiological researchand neutron theraphy.The radionuclide Ga-67, In-Il l , J-123, Tl-199 have been produced on the U-120 cyclotron formany years.This year we finished the experiments on the obtaining of In-111 by deuteron bombarding ofCd-110 targets.

Ten sessions of the theraphy with fast neutron beem from U-120 (one week per month cycle)were run in 1993. Theraphy was run for the patients of the Oncological Centre in Cracow.

For the first time we have accelerated alpha-particles up to 30 MeV (before we were ableto reach only 28 MeV). According to the plan of modernization we have manufactured a newpower supply for the main magnet coils. It is a high stability arrangement with a range of directcurrent up to 600 A.

We have constructed and manufactured a head of the press for preparing the tablet targetsfor radio chemical needs and a distance control stand for the production of neutron-deficientradioizotopes.

280

2. AIC-144 Cyclotron SectionOur new AIC-144 isochronous cyclotron has the following parameters:

Magnet pole diameter: 144 cmMagnetic structure: 4 sectors with the spirals angle of 54°Magnetic field: 8.5 - 18 kGsFields' variation: B4/< B > = 0.2Frequency of the betatron oscillators: Qz = 0.42; Qz = 0 - 106Number of concentric coils: 20Number of azimutal coils: 8Number of dees: 1 (a = 180°)Radiofrequency generator: 8-26 MHz/150 kWDee voltage: 50 kvExtraction radius: 62 cmIon source: internal, PIG typeAcceleration coeff: K = 60Range of energy:Protons: 10 - 60 MeVDeuterons: 15 - 30 MeVa-particles: 30 - 60 MeVEmittance: ex — 25 mm-mrad, ez = 20 mm-mrad.

The AIC-144 cyclotron has been built and tested in a vault without radiation shields. We areplanning to instal it in a proper operation vault. The simplest and the cheapest way of achievingthis is to finish using the U-120 cyclotron and to install the AIC-144 in its place. Now, thecyclotron for future exploitation.

In 1993 we succesfully ran many tests in the following parameter areas:

1) B = 14.2 kGs and f = 10.8 MHz2) B = 16.1 kGs and f = 12.2 MHz3) B = 17.2 kGs and f = 13.0 MHz4) B = 18.0 kGs and f = 13.5 MHz

In July the test on the maximum intensity of the internal beam was carried out. We obtained abeam current of over 200 /xA (for deuterons, with B = 14.2 kGs and f = 10.8 MHz). The expe-riments on acceleration of the molecular hydrogen have failed to show good results, probablybecause the vacuum was not good enough. For improving the vacuum, we have installed a newset up for vacuum controlling inside the acceleration chamber. We have also worked out a newsystem to improve the residual gas pumping, especially from the deflector area.

As a result of many tests we have optimized the parameters of ion's source and reduced thegas losses. Changing the trimmers' capacity and improving the resonance circuit gives betterstability and more precise controlling of the RF-generator.

LECTURES AND COURSES:

1. E. Bakewicz, M.Sc.E.E., "Development of the Cyclotrons in Institute of Nuclear Physicsin Cracow"; a lecture given at the Institute of Nuclear Physics KFA Julich, Germany.

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SHORT TERM VISITORS TO THE DEPARTMENT:

1. DT E. VeraRuiz, Industrial Application and Chemistry Section of the International Atomic EnergyAgency, Vienna, Austria, August 1993

2. Prof, dr A.T. RutchikUkr. Academy of Sciences, Kiev, October 1993

3. DT M.F. ShabashovJoint Institute for Nuclear Research, Dubna, November 1993.

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PL9601139

CYCLIC ACCELERATORR & D LABORATORY

Head of the Research Group: Assoc.Prof. Jerzy SchwabeSecretary: Halina Szymańskatelephone: (48) (12) 37-02-22 ext.: 381, 371e-mail: schwabe@bron.ifj.edu.pl

PERSONNEL:Research Staff:

Jerzy SchwabeAndrzej BalmasHelena GodunowaMaria Potempa

Administration:Halina Szymańska

Since the time that the AIC-144E has been in operation in IFJ, our group has been engaged ininvestigating and developing the physics and techniques of cyclic accelerators as an independentlaboratory. During building the AIC-144E our staff gained considerable experience as regardsto the isochronous cyclotrons.

The investigations concerning the improvement of the operation parameters of cyclotronsthat are at present operating in the world are one of the main subjects of our interest. TheAIC-144S is the basic tool for some experimental investigations devoted to the aforementionedtopic.

The theoretical explorations of the acceleration processes are based on computer codes de-veloped in our laboratory.

Here are some of the topics that we are able to design with high accuracy and quality:• dynamic of charged particle acceleration in three dimensional structures of HxE fields• basic parameters of conventional isochronous cyclotrons as well as sector ring isochronouscyclotron with separated magnets• HF - Resonator cavity and RF - Generator for isochronous cyclotrons• magnetic field spatial structure• effects of the resonance excitation in the accelerated beam on the isochronous cyclotrons• compact cyclotron for therapeutical purposes and for the production of neutron deficientradioisotopes.We invite also other research groups which are interested by the topics to collaboration on

them.

283

REPORTS ON RESEARCH IHI™ "L9601 140

Investigating and Developing the Physics and Techniqueof the Cyclic Accelerators

J. Schwabe, M. Potempa, A. Balmas, H. Godunowa

l.The AIC-144S Operation Investigations (01.01.93-05.06.93)

To get the optimum parameters of AIC-144S was the main topic of experimental work onthe AIC-144E carried out by our group this year. Here we present it in headlines:a. Increasing the accelerated beam energy (Z/A = 0.5) for deuterons and for \He.

b. The extraction of the accelerated beam by using the modified magnetic extraction system.The extraction coefficient has been increased to about 3-5%.c. Designing and testing the water cooled probe aimed at the irradiation of the isotope targetson the internal beam.d. Designing and applying the beam energy measurement method.e. Putting into operation at 60 kW power (pulse mode) the R.F. Generator (MBC). The MBChas operated on AIC-144S in pulse mode with duty factor of 27%.

2. The AIC-144S Theoretical Investigations (15.09.93-31.12.93)

The following topics were investigated:

a. The high efficient extraction problems on isochronous cyclotrons. The AIC-144E has beenutilized as an experimental investigation model [1].b. The most economical operation conditions for the proton beam acceleration up to 60 MeV.Theoretical investigations and the design of its applicatios on AIC-144S were worked out [2].c. Dynamics of the H~ acceleration process on GC-80 Isochronous Cyclotron (designed inGatchina, Russia) were simulated by using the AMIC-II computer code [3].d. The conditions of the mirror axial inflection of the H~ ions accelerated on GC-80 wasestimated and optimized with the aid of AMIC-IH computer code [4].

Short Outline of Selected Topics

la. Increasing the accelerated beam energy on AIC-144S

Since the MBC is not at present put into operation at full power the excitation power on thewanted frequency is unachievable. Therefore the investigations were carried out in the deuteronacceleration operation mode on the AIC-144S (Z/A — 0.5). The beam energy increase wasachieved in two steps:

E=22MeV (d)E=24MeV (d)

The AIC-144S operation parameters and its energy dependencies are given in Fig.l. Theprecession and the deformation of the orbits were observed within the radius range 54-57 cmduring the acceleration process. These phenomena have taken place in the region of extractionradius where there are the isochronous operation conditions and the AIC-144S has been opera-ting in the higher beam energy mode. The valley correction coils were used to compensate inlarge part these effects.

284

The phenomenon analysis made by using the AMIC-II code [3] has shown that there aretwo reasons which could cause these effects: either the first subharmonic is appearing in themagnetic field structure (see Fig.2), or there is the beam excitation effect during the time of thebeam passage along the coupling resonance zone; 2Qz + Qr = 0; AR=53-57cm (see Fig.3). Inorder to solve the problem further investigations have to be carried out.

lb. The accelerated particle extraction from AIC-144S

The passive magnetic expander was used in the AIC-144S extraction system. It has beenset in the place where the electrostatic expander had been located before. The magnetic fieldperturbation of the expander has increased the extraction coefficient t] up to 12-15%.

The computer simulation of the extraction process has shown its influence on the orbit dis-tribution, the results are shown in Fig. 4a, 4b, where the shift of the orbit maximum separationpoint from A to A! is marked. The analysis of this simulation has indicated that there is a pos-sibility to control the beam input in the non-linear excitation space ( Qr — N/q, for N = q = 4)and thus to optimize the extraction process in the required direction.

2b. The most economical operation conditions for the acceleration of protonbeam up to 60 MeV

The AIC-144S cyclotron has been designed for operation in the wide range of proton beamenergies (K = 20 - 55MeV) and with a variety of accelerated particles and ions in the range ofZ/A = 1 - 0.285. The wide range of possibilities results in the uneconomical conditions of theresonator cavity operation.

It is proposed to apply the AIC-144E for proton therapy. In this case it will be operatedin its highest energy mode and it follows that the economical operation rate has become theimportant parameter. Therefore the conversion of the acceleration system that enables one tolimit, the excitation power to 42-45 kW at frequency of 26.1 MHz has been designed. Thisconvertion allows one to reduce R.F. power consumption by about 100 kW against the primarydesign. The lower band of the frequency range on cavity will be only slightly limited by thisconversion. If need be it will be possible to return quickly to the primary construction of thecavity.

20

ACCELERATION OF ALPHA PARTICLESAIC-144 8 :ENERQY , Bis . FrequenoyBls(KO») TK(MEV)

10100

"Series 1TKCMEV)

200 300I mag (A)

- • - 8erteB 2 -

400

-Series 3FOtMttt)

600

Figure 1: AIC-144S operation parameters

285

DYNAMICS OT ACCBISgAIION (24.5 SfeV (D) : AIC-144 S

i 1 3 . 1 7 8 3>A.-a.mewa. OKILMTSQNS• Cen>

ACC.PtMSE (rad)

0 0 100 120

Figure 2: First subharmonic influence on orbit distribution

9. SIS R=5-ł.7M DR—B.SJS RNB4K-144 8 t OMITS* PE8CSSSI0K ON R>fi4-fiB Of

1 t-csawatoHicB w H M . rta*

rcst.rnu

=2 ZOB=I EPS=0.156 NR=fi

Figure 3: Coupling resonance excitation of the accelerated beam at radius 54 cm

AIC-1** S

>9 B

2

KKnUCTKM SISTOt |

-14.36 SB.M.:,

1

•u < < ^^^^B^^%S

:I EP3=0.123

4B TKKS.

FOB-10.

N R = 1 1

91 10

1

;

Figure 4a: Extraction of the beam by electrostatic expander field

286

A l C - m S DETRACTION SYSTEM i 4C VSRS.

MCKIIC n o * rwwuMTjm • • MC.E

MT.I

=1 EPSse NR=I2

Figure 4b: Extraction of the beam by magnetic expander field

References:[1] J. Schwabe, "AIC-144 Isochronous Cyclotron Conversion Aimed at Using it RightAway for Medical Purpose" (to be published)[2] J. Schwabe, "The High Efficiency Extraction Problems on Isochronous Cyclotron" (to bepublished)[3] Mathematical Analogue of the Isochronous Cyclotron -Ilcomputer code, developed byJ. Schwabe[4] Mathematical Analogue of the Isochronous Cyclotron -HI computer code, developed by J.Schwabe

LECTURES AND COURSES:/ . Schwabe

Lectures given in KINPh Gatchina near St. Petersburg, Russia, November 1993:1. "AIC-144S Status: Extraction and Dynamics of the Accelerated Beam"2. "Some Design Problems of the Beam Dynamics on Isochronous Cyclotron GC-80, Gatchina"3. "Exploration of the Axial Extraction of the Beam Accelerated on GC-80"

4. "The Possibility of the AIC-144S Conversion Aimed at Obtaining the Proton Accelerationup to 60 MeV". Lecture given in JINR Dubna, Russia, December 1993.

INTERNAL SEMINARS:

J. Schwabe, "The Orbit Symmetrization of the Accelerated Beam on AIC-144S".J. Schwabe, "Increasing the Accelerated Beam Energy on AIC-144S: problems and realization".J. Schwabe, "Beam Extraction from Isochronous Cyclotrons: The High Efficient ExtractionMethods".

SHORT TERM VISITORS:

V.A. Eliseev and E.M. Ivanov - KINPh, Gatchina, near St. Petersburg, Russia.

H.C.J. Fliderbaum and M. Grynberg - Providers Export International Inc. USA

287

PL9601141

ELECTRONICS LABORATORY

Head of Laboratory: M. Kajetanowicz, M.Sc.E.E.,Deputy Head of Laboratory: F. Kościelniak, M.Sc.E.E.Secretary: Jolanta Pluta,telephone: (48) (12) 37-02-22 ext.: 432e-mail: kajetan@bron.ifj.edu.pl

PERSONNEL:Design Section:

Head of the Section: Adam Czermak, M.Sc.E.E.

Engineers :Elżbieta Banaś Barbara Dulny1

Wiesław Iwański Jan KapłonPiotr Kapusta2 Krzysztof KorcylJolanta Olszowska Wacław Ostrowicz

Technicians:Adam Adamski Jacek GarwolińskiTomasz Gdański Bogdan Sowicki

Maintenance Section:Head of the Section: Franciszek Kościelniak, M.Sc.E.E.

Engineers:Ryszard Lerch Maria Wasik

Technicians:Wacław Kozub Edward KochanBogdan Lipka Artur Włodarczyk

Administration:Kazimiera Drożyńska Jolanta Pluta

The main activities of the Electronics Division are:

• design and test of electronic equipment for experiments in physics,• development of software for trigger and data acquisition systems,• maintenance of Institute electronic equipment.

Division designers take part, together with physicists, in big, international collaborations setup for the preparation of experiments in physics. Our main partners are CERN in Geneve andDESY in Hamburg.

In CERN we participate in the DELPHI experiment on LEP accelerator and in the futureATLAS experiment on the new LHC accelerator. We take part in four research and developmentprograms for LHC experiments: RD6, RD11, RD16 and RD20.

xon leave of absence to Max Planck Institute, Munich,3on leave of absence to CERN, Geneve.

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• DELPHI: the work concerned the development of Inner Detector software. The main areaof our activity was the optimalization and maintenance of the on line data acquisitionsystem as well as local third level triggering system,

• ATLAS:

- RD6: VME test system composed of four VME modules has been designed andmanufactured. It is aimed for tests of the front-end electronics for the TransitionRadiation Tracker (TRT), one of the future ATLAS detectors. In the second half ofthe year the system was extensively used for tests in CERN,

- RD11: Modelling of local and global architectures for second level triggering at theATLAS experiments using MODSIM II language. Study on algorithms for the localsecond level trigger system for the calorimeter in the ATLAS experiment,

- RD16: Modelling of the architecture of the ATLAS calorimeter readout board,•— RD20: tests of the ATLAS silicon tracker front-end electronics comprising ampli-

fier/shaper, analog delay buffer and analog pulse shape processor. Participation indesign of a chip comprising whole front-end readout electronics for the ATLAS sil-icon tracker. Study on readout architecture for the silicon tracker in the ATLASexperiment. Design of a hybrid board for readout electronics for the silicon stripdetector.

In DESY our engineers were involved in preparing the Hi experiment. Software providing afast link between the VME 0S9 station and monitoring micro VAX computer was developed. Itwas used in the data acquisition system for Liquid Argon Calorimeter LAR. Our designers alsotook part in the development of calibration software for Liquid Argon Calorimeter LAR and forthe local LAR level one triggering system.

The control part of the monitoring software for the HI second level trigger system is underdevelopment in cooperation with LAL Orsay, France.

An 8 bit pipeline Analog to Digital Converter developed in cooperation with CNR in Stras-bourg has been tested. A new, improved ADC chip has been designed. The design was formu-lated using in AMS 1.2 /xm CMOS technology.

An upgraded multiparameter data acquisition system for experiments in nuclear spectroscopyhas been developed and succesfully tested.

Two university students have begun their thesis in the the Electronics Division. One thesisis in VLSI intergrated circuit design and another in data acquistion with digital signal processor.

Two university students had their summer placement at the Electronics Division.

M. Kajetanowicz

289

REPORTS ON RESEARCH: PL9601142

" J Low offset, low power comparator for silicon strip detectorreadout

M. Kajetanowicz and J. Kapłon

Abstract:A comparator chip required for use in silicon strip detector read-out was designed and ma-

nufactured using 1.5 firn bulk CMOS DM DP Mietec technology. This paper presents a shortdescription of the comparator and the results of tests carried out on four chips.

Introduction:In currently designed experiments on LHC, and especially in silicon trackers, data compres-

sion in front end electronics is indispensable. This is a result of the very big channel number andthe low occupancy of detector. Besides an analog signal from the strip digital information is alsonecessary to know if a given strip was hit. Thus, a comparator in each channel is necessary. Thecomparator design was done within the scope of the RD20 research and development programmeat CERN.

Technical specification:Comparator parameters are defined by the gain and signal to noise ratio in the read-out

chain. Assuming a signal to noise ratio 15 and gain 60 mV/MIP the offset variation of 5 mVis satisfactory. Because of the great number of detector channels a very small amount of powershould be dissipated in one channel. A trade-off between speed and power is necessary. Thefollowing parameters were assumed in this comparator:

• dissipated power less than 0.4 mW,• offset spread less than 4 mV,• response delay 100 ns.

Principle of operation:The comparator circuit is composed of two stages. A differential amplifier in a transconduc-

tance amplifier configuration is the first stage and a D-type flip-flop is the second one. Becauseof a high transconductance of the input transistors the comparator offset depends only on theirthreshold voltage mismatch. Aspect ratio of the input transistors is optimized according to thisparameter. The high slew rate of the comparator is guaranteed by the strong positive feedbackof the second stage. Refresh signal - COMPARE - is provided to cancel the hysteresis of thecomparator. The high level of this signal resets a flip-flop, i.e. an output voltage goes to a Vsslevel. The comparator schematics shown in Fig.l.

The output voltage level is established as a result of opening the switches. When i\ is greaterthan i2 the output goes to VDD level and in the opposite case goes to Vss level. The outputslew rate is defined by equation (1).

9mf

where:

• gmf - D flip/flop transconductance• gm - differential pair transconductance

290

tnp

o-2r

o-

COMPARE

Fig.l Schematic view of the comparator.

Tests:The comparator chip was tested in conditions similar to those required for an operation of

the ATLAS silicon tracker read-out chip.

Test set-up:The chip supply voltage is ± 2 V, the input voltage has a step of 0.1 mV. The COMPARE

signal has a frequency of 250 kHz. A counter is on the output of the comparator. An inte-grated Gaussian curve was recorded by counting the output pulses when the input voltage waschanged from -5mV to +5mV. The bending point on that curve is the offset of the comparator.The comparator noise is extracted after differentiating the experimental plot which results in aGaussian curve.Results:

Four chips, 24 channels each, were tested. The following results were recorded:

• integrated Gaussian plots,• offset distribution depending on channel,• histogram of offset distribution.

The maximum offset spread among comparators from different chips is less than 4 mV and inone chip is less than 3 mV. The standard deviation <r of the offset spread is in the range of 0.4 -0.9 mV depending on the chip. The delay time from the trailing edge of the COMPARE signalto the comparator output is 50 ns for a 10 mV input. The power dissipated by the comparatoris 300 fiW.References:

1. P.E. Allen, D.R. Holberg, "CMOS Analog Circuit Design", Holt, Rinehart and Winston,inc., 1987

2. V. Valencic, "Low-Power and Fast CMOS A/D Converters", Front End Electronics Wor-king Group CERN/ECP Jan 29, 1992

3. R. Brenner et al., "Performance of a LHC FRONT-END running at 67 MHz", CERN-PPE/93-139 July 5, 1993

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PL9601143

Development of VLSI electronics for readout of X-ray siliconstrip detectors

A. Czermak and J. Kapłon

This work has been supported by the Commisssion of EC, grant nr 941 and performed inLEPSI-Strasbourg as a joint project with INP-Cracow.

Two VLSI fully custom designed integrated circuits of 1.2 fim. CMOS technology have beendesigned and placed for production at AMS-Austria.

The first prototype chip contains four channels of low noise preamplifiers, after which stretch-ers and discriminators follow. In a foreseen imaging application of such front-end electronicswith low energy X-ray Si detectors, it is necessary that the chip provides also a trigger, in orderto tell the external readout system to record the hit when the photon is fully absorbed withinthe silicon detector.

This circuit has been simulated with the HSPICE signal simulator, before and after layoutprocesses. The noise performance of the charge preamplifier has been optimized so as to guaran-tee the measurements of X-ray energies starting from 3.5 keV with a resolution (FWHM) of lessthan 1.0 keV. These features of the chip should facilitate the investigation of biological objectsusing low energy X-ray sources.

The second prototype chip contains logic for a spars-scan-readout of 64 channels. The chiphas been designed to reduce and compress data from Silicon Strip Detectors. Together with aneight-bit pipeline ADC, which has been already designed and tested successfully, and with someFIFO buffor, which is under consideration for construction in the near future, the logic shouldbe placed into a single chip. Having such a complete circuit fast data readout from Si stripdetectors should be demonstrated. This should considerably facilitate some real-time imagingapplications of X-ray detectors as well as having some influence on the proposed architecture ofthe readout system for Si tracker detectors for future experiments on the LHC. The simplifiedblock diagram of the whole spars-scan-readout circuits is presented in Fig.l.

CONTROLUNIT

CONTROL SIGHALS

APSP

PRIORITYENCODER

1 2 8 > 12BADORESS

APSP ANALOGANALOG \SELECTOR /

ADC8bit

ADDRESS

(DATA

MEMORY

V

W

Fig.l Block diagram of spars-scan-redout circuits.

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PL9601144

Modelling of architecture of the ŁHC calorimeter readoutboard f

W. Iwański

The FERMI [1] is a digital multichannel front-end module intended for acquisition of calorime-ter data in ATLAS detector at Large Hadron Collider. It is designed as a microsystem consistingof on-chip shapers, amplifiers, ADC and memories to serve autonomously up to 9 input chan-nels. However, the communication of the FERMI chip with the rest of a system strongly dependson the external environment. A dedicated controller is needed in order to provide chips withpointers to internal memory, to receive requests or to initiate data transfers to triggers and dataacquisition systems.

FERMI chips are grouped on boards (FERMI boards) together with electronics, which or-ganise data transfers.

Two types of data transfers are assumed :

• filtered value,• full time frame data.

In the first case only one word represents data stored for one bunch crossover signal (BCO),in the second one the set of ADC samples reflects the data concerning particular BCO.

The conceptual view of the FERMI board is presented in Fig.l. There are 36 FERMI chipson board in the current implementation. They are read out in a chain, pointers and strobesignals are asserted by the Readout sequencer. After being read, the data are compared withthe programmed threshold. The data which survived the comparator veto are stored togetherwith an associated identifier in Data or Tag Buffers, respectively. When reading full time framedata, the zero suppress option is disabled. After scanning all chips, the next sequence for thenew event can be started. Simultanously, the data which have already been read out are fetchedby the Sending controller, which builds the message and then sends it off the board over a seriallink.

Behavioural models of the board components were coded in VHDL language [2]. Differentcofigurations of the board are tested in ongoing simulations. High radiation in a real experi-ment makes this design very demanding. The board should be simple to be fault tolerant andconcurrently to have enough functionality.

The following concepts are considered:

• dividing of the board into local and global parts, where only the local part will be mountedon the detector and communicate with the global one via serial link,

• multiplexing of output messages coming from different boards belonging to the same energytower into one fast optical link.

The goal of this work is to build and simulate a full VHDL model, containing internaldescription of the FERMI chip and functional description of the external environment. Thiswork is carried out in collaboration with Stockholm University as a part of the EAST [3] andFERMI collaboration activities.References:

1. The FERMI collaboration: "A Digital Front-end and Readout Microsystem forCalorimetry at LHC", CERN/DRDC/90-74, December 1990.

2. Mentor Graphics Corporation - VHDL 1076 System Reference Manual.3. Embedded Architectures for Second-level Triggering (EAST),

Status Raport CERN/DRDC/92-11, March 1993.

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to(O

36 x FERMIchips

Fig The architecture of the readout channel in the FERMI controller

PL9601145

COMPUTING AND NETWORKSA. Cyz, E. Górnicki, St. Jagielski*, A. Kotarba, W. Krupiński, B. Madeyski, P. Malecki,

K. Oliwa, A. Sobala, and W. Wajda

The computer network and computing services are managed and maintained by two groupssharing the work and responsibilities: Computing Group at the Institute's main site and theGroup of Numerical Computing of the High Energy Physics Laboratory at Kawiory.

1993 was a year in which our two clusters of DEC servers and workstations continued smoothrunning of the DEC VMS operating system. Network services were supported by TGV Multinet,upgraded and updated to the version 3.2 rev. B. It was, very likely, the last year of the dominanceof the VMS machines. The number of UNIX computers increased considerably and some morehave been ordered. Among them the Silicon Graphics Challenge L server, which will be installedin the first half of 1994.

Two VAXservers 3400 have been upgraded to improve the network services. The 8 Mbytememory module and 8 channel multiplexer card have been added to each one as well as "intel-ligent" SCSI interface.

The local area network (LAN) continued to grow. The number of users exceeded 200,connected via terminal servers or Ethernet adapters. More Ethernet lines have been installed,increasing the total length of lines by about 3 km. New Ethernet repeaters (DEMPR) andterminal servers improved the LAN infrastructure.

Basic software tools like CERN program library and TeX were maintained and continuouslyupdated. Some new application programs have been installed and tested. In particular: NEWS,a system which organize an exchange of information inside the Institute and WWW, a world widecommunication tool. Our software experts spent considerable part of their time as consultants tousers. Our groups provided all necessary information and expertise in preparations for orderingnew equipment by various divisions or projects.

Behind the scenes, several important activities have been completed such us e.g., taking overthe nameservicing for our domain (.ifj.edu.pl), introduction and improvement of the dynamicrouting on our CISCO gateway, extension of mail services to the TCP/IP, connection to thenational IP network NASK (hardware and software), optimization of the system tuning, newmeasures for the system safety, implementation of a limited (but safe) procedure to intervene insome system actions by advanced users etc.

The hardware problems were fortunately rather rare. The most troublesome were causedby the instability of the Fideltronik's UPSes. Almost all devices have been replaced by thecorrected model and, recently, a considerable improvement has been observed.

Particularly annoying were occasional breakdowns caused by bad contacts on the Ethernetand/or by the wrong use of the Ethernet cable of which the grounding of the coaxial cable outerconductor was a too frequent mistake. (An Ethernet cable is required to be earthed at one pointonly, so, the care must be taken to cover all barrel connectors with the non-conducting sleeve incase it comes into contact with neighbouring metal objects).

There were some hardware losses: two Exabyte drives, system disk at one of VAXserversand TK70 cassette tape drive, also for 3400 server. And some local triumphs as well: a seriouscrush of the gateway CISCO have been bravely repaired by our staff within few hours, savingus a lot of money and pain.

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Coming year activities will be dominated by the further transitions to the UNIX system and,hopefully, by consequences of the development of the Metropolitan Area Network, in particularby its fiber optic link between Bronowice and Kawiory.

Faculty of Nuclear Physics and Techniques, Academy of Mining and Metallurgy

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DIVISIONOF MECHANICAL CONSTRUCTION

Head of Division: Włodzimierz Janczur, M.Sc.M.E.Deputy Head of Division: Leszek Zródłowski, M.Sc.M.E.telephone: (48) (12) 37-02-22 ext.: 450e-mail: janczur@vsb01.ifj.edu.pl

PERSONNEL:Design Section

Head of Section: Leszek Zródłowski

Engineers:

Zbigniew CiochJerzy KotułaAndrzej Ryś

Technicians:

Bogusława HożewskaJózef LigockiKrzysztof Wiśniewski

Władysława Materkowska

Construction Section

Head of Section: Włodzimierz Janczur

Engineers:

Adam Sokołowski Tadeusz Śmiałowski

Technicians:Jarosław AdamekJerzy GrzybekWładysław KowalskiJózef MichniakWacław NędzaPiotr PiotrowskiMaciej RachwalikAdam RzepaWładysław SzwajaZygfryd TrulkaRyszard ZającBogusław Zięba

Zdzisław BłaszczakJerzy KantorskiJan KromkaKrzysztof MistelaMirosław PapieżKazimierz PukałaJózef RogowskiAndrzej SewerynHenryk ŚwierkJerzy WcisłoZbigniew ZasadzkiJan Zwoliński

Mirosław DubielKrzysztof KercJan MajkaJulian MiziołStanisław PelcRyszard PyziołRoman RomanówMaciej SowińskiZbigniew TochPiotr WójtowiczTadeusz Zdziarski

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The Department of Mechanical Construction has been established two years ago joining theDesign Group and Central Mechanical Workshop. The activity of the department includes thefollowing items:

• complex designs of devices and equipment for experiments in physics and their mechanicalconstruction and assembly,

• maintenance and upgrade of existing installations and equipment in our Institute,• the participation of our engineers and technicians in design works, assembly of an equip-

ment and maintenance for the experiments in foreign laboratories.

In 1993 our design group has been equipped with microcomputers PC-486 and PC-386 typeand graphic software AutoCAD, with its last version - release 12 that allows to make the drawingsand mechanical documentation corresponding to the world standards required by such scientificcenters like CERN, NIKHEF, MIT.

Our mechanical workshop can offer the wide range of machining and treatment methodswith satisfactory tolerances and surface quality. The possibilities of our mechanical workshopinclude:

• turning - cylindrical elements of a length up to 2000 mm and a diameter up to 400 mm,and also disc type elements of a diameter up to 600 mm and a length not exceeding 300mm,

• milling - elements of a length up to 1000 mm and gear wheels of a diameter up to 300mm,

• grinding - flat surfaces of dimensions up to 300 mm x 1000 mm and cylindrical elementsof a diameter up to 200 mm amd a length up to 800 mm,

• drilling - holes of a diameter up to 50 mm,• welding - electrical and gas welding in argon, vacuum tight welding,• soft and hard soldering,• mechanical works including precision engineering,• plastics treatment - machining, modelling, lamination of various shapes, polishing;

technology of forming plexiglas and scintillators is under a development,• painting - paint spraying with possibility of using furnace fired drier of internal dimensions

800 mm x 800 mm x 800 mm.

In 1993 the Department of Mechanical Construction designed and manufactered the equip-ment for the following laboratories:

1. Institut fur Kernphysik, Julich, FRG,2. Institut fur Mittelenergie Physik, Zurich, Switzerland,3. Joint Institute of Nuclear Research, Dubna, Russia,4. Jagellonian University, Cracow,5. Academy of Mining and Metallurgy, Cracow,

W. Janczur

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REPORTS ON ACTIVITY: PL9601146

The detectors for Institut fiir Kernphysik, Julich

In the frame of the cooperation with Institute of Physics of Jagellonian University andaccording to their requirements and foredesigns two sets of detectors for the experiment on COSYstorage ring in the Institut fur Kernphysik have been designed and built in our department.

Transmission Polarimeter.The polarimeter (Fig. 1) will be installed at the inlet of COSY-storage ring to test the

proton beam and define its parameters. The collimated proton beam will collide with a targetinside the polarimeter vacuum chamber and scattered products of the collision will be read-outby the scintillators after the crossing the windows covered with the thin (0.01 mm) stainless steelfoil. The main part of the transmission polarimeter is the vacuum chamber made of amagneticstainless steel (AISI 316L type) with 8 windows arranged in two perpendicular planes (horizontaland vertical) enabling the read-out of particles scattered in a front and a rear hemisphere atangles from 25 to 75 degrees. The scintillating detectors together with their photomultipliersmove over each window along the circumference of a radius of 375 mm. They are fastened tothe carriages driven independently by using remote controlled DC motors and moving angularlyin the range from 25 to 75 degrees. The angular position of the particular scintillating detectorsis denned with the accuracy ± 10'. The polarimeter is supported on the base-frame whichenables its positioning and a precise adjustment to ensure the proper alignment with the existingelements of COSY-storage ring. The target mechanism of the polarimeter ensures the vacuumtight transfer and positioning of the replaceable frame with 5 different targets. The targetmechanism is driven by the remotely controlled DC motor.

Targetmechanism

SctntiUatngdetectors

Fig. 1 Transmission Polarimeter.

299

PL9601148 PL9601147Transit Time Detector Set.The detector set consists of the vertical frame of the drift chamber and the frame fixing the

stationary scintillating detectors and the movable scintilllating detectors sets. The stationarydetectors set is equipped with 17 x 4 scintillators which cover the active window of the driftchamber (1680 mm x 433 mm). These detectors are provided for precise measurements ofcharged particles trajectories and particularly two protons produced in the coincidence. Themovable detectors set is a unit of 16 scintillators covering 2 sets (8 scintillators) of the stationarydetectors. Scintillating detector AMADEUS is a separate part of the experiment used directlyfor the measurements of the particle transit time. The detector has been manufactured in ourworkshop according to the drawings provided by Institut fur Kernphysik. This set of detectorswill be used in COSY-11 experiment at COSY-storage ring.

The equipment for Institut fur Mittelenergie Physik, Zurich.Movable Targets Stand.The stand consists of the flat frame equipped with the toothed bar in its lower part and

the guiding unit which enables the frame movement relatively to the beam axis. Replaceabletargets are fixed to the frame and can move together with it. The distance between the targetcenters is 1200 mm. The frame is driven by using DC flywheel motor and the transmissionmechanism including the gear box, the transmission shaft and the secondary gear box whichis meshed with the toothed bar of the target frame. The movement of the frame is controlledby the computer control system which ensures the target positioning accuracy of 0.1 mm. Thetarget frame moves periodically, every 0.5 s. While the first target crosses the beam, the otherone is inside the read-out part of the detector. Then the targets exchange their positions.

Magnetic Field Correction Coils.The coil set consists of six self-supporting coils which form regular cube - 1000 mm x 1000

mm x 1000 mm. The coils are supported on the base-frame and their vertical position canbe adjusted by using adjusting screws. Each of the coils can be operated independently whatenables to achieve the required direction of the magnetic field. The coil set is used to correctthe magnetic field on the movable targets stand.

The detector for Joint Institute of Nuclear Research, Dubna.The detector is a kind of geometrical connection of two detecting systems: FOBOS - the

system of gaseous detectors arranged in spherical geometry already existing and installed atU400M accelerator and new detector -ARGUS including scintillating detectors also spaced in 4TTgeometry. Our part of detector plays a role of an intermidiate part connecting these two detectingsystems and simultaneously a support structure for the central part of ARGUS detector. Thedetector (Fig. 2) has been designed and manufactured in close cooperation with Hahn-MeitnerInstitute in Berlin and Forschungszentrum Rossendorf.

ARGUS scintillating detector is equipped with 92 photomultipliers spaced on the supportingrings covering the part of hemisphere of an angle - 50 degrees. The detector is fixed to the flangein the rear part of the FOBOS body. The whole unit of ARGUS is spatially adjustable. Thedesign solution had to fulfil the following requirements:

• to ensure the insertion of about 200 cables (HV supply to and signal cables from photo-multipliers),

• effective cooling system for supporting elements of ARGUS detector,• to find the procedure of assembling and design a device enabling an assembly and fixing

ARGUS detector to the existing body of FOBOS detector and their relative alignment.

The designed and manufactered detector should fulfil all above mentioned requirements.

300

Shielding

Fig. 2 ARGUS - FOBOS Intermediate Detector.

Apart from the detectors and installations describesd above some other interesting designshave been made in the last year:

• Vacuum tight test chamber for testing the gaseous detectors with radioactive sourcesmanufactered for Institute of Physics of Jagellonian University.

• Smelting furnace for monocrystal production and grinding machine for monocrystals ma-chining - both made for Laboratory of the Structure of Nucleus of our Insitute.

• Design and construction works for the isochronic cyclotron AIC 144 S and for the Van deGraaff accelerator.

Engineers and technicians of our department participated in research works for ATLASexperiment at future accelerator LHC at CERN, PHOBOS experiment on RHIC acceleratorat Brookhaven National Laboratory and also in assembly and maintanance for ZEUS and HIexperiments at HERA accelerator at DESY in Hamburg, in the frame of the activity of theDepartment of High Energy Physics.

301

ENERGY EFFICIENCY CENTER

Head of Center: Assoc.Prof. Edward ObrykSecretary: Anna Śpiewaktelephone: (48) (12) 37-02-22 ext.: 280e-mail: obryk@bron.ifj.edu.pl

OVERVIEW:The Agreement on Cooperation between the Institute of Nuclear Physics and the Institutt

for Energiteknikk, Kjeller (Norway) has initiated in the Institute new activities in the field ofenergy efficiency at Institute. In accordance with this Agreement the Energy Efficiency Center(EEC) has been established at the Institute of Nuclear Physics. The Center scope covers a widerange of activities related to all aspects of energy efficiency. Special emphasis is paid to theimprovement of efficiency in the utilization of the final energy carriers.

The main activities have been carried on within the framework of the Programme Proposalfor Energy Efficiency Scheme, sponsored by the Government of Norway. This Programme in-cludes the following activities:

• Show-room,• Courses, Training of Staff,• Housing Projects,• Energy Efficiency Studies.

The Center has also assisted the Institutt of Energiteknikk in carrying out the IndustrialEfficiency Programme in Poland.

GENERAL ACTIVITIES:

The EEC has established relations with the local and central authorities in the field ofenergy efficiency. Also roTnTnnnir.ftt.ioTi with producers and dealers of equipment and systems forimprovement of of energy consumption has been established. Staff members of the EEC tookpart in many meetings, seminars, exhibitions etc. The EEC organized the Polish-NorwegianSeminar on Energy Efficiency as an Essential Factor in Solutions of Energy and EnvironmentalProblems.

SHOW-ROOM:

It was an ambitious and difficult task to establish, in a relatively short time, a modernShow-room appropriate for Polish conditions and needs.

Due to the coherent efforts of the Norwegian specialists and the EEC staff the Show-roomhas been successfully organized, arranged and equipped. It was formally opened on June 8, 1993with participation of officials from both, Norwegian and Polish side.

The Show-room serves as a place for meetings of professionals in the field of energy efficiency,for courses and conferences and also lectures about energy and energy efficiency in everyday lifefor high school students.

In the 1994 several courses related to energy efficiency in industry, public and apartmentbuildings and also lectures about energy efficiency in everyday life for students and generalpublic in our Show-room are planned.

302

The Show-room will be equipped with more software and hardware, including an upgradingof the EDAS (Energy Data Acquisition System) installed at the Show-room.

COURSES AND STAFF TRAINING:

Three courses for the staff of the EEC have been organized and carried out:

• Basic Energy Efficiency,• Measurements and Control,• Boilers, Steam and Condensate.

The courses were very well prepared, lecturers were carefully selected and lectures very wellpresented. These courses gave a sound background for the staff for their activities in the fieldof energy efficiency, especially energy studies. The courses should be considerd very successfulones. On the basis of the above, materials for several future courses heve been prepared. Duringthe 1994 about 3-5 such courses are planned.

HOUSING PROJECT:

Monitoring of the parameters related to the heat supply of three centrally heated apartmentbuildings, with about 160 flats, will be done during the 1993/1994 heating season. Monitoringis carried out on a daily basis. The obtained informations will be important not only forthe monitored but for other buildings as well. The operation of these new control units aresatisfactory. It should improve comfort and at the same time save about 10 % of energy and cutsubstantially energy bills. This project shall be considered highly successful and its continuationshould demonstrate the proper way for improvement of energy efficiency in apartment buildingsin Poland.

ENERGY EFFICIENCY STUDIES:

Energy efficiency studies for two dairy plants and one hospital are carried on under theguidance of Norwegian consultants. These studies will be completed at the beginning of 1994.

It seems that the staff of the EEC has sufficient knowledge and experience to carry out suchactivities on their own. One obvious disadvantage of the EEC in these activities is its lack ofportable measuring equipment and data logger for energy breakdown (plants in Poland are verypoorly equipped with measuring equipment). The most welcomed assistance from the Norwegianside will be the supply of these necessary measuring equipment. In 1994 energy efficiency studieswill be in 50 % supported by the Norwegian side and in 50 % of the cost will be covered bythe companies involved. This should provide a smooth entrance for the EEC on the auditingmarket in Poland.

INDUSTRIAL PROJECT:General Remarks:In 8 plants in the Katowice and Kraków regions, data monitoring of energy and water

consumption has been carried out. The quality of data were generally good. All data wereprocessed using the 3-R Program (Norwegian software). This processing gives a clear picture ofthe energy situation.

In many plants there is no sufficient measuring equipment to identify the full picture ofenergy flow in a plant. The installation of several water meters for condensate return will allownot only the establishment of heat distribution between processes, space heating and warm waterbut will also help to find the incorrect switching on the valves causing of high power peak onsteam supply. There has been a lot of advises to the plants management relating to energyefficiency measures. A reasonable fraction of which has been considered and followed. In each of

303

plant participating in this project there has been made some improvement in energy and watermanagement. In several cases it has led to significant savings. Probably far more importantis fact that management has become aware of the problem and the opportunity for energyefficiency. This will produce a lasting influence on energy management and energy efficiency.

The plants involved, as most of the plants in Poland, are in a difficult financial situation,having no clear perspective. Due to this fact managements are afraid to take credit for investmenteven if the payback period is reasonably short. On top of that it is clear that energy efficiencyrelated investment has no high priority. One rather sad fact is, that in Poland there is noinstitution supporting activities related to energy efficiency in industry (it is assumed that thefree market will solve everything).

Assoc.Prof. E. Obry

SHORT TERM VISITORS TO THE CENTER FROM NORWAY:

William Christensen, Arne Palm,Per Finden, Tore Pettersen,Ola Fladmark, Einar Rensaa,Thor Gulbrandsen, Harald Rikheim,Harald Gundersen, Ingar Skallerud,Kjell Moe, Ole Veiby

304

INP AUTHOR INDEX:

Adamczak A., 13Adamski A., 142Andiuszków J., 170Bajorek A., 104Balmas A., 284Bałanda M., 104Bartke J 180Bednarczyk P., 38, 40, 42Białas A., 189Bilski P., 271, 272Biiczyński A., 241Blocki J., 142, 146, 161, 163, 198Bochnacki P., 118Bogacz J., 217Borzemski P., 170, 171Bożek A., 159Bożek P., 113Broda R., 36, 38, 40, 42, 43, 258Broniowski W 115Brückman P., 142, 146Budzanowski A., . . .7, 13, 14, 20, 21, 22, 23, 189Budzanowski M., 270, 271Budziak A., 142, 150Cebulska-Wasilewska A., 228, 229, 231Cerkaski M., 115Cetnar K., 166Chwastowski J., 161, 170, 171Coghen T., 189Cywicka-Jakiel T., 216, 217Cyz A., 295Czerski P., 116Czermak A., 161, 165, 292Czubek J.A., 216Czyż W., 117, 189Daniluk W., 170Dąbrowska A., 185, 186Dąbrowski B., 170Dąbrowski W., 165Despet M., 142, 198Drozdowicz K., 217Drożdż S., 2, 5, 7, 114Drwifga M., 83, 86Dryzek E., 66Dryzek J., 66Dutkiewicz E.M 76, 252Dworak D., 217Dwuraźny A., 171Eskreys A., 170, 171, 176

Figiel J., 176Florek A., 142, 150, 198Fłorek B., 142, 150, 198Florkowski W., 116, 117Fornal B., 36, 40, 42, 43Freindl L., 14, 20, 22Gabańska B., 217Gadomski S., 161, 162, 163Gałuszka K., 142, 198Gdański T., 142, 146Glebowa L., 76Gładysz-Dziaduś E., 180Godlewski J., 142, 146, 161, 163, 189, 198Godunowa H., 284Golec-Biernat K., 117, 118Górnicki E., 295Grębosz J., 36, 63Gruszecki M., 18, 19Gruszecki P., 142Hajduk Z., 142, 148, 159, 161, 166, 168Hennel F., 240Hołyński R., 185, 186, 189, 193Horzela A., 118, 119Hrynkiewicz A., 56, 57, 69Huczkowski J., 233Idzik M., 165Igielski A., 217IwańskiW., 63, 161, 168, 293Jagielski S., 166, 295Jakubowski Z., 171Jałocha P., 142, 146Janik J.A., 103Janiszewska B., 233Janiszewski T., 233Jasiński A., 240Jasińska M., 258, 262Jurak A., 185, 186Jurkiewicz P., 166, 170Kajetanowicz M., 63, 161, 165, 290Kamiński P., 8, 114Kamiński R., 119Kantor W., 23Kapłon J., 161, 165, 290, 292Kapuścik E., 118, 119Karcz W., 14, 16Kasper E., 228Kempczyński J., 118Kisielewski B., 166

305

Kliczewski S., 14, 18, 19, 20, 22Kmieć R., 67Kopeć M., 273Korcyl K., 63, 142, 161, 168Kotarba A., 166, 170, 295Kotuła J., 189, 198Kowalski M., 180, 182Kozak K., 258, 262Kozik E., 13Kraczka J., 69, 70Krasnowolski S., 233Krasny W., 118Królas W., 36, 40, 42, 48, 51Krupiński W., 142, 295Krynicka E., 217, 218Krzykwa B., 228Kubka B., 253, 255Kucewicz W., 142, 146Kulczykowska K., 233Kutschera M., 120Kwiatkowska J., 78Kwiatek W.M. 72, 73, 76, 258Kwieciński J., 118, 120, 121, 122Lach M., 38, 46Lalowicz Z.T., 241Lekki J., 73, 80, 82Lemler M., 189, 198Lesiak T., 142, 143Leśniak L., 119, 122Lipińska E., 83, 86Litwiniszyn M., 229Łachut J., 86Łazarska B., 233Łoskiewicz J., 216, 217Macharski P., 258, 262Madeja M., 14, 18, 19Madeyski B., 295Maj A 48, 50, 51, 52, 53, 54Makowska-Rzeszutko M., 21Malecki P., 161, 166, 176, 189, 295Maniawski F., 78Marczewska E., 72, 76Marszałek M., 57, 62Mazur J., 217Męczyński W., 38, 46, 63Michałowski J., 142, 146, 150, 198Mietelski J.W 258, 261, 262Moszczyński A.S., 161, 165Muryn B., 142, 145, 146Natkaniec Z., 161, 166Niewiadomski T., 270, 273, 274Nizioł B., 171Okołowicz J., 7Oliwa K., 170, 295Ołkiewicz K., 176Olko P., 270, 271, 272, 273Olszewski A., 186, 189

Okzowska J 161, 166Ostrowicz W., 161, 166Pacyna A. W 103Pakoński K., 189, 198Palarczyk H., 189Pałka B., 229Pałka H., 142, 146, 159Parliński K., 242Pawłat T., 36, 40, 42Pawłyk I., 231Pawlik B., 176Piotrzkowski K. 170, 171Płoszajczak M., 8, 113, 114Polok G., 142, 150Potempa M., 284Przybycień M., 170Rajchel B., 83, 86Różańska M 158Rybicki K., 142, 159 160Ryłko R., 160Schwabe J., 284Sellmann A., 86Siwek A., 23Siudak R., 21Skwirczyńska I., 14Sóbala A., 161, 295Sosnowski W., 142Sowa M., 76Srokowski T., 7Stachuia Z., 80, 82Stefański P., 180Sternik M., 242Stodulski M., 142, 189. 198Stopa P., 176Stopa Z., 142, 198Strączek A., 142, 198Strçk M., 142, 198Styczeń J., 38, 45, 46, 48Sułek Z., 240, 241Swakoń J., 217Szarska M., 185, 186Szczurek A., 10, 11Szeglowski Z., 253, 254, 255, 257Szmider J., 14, 18, 19Tracz G 216, 217Trzupek A. 186, 189Turała M., 142, 161, 163, 165Wajda W., 295Waligóiski M. 272, 274Was B., 261Wierba M., 83, 86Wierba W., 170Wierzewska A., 228Wilczyńska B., 186, 189, 193, 233Wilczyński H., 186, 193Witek M., 142, 148, 159Witek W., 103

306

Wodniecka B 56, 57Wodniecki P., 56, 57, 59, 60Wolak A., 161, 163Wolski R., 14Wolter W., 186, 193Wosiek B. 180, 185, 186, 189Woźnicka U., 217Woźniak K., 185, 186, 189Wrzesiński J., 65Zachara M., 170, 171Zagrodzki P., 252Zalewska A., 142, 146Zalewski K., 189Zawiejski L., 170, 171Zazula J.M 217Ziębliński M., 63Zuber K 45Żenczykowski P., 123

307