cosmogenic induced activity

Cosmogenic induced activityCosmogenic induced activity

Susana Cebrián [email protected]

University of Zaragoza (Spain)

IDEA (Integrated Double-beta decay European Activities)

Zaragoza, 7th-8th November 2005

Task coordinators: Maura Pavan, Susana Cebrián

mailto:[email protected]

Implementation plan

Outline of the talk

• Simulation-based work

• Irradiations tests

• Outlook and summary

S. Cebrián, Cosmogenic Induced Activity IDEA meeting, Zaragoza, November 2005

WP Task

9.R2 - Table 1 – IDEA - Second 18 months Execution Plan

13st to 18th month (1.04.2005-30.09.2005)

19th to 24th month(1.10.2005-31.03.2006)

25th to 30th month(1.04.2006-30.09.2006)

4 B1

Tasks

- Up-grade and development of simulation codes

- Upgrading of existing codes for n/p activation- Design of further n/p activation tests on Ge and TeO2

- further n/p activation experiments

- Start-up of tests at CERN and other labs on Ge and TeO2

Milestones and Delivera

bles

- Upgraded codes for n/p activation and related technical report

- progress report

CONFERENCES:

Talk on “Cosmogenic activation in germanium Double Beta Decay Experiments” by s. Cebrián et al at TAUP2005 Conference, Zaragoza (Spain), September 2005

(available at http://ezpc00.unizar.es/taup2005/talks.htm)


MEETINGS:

Common Meeting on Monte Carlo studies (JRA1 / N3 / JRA2) held in Zaragoza, on 15th September 2005

(minutes and transparencies available at http://www.unizar.es/ilias/JRA1/05.htm)

• Interest on copper activation by JRA1• Interface with GEANT4 Collaboration

General issues

http://ezpc00.unizar.es/taup2005/talks.htm

http://www.unizar.es/ilias/JRA1/05.htm

• Activation study for Cu

• Improvements in GEANT4


Simulation-based work

GOAL: Identification of the most reliable codes and of the weak points of computations for treating our problems in order to improve them

Studies for relevant activation problems in DBD using different codes and comparing with data when possible: Te, Ge

In the first year …

In the last six months …


Activation study for Cu

Similar work to that done for Te and Ge:

1. Comparison of excitation functions to find the most reliable evaluation for relevant products using:

Why copper?

• Common material in set-ups of rare event experiments

• A large amount of experimental data for production cross sections!

• Measurements with beams: protons: lots of data at EXFOR database neutrons !!!: E. J. Kim et al, J. Nucl. Sci. Tech. 36 (1999) 29-40

• Calculations based on semiempirical Silberberg & Tsao formulas: YIELDX p >100 MeV

• Monte Carlo calculations:MENDL-2 (using versions of ALICE) p <200 MeV, n <100 MeV

2. Calculation of production rates of induced nuclei

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Michel'97 Grutter'82 Michel'95 Aleksandrov'87 Aleksandrov'90

Yashima'02 Greenwood'84 Orth'78 Orth'76 Mills'92

Kozma'90 Cumming'74 MENDL(p) MENDL(n) YIELDX

Michel'89 Michel'86 Kim'99(n)

Activation study for Cu: excitation functions


57Co production in nat Cu

YIELDX works very well at E>200-300 MeV but overestimates below

MENDL for p gives good agreement with measurements at low energy

MENDL for n is above results from Kim’99

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Mills'92 Aleksandrov'90 Williams'67 Grutter 82 Heydegger'72

Orth'76 Kozma'90 Michel'89 Greengood'84 (CUM) Cumming'74

Michel'97 Schiekel'96 Michel'95 Michel'86 Cline'71

MENDL(n) MENDL(p) YIELDX Kim'99(n)


Much worse agreement between measurements and calculations

60Co production in nat Cu

In MENDL predictions production by neutrons is higher and with lower threshold than by protons MENDL results for n seem to be

below Kim’99 data


Deviation factors

Our selection for the excitation functions in Cu:

at low energies (<100 MeV): MENDL results for neutrons, normalized to experimental data when possible

at higher energies: experimental data for protons combined with YIELDX

MENDL(n) MENDL(p) YIELDX YIELDX

<100 MeV <200 MeV 200-300MeV >300MeV56Co 3,6 1,8 1,1 1,257Co 1,4 1,1 1,4 1,158Co 1,3 1,8 6,8 2,960Co 1,4 2,6 2,0 1,654Mn 1,5 1,5 1,559Fe 2,5 5,0 3,6 1,746Sc 1,8 1,365Zn 1,7 1,3 1,9

At low energies there can be significant differences in F between products

very important to reproduce experimental production rates!


Activation study for Cu: production rates

J. F. Ziegler, IBM Journal of Research and Development 42 (1998) 1.

E>20 MeV:4.5 10-3 n/cm2/s

Cosmic neutron spectrum: parameterization based on measurements

)()( EEdER n

dectt eeRA )1( exp


Thanks are due to G. Heusser for informing us on their measurements

Production rates (kg-1d-1)

Deduced from experimental data (Fisher et al., PLB 218 (1989) 257)

J. A. Formaggio, C. J. Martoff, Annu. Rev. Nucl. Part. Sci. 54 (2004) 361

LE ME HE 56Co 2,6 + 18,0 + 2,3 22,957Co 29,7 + 55,8 + 2,8 88,358Co 90,4 + 65,7 + 3,5 159,660Co 81,8 + 14,2 + 1,4 97,454Mn 3,6 + 25,9 + 3 32,559Fe 4,3 + 1,9 + 0,3 6,546Sc 0 + 2,5 + 1,3 3,8

COSMO F&M '04 Heusser'05

972,3 19,9±2,6

30,5 155±35

131,5 142,6±7,8

25,7 2675,5 181±16

134,2 52,2 18,6±1,8

39±10

4,6±1,6

Contributions up to 100 MeV (LE), 100-1000 MeV (ME) and above 1 GeV (HE)

Measurements following a long exposure at LNGS surface

G. Heusser, LRT2004, Sudbury, December 2004.

G. Heusser, M. Laubenstein, H. Neder, to appear in “Radionuclides in the Aquatic environment” (Ed. Povinec) Elsevier, 2005

Calculations based on modified COSMO

L. Baudis, R. W. Schnee, NUSL White Paper, 2002


Production rates (kg-1d-1)

COSMO F&M '04 Heusser'05

972,3 19,9±2,6

30,5 155±35

131,5 142,6±7,8

25,7 2675,5 181±16

134,2 52,2 18,6±1,8

39±10

4,6±1,6

at LNGS

48,1

185,5

335,1

204,5

68,3

13,6

8,0

Differences are understandable if just semiempirical cross sections are considered: for 60Co low energy neutron contribution is missed

Extremely high rates justified by Chernobyl

58Co production not understood: measured production cross sections for n and for p higher than for 60Co but this is not true for production rates

Discrepancies for other products could be (qualitatively) understood mainly due to the selected excitation functions at medium energies: based on p measurements not continuous with n measurements at lower energies

LE ME HE 56Co 2,6 + 18,0 + 2,3 22,957Co 29,7 + 55,8 + 2,8 88,358Co 90,4 + 65,7 + 3,5 159,660Co 81,8 + 14,2 + 1,4 97,454Mn 3,6 + 25,9 + 3 32,559Fe 4,3 + 1,9 + 0,3 6,546Sc 0 + 2,5 + 1,3 3,8

x 2.1


Summary of the activation study in Cu

• Deviations between measured production cross sections (for p and even

for n) and calculations (using YIELDX and MENDL library) have been

evaluated for different products.

• For the production of some nuclei, the use at low energies of the excitation

function specific for neutrons is essential

• Semiempirical calculations reproduce quite well cross sections above

~300 MeV, but they cannot be the only source of information to derive

reliable production rates

• Apart from 58Co, some discrepancies between our calculated production

rates and the direct measurements at Gran Sasso could be understandable

and could be reduced if some information of cross sections for neutrons

at medium energies (hundreds of MeV) was available.

Improvements in GEANT4

Contact has been established between ILIAS MC working groups and the GEANT4 Collaboration to pass on to them underground physics interests on simulations


Ongoing validation effort regarding isotope production within the GEANT4 Collaboration


Calculations for Ge using GEANT4

# Z A1 4 72 11 243 19 424 19 435 21 436 21 447 21 448 21 469 21 4710 21 4811 23 4812 24 5113 25 5214 25 5415 25 56

16 26 5917 27 5518 27 5619 27 5720 27 5821 27 6022 27 6123 28 5724 29 6125 29 6726 30 6227 30 6528 30 6929 30 7130 30 7231 31 6632 31 6733 31 6834 31 7235 31 7336 32 6637 32 6838 32 6939 32 7540 33 7141 33 7242 33 74

Irradiation experiment Aleksandrov’91 simulated obtaining production • with 660 MeV protons

• on natural Ge

• using different GEANT4 models (Bertini and Binary cascades) and semiempirical YIELDX J. P. Wellisch, nucl-th/0306006, nucl-th/0306008, nucl-th/0306016


model deviation factor F

YIELDX 1.87

GEANT4 (Binary) 5.88

GEANT4 (Bertini) 3.18

• YIELDX gives better agreement than GEANT4

• Bertini model seems to work better than Binary cascade, as found in Te

simulations (Heidelberg presentation) and in the GEANT4 Collaboration validations

Global deviation factor from Aleksandrov’91 results

• Experiment at CERN on TeO2

• Proposals for Ge experiment

Some crucial questions regarding activation in Te, Ge were identified giving rise to possible irradiation tests

In the last six months …


Irradiation tests

GOAL: to measure the production cross-sections and/or rates of production with n/p beams on the targets of interest

Essential to validate calculations with codes

In the first year …

Experiment at CERN on TeO2


Initial problem

1,E-05

1,E-04

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1,E+00

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1,E+02

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Silberberg &Tsao (YIELDX) measurement Berkeley measurement CERN

GEANT4 modified COSMO

Irradiation experiment proposed and already carried out at CERN with 1.4 GeV p

COSMO predicted a high production cross section of 60Co in Te between 1-3 GeV

60Co production in nat Te

Disagreement with YIELDX calculations and measurement for 1.85 GeV p at Berkeley by Bardayan’97


Features of experiment

Beam (p) energy Fluence Sample mass Te mass

1.4 GeV 1.65 1015 p/cm2 0.457 g 0.365 g

Results

• Two long gamma countings (several days) performed

• Activation yields of many different products identified (Rb, Rh, Sn, In, Sb isotopes) including 60Co

• Complete evaluation of production cross sections and comparison with YIELDX calculations (together with results of a previous irradiation at 24 GeV also at CERN) underway

• 60Co production cross sections (mb):

energy (GeV) CERN Berkeley CERN YIELDX

24 1.14±0.19 1.15

1.85 0.63±0.15 0.85

1.4 0.40±0.06 0.77

preliminary!

Sensitivity of CUORE to 130Te DBD is not jeopardized by cosmogenic 60Co in crystals and YIELDX calculations in good agreement with measurements

Proposals for Ge irradiation experiment


An irradiation experiment with germanium as target is being planned

• target sample: natural or enriched?

• projectile: n or p?

• energy beam: mono-energetic?

• facility and time: for irradiation and for gamma-counting

• to shed light on 68Ge activation (there are important discrepancies between calculated and experimental production rates) low energy neutron beams would

be highly recommended

• the use of both natural and enriched targets would be advisable

Several possible experiments have been analyzed:

• facilities, beam features, cost

• actvivity yields and possible counting

1 2 3 4

Facility ITEP, Moscow, Russia Svedberg Laboratory (TSL), Uppsala, Sweden

Centre de Reserches du Cyclotron (CRC), Louvain, Belgium

Natural irradiation

Beam 800 MeV p on W target producing n with a continuous energy spectrum Total fluence: 1015 p W target: D=5cm, L=3 cm

Fully monoenergetic n beam 20-175 MeV Fluence: 5 105 n/cm2/s (2-30 cm , up to 106 n/s)

Quasi-monoenergetic n beam 20-65 MeV Fluence: 1.3 104 n/cm2/s (10 cm , up to 2 106 total n/s)

Cosmic rays at sea level

Availability Beam for therapy, industry and basic research. Deadlines for proposals: 15 October, 15 January TARI access in 2004-2007

Beam for industry and research. Deadline for Proposals: December 2005 for operation in February-July 2006

Gamma counting

Included. Possibility of sending the sample for further measurements.

Not available. Possible.

Cost Irradiation: 3000 € Personnel: 3000 €+ 500 €/sample Gamma counting: 150 €/day Samples: 1.4$/mg 70Ge (buying); 300-500 €/half a year (renting)

Irradiation: 400 €/hour + sample

Irradiation: 516 €/hour for industry. Offered free irradiation if proposal accepted + sample

Sample

More info “Pilot activation experiment at ITEP”, V. Kornoukhov

- http://www.tsl.uu.se - On the beam and facility: L. Andersson et al, Proceedings of EPAC2004, Lucerne, Switzerland.

- http://www.cyc.ucl.ac.be - On the beam and facility: H. Schuhmacher et al, NIMA 421 (1999) 284 - Irradiation experiment in Ge at CRC: J. E. Naya et al, NIMA 396 (1997) 374.


IRRADIATION


YIELDS (for 68Ge, 1 g sample)

1, ITEP 2, Uppsala 3, Louvain 4, Nat irradiation

Activity mBq

5787 (for 1 g 70Ge) (V. Kornoukhov)

~25 (for nat Ge after 1 hour of irradiation, assuming =60 mb)

~0.5 (for nat Ge after 1 hour of irradiation, assuming =60 mb and completely monoenergetic beam)

0.3 10-3 (for nat Ge after 1 y of irradiation assuming R=50 kg-1 d-1)

counting at 1077 keV counts/day (I=3%, =2%)

300 1.3 0.026 1.5 10-5

X-rays at 9.2 keV counts/day (I=39.7%, =100%)

~2x105 ~850 ~17 ~0.01

PROS & CONS 1, ITEP 2, Uppsala 3, Louvain 4, Nat irradiation Possibility of seeing other activation products

++ - -- + Continuation with enriched samples

++ - - - Extrapolation of results - + + -

Sample=detector approach:

+ higher efficiency for measuring the yield, allowing lower neutron fluxes

- irradiation of components other than Ge crystal

- not easy continuity for enriched samples

Activity ratios: 10000 : 50 : 1 : 0.001

Only X-ray counting possible

Very massive samples required

WP Task

9.R2 - Table 1 – IDEA - Second 18 months Execution Plan

13st to 18th month (1.04.2005-30.09.2005)

19th to 24th month(1.10.2005-31.03.2006)

25th to 30th month(1.04.2006-30.09.2006)

4 B1

Tasks

- Up-grade and development of simulation codes

- Upgrading of existing codes for n/p activation- Design of further n/p activation tests on Ge and TeO2

- further n/p activation experiments

- Start-up of tests at CERN and other labs on Ge and TeO2

Milestones and Delivera

bles

- Upgraded codes for n/p activation and related technical report

- progress report

Outlook


Summary

A study of activation in Cu using available experimental

data and different calculations is underway, allowing a better

validation of codes.

GEANT4 has started a validation effort for isotope

production

S. Cebrián, Cosmogenic Induced Activity

An irradiation test on Te has been carried out at CERN

and preliminary results are available for 60Co.

Different options for an irradiation experiment with Ge

have been studied.

IDEA meeting, Zaragoza, November 2005

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YIELDX (Silberberg&Tsao) Aleksandrov'91 MENDL-2P (p)

MENDL-2 (n) Horiguchi'83 ISABEL (Majorana, n)

CEM95 (p) HMS-ALICE (p) HMS-ALICE (n)

GEANT4 LHEP_PRECO (p) GEANT4 LHEP_BERT (p) GEANT4 LHEP_BIC (p)


68Ge production in nat Ge

cosmogenic induced activity

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