1

Local Organising

Committee

Ad M. van den Berg, ChairpersonArjen van Rijn, TreasurerDavid BergeGianfranco BertoneAlexey BoyarskySijbrand de JongJan-Willem den HerderAart HeijboerJörg HörandelPaul KooijmanOlaf ScholtenJacco VinkPeter Wenzel

Program Committee

Laura BaudisGalina BazilevskayaRolf BütikoferJin ChangPaschal CoyleElisabete de Gouveia Dal Pino Silvia DallaMihir DesaiBrenda DingusFiorenza DonatoRoelf Du Troit StaussLucy FortsonMasaki FukushimaStefano GabiciPiera GhiaPeter Gorham

Sunil GuptaJim Hinton

Dan HooperPer Olof HulthUli KatzBerndt KleckerRafael LangDavid LarioOlga MalandrakiRichard MarsdenJulie McEneryPaolo PriviteraVladimir PtuskinSylvie Rosier-LeesGavin RowellRoberto Ruiz de AustriDorothea SamtlebenPiera Sapienza

Tracy SlatyerPierre SokolskyRoberta SparvoliTim TaitMasahiro TeshimaShoji ToriiNick Van EijndhovenScott Wakely

IUPAP C4

Members

Karl-Heinz Kampert, Chair Sunil K. Gupta, Vice-chair R. Adriaan Burger, SecretaryMasaki Mori Jörg HörandelEun-Suk SeoMichal Ostrowski

Zhen CaoMichael KachelriessRyan NicholMikhail Panasyuk Pasquale BlasiJoakim EdsjöPierre Binetruy

IUPAP C4

Associate Members

Steven W. BarwickElisabete de Gouveia Dal PinoMark Lester

July 30 - August 6, 2015The Hague, The Netherlands

www.icrc2015.nl14231 ICRC poster_DEF.indd 1 02-02-15 11:10

2

Cosmic-ray energy spectra

3

Precision measurement of the proton flux with AMS33RD INTERNATIONAL COSMIC RAY CONFERENCE, RIO DE JANEIRO 2013

Fig. 5: Daily variation of normalized flux. We have observed the gradual decrease of flux in the low rigidity region(R <∼10 GV) as well as some spikes in ∼1 GV which correspond with solar events on 9 August 2011 (X6.9), 27 January2012 (X1.7), 7 March 2013 (X5.4), and 17 May 2012 (M5.1).

Fig. 6: The average proton flux over the two years of AMS-02 observation as a function of kinetic energy (E) multi-plied by E2.7 together with the previous experimental da-ta [17]–[34].

Level Enhancement (GLE) event in Solar Cycle 24. Weobserved a few other small spikes which correspond to so-lar events on 9 August 2011 (X6.9) and 27 January 2012(X1.7) and several Forbush decreases including the largeone from 27 September 2011.

9 Result and conclusionFig. 6 shows the average proton flux over the two yearsof AMS-02 observation as a function of kinetic energymultiplied by corresponding bin central value [16] in the2.7 power and compared with previous experimental da-ta [17]–[34]. In the high energy region above 100 GeV thespectrum is consistent with a single power law spectra andshows no fine structure nor break.

AcknowledgementsThis work has been supported by acknowledged personand institutions in [1].

References[1] M. Aguilar et al., Phys. Rev. Lett 110 (2013) 141102.

[2] K. Luebelsmeyer et al., Nucl. Instrum. Methods A654 (2011) 639.

[3] B. Alpat et al., Nucl. Instrum. Methods A 613 (2010)207;

[4] A. Basili et al., Nucl. Instrum. Methods A 707 (2013)99; V. Bindi et al., Nucl. Instrum. Methods A 623(2010) 968.

[5] P. Zuccon et al., ICRC (2013) 1064.[6] C. Delgado et al., ICRC (2013) 1260.[7] C. Stoermer, The Polar Aurora (Oxford University,

London, 1950).[8] P. Saouter et al., ICRC (2013) 789.[9] Q. Yan et al., ICRC (2013) 1097.[10] S. Schael et al., ICRC (2013) 1257; B. Bertucci et

al., ICRC (2013) 1267.[11] J.Z. Wang et al., Astrophs. J. 564 (2002) 244.[12] J.D. Sullivian et al., Nucl. Instrum. Methods 95

(1971) 5.[13] S. Agostinelli et al., Nucl. Instrum. Methods A 506

(2003) 250.[14] J. Bazo et al., ICRC (2013) 849.[15] A. Kondor, Nucl. Instr. Meth. 216 (1983) 177; G.

Agostini, Nucl. Instr. Meth. A 362 (1995) 487.[16] G.D. Lafferty, T.R. Wyatt, Nucl. Instr. Meth. A 355

(1995) 541.[17] O. Adriani, et al., Science, 332 (2011) 69; O.

Adriani, et al., Astrophys. J. 765 (2013) 91.[18] J. Alcaraz et al., Phys. Lett. B 490 (2000) 27.[19] A.D. Panov et al., Bull. Russian Acad. Sci. 73

(2009) 564.[20] M. Ichimura et al., Phys. Rev. D 48 (1993) 1949.[21] Y. Shikaze et al., Astropart. Phys. 28 (2007) 154.[22] T. Sanuki et al., Astrophys. J. 545 (2000) 1135.[23] S. Haino et al., Phys. Lett. B 594 (2004) 35.[24] K. Sakai et al., ICRC (2013) 974.[25] M. Boezio et al., Astrophys. J. 518 (1999) 457.[26] M. Boezio et al., Astropart. Phys. 19 (2003) 583.[27] Y.S. Yoon et al., Astrophys. J. 728 (2011) 122.[28] W. Menn et al., Astrophys. J. Lett. 533 (2000) 281.[29] K. Asakimori et al., Astrophys. J. 502 (1998) 278.[30] R. Bellotti et al., Phys. Rev. D 60 (1999) 052002.[31] E. Diehl et al., APh 18, 487 (2003)[32] M. Hareyama et al., J. Phys. Conf. 31 (2006) 159.[33] I.P. Ivanenko et al., Proc. ICRC 2 (1993) 17[34] D. Maurin et al., arxiv:1302.5525 (2013).

Protons (Hydrogen)

AMS, ICRC 20134

!!!!!

Rigidity (GV)10 210 310

2.7

xR

-1sr

sec

GV)

2He

Flu

x (m 310

AMS-02(2011-2013)PAMELA(2006-2008)CREAM-I(2004-2005)ATIC-02(2003)BESS-Tev(2002)BESS-98(1998)AMS-01(1998)CAPRICE(1998)IMAX(1992)Baloon(1991)MASS-91(1991)

"#!$%&%"'! ()!*+,-./,!!012!*,3345,647,8!9*:*!#;"'!

Helium

AMS, ICRC 20135

LETTERS

An asymmetric solar wind termination shockEdward C. Stone1, Alan C. Cummings1, Frank B. McDonald2, Bryant C. Heikkila3, Nand Lal3 &William R. Webber4

Voyager 2 crossed the solar wind termination shock at 83.7 AU inthe southern hemisphere, 10 AU closer to the Sun than found byVoyager 1 in the north1–4. This asymmetry could indicate an asym-metric pressure from an interstellar magnetic field5,6, from tran-sient-induced shock motion7, or from the solar wind dynamicpressure. Here we report that the intensity of 4–5MeV protonsaccelerated by the shock near Voyager 2 was three times thatobserved concurrently by Voyager 1, indicating differences inthe shock at the two locations. (Companion papers report on the

plasma8, magnetic field9, plasma-wave10 and lower energy par-ticle11 observations at the shock.) Voyager 2 did not find the sourceof anomalous cosmic rays at the shock, suggesting that the sourceis elsewhere on the shock12–14 or in the heliosheath15–19. The smallintensity gradient of Galactic cosmic ray helium indicates thateither the gradient is further out in the heliosheath20 or the localinterstellar Galactic cosmic ray intensity is lower than expected21.

Low energy ions accelerated at the termination shock are observedupstream of the shock and in the heliosheath (Fig. 1). Voyager 2

1California Institute of Technology, Pasadena, California 91125, USA. 2Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.3NASA/Goddard Space Flight Center, Greenbelt,Maryland 20771, USA. 4Department of Physics and Astronomy, NewMexico State University, Las Cruces, NewMexico 88003, USA.

2003 2004 2005Time (year)

2006

HSV2 TSP

R

To Sun

T

2007 2008

2003 2004 2005Time (year)

2006 2007 2008

85

68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85

101

100

10–1

101

100

10–1

10–2

10–3

10–4

101

100

10–1

101

100

10–1

10–2

10–3

10–4

86

Str

eam

ing

inde

x,(A

+B)/(

2C)

Pro

ton

inte

nsity

(cm

2 s

sr M

eV)–

1S

trea

min

g in

dex,

C/A

Pro

ton

inte

nsity

(cm

2 s

sr M

eV)–

1

87 88 89 90

V1 TSP1 V1 TSP2 Heliosheath

91 92 93 94 95

Distance of Voyager 1 from Sun (AU)

Distance of Voyager 2 from Sun (AU)

Voyager 1

Voyager 2

96

H 0.5–0.7 MeV

H 0.5–0.7 MeV

H 3.3–7.8 MeV

H 3.3–7.8 MeV

(A+B)/2A

BC

CC

A

A

C

97 98

R

T

To Sun

99 100 102 104

a

b

c

d

Figure 1 | Daily-averaged intensities andstreaming of energetic termination shockparticles that are accelerated at nearby regions ofthe shock. Voyager 1 and Voyager 2 crossed theshock and entered the heliosheath on 2004.96 (16December 2004) at heliographic coordinates of(34.3u, 173u) and on 2007.66 (30 August 2007) at(227.5u, 216u), respectively. Insets, telescope (A, Band C) viewing directions projected into the R–Tplane, where2R is towards the Sun and T isazimuthal. Error bars on black filled circles,61s.d.a, The proton intensities (H) at 3.3–7.8MeVobserved byVoyager 1 particle telescopes (A1B)/2(blue trace) and by C (red trace) are highly variableupstream of the shock owing to variations in theconnectivity along the spiral field line28,29. Theenergetic ions are convected into the heliosheath,resulting in reduced variations. Similar propertiesare apparent in the intensity of 0.5–0.7MeVprotons observed by telescope A (black filledcircles) and shown when the backgroundcorrection was,60%. V1 TSP1 and V1 TSP2, twoepisodes of termination shock particles observedby Voyager 1. b, The streaming index (A1B)/(2C)for 3.3–7.8MeV protons shows that upstream theions at Voyager 1 were strongly beamed in the –Tdirection,with intensities in the oppositelydirecteddetectors differing by up to a factor of 10. Theintensities are more nearly isotropic in theheliosheath. Blue indicates that the averageintensity in telescopes A and B exceeds that in C,indicating flow in the–Tdirection; red indicates theopposite. c, Same as a for Voyager 2 except thatonly telescopesAandCareused indetermining thedirectional intensities of 3.3–7.8MeV protons.d, Same as b for Voyager 2 except that onlytelescopes A and C are used. The upstreambeaming was mainly in the1T direction, oppositeto that observed by Voyager 1 and consistent withthe predicted east–west shock asymmetry resultingfroma local interstellarmagnetic field5,6,30. Voyager2 began observing upstream energetic ions at 75 AU

from the Sun1, 10 AU closer than did Voyager 1,leading to predictions that the shock would becloser in the southern hemisphere than in thenorth, but with significant differences in thepredicted asymmetry5–7. HS, heliosheath.

Vol 454 |3 July 2008 |doi:10.1038/nature07022

71 ©2008 Macmillan Publishers Limited. All rights reserved

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9

LETTERS

An asymmetric solar wind termination shockEdward C. Stone1, Alan C. Cummings1, Frank B. McDonald2, Bryant C. Heikkila3, Nand Lal3 &William R. Webber4

Voyager 2 crossed the solar wind termination shock at 83.7 AU inthe southern hemisphere, 10 AU closer to the Sun than found byVoyager 1 in the north1–4. This asymmetry could indicate an asym-metric pressure from an interstellar magnetic field5,6, from tran-sient-induced shock motion7, or from the solar wind dynamicpressure. Here we report that the intensity of 4–5MeV protonsaccelerated by the shock near Voyager 2 was three times thatobserved concurrently by Voyager 1, indicating differences inthe shock at the two locations. (Companion papers report on the

plasma8, magnetic field9, plasma-wave10 and lower energy par-ticle11 observations at the shock.) Voyager 2 did not find the sourceof anomalous cosmic rays at the shock, suggesting that the sourceis elsewhere on the shock12–14 or in the heliosheath15–19. The smallintensity gradient of Galactic cosmic ray helium indicates thateither the gradient is further out in the heliosheath20 or the localinterstellar Galactic cosmic ray intensity is lower than expected21.

Low energy ions accelerated at the termination shock are observedupstream of the shock and in the heliosheath (Fig. 1). Voyager 2

1California Institute of Technology, Pasadena, California 91125, USA. 2Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742, USA.3NASA/Goddard Space Flight Center, Greenbelt,Maryland 20771, USA. 4Department of Physics and Astronomy, NewMexico State University, Las Cruces, NewMexico 88003, USA.

2003 2004 2005Time (year)

2006

HSV2 TSP

R

To Sun

T

2007 2008

2003 2004 2005Time (year)

2006 2007 2008

85

68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85

101

100

10–1

101

100

10–1

10–2

10–3

10–4

101

100

10–1

101

100

10–1

10–2

10–3

10–4

86

Str

eam

ing

inde

x,(A

+B)/(

2C)

Pro

ton

inte

nsity

(cm

2 s

sr M

eV)–

1S

trea

min

g in

dex,

C/A

Pro

ton

inte

nsity

(cm

2 s

sr M

eV)–

1

87 88 89 90

V1 TSP1 V1 TSP2 Heliosheath

91 92 93 94 95

Distance of Voyager 1 from Sun (AU)

Distance of Voyager 2 from Sun (AU)

Voyager 1

Voyager 2

96

H 0.5–0.7 MeV

H 0.5–0.7 MeV

H 3.3–7.8 MeV

H 3.3–7.8 MeV

(A+B)/2A

BC

CC

A

A

C

97 98

R

T

To Sun

99 100 102 104

a

b

c

d

Figure 1 | Daily-averaged intensities andstreaming of energetic termination shockparticles that are accelerated at nearby regions ofthe shock. Voyager 1 and Voyager 2 crossed theshock and entered the heliosheath on 2004.96 (16December 2004) at heliographic coordinates of(34.3u, 173u) and on 2007.66 (30 August 2007) at(227.5u, 216u), respectively. Insets, telescope (A, Band C) viewing directions projected into the R–Tplane, where2R is towards the Sun and T isazimuthal. Error bars on black filled circles,61s.d.a, The proton intensities (H) at 3.3–7.8MeVobserved byVoyager 1 particle telescopes (A1B)/2(blue trace) and by C (red trace) are highly variableupstream of the shock owing to variations in theconnectivity along the spiral field line28,29. Theenergetic ions are convected into the heliosheath,resulting in reduced variations. Similar propertiesare apparent in the intensity of 0.5–0.7MeVprotons observed by telescope A (black filledcircles) and shown when the backgroundcorrection was,60%. V1 TSP1 and V1 TSP2, twoepisodes of termination shock particles observedby Voyager 1. b, The streaming index (A1B)/(2C)for 3.3–7.8MeV protons shows that upstream theions at Voyager 1 were strongly beamed in the –Tdirection,with intensities in the oppositelydirecteddetectors differing by up to a factor of 10. Theintensities are more nearly isotropic in theheliosheath. Blue indicates that the averageintensity in telescopes A and B exceeds that in C,indicating flow in the–Tdirection; red indicates theopposite. c, Same as a for Voyager 2 except thatonly telescopesAandCareused indetermining thedirectional intensities of 3.3–7.8MeV protons.d, Same as b for Voyager 2 except that onlytelescopes A and C are used. The upstreambeaming was mainly in the1T direction, oppositeto that observed by Voyager 1 and consistent withthe predicted east–west shock asymmetry resultingfroma local interstellarmagnetic field5,6,30. Voyager2 began observing upstream energetic ions at 75 AU

from the Sun1, 10 AU closer than did Voyager 1,leading to predictions that the shock would becloser in the southern hemisphere than in thenorth, but with significant differences in thepredicted asymmetry5–7. HS, heliosheath.

Vol 454 |3 July 2008 |doi:10.1038/nature07022

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Galactic Cosmic Rays and the Heliosphere

6

Paolo Maestro

In  August  2012,  Voyager  1  entered  the  LISM

#875 Stone

For the first time, GCR were measured in their unmodulated state

7

Paolo Maestro

The  heliosphere  is  a  shield  that  excludes  >75%  of  the  GalacDc  Cosmic  Rays  with  >70  MeV

CRS

Mainly  >70  MeV  protons  

Galactic Cosmic Rays

Termination shock

August 25, 2012Interstellar Space

8

Paolo Maestro

Cosmic Rays >70 MeV from outside

Heliospheric ions0.5-30 MeV

2012CRS

Cosmic rays from outside increased at same time as ions from inside escaped

The transition was complex over ~30 days and ~0.3 AU

9

Paolo Maestro 10

Similar spectra with H/He=12 from 3-300 MeV/nNo low energy turn-up: no recent nearby sourceH and He spectra broad peak at the same energy/n implying spectra are not affected by solar modulation. Supports idea that Voyager is in LISM.

Ionization rate only 1.5x10-17, not 1.8x10-16 s-1 in molecular clouds 10

Paolo Maestro 11

V1  spectra  for  2012/342-­‐2014/365  for  Li  –  Ni  together  with  high-­‐energy  HEAO-­‐3-­‐C2  data  (>=  3.35  GeV/nuc).  Models  are  constrained  by  the  new  Voyager  observaDons  and  by  the  HEAO  observaDons.  All  calculaDons  of  ionizaDon  rate  and  energy  density  use  the  models,  starDng  at  3  MeV/n.

#702 Cummings

11

Proceedings of ICRC 2001: 3769 c� Copernicus Gesellschaft 2001 ICRC 2001

Solar modulation of the galactic cosmic ray spectra since theMaunder minimumG. Bonino1, G. Cini Castagnoli1, D. Cane1, C. Taricco1, and N. Bhandari21Dipartimento di Fisica Generale, Universit di Torino and Istituto di Cosmogeofisica, CNR, To rino, Italy2Physical Research Laboratory, Ahmedabad, India

Abstract. Investigations on the galactic cosmic ray (GCR) flux in the past centuries are important for understanding the heliospheric modulation effects during prolonged solar quiet periods like the Gleissberg minima and the Maunder minimum of solar activity. We inferred the GCR annual mean spectra on the basis of the following data: primary spectra of cosmic rays obtained from balloon and spacecraft measurements during different phases of the solar cycles # 20-23; the Climax neutron monitor time series available since 1953; variation of the annual means of the coronal source magnetic flux as derived from the aa index available since 1868 and of the evolution of the Sun's large scale magnetic field; the sunspot number time series from 1600. The differential flux of the galactic cosmic ray JG(T,M) (particles/m2 s sr MeV) has been characterized by the parameter M (MeV), the energy lost by particles in traversing the heliosphere, which depends on the modulation by the solar magnetic field. The relations among these data sets were extrapolated back to 1700. 1 Introduction The GCR flux modulated by the solar activity and measured at 1 AU shows well established periodicities from days to decades. The 11 year cycle, in addition to the direct measurement of primary and secondary cosmic rays, is clearly shown by the cosmogenic 22Na (T!=2.6 yr) in meteorites which fell in the last decades (Evans et al., 1982; Bhandari et al., 1994; Bonino et al., 1997) and by 10Be measured in Greenland ice core (Beer et al., 1990). All these measurements show a clear anticorrelation between the GCR flux and the sunspot number R series. A century scale modulation (Gleissberg cycle), expected by the R series, has been shown in the cosmogenic 44Ti (T!=59.2 yr) activity measured in meteorites which fell in the last two centuries (Bonino et al., 1995; 1999) and in the time series of 14C in tree rings (e.g. Damon and Sonett, 1991). Correspondence to: G. Bonino (bonino@ph.unito.it)

The century scale modulation of GCR recorded both in meteorites and in terrestrial archives shows that during prolonged solar quiet periods, like the Gleissberg minima, the cosmogenic radionuclide concentrations were higher than during the short lasting recent decadal minima. In terrestrial archives these concentrations may be also controlled by Earth’s effects such as deposition rate variations of the 10Be in ice cores, carbon cycle variations for 14C, etc., while in meteorites, being produced in space, they are free from terrestrial influences. We observed that the 44Ti variations from century minima and maxima are about four time higher than calculated on the basis of the GCR flux measured in the last decades and extrapolated in the past simply on the basis of the sunspot number (Bonino et al., 1995; 1999). We present here a different procedure for the calculation of the GCR spectra based on the annual mean of the coronal source magnetic flux as derived from the aa index (Lockwood et al., 1999) and of the evolution of the Sun’s large scale magnetic field (Solanki et al., 2000). The calculated GCR flux, extrapolated back to 1700, can be validated with our measurements of the 44Ti activity in meteorites which fell in the last two centuries. 2 GCR Spectra and the solar modulation parameter Comparison of the sunspot number R with the Climax neutron monitor counting rate, available since 1953, shows an anticorrelation between the two time series. However it is also known that the solar modulation processes are more complex than a simple anticorrelation with the solar activity indexed by some parameter like R. The modulation is larger at lower GCR energies and has little influence on high energy particles (> 10 GeV/n). The modulation of GCR as a function of position, energy and time in the heliosphere is a complex combination of different mechanism (e.g. Jokipii, 1991; Potgieter, 1993). Models of the inward transport of GCR have been successful. However, because of the complexity of the

3770

modulation dynamics they do not allow to determine unambiguously the GCR fluxes for any solar activity cycle. We have to look at a theoretical model which gives a good fit with the observed modulation at different energies and for different solar cycles. Cini Castagnoli and Lal (1980) adopted the force field approximate solution of the transport equation as given by Urch and Gleason (1972). The differential flux JG(T,M) (particles/m2 s sr MeV) of protons is given in terms of the solar modulation parameter M:

!+

+!=

)()2(109.9),( 08

MTETTMTJG

)2(

))105.2(exp780(0

65.24

EMTTMT

++

!"!++!

""

(1)

where T is the kinetic energy per nucleon and E0 is the rest energy of a nucleon. Since solar cycle 20, several balloon and spacecraft observations of GCR protons are available. We considered here 29 experimental spectra covering the time interval 1963-1998 for our calculations. For each experiment we have obtained the corresponding solar modulation parameter M from the best fit of the experimental JG(T) with Eq. (1). Fig. 1 shows some comparison of the fitted JG spectra with the experimental values, obtained in 1965 (Ormes and Webber 1968), 1968 (Hsieh et al., 1971), 1980 (Kroeger, 1986), 1989 (Webber et al., 1991) and giving M =390, 600, 820, 1080 MeV, respectively. We can observe a quite good agreement between measured and calculated JG.

3. Extrapolation of the GCR spectra In previous papers (Bhandari et al., 1989; Bonino et al., 1995) we have calculated JG(t) over the last two centuries with the following procedure. The polynomial regression between the Climax neutron monitor count rate Nm(t) and the annual sunspot number, R, for the period 1953 to 1992 was extrapolated back to 1750 from R(t). JG(t) was then calculated by a linear regression between Climax neutron monitor count rates normalized to that of January 1965 (4291.7 counts/h*100=1) and balloons measurements of GCR protons during solar cycles 20 and 21. JG(t) extrapolated to 1750 was utilized for calculation of the expected activity of the cosmogenic 44Ti in meteorites by means of isotope production model. Although the calculated absolute activity may be model dependent, its variation is function of JG(t). We compared the calculate profile with the 44Ti activity measured by us in several chondrites which fell in the last 160 years. We observed that the phase of the measured profile agreed with that expected, but the amplitude of the secular excursions was about four time higher then calculated. We deduced that during prolonged solar minima, such as Dalton and Modern minima, the heliosphere admitted a higher GCR flux compared to that deduced from observations in the last decades and extrapolated in the past, solely by sunspot number R(t), following the procedure reported above (Bonino et al., 1995; 1999). We evaluate here the GCR spectra in the past on the basis

0.001

0.01

0.1

1

10

10 100 1000 10000 100000Energy (MeV)

Jg (p

roto

ns m

-2 s

-1 s

r-1 M

eV-1

)

1965 1968 1980 1989

390 MeV

1080 MeV

600 MeV

820 MeV

M

Fig. 1. Differential cosmic-ray spectra obtained from Eq. (1) for different values of the solar modulation parameter M = 390, 600, 820, 1080 MeV corresponding to the measurements performed with balloons or spacecrafts during 1965, 1968, 1980 and 1989 respectively.

3771

of the recent evaluation of the Sun’s magnetic field since 1700 and following the procedure reported below. Lockwood et al. (1999) showed that the solar magnetic flux emanating through the coronal source, as derived from the aa geomagnetic index available since 1868, has about doubled in the past 100 years. Solanki et al. (2000) developed a model describing the long-term evolution of the Sun’s large-scale magnetic field, !0, which reproduces the doubling of the interplanetary field and evaluated the evolution of !0 since 1700.

On the basis of these new results and following basically our procedure reported above we have calculated the GCR spectra until 1700. From a linear regression between the Climax Nm and !0 (since 1953) and a quadratic regression between the solar modulation parameter M and the normalized Nm* for the years of the balloon and spacecrafts measurements of GCR protons (covering the time interval 1963-1998) we deduced JG(T,t). Then we extrapolated JG to 1700 on the basis of these regressions and of !0 given by Solanki et al. (2000). Fig. 2 shows JG(t) for different "T.

0.0

0.5

1.0

1.5

2.0

2.5

1700 1750 1800 1850 1900 1950 2000year

Jg (p

roto

ns c

m-2

4#

sr-1

)

100 -200 MeV 200 -400 MeV400 -800 MeV

0.0

0.5

1.0

1.5

2.0

2.5

1700 1750 1800 1850 1900 1950 2000year

Jg (p

roto

ns c

m-2

4#

sr-1

)

800 -1600 MeV 1600 -3200 MeV3200 -6400 MeV 6400 -12800 MeV12800 -25600 MeV

Fig. 2. Proton flux JG(t): a) for the kinetic energy intervals "T = 100-200 MeV, 200-400 MeV, 400-800 MeV; b) for "T = 800-1600 MeV, 1600-3200 MeV, 3200-6400 MeV, 6400-12800 MeV, 12800-25600 MeV.

a)

b)

12

Carbon 14 method

decay of 14Chalf life time 5730 years

14C à 14N + e-

14N + 1n à 14C + 1p

formation of 14C

13

Carbon 14 method

decay of 14Chalf life time 5730 years

14C à 14N + e-

14N + 1n à 14C + 1p

formation of 14C

14

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Solar flares

15

32nd International Cosmic Ray Conference, Beijing 2011

Data Analysis

Events selectionChoose good single track

1 hodoscope has hits both the Upper and Lower TOFOnly 1 track in the Drift Chambers

Require track qualityParticle Identification

TOF-β selection|Z| = 2 selection

m = ZeR 1/β2 -1

32nd International Cosmic Ray Conference, Beijing 2011

BESS-Polar: Search for antihelium #1230Sasaki

32nd International Cosmic Ray Conference, Beijing 2011

Search ResultParticle Identification using the TOF information

No antihelium candidate was found between -14 and -1 GV after all selection among 4 x 107 Helium events.

The figure below shows remaining events after all selections applied.

TOF-β selection

|Z| = 2 selectionUpper TOF

|Z| = 2 selectionLower TOF

After all selection

No He candidate

-14GV

32nd International Cosmic Ray Conference, Beijing 2011

32nd International Cosmic Ray Conference, Beijing 2011

Limit and Summary• BESS-Polar I antihelium upper limit 4.4 x 10-7.

• We set the upper limit of 9.4 x 10-8 by using the BESS-Polar II flight data.

• We set the upper limit of 6.9x 10-8 by using all BESS flight data.

• This limit is two orders of magnitude improvement since our first report.

X 1/100

32nd International Cosmic Ray Conference, Beijing 2011

16

Search for cosmic-ray antideuterons with BESS-Polar

#1259Yoshimura

Apply the same selection as deuteron selection.

Box has not be fully opened except the BG-free region yet....

NO Antideuteron was found in rigidity below 2.5 GeV/c.

(K.E. ~ 0.62 GeV/nucleon)

p

eμ!

Rigidity (GV)

No d

Negative curvature

0.62 GeV/n

17

The TRACER Detector

Summary of Measurements with TRACER

� Two LDB flights� Antarctica 2003,.� Sweden 2006.

� Ten elements� 5 ≤ Z ≤ 26.� Primary > 1014 eV.� Boron > 1013 eV.

� Dashed line� Power-law fit.� Average exponent 2.65.

� Measurements arestatistics limited

� TRD not saturated. 1 10 10 2 10 3 10 4 10 5 10 610

-22

10-19

10-16

10-13

10-10

10-7

10-4

10-1

10 2

10 5

10 8

10 11

Kinetic Energy (GeV)

Flux

(m2 s

r s G

eV-1

)B

C

O

NeMgSi

SAr

CaFe

x 1011

x 108

x 105

x 103

x 101

x 10-1

x 10-3

x 10-5

x 10-7

x 10-10

P.J. Boyle for TRACER (UofC, EFI) New Measurements with TRACER 15. August ’11 - ICRC, Beijing (China) 11 / 11

TRACER: Energy spectra for individual elements

P. Boyle et al., ICRC 2011

TRACER 2003

TRACER 2006

A. Obermeier et al., ApJ 752 (2012) 69

18

2 24. Cosmic rays

where E is the energy-per-nucleon (including rest mass energy) and α (≡ γ + 1) = 2.7is the differential spectral index of the cosmic ray flux and γ is the integral spectralindex. About 79% of the primary nucleons are free protons and about 70% of the rest arenucleons bound in helium nuclei. The fractions of the primary nuclei are nearly constantover this energy range (possibly with small but interesting variations). Fractions of bothprimary and secondary incident nuclei are listed in Table 24.1. Figure 24.1 shows themajor components for energies greater than 2 GeV/nucleon.

Figure 24.1: Major components of the primary cosmic radiation from Refs. [1–12].The figure was created by P. Boyle and D. Muller. Color version at end of book.

The composition and energy spectra of nuclei are typically interpreted in the contextof propagation models, in which the sources of the primary cosmic radiation are locatedwithin the galaxy [13]. The ratio of secondary to primary nuclei is observed to decreasewith increasing energy, a fact interpreted to mean that the lifetime of cosmic rays in thegalaxy decreases with energy. Measurements of radioactive “clock” isotopes in the lowenergy cosmic radiation are consistent with a lifetime in the galaxy of about 15 Myr.

July 30, 2010 14:36

19

20

!"!"

!"#$ %&'(()*+,,*-

e- only

21

! !"#$%&'( )* +,&##(#*% -)%. /%.#&0 1 0/2%#&0"#$%&'( +3/4# 56 7#80"#$%&'( +3/4# 6 7#8

9696

!"#$ %&'()*

e- & e+

22

23

24

25

Relative abundance of elements at Earth

~ 1 GeV/n

Si = 100

JRH, Adv. Space Res. 41 (2008) 442

àCosmic rays are „regular matter“, accelerated to extremely high energies

26

Origin of the Elements

~ 1 GeV/n

Si = 100

big bang cosmology

stellar burningfussionstellar burningfussion

stellar burningfusion

supernova explosions

27