1. High energy cosmic rays
Roberta Sparvoli
Rome “Tor Vergata” University
and INFN, ITALY
Nijmegen 2012

2. SATELLITE and ISS EXPERIMENTS FUTURE activities
Lecture # 2 : outline
SATELLITE and ISS EXPERIMENTS
FUTURE activities

3. Satellite flights

4. PAMELA Payload for Matter/antimatter Exploration and Light-nuclei Astrophysics
Direct detection of CRs in space
Main focus on antiparticles (antiprotons and positrons)
PAMELA on board of Russian satellite Resurs DK1
Orbital parameters:
inclination ~70o ( low energy)
altitude ~ km (elliptical)
active life >6 years ( high statistics)
 Launched on 15th June 2006
 PAMELA in continuous data-taking mode since then!
Launch from Baykonur

5. PAMELA detectors + - Main requirements:
PAMELA detectors
Time-Of-Flight
plastic scintillators + PMT:
Trigger
Albedo rejection;
Mass identification up to 1 GeV;
- Charge identification from dE/dX.
Electromagnetic calorimeter
W/Si sampling (16.3 X0, 0.6 λI)
Discrimination e+ / p, anti-p / e-
(shower topology)
Direct E measurement for e-
Neutron detector
36 He3 counters :
High-energy e/h discrimination
Main requirements:
- high-sensitivity antiparticle identification
- precise momentum measurement
Overview of the apparatus
Spectrometer
microstrip silicon tracking system permanent magnet
It provides:
- Magnetic rigidity  R = pc/Ze
Charge sign
Charge value from dE/dx
GF: 21.5 cm2 sr Mass: 470 kg
Size: 130x70x70 cm3
Power Budget: 360W

6. Flight data:
0.169 GV electron
0.171 GV positron

7. Antiparticles
SECONDARY ORIGIN, COMING FROM INTERACTION OF PRIMARy CR WITH THE INTERSTELLAR MEDIUM

8. Antiprotons Antiproton/proton identification:
Negative/positive curvature in the spectrometer
 p-bar/p separation
Rejection of EM-like interaction patterns in the calorimeter
 p-bar/e- (and p/e+ ) separation
Main issue:
Proton “spillover” background:
wrong assignment of high energy due to finite spectrometer resolution
Strong tracking requirements
Spatial resolution < 4mm
R < MDR/10
Residual background subtraction
Evaluated with simulation (tuned with in-flight data)
~30% above 100GeV
Antiprotons

9. Antiproton flux Largest energy range covered hiterto
(Donato et al. 2001)
Diffusion model with convection and reacceleration
Uncertainties on propagation param . and c.s.
Solar modulation: spherical model ( f=500MV )
Antiproton flux
Largest energy range covered hiterto
Overall agreement with pure secondary calculation
Experimental uncertainty (statsys) smaller than spread in theoretical curves  constraints on propagation parameters
Adriani et al. - PRL 105 (2010)
Dotted lines: (Donato et al 2001) uncertainty band of propagation parameters for different diffusion models
Dashed lines: (Donato et al 2001) uncertanty band of production cross section
Solid line: (Ptuskin et al 2006) plain diffusion model
(Ptuskin et al. 2006) GALPROP code
Plain diffusion model
Solar modulation: spherical model ( f=550MV )

10. Antiproton-to-proton ratio
Adriani et al. - PRL 105 (2010)
Overall agreement with pure secondary calculation
Very stringent constraints
to exotic production mechanisms!

11. New antiproton/proton ratio
Preliminary
Using all data till 2010 and multivariate classification algorithms 20-50% increase in respect to published analysis

12. New positron fraction data
Preliminary
Using all data till 2010 and multivariate classification algorithms about factor 2-3 increase in respect to published analysis

13. Positrons Positron/electron identification:
Positive/negative curvature in the spectrometer
 e-/e+ separation
EM-like interaction pattern in the calorimeter
 e+/p (and e-/p-bar) separation
Main issue:
Interacting proton background:
fluctuations in hadronic shower development: p0 gg mimic pure e.m. showers
p/e+:
Robust e+ identification
Shower topology + energy-rigidity match
Residual background evaluation
Done with flight data
No dependency on simulation
Positrons S1 S2
CALO S4
CARD
CAS
CAT
TOF
SPE S3 ND

14. 32.3 GV positron

15. Positron fraction Low energy  charge-dependent solar modulation
Adriani et al. , Nature 458 (2009) 607
Adriani et al., AP 34 (2010) 1 (new results)
Positron fraction
Low energy  charge-dependent solar modulation
High energy  (quite robust) evidence of positron excess above 10 GeV
(Moskalenko & Strong 1998)
GALPROP code
Plain diffusion model
Interstellar spectra

16. Adriani et al. , Nature 458 (2009) 607
Adriani et al., AP 34 (2010) 1 (new results)
Positron fraction
Low energy  charge-dependent solar modulation (see tomorrow)
High energy  (quite robust) evidence of positron excess above 10 GeV
(Moskalenko & Strong 1998)
GALPROP code
Plain diffusion model
Interstellar spectra

17. New positron fraction data
Preliminary
Using all data till 2010 and multivariate classification algorithms about factor 2-3 increase in respect to published analysis

18. Positron Flux

19. A challenging puzzle for CR physicists
Positrons
 Evidence for an excess
Antiprotons
 Consistent with pure secondary production

20. Positron-excess interpretations
(Cholis et al. 2009)
Contribution from DM annihilation.
Positron-excess interpretations
Dark matter
boost factor required
lepton vs hadron yield must be consistent with p- bar observation
Astrophysical processes
known processes
large uncertainties on environmental parameters
(Hooper, Blasi and Serpico, 2009)
contribution from diffuse mature & nearby young pulsars.
(Blasi 2009)
e+ (and e-) produced as secondaries in the CR acceleration sites (e.g. SNR)

21. Interpretation: DM Which DM spectra can fit the data?
M. Cirelli et al., Nucl. Phys. B 813 (2009) 1; arXiv: v3
Which DM spectra can fit the data?
DM with and dominant annihilation channel (possible candidate: Wino)‏
positrons
antiprotons
Yes!
No!

22. Interpretation: DM Which DM spectra can fit the data?
M. Cirelli et al., Nucl. Phys. B 813 (2009) 1; arXiv: v3
Which DM spectra can fit the data?
DM with and dominant annihilation channel (no “natural” SUSY candidate)‏
But B≈104
positrons
antiprotons
Yes!
Yes!

23. Interpretation: DM DM with and dominant annihilation channel
M. Cirelli et al., Nucl. Phys. B 813 (2009) 1; arXiv: v3
DM with and dominant annihilation channel
positrons
antiprotons
Yes!
Yes!
Yes!

24. Interpretation: DM
I. Cholis et al. Phys. Rev. D 80 (2009) ; arXiv: v1

25. Astrophysical Explanation: SNR
Positrons (and electrons) produced as secondaries in the sources (e.g. SNR) where CRs are accelerated.
But also other secondaries are produced: significant increase expected in the p/p and B/C ratios.
P.Blasi et al., PRL 103 (2009) arXiv:

26. Astrophysical Explanation: Pulsars
Are there “standard” astrophysical explanations of the high energy positron data?
Young, nearby pulsars
Geminga pulsar
Not a new idea: Boulares, ApJ 342 (1989), Atoyan et al (1995)‏

27. Astrophysical Explanation: Pulsars
Mechanism: the spinning B of the pulsar strips e- that accelerated at the polar cap or at the outer gap emit γ that make production of e± that are trapped in the cloud, further accelerated and later released at τ ~ 105 years.
Young (T < 105 years) and nearby (< 1kpc)
If not: too much diffusion, low energy, too low flux.
Geminga: 157 parsecs from Earth and 370,000 years old
B : 290 parsecs from Earth and 110,000 years old.
Diffuse mature pulsars

28. Astrophysical Explanation: Pulsars
H. Yüksak et al., arXiv: v2
Contributions of e- & e+ from Geminga assuming different distance, age and energetic of the pulsar
diffuse mature &nearby young pulsars
Hooper, Blasi, and Serpico arXiv:
Mirko Boezio, Innsbruck, 2012/05/29

29. How to clarify the matter?
Courtesy of J. Edsjo

30. Positrons vs antiprotons
(Strong & Moskalenko 1998)
GALPROP code +
(Kane et al. 2009)
Annihilation of 180 GeV wino-like neutralino
consistent with PAMELA positron data
Positrons vs antiprotons
Large uncertainties on propagation parameters allows to accommodate an additional component
A p-bar rise above 200GeV is not excluded
Adriani et al. - PRL 105 (2010)
(Blasi & Serpico 2009)
p-bar produced as secondaries in the CR acceleration sites (e.g. SNR)
consistent with PAMELA positron data
Dashed line: additional primary antiprotons from 180GeV wino-like neutralinos (Kane et al. 2009). Model tuned to explain positron excess
Dashed-dotted: GALPROP with proper choice of propagation parameters to accommodate wino-signal
Continuous line: production of acceleration sites (Blasi&Serpico 2009). Model tuned to describe positron excess without assuming a primary component
Dotted lines: limits for pure secondary production for diffusion-reacceleration-convection model (Donato et al 2009)
(Donato et al. 2009)
Diffusion model with convection and reacceleration

31. Theoretical uncertainties on “standard” positron fraction
γ = 3.54
γ = 3.34
Flux=A • E-
T. Delahaye et al., Astron.Astrophys. 501 (2009) 821; arXiv: v3

32. Absolute fluxes of primary GCRs
Needed for:
identify sources and acceleration propagation mechanisms of cosmic rays;
estimate the production of secondary particles, such as positrons and antiprotons, in order to disentangle the secondary particle component from possible exotic sources;
estimate the particle flux in the geomagnetic field and in Earth's atmosphere to derive the atmospheric muon and neutrino flux.

33. Adriani et al. , Science 332 (2011) 6025
H & He absolute fluxes
First high-statistics and high-precision measurement over three decades in energy
Dominated by systematics (~4% below 300 GV)
Low energy  minimum solar activity (f = 450÷550 GV)
High-energy  a complex structure of the spectra emerges…

34. P & He absolute fluxes @ high energy
2.85
2.67
232 GV
Spectral index
P & He absolute high energy
2.77
2.48
243 GV
Deviations from single power law (SPL):
Spectra gradually soften in the range 30÷230GV
Abrupt spectral hardening @ ~235 GV
Eg: statistical analysis for protons
SPL hp in the range 30÷230 GV >95% CL
SPL hp above 80 GV >95% CL
Solar modulation
Solar modulation ? ?
Standard scenario of SN blast waves expanding in the ISM needs additional features

35. H/He ratio vs R Instrumental p.o.v.
Systematic uncertainties partly cancel out (livetime, spectrometer reconstruction, …)
Theoretical p.o.v.
Solar modulation negligible  information about IS spectra down to GV region
Propagation effects (diffusion and fragmentation) negligible above ~100GV  information about source spectra
(Putze et al. 2010)

36. P/He ratio vs R aHe-ap = 0.078 ±0.008 c2~1.3
First clear evidence of different H and He slopes above ~10GV
Ratio described by a single power law (in spite of the evident structures in the individual spectra)
aHe-ap = ±0.008
c2~1.3

37. 2H and 1H flux H/1H
Preliminary

38. 3He and 4He flux He/4He
Preliminary

39. 2H/4He

40. Boron and Carbon nuclei spectra

41. Anisotropy studies (p up to 1 TeV)

46. Electrons
Needed for:
Recalculathe the expected positron fraction with better accuracy
Closeby sources?

47. Results from ATIC

48. FERMI All-Electron Spectrum
Theoretical uncertainties on “standard” positron fraction
FERMI e+ + e- flux (2009)
A. Abdo et al., Phys.Rev.Lett. 102 (2009)
M. Ackermann et al., Phys. Rev. D 82, (2010)

49. Electrons measured with H.E.S.S.

50. Electron energy measurements
Adriani et al. , PRL 106, (2011)
Electron energy measurements
spectrometer
Two independent ways to determine electron energy:
Spectrometer
Most precise
Non-negligible energy losses (bremsstrahlung) above the spectrometer  unfolding
Calorimeter
Gaussian resolution
No energy-loss correction required
Strong containment requirements  smaller statistical sample
calorimeter
Electron identification:
Negative curvature in the spectrometer
EM-like interaction pattern in the calorimeter

51. Electron absolute flux
e+ +e- e-
Adriani et al. , PRL 106, (2011)
Largest energy range covered in any experiment hitherto with no atmospheric overburden
Low energy
minimum solar activity (f = 450÷550 GV)
High energy
No significant disagreement with recent ATIC and Fermi data
Softer spectrum consistent with both systematics and growing positron component
Spectrometric measurement
Calorimetric measurements

52. New data: PAMELA Electron & Positron Spectra
Preliminary
Flux=A • E-
 = 3.18 ±0.04
Flux=A • E-
 = 2.70 ±0.15

53. (e+ + e- ) absolute flux ONLY AN EXERCISE ……..
Compatibility with FERMI (and ATIC) data
Beware: positron flux not measured but extrapolated from PAMELA positron flux!
Low energy discrepancies due to solar modulation

54. (e+ + e- ) absolute flux ONLY AN EXERCISE ……..
Compatibility with FERMI (and ATIC) data
Beware: positron flux not measured but extrapolated from PAMELA positron flux!
Low energy discrepancies due to solar modulation

55. Solar and terrestrial physics

56. Discovery of geomagnetically Trapped antiprotons
First measurement of p-bar trapped in the inner belt
29 p-bars discovered in SAA and traced back to mirror points
p-bar flux exceeds GRC flux by 3 orders of magnitude, as expected by models
Adriani et al. –APJ Letters 737 L29, 2011

57. Discovery of geomagnetically Trapped antiprotons
The geomagnetically trapped antiproton-to- proton ratio measured by PAMELA in the SAA region (red) compared with the interplanetary (black) antiproton-to-proton ratio measured by PAMELA, together with the predictions of a trapped model.

58. Solar modulation: p and He spectra

59. Solar modulation: e+ and e-

60. All particles PAMELA results
Results span 4 decades in energy and 13 in fluxes

61. FERMI OBSERVATORY

71. Orbiting Space Station

72. ALPHA MAGNETIC SPECTROMETER
Search for primordial anti-matter
Indirect search of dark matter
High precision measurement of the energetic spectra and composition of CR from GeV to TeV
AMS-01: (10 days) - PRECURSOR FLIGHT ON THE SHUTTLE
AMS-02: Since May 19th, 2011, safely on the ISS. Four days after the Endeavour launch, that took place on Monday May 16th, the experiment has been installed on the ISS and then activated.

COMPLETE CONFIGURATION FOR >10 YEARS LIFETIME ON THE ISS

73. » 500 physicists, 16 countries, 56 Institutes
AMS-02 : the collaboration
FINLAND
RUSSIA
HELSINKI UNIV.
UNIV. OF TURKU
I.K.I.
ITEP
KURCHATOV INST.
MOSCOW STATE UNIV.
DENMARK
NETHERLANDS
UNIV. OF AARHUS
ESA-ESTEC
NIKHEF
NLR
GERMANY
RWTH-I
RWTH-III
MAX-PLANK INST.
UNIV. OF KARLSRUHE
KOREA
USA
A&M FLORIDA UNIV.
JOHNS HOPKINS UNIV.
MIT - CAMBRIDGE
NASA GODDARD SPACE FLIGHT CENTER
NASA JOHNSON SPACE CENTER
UNIV. OF MARYLAND-DEPRT OF PHYSICS
UNIV. OF MARYLAND-E.W.S. S.CENTER
YALE UNIV. - NEW HAVEN
EWHA
KYUNGPOOK NAT.UNIV.
FRANCE
ROMANIA
CHINA
BISEE (Beijing)
IEE (Beijing)
IHEP (Beijing)
SJTU (Shanghai)
SEU (Nanjing)
SYSU (Guangzhou)
SDU (Jinan)
GAM MONTPELLIER
LAPP ANNECY
LPSC GRENOBLE
ISS
UNIV. OF BUCHAREST
SWITZERLAND
ETH-ZURICH
UNIV. OF GENEVA
TAIWAN
SPAIN
CIEMAT - MADRID
I.A.C. CANARIAS.
ITALY
ACAD. SINICA (Taiwan)
CSIST (Taiwan)
NCU (Chung Li)
NCKU (Tainan)
NCTU (Hsinchu)
NSPO (Hsinchu)
ASI
CARSO TRIESTE
IROE FLORENCE
INFN & UNIV. OF BOLOGNA
INFN & UNIV. OF MILANO
INFN & UNIV. OF PERUGIA
INFN & UNIV. OF PISA
INFN & UNIV. OF ROMA
INFN & UNIV. OF SIENA
MEXICO
UNAM
PORTUGAL
LAB. OF INSTRUM. LISBON
» 500 physicists, 16 countries, 56 Institutes
Y _1Commitment

74. The AMS-02 detector

75. AMS first events
42 GeV Carbon nucleus

76. FIRST AMS RESULT?
So far no physics results given by the collaboration to the science community;
First results expected for the the 4th  International Conference on Particle and Fundamental Physics in Space (SpacePart), which will take place at CERN from November 5th  to November 7th  2012.

77. Future experiments

78. CALET: Calorimetric Electron Telescope
Main Telescope: Calorimeter (CAL)
Electrons: 1 GeV – 20 TeV
Gamma-rays: 10 GeV – 10* TeV
(Gamma-ray Bursts: > 1 GeV)
Protons and Heavy Ions:
　　 several tens of GeV – 1,000* TeV
Ultra Heavy Ions： over the rigidity cut-off
Gamma-ray Burst Monitor (CGBM)
X-rays/Soft Gamma-rays: 7keV – 20MeV
(* as statistics permits)
CGBM
CAL
Science objectives:
Nearby cosmic-ray sources through electron spectrum in the trans-TeV region
Signatures of dark matter in electron and gamma-ray energy spectra in the 10 GeV – 10 TeV region
Cosmic ray propagation in the Galaxy through p – Fe energy spectra, B/C ratio, and UH ions measurements
Solar physics through electron flux below 10 GeV
Gamma-ray transient observations

79. CALET Payload Overview
CGBM/SGM
FRGF( Flight Releasable Grapple Fixture)
CGBM/HXM
ASC　(Advanced Stellar Compass)
CAL/CHD
GPSR　(GPS　Receiver)
Launch carrier: HTV-5
Launch target date: CY 2014
Mission period: More than 2 years
(5 years target)
MDC　(Mission Data Controller)
CAL/IMC
CAL/TASC
Mass: 650kg (Max)
Standard Payload Size
Power: 500W (Max)
Data rate:
Medium data rate: 300 kbps
Low data rate: 20 kbps

80. Main Telescope: CAL (Calorimeter)
450 mm
Shower particles
CHD (Charge Detector):
Double layer segmented plastic scintillator array (14 x 2 layer with a unit of 32mm x 10mm x 450mm)
Charge measurement (Z=1 – 40)
IMC (Imaging Calorimeter):
7 layers of tungsten plates with 3 r.l. separated by 2 layers of scintillating fiber belts which are readout by MA-PMT.
Arrival directions, Particle ID
TASC (Total Absorption Calorimeter):
12 layers of PWO logs (19mm x 20mm x 326mm) with total thickness of 27 r.l. The top layer is used for triggering and readout by PMT. Other layers are readout by PD/APD.
Energy measurement, Particle ID

81. Gamma-400 on Russian satellite
It will combine for the first time photon and particle (electrons and nuclei)
detection in a unique way
Excellent Silicon Tracker (30 MeV – 300 GeV),
breakthrough angular resolution 4-5 times better than Fermi-LAT at 1 GeV
improved sensitivity compared with Fermi-LAT by a factor of 5-10 in the energy range 30 MeV – 10 GeV
Heavy Calorimeter (25 X0) with optimal energy resolution and particle discrimination
Electron/positron detection up to TeV energies
Nuclei detection up to 1015 eV energies

83. Counts estimation, electrons
G400 configuration: CsI(Tl), 20x20x20 crystals
Size: 78.0x78.0x78.0 cm3 – gap 0.3 cm
Taking into account: geometrical factor and exp. duration +
selection efficiency 80%
Experiment
Duration
Planar GF (m2 sr)
Calo s(E)/E
Calo depth
e/p rejection factor
E > 0.5 TeV
E > 1 TeV
E > 2 TeV
E > 4 TeV
CALET
5 y
0,12
~2%
30 X0
105
3193
611 95 10
AMS02
10 y
0,5**
16 X0
103 **
26606
5091
794 84
ATIC
30 d
0,25
18 X0
104
109 21 3
FERMI
GeV *
GeV *
~15%
8,6 X0
59864
2545
G400
8,5
~0,9%
39 X0
106
452303
86540
13502
1436
* efficiencies included
** calorimeter standalone

84. Counts estimation, protons and helium nuclei
Polygonato model
G400 configuration: CsI(Tl), 20x20x20 crystals
Size: 78.0x78.0x78.0 cm3 – gap 0.3 cm
Taking into account: geometrical factor and exp. duration + selection
efficiency 80%
~ knee
Experiment
Duration
Planar GF
(m2 sr)
e sel
Calo s(E)/E
Calo depth
E > 0.1 PeV
E > 0.5 PeV
E > 1 PeV
E > 2 PeV
E > 4 PeV
e conv p He
CALET
5 y
0,12
0,8
~40%
30 X0 1,3 l0
146
138 9 10 2 3 1
0,5
CREAM
180 d
0,43
~45%
20 X0 1,2 l0 41 39
0,4 CT*
ATIC
30 d
0,25
~37%
18 X0 1,6 l0 5
0,5 CT*
TRACER -
TRD
200
189 12 13 4
G400
10 y
8,5
~20%
39 X0 1,8 l0
16521
15624
979
1083
261
326 60 92 21
0,4
* carbon target

85. Counts estimation, heavier nuclei (3 ≤ Z ≤ 24)
Polygonato model
G400 configuration: CsI(Tl), 20x20x20 crystals
Size: 78.0x78.0x78.0 cm3 – gap 0.3 cm
Taking into account: geometrical factor and exp. duration + selection
efficiency 80%
~ knee
Experiment
Duration
Planar GF (m2 sr)
e sel
Calo s(E)/E
Calo depth
E > 0.1 PeV
E > 0.5 PeV
E > 1 PeV
E > 2 PeV
E > 4 PeV
e conv
3Li to 9F
10Ne to 24Cr
CALET
5 y
0,12
0,8
~30%
30 X0 1,3 l0 68 70 5 1 2
0,5
CREAM
180 d
0,46
~45% **
20 X0 1,2 l0 21
0,4 CT*
ATIC
30 d
0,25
~37%
18 X0 1,6 l0
0,5 CT*
TRACER
TRD 93 96 6 7 -
G400
10 y
8,5
~17%
39 X0 1,8 l0
7698
7910
533
555
169
180 51 60 15 17
0,4
*carbon target
** better than 20% using TRD

86. ISS-CREAM
The idea is to put the CREAM detector, developed as a Long Duration balloon experiment, onboard the ISS, at the Japanese Experiment Modules Exposed Facility (JEM-EF) KIBO.
The 1,200 kg estimated mass of the payload is over twice the mass of any previously launched payload using the JAXA’s HTV. The development team will modify the existing instruments to meet the new requirements of the launch vehicle and ISS.
Very good chance to reach 1015 eV.

87. Conclusions High energy line Composition line
With respect to the standard GCR scenario, what have we learned by the recent direct measurements?
High energy line
H and He spectra are different
H and He spectra harden with energy (230 GV)
Hi-Z spectra might show similar hardening
Energy dependance of propagation still undecided
Composition line
Source matter must be a composition of old ISM with newly sinthetized matherial, in percentage 80%-20% (sites of acceleration rich in massive stars?)

88. Conclusions Antimatter line
All electron spectrum shows enhancement at high energy (hundreds GeV). Nearby source?
Positrons show enhancement in the E>10 GeV region (new e+ e- source. Correlated to previous?)
No antiproton excess observed both at low and high energy (several DM models and exotics ruled out)
No heavier anti-nucleus observed (very stringent limits)
New fresh data from AMS-02 could improve the understanding of some of the still open issues in the direct measurements sector
THANK YOU!