1. INFN & University of Roma “Tor Vergata”
PAMELA SPACE MISSION
20th ECRS Lisbon
Piergiorgio Picozza
Pamela collaboration
INFN & University of Roma “Tor Vergata”

2. PAMELA Payload for Antimatter Matter Exploration and Light Nuclei Astrophysics
Launched in orbit on June 15, 2006, on board of the DK1 satellite by a Soyuz rocket from the Bajkonour launch site.
From July 11 Pamela is in continuous data taking mode

3. PAMELA Collaboration Italy: Russia: Germany: Sweden: Bari Florence
Frascati
Italy:
Trieste
Naples
Rome
CNR, Florence
Russia:
Moscow
St. Petersburg
Germany:
Siegen
Sweden:
KTH, Stockholm

4. WiZard Russian Italian Missions
PAMELA

5. PAMELA Instrument ToF Anticoincidence shield Magnetic spectrometer
GF: 21.5 cm2 sr Mass: 470 kg
Size: 130x70x70 cm3
Power Budget: 360W
ToF
MAGNETIC SPECTROMETER
B=0.48T Nd-B-Fe
6 planes double sided
Si strips 300 m thick
Spatial resolution ~3m
MDR = 1 TV/c
IMAGING CALORIMETER
44 Si layers intervealed with 22 W planes
16.3 X0 / 0.6 l0
e+/p and p/e- at level of ~ 10-5
ANTICOINCIDENCE SHIELD
Scintillator paddles 10 mm thick
Dynamic range of 1÷1000 mip
NEUTRON DETECTOR
36 3He counters in polyetilen
moderators to discriminate between very high energy electron and proton components
SHOWER TAIL CATCHER SCINTILLATOR
Neutron Detector Trigger
TOF
First level trigger
Particle identification
(up to 1GeV/c)
dE/dx
Anticoincidence
shield
Magnetic spectrometer
Calorimeter
Shower tail catcher
Scintillator
Neutron Detector

6. PAMELA capabilities in 3 y. of operation
Particle
Number (3 yrs)
Energy Range
Protons
3.108
80 MeV – 700 GeV
Antiprotons
>3.104
80 MeV – 190 GeV
Electrons
6.106
50 MeV – 2 TeV
Positrons
>3.105
50 MeV – 270 GeV He
4.107
80 MeV/n – 700 GeV/n Be
4.104 C
4.105
Antihelium Limit
5.10-8
80 MeV/n – 30 GeV/n

8. Resurs-DK1 Spacecraft TsSKB-Progress

13. Ground Station(s)
Main Station: Research Centre for Earth Operative Monitoring “NtsOMZ” (Moscow, Russia);
Scheme of PAMELA control room in NTsOMZ
Main antenna in NTsOMZ
Additional Station: Khanty-Mansisky (Siberia, Russia). Not yet officially established.

14. Flight data: 2.8 GV electron

15. Flight data: 1.56 GV positron

16. Flight data: 4.2 GV electron
PAMELA event
Flight data: 4.2 GV electron

17. Flight data: ~500 GV electron

18. non-interacting proton
PAMELA event
Flight data: 14.4 GV
non-interacting proton

19. non interacting antiproton
Flight data: 15 GV
non interacting antiproton

20. PAMELA event
Flight data: 36 GV
interacting proton

21. PAMELA event
Flight data: 9.7 GV
non-interacting
Helium Nucleus

22. PAMELA event
Flight data: 13 GV
Interacting
Helium Nucleus

23. Orbit characteristics
quasi-polar (70°)
elliptical (350÷600 km)
3-years-long mission
Orbit characteristics
SAA OK

24. Example: Trigger rate with 3 different trigger configurations

27. The first three months of Pamela
June, 15: Launch
June, 15 – July, 11: satellite and instruments commissioning
JuLy, 11 – September, 7:
-- Satellite commissioning;
-- Pamela data taking for 1064 hours for a live time of 733 hours.
12 Caprice 98 balloon flights and about three HEAT balloon flights.
Estimation:
~ 210 antiprotons detected, 66 between GeV
~ 2200 positrons, 400 between GeV

28. The Science of Pamela

29. Cosmic-ray Antimatter Search
PAMELA

30. Antiproton Measurements

31. •Background from normal
Distortion on the secondary antiproton flux induced by an Extragalactic Antimatter and Black Hole evaporation components
Extragalactic Antimatter
•Background from normal
secondary production
Black Hole evaporation
•Mass91 data from
XXVI ICRC, OG , 1999
•Caprice94 data from
ApJ , 487, 415, 1997
•Caprice98 data from
ApJ Letters 534, L177, 2000

32. Dark Matter What do we espect from Pamela?

33. NEUTRALINO ANNIHILATION
a) CDM neutralinos annihilation in the Galactic halo in minimal SUSY
b) In R-parity- violating SUSY

34. Search of structures in antiproton spectrum
Primary production from
 annihilation
(m() = ~ 1 TeV)
( astro-ph )
Secondary production (upper and lower limits)
Simon et al.
Secondary production (CAPRICE94-based)
Bergström et al.

35. PAMELA: Cosmic-Ray Antiparticle Measurements: Antiprotons
MSSM
fd: Clumpiness factors needed to disentangle a neutralino induced component in the antiproton flux
A.Lionetto, A.Morselli, V.Zdravkovic
JCAP09(2005)010 [astro-ph/ ]

36. Distortion of the secondary positron fraction induced by a signal from a heavy neutralino.
Baltz & Edsjö
Phys.Rev. D59 (1999)
astro-ph

37. Positron with HEAT

38. Cosmic-ray antiparticle measurements: positrons
Secondary production ‘Moskalenko + Strong model’ (1998) without reacceleration
Charge dependent
modulation effects
Secondary production
‘Leaky box model’ (Protheroe 1982)
Primary production from  annihilation (m() = 336 GeV)
PAMELA energy range

39. Primary and Secondary Spectra
Unambiguous interpretation of exotic matter signature requires a clear understanding of the secondary spectra and their sources.
Primary cosmic ray spectra as a powerful tool for quantify the source of atmospheric neutrino anomaly.

40. Secondary to Primary ratios

41. Helium and Hydrogen Isotopes

42. Protons Helium

44. High Energy electrons
The study of primary electrons is especially important because they give information on the nearest sources of cosmic rays
Electrons with energy above 100 MeV rapidly loss their energy due to synchrotron radiation and inverse Compton processes
The discovery of primary electrons with energy above 1012 eV will evidence the existence of cosmic ray sources in the nearby interstellar space (r300 pc)

45. High Energy Radiation Belts
– High energy from ~ 1 GeV to ~ 10 GeV – Content of e+, e-, p, 3He – Low L- shell  low altitude – Life time O(seconds)  Secondary production from CR interaction with atmosphere

46. ≈
PAMELA will be able to measure electrons at very high energy to discover sources near the solar system

47. wizard.roma2.infn.it/pamela
Earliest example of the interplay between particles physics and cosmology
“We must regard it rather an accident that the Earth and presumably the whole Solar System contains a preponderance of negative electrons and positive protons. It is quite possible that for some of the stars it is the other way about”
Dirac Nobel Speech (1933)
wizard.roma2.infn.it/pamela
The belief that the Universe was baryon symmetric was a mainstream view from the 1930’s into the 1960’s.