1. for the PAMELA collaboration
Abundance of light nuclei in cosmic rays measured by the space experiment PAMELA
Roberta Sparvoli
for the PAMELA collaboration
University of Rome “Tor Vergata”, Italy

2. What is PAMELA ? Dimensions: 130 x 70 x 70 cm3 Total weight : 470 kg
All details: P. Picozza et al., Astroparticle Physics, 27, 296, 2007

3. PAMELA Science PAMELA is:
Searching for antimatter in CR (antiprotons, positrons, anti-nuclei)
Searching for dark matter (by indirect signature in antiproton/positron signals)
Studing cosmic-ray propagation (by measuring light-nuclei fluxes)
Studing magnetosphere physics
Studing solar physics and solar modulation
This proposal !

4. PAMELA in Space
On June 15th 2006 at 08:00 UTC the RESURS DK-1 satellite housing the PAMELA apparatus was successfully launched in space for the Russian cosmodrome of Baikonur.
PAMELA was switched on for the first time on June 21st 2006.
In the following days PAMELA was on for several hours and continuously since the 11th of July 2006.
On September the 15th the commissioning phase of the RESURS was completed.

5. Flight data: 13 GV
interacting proton

6. interacting antiproton
Flight data: 41 GV
interacting antiproton

7. Flight data: 70 GV
positron

8. First results: pbar/p ratio
To be published soon in Phys. Rev. Lett.

9. First results: proton flux & solar modulation
Flux (P/(cm^2 sr GeV s))
Blue: July
Red: August 2007
Kinetic energy (GeV)

10. Nuclei detection (calorimeter)

11. Nuclei detection (tracker)

12. Preliminary measurement: B/C

13. PAMELA on beam
PAMELA was optimized for detecting cosmic antimatter, so Z=1 particles;
Before delivery to Russia several beam tests at CERN/SPS were performed (p, e-, m, p);
No time for light nuclei calibration before the flight;
Nuclei calibration postponed after launch with the Technological Model
test response of electronics to high deposits (deviations from linearity)
evaluate charge resolution for every detector
tune MC simulations
tune analysis algorithms

14. February 2006 GSI test beam Particle Energy (MeV/n) Target Angle (°)
Events
12C
1200
269896 ×
123194
200 45
30378
196139
50Cr
500
15976
173960
52241

15. Why a new test beam?
In Feb we were parasites, so we could not optimize particles, energies and fluences;
No CALO under test;
HV settings for PM not representative of the flight situation;
Not enough statistics for nuclei from fragmentation.

16. Our new set-up E.M. Calo beam S1 S2 S3 80 cm 40 cm
Magnetic
Spectrom.
E.M.
Calo
beam S1 S2 S3
80 cm
40 cm
Global dimensions: 0.5 x 0.5 x 1,5 m3 (electronics included)
Weight : about 50 kg

17. Our requests (dreams’ list)
Particle (Z)
Energy (MeV/u)
Shifts 2
E_1 1 3 4 5
E_2 6
E_1 : energy > 200 MeV/u
E_2 : energy > 200 MeV/u and different from E_1
Fluences : not more than 100 particles/s
Minimal request : 2 different particle types !!

18. Thank you in any case!
Visit PAMELA web site 