PAMELA

The PAMELA experiment is a part of the Russian Italian Mission (RIM) program, which foresees several space missions with different scientific programs. The RIM-1 experiment studies the isotopic composition of cosmic nuclei by means of the silicon telescope NINA carried by the russian polar orbit satellite Resource-04. The NINA instrument has been launched succesfully from Bajkonur on July 10^th, 1998 and is currently taking data. The RIM-2 mission is the PAMELA experiment while the RIM-3 project, called GILDA, is supposed to study high energy cosmic gamma rays.

The PAMELA apparatus will be installed onboard of the russian Resource-05 satellite and will be launched in the 2002. The sun-synchronous, 680 km polar orbit will allow studying the low energy cosmic rays, close to the poles. The main scientific objectives of the experiment are the precise measurement of the positron and antiproton fluxes at energies from 100 MeV to above 100 GeV, as well as the search for antihelium with a sensitivity of 10^-7 in the antiHe/He ratio.

The PAMELA apparatus has an overall height of about 1.2 m and consists of:

• a Transition Radiation Detector (TRD) to identify electrons and positrons;
• a spectrometer based on a permanent magnet equipped with a silicon microstrip tracker to measure particle tracks and momenta;
• an imaging calorimeter which is responsability of our group;
• a Time of Flight (TOF) and first level trigger system based on plastic scintillators;
• an anticoincidence system , also based on plastic scintillators.