M. Casolino

Spectra of primary cosmic-ray positrons and electrons in the PAMELA experiment

The PAMELA experiment is being conducted aboard the Russian satellite Resurs-DK 1, which was launched into a near-Earth circumpolar orbit on June 15, 2006. The instrument, which includes a magnetic spectrometer and an electromagnetic calorimeter (16X0), allows us to measure the fluxes of cosmic-ray electrons and positrons over a wide range of energies from ∼100 MeV to hundreds of GeV. This work presents the measurement data collected from July 2006 through January 2010 on the spectra of primary cosmic-ray electrons and positrons. At low energies, this spectrum is in good agreement with a diffusion model that includes reacceleration and damping. At high energies, the measured spectrum is harder than the one predicted.

Detection of the high energy component of Jovian electrons in Low Earth Orbit with the PAMELA experiment.

Abstract The PAMELA experiment is devoted to the study of cosmic rays in Low Earth Orbit with an apparatus optimized to perform a precise determination of the galactic antimatter component of c.r. It is constituted by a number of detectors built around a permanent magnet spectrometer. PAMELA was launched in space on June 15th 2006 on board the Russian Resurs-DK1 satellite for a mission duration of 3 years. The characteristics of the detectors, the long lifetime and the orbit of the satellite, will allow to address several aspects of cosmic-ray physics. In this work we discuss the observational capabilities of PAMELA to detect the electron component above 50xa0MeV. The magnetic spectrometer allows a detailed measurement of the energy spectrum of electrons of galactic and Jovian origin. Long term measurements and correlations with Earth–Jupiter 13 months synodic period will allow to separate these two contributions and to measure the primary electron Jovian component, dominant in the 50–70xa0MeV energy range. With this technique it will also be possible to study the contribution to the electron spectrum of Jovian e − reaccelerated up to 2xa0GeV at the Solar Wind Termination Shock.

Searching for cosmic ray anisotropy using the calorimeter in the PAMELA experiment

The satellite-borne PAMELA experiment studies cosmic ray spectra over a wide range of energies. The instrument was placed in orbit in June 2006 and remains there to the present day. A position-sensitive calorimeter is one of the main parts of the PAMELA instrument. The calorimeter data are used to determine the energy of particles that interact within it, separate the electron component of the detected radiation from the nuclear component, and reconstruct the tracks of particles passing through the instrument. The special calorimeter and S4 scintillation shower detector triggers enables us to expand our statistics considerably. Using the calorimeter data in generating these triggers means we can study the anisotropy of cosmic rays with energies in excess of tens of GeV. This method of anisotropy detection is based on reconstructing the direction of a particle’s arrival from the axis of the secondary particle cascade in the calorimeter.