Observations of Trapped Electrons and Positrons with E > 50 MeV in the Inner Radiation Belt by the PAMELA Magnetic Spectrometer

Geomagnetically trapped electrons and positrons with energy above 50 MeV were observed in PAMELA experiment on board Resurs DK satellite. The instrument consists of magnetic spectrometer, imaging electromagnetic calorimeter, time-of-flight system, anticoincidence and neutron detectors that provide unique particle identification and background rejection. PAMELA was collecting data since June 2006 till January 2016. The satellite orbit with initial altitude 350–600 km and inclination 70° crosses the inner radiation belt in South Atlantic Anomaly at L-shell ∼1.2. The trapped electrons and positrons were selected on the basis of a trajectory simulation in the Earth magnetic field. Features of the energy spectra of electrons and positrons at low energies are analyzed.