Mapping Earth’s radiation belts using data from STS91 mission of AMS

The data obtained during the AMS flight permitting to probe the Earth’s radiation belts are discussed. The data provide an evidence of the presence of positrons in the belts with the fluence comparable to that of electrons. Using a model of the Earth’s atmosphere and magnetic environment the origin of the belts, their shape, content and energy spectra of particles making up the belts are determined.