THE ALPHA MAGNETIC SPECTROMETER, A PARTICLE PHYSICS EXPERIMENT IN SPACE

Abstract

The Alpha Magnetic Spectrometer (AMS) is a state of the art detector for the extrater-restrial study of matter, antimatter and missing matter. During the STS-91 precursor flight in may 1998 AMS collected nearly 100 millions of Cosmic Rays on Low Earth Orbit, measuring with high accuracy their composition. We review the results on the flux of proton, electron, positron and helium. Analysis of the under cutoff spectra indicates the existence of a new type of belts of energetic trapped particles characterized by a dominance of positrons versus electrons. AMS is currently being refurbished for a three year mission on the International Space Station where the its sensitivity to rare events will be increased by three to four orders of magnitude.