The RICH detector of the AMS-02 experiment aboard the International Space Station

Abstract

The Alpha Magnetic Spectrometer (AMS) is a high-energy particle physics magnetic spectrometer installed on the International Space Station (ISS) in May 2011, successfully operating and taking data since then. The goal of the experiment is to carry out accurate measurements of galactic Cosmic Rays spectra in a wide energy range from GeV/n to TeV/n and search for rare components as hints of the presence of Dark Matter and Anti-Matter. The AMS instrument includes a Ring Imaging Čerenkov (RICH), which provides a precise measurement of the particle velocity and electric charge. The AMS-RICH layout follows a proximity focusing design with two radiators: at the center there are sodium fluoride tiles surrounded by silica aerogel ones. No significant indications of degradation of the radiator properties have been observed in more than 11 years of operation in space and 95% of the detection sensors is working nominally. The velocity and charge responses are stable in time and their resolution fulfills the design requirements. The impact of the RICH detector in the AMS physics program will be highlighted and the most recent results on light isotopes in cosmic rays will be discussed, with a particular attention to the AMS capabilities to identify Beryllium isotopes.