The Alpha Magnetic Spectrometer (AMS-02) is a high-energy particle physics magnetic spectrometer installed on the International Space Station since May 2011, and operating continuously since then. Thanks to the large acceptance, long exposure time and particle identification capabilities, AMS-02 measures cosmic rays fluxes in the kinetic energy range between a fraction of GeV/n to multi-TeV/n with unprecedented precision.
The AMS-02 Ring Imaging Cherenkov counter (RICH) detector provides a precise measurement of the particle velocity and charge. The detector has shown stable and nominal response during the past 7 years of continuous data taking without showing significant degradation. With the additional use of the Silicon Tracker momentum measurement, the RICH is able to measure the isotopic composition of the light elements (up to charge Z=5) in the kinetic energy range from few GeV/n to about 10 GeV/n.
In particular this contribution will focus on the separation of cosmic rays species with |Z|=1. For positive rigidities (Z=+1), the measurement of individual p and D fluxes and their ratio are important for the understanding of CRs propagation in our galaxy, being the D an almost entirely secondary product of the interaction of cosmic rays with the interstellar matter, while p is mainly produced by astrophysical sources. The negative rigidity sample (Z=-1) is promising for indirect search of Dark Matter, looking at the p-bar and at d-bar components. These species are rare secondary products of CRs propagation and therefore an excess due to new physics could be more significantly seen on top of their faint expected flux. AntiDeuterons in particular have never been observed so far in CRs. The current status of this work will be presented.