A RICH prototype for the AMS experiment

The AMS spectrometer will be installed on the International Space Station at the end of 2003. Among other improvements over the first version of the instrument, a ring imaging Cherenkov detector (RICH) will be added which latter should open a new window for cosmic-ray physics, allowing isotope separation up to A~25 between 1 and 10 GeV/c and elements identification up to Z~25 between threshold and 1 TeV/c/nucleon. It should also contribute to the high level of redundancy required for AMS and reject efficiency albedo particles. The results of the first generation prototype and the expected results of the new one are discussed.