Isotopic mass separation with the RICH detector of the AMS Experiment
  The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cerenkov detector (RICH). Reconstruction of the Cerenkov angle and the electric charge with RICH are discussed. A likelihood method for the Cerenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution around 0.1%. The electric charge reconstruction is based on the counting of the number of photoelectrons and on an overall efficiency estimation on an event-by-event basis. The isotopic mass separation of helium and beryllium is presented. 
Lu\'isa Arruda, Fernando Bar\~ao, Jo\~ao Borges, Patr\'icia   Gon\c{c}alves, Rui Pereira, M\'ario Pimenta, Fernando Carmo