The AMS02 Cherenkov imager prototype : In-beam tests with high-energy ions

Abstract A prototype of the AMS Cherenkov imager has been tested at CERN with 20 and 158 GeV / c per nucleon ion obtained by fragmentation of a primary beam of Pb and In ions, respectively. Data have been collected with single low-intensity beam settings, over the range of nuclear charges 2 Z ≲ 45 in various beam conditions and using different radiators. The charge Z and velocity β resolution of the prototype have been measured and the aerogel material properties investigated.