Performance of the high momentum particle identification CsI-RICH for ALICE at CERN-LHC

The ALICE High Momentum Particle Identification (HMPID) detector consists of an array of seven identical proximity focusing Ring Imaging Cherenkov counters. It has been designed to identify charged pions and kaons in the range 1< pt and protons in the range 2< pt . The total active area of this detector is about and represents the largest scale application of CsI photocathodes to date. The detector performance, as being evaluated in test beam at CERN, will be discussed for the first five modules.