  The ALICE HMPID (High Momentum Particle IDentification) detector has been
designed to identify charged pions and kaons in the range 1 < p < 3 GeV/c and
protons in the range 1.5 < p < 5 GeV/c. It consists of seven identical
proximity focusing RICH (Ring Imaging Cherenkov) counters, covering in total 11
m2, which exploit large area MWPC equipped with CsI photocathodes for Cherenkov
light imaging emitted in a liquid C6F14 radiator. The ALICE detector has been
widely commissioned using cosmics and LHC beam from December 2007 until October
2008. During the cosmics data taking the HMPID detector collected a large set
of data, using mainly the trigger provided by the TOF detector. We present here
preliminary results of detector alignment using TPC tracking. The HMPID could
be operated in a stable way, at a safe HV setting, also during LHC beam
injection and circulation tests, when a very large occupancy (up to 50%) was
achieved. Resulting gain mapping and overall detector performance will also be
discussed.
