PARTICLE IDENTIFICATION WITH A SOLID PHOTOCATHODE RICH IN ALICE AT LHC

We present a simulation of the response of a solid photocathode (CsI) proximity focusing RICH detector for the future heavy ion ALICE experiment at the LHC accelerator at CERN. The UV detector is a pad chamber with fast analog readout, the pad size being 8 X 8 mm2. The radiator is envisaged to be 1 cm of liquid freon. The simulation includes full pad response and single particle and Cherenkov photon generation and tracking through various media. The input consists of a realistic particle density and momentum distribution as expected in a lead-lead collision at LHC energies. A novel analysis method is given which proves to be satisfactory for a 3sigma separation between pions and kaons in the momentum range of interest at the expected particle densities of 50-70 particles/m2. The method is a ''Hough-like'' transform that maps the pad coordinate space directly to the Cherenkov angle parameter space. It proves to be robust enough to be able to handle the high particle densities with sufficient precision.