BEAM TESTS OF A FAST-RICH PROTOTYPE WITH VLSI READOUT ELECTRONICS

In this report we discuss the Fast Ring Imaging Cherenkov technique that we have developed for application to proximity-focused LiF (or CaF2) solid radiator and multiwire chamber photon detector with cathode-pad readout using TEA in CH4 as photosensor. We describe the full-scale Prototype of 12 000 pads (5.334 x 6.604 mm2) we have built, and briefly the dedicated VLSI readout electronics we have developed. We report in detail the investigations we have performed in a hadron test beam at the CERN PS, and compare the results obtained to the expected performances. The maximum momentum for pi/K separation at 3sigma achieved in these tests is 2.86 GeV/c for LiF (2.39 GeV/c for CaF2). The experimentally achieved Cherenkov merit factors, after correction for azimuthal angle acceptance, are N0 = 65.5 cm-1 (57.7 cm-1), to be compared with 53.8 cm-1 (50.2 cm-1) from Monte Carlo calculations. Operation of the detector over several months has proven the technique reliable and robust, and suitable for application in high-luminosity hadron colliders like LHC, as well as e+e- B-Factories like KEK (Japan), SLAC (USA), and Cornell (USA).