Characterization of the Hamamatsu MPPC S11834 as photon sensor for RICH

Recent development of SiPMs makes them a promising candidate for replacement of photomultiplier tubes in Ring Imaging Cherenkov (RICH) counters. A commercially available 8×8 SiPM array, Hamamatsu MPPC S11834 with a rather low dark count rate, was tested as a single photon sensor in a RICH counter. To increase its overall geometrical acceptance, light concentrators were employed. The various factors that influence their efficiency are estimated and the results of measurements with polarized light are presented, showing a good agreement with a Monte Carlo study.