Study of 144-channel multi-anode hybrid avalanche photo-detector for the belle ii rich counter

Abstract

We have developed a new hybrid avalanche photo-detector (HAPD) as a photon sensor for the Belle II RICH counter. We investigated the basic device characterizations including single-photon response. In addition, radiation damage due to g rays and neutrons was studied in detail. Further- more, we report on the results of a test beam experiment carried out using a prototype consisting of 6 photo-detectors. We successfully observed a clear Cherenkov image and the π/K separation power was obtained to be more than 5 σ at 4 GeV/c.