Radiation damage to MPPCs by irradiation with protons

Abstract

Radiation damage of Multi-Pixel Photon Counters (MPPCs) caused by proton and neutron irradiation was evaluated. An increase of the leakage current, which is an indication of radiation damage on silicon devices, was observed after both the proton and neutron irradiation. Darknoise rates significantly increased due to the damage and this effect resulted in the loss of the photon counting capability because of the noise pile-up. From the leakage current measurement we found the damage level of the MPPCs caused by the neutron influence of 10 9 n/mm2 is almost same level as the case of 20 Gy proton irradiation. © Copyright owned by the author(s).