Characterization of radiation damage caused by 23MeV protons in Multi-Pixel Photon Counter (MPPC)

• DOI: 10.1016/j.nima.2016.03.092
• Publication Date: 2016-03-31T21:37:52Z
• Authors: Zhengwei Li; Yupeng Xu; Congzhan Liu; Yudong Gu; Fei Xie; Yanguo Li; Hongliang Hu; Xu Zhou; Xuefeng Lu; Xufang Li; Shuo Zhang; Zhi Chang; Juan Zhang; Zhenling Xu; Yifei Zhang; Jianling Zhao
• Keywords: 0103 physical sciences; 01 natural sciences; 7. Clean energy

Abstract A automatic gain control system (AGC) is designed to continuously monitor and automatically control the gain of the phoswich detectors onboard the Hard X-ray Modulation Telescope (HXMT). It consists of a Am 241 radioactive source and a photo-detector. The Am 241 radioactive source is tagged within a plastic scintillator (BC440M). The scintillating photons produced by the decayed alpha particles from the radioactive source is readout by the photo-detector. The Multi-Pixel Photon Counter (MPPC) produced by Hamamatsu is used as the photo-detector for AGC. To verify the feasibility of its application in space environment, four MPPCs (S10362-33-050C) were irradiated by a beam of 23 MeV protons. The integrated proton fluence that exposed to the four MPPC samples are 1.0 × 10 8 p cm − 2 , 2.0 × 10 8 p cm − 2 , 4.0 × 10 8 p cm − 2 and 1.0 × 10 10 p cm − 2 respectively. It is found that the increment leakage current of the MPPC samples caused by irradiation damage increase linearly with the integrated fluence. The pulse-height resolution of the MPPC has deteriorated hardly after irradiation. When irradiated up to 1.1 × 10 9 cm − 2 1 MeV equivalent neutrons, the MPPC completely lost its photon-counting capability but could still work as a photo-detector for AGC. The MPPC fails as a photo-detector for the AGC when the irradiated 1 MeV neutron equivalent fluences is up to 2.7 × 10 10 cm − 2 .