SiPM proton irradiation for application in cosmic space

This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170MeV protons with fluence up to 4.6x10(9) particles/cm(2). In our work, three types of silicon photodetectors from Hamamatsu with areas 3x3 mm(2) and different subpixel sizes of 25x25 mu m(2), 50x50 mu m(2), and 75x75 mu m(2) were used. The changes in the SiPM dark count rate (DCR) spectrum before and after irradiation in temperatures in the range of 20 degrees C to -65 degrees C are presented. The influence of the DCR changes on the energy resolution of the 662 keV gamma line from the Cs-137 for a non-irradiated GAGG:Ce (1%) scintillator is investigated. The time period of usability of the SiPM detector irradiated by protons in cosmic space was estimated.