SiPM proton irradiation for application in cosmic space

Abstract

This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170 MeV protons with fluence up to 4.6$\times$10${}^9$ particles/cm${}^2$. In our work, three types of silicon photodetectors from Hamamatsu with areas 3$\times$3 mm${}^2$ and different subpixel sizes of 25$\times$25 $\mu$m${}^2$, 50$\times$50 $\mu$m${}^2$, and 75$\times$75 $\mu$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 ${}^{\circ }$C to -65 ${}^{\circ }$C are presented. The influence of the DCR changes on the energy resolution of the 662 keV gamma line from the ${}^{137}$Cs 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.