International Conference on the Advancement of Silicon Photomultipliers

During my talk I would like to show and discuss results of evolution of MPPC properties during irradiation by neutrons. Two models of Multi-Pixel Photon Counters: S13360-3050CS and S13360-6050CS from Hamamatsu with different size (3x3 mm${}^{-2}$ and 6x6 mm${}^{-2}$, respectively) and the same subpixel pitch size (50 $\mu m$) were irradiated by neutrons from two sources: PuBe source with continuous energy spectrum up to 11~MeV and mono-energetic 4.8~MeV neutrons produced in (d,d) reaction. For both cases the neutron fluence/(MPPC size) in a range of 10${}^9$ mm${}^{-2}$ was achieved. The observed changes of current-voltage characteristics and breakdown voltage evolution for neutron fluence increase will be shown . The energy resolution degradation of 662 keV gamma line from ${}^{137}$Cs, obtained for non-irradiated GAGG scintillator, as a function of neutron fluence will be presented. Finally, calculated contribution of noise component in measured energy resolution will be also shown.