Neutron damage and recovery studies of SiPMs

SiPM lost its performance characteristics when exposed to high dose of neutrons. However, the distinct hallmark of SiPMs, low dark count and excellent photon-number-resolving capability, can be recovered by thermal annealing. Several SiPMs from different vendors are characterized before and after exposure of up to 10
¹⁰
neutron/cm
²
dosage using a 14 MeV neutron generation source. Collectively, we established that the typical orders of magnitude increase in dark current upon neutron irradiation can be lowered substantially after processing them with a thermal annealing procedure, and single-photon detection are to some extent recovered. Moreover, we found no significant difference on neutron damaged behavior when SiPMs are irradiated at room or liquid nitrogen temperatures suggesting that there is no evidence of radiation hardening when SiPMs are operated in cryogenic temperatures.