Proton and X-rays radiation effects on Silicon Photomultipliers

Silicon photomultipliers (SiPMs) are single-photon sensitive large-area detectors widely used in many applications. Among them, they are used in several radiation-harsh applications, like high-energy physics and experiments in space, where they receive a significant radiation dose. The effect of ionizing and nonionizing radiation dose on their performance is very interesting for those applications. In this contribution we irradiated several silicon photomultipliers technologies produced at FBK with 74MeV protons and with 40 keVX-rays (up to to 100kGy dose in silicon). We monitored the reverse current after each proton or X-ray irradiation step. We also characterized the SiPMs functionally after the irradiation and after few weeks of room temperature annealing. We studied the main degradation effects and the main difference in the functional performances modification among the SiPM technologies. Having a complete knowledge of the internal structures of the SiPMs and being able to compare directly the effects on performances degradation of different SiPM technologies is very interesting for a future development of a more radiation-tolerant SiPM technology.