Performance Analysis and Characterization of Silicon Photomultipliers Upon Irradiation

Silicon Photomultipliers (SiPMs) are highly used photodetectors in multiple fields of operation: High Energy Physics, Time of Flight Positron Emission Tomography (TOF-PET), lifetime fluorescence spectroscopy, distance measurements in LIDAR applications, astrophysics and quantum-cryptography. Major advantages of the SiPM include high gain, low voltage operation, excellent timing performance, high sensitivity (down to a single photon), and immunity to magnetic fields (as compared to PMTs). These characteristics make the SiPM a proper candidate for light detection applications from single and up to several thousand photons. As some of the mentioned applications operate in radiation harsh environments, the SiPMs are subjected to the risk of performance degradation after irradiation. Therefore, a study before and after irradiation is called for. In this work we study the effect of irradiation on the SiPMs parameters and the related impact on the performances of the scintillator detector composed of a scintillator coupled to SiPM, in terms of timing and energy resolution. The recovery from such damage by annealing was also studied both in room temperature and with temperature at 40◦C and 60◦C. The results test the adequacy of several SiPMs from various producers with different SPAD sizes mounted with 2x2x3mm3 LYSO(Ce) crystals under three increasing doses of irradiation: (i) 1.6 · 108 [neq/cm2 ], (ii) 19.2 · 108 [neq/cm2 ] and (iii) 192 · 108 [neq/cm2 ]. The main focus of this work was on a 15µm and a 50µm SPAD sized SiPMs.