Performance Evaluation of Scintillator Readout with SiPM

In recent years, silicon photomultipliers (SiPMs) have been widely used to replace photomultiplier tubes (PMTs) for scintillator readout, especially in high performance neutrino experiments. SiPMs offer gains similar to those of PMTs, but with merits such as higher quantum efficiency, lower bias voltages, compact volume, high ruggedness, and magnetic field compatibility. However, SiPMs are indeed inferior in dark noise rates compared with PMTs. In this study, the performance of various scintillators readout with SiPMs is systematically evaluated and compared with those measured with PMTs for both energy measurements and pulse shape discrimination (PSD) applications. The energy resolution of the widely used NaI(Tl) scintillator coupled to SiPM arrays with different sizes was evaluated. A gamma and neutron phoswich consisting of NaI(Tl) crystal and LiI(Eu) crystal with readout SiPM arrays was developed for mixed radiation detection. The characteristics of CLYC scintillator which is sensitive to both gamma-rays and neutrons were evaluated with SiPM readout and dedicated circuit. The PSD performance of the latest EJ-276 and EJ-301 organic scintillators coupled to SiPM arrays was investigated. Our results show that both the energy resolution and PSD performance of scintillators readout with SiPMs are comparable with those using PMTs.