PSD performance of EJ-276 and EJ-301 scintillator readout with SiPM array

Abstract

The pulse shape discrimination (PSD) performance of EJ-276 and EJ-301 scintillator readout with silicon photomultiplier (SiPM) was evaluated. Scintillator with 1-inch and 2-inch size was coupled to an 8 × 8 SiPM array, consisting of 3 mm and 6 mm SiPM respectively. The SiPM array was divided into four groups, each amplified with a transimpedance circuit (TIA) and then summed to form a single output. The pulse waveforms were collected with a 500 MHz/12 bit digitizer and analyzed off-line. The PSD performance was evaluated based on the charge comparison method. The 1-inch EJ-276 scintillator combined with SiPM array exhibited a figure of merit (FOM) of 1.41 for an energy threshold of 250 keVee (electron equivalent). The FOM of 2-inch EJ-276 and 1-inch EJ-301 scintillator were 1.15 and 2.15 respectively with the same condition. The experimental results demonstrated the feasibility of a compact fast neutron detector using EJ-276 or EJ-301 scintillator readout by SiPM array with reasonable n/γ discrimination capability.