Characterization of Stilbene Scintillation Detectors with Light Guide Coupling and Silicon Photomultiplier Readout

Abstract

We experimentally investigated the low energy pulse shape discrimination (PSD) capabilities of four cubic stilbene crystals with 6 mm, 10 mm, 15 mm, and 20 mm sides. We used a $6\times 6\mathrm {m}\mathrm {m}^{2}$ silicon photomultiplier (SiPM) for readout, and coupled the crystals both with and without light guides, optimizing light guide wrapping for PSD. We compared the crystals’s figure of merit (FOM) dependence on light output. For the smaller three crystals, direct coupling provided better PSD (roughly 116% FOM of the guided at 100 – 150 keVee). For the 10 mm sided crystal the trend was reversed and the light guide became advantageous (105% FOM of the direct at 100 – 150 keVee).