Characterization of SiPMs for COHERENT’s proposed 1-ton Liquid Argon Detector

In 2017, the COHERENT collaboration announced the discovery of coherent elastic neutrino-nucleus scattering (CEvNS) at 6.7σ via a 14-kg CsI[Na] detector stationed at the Spallation Neutron Source (SNS) in Oak Ridge National Lab. In order to demonstrate the characteristic N²-dependence of the CEvNS cross-section with high precision, COHERENT plans to deploy additional detectors that utilize different nuclei.  One proposal is a 1-ton liquid argon (LAr) detector which, will also be stationed at SNS, and would collect ~5000 CEvNS events/year. One crucial decision regarding the design of this detector is whether to measure the LAr scintillation using silicon photomultipliers (SiPMs) or photomultiplier tubes. Through researching various characteristics of our proposed SiPMs such as single-pixel resolution, gain, dark count rate, and how these values change at different temperatures, we herein provide our findings for the final design of the detector.