Characterization of Silicon Photomultipliers for nEXO

Neutrinos are constantly bombarding us, but their interactions are so weak that studying their properties, including their fundamental nature, can be challenging. Neutrinoless double beta decay (0vββ) is a rare nuclear process that can shed light on the matter-antimatter nature of neutrinos. The next-generation nEXO experiment is a planned experiment that would use 5000 kg of isotopically enriched liquid xenon in a time projection chamber to look for 0vββ in ¹³⁶Xe with a target half-life sensitivity of about 10²⁸ years. nEXO plans to use SiPMs as photosensors to detect liquid xenon scintillation light because they are radiopure devices operated at low voltages with high gain. My objective is to characterize SiPMs at cryogenic temperature and ensure that this application will achieve the nEXO goal of ~1% energy resolution at the Q-value of 0vββ of ¹³⁶Xe.