Characterizing SiPM Response at Reduced Operating Voltages

Silicon photomultipliers (SiPMs) coupled with lead fluoride (PbF₂) crystals are being investigated in order to characterize their response under low-bias conditions all the way down to the breakdown voltage. PbF₂ is a good Cherkenov radiator that allows for precise timing results, making it well suited for reducing pileup in high rate precision experiments like the Muon g-2 experiment. This investigation focuses on understanding SiPM response and noise performance as bias voltage is reduced down to the breakdown voltage, with the goal of identifying a stable, low voltage operating region that still maintains adequate sensitivity. Understanding SiPM behavior at low voltages will give insight into future detector performance when these crystals are deployed into a higher energy beam in an experiment such as MUonE.