Characterisation of a SiPM Array in Liquid Xenon

Silicon-photomultipliers (SiPMs) have grown in attention and application among direct dark matter search and neutrino physics experiments due to some advantages compared to the traditional photomultipliers (PMTs). Using the liquid xenon detector R&D setup at the University of California San Diego, we installed 96 Hamamatsu VUV4 SiPMs surrounding a sensitive volume of about one litre, intending to detect sub-keV recoils in liquid xenon for the NUXE experiment. The number of the VUV4 SiPMs used is unprecedented for low-energy liquid xenon experiments. For a few months, we monitored the readout noise level and the gain of individual SiPM in either gaseous or liquid xenon. The gain-to-overvoltage ratio has been stable within months of measurement. We also tested the light collection efficiency (LCE) of the device in liquid xenon, as will be reported in this talk.

We acknowledge the financial support from Karlsruhe House of Young Scientists through a Research Travel Grant to visit and work at UCSD.