First imaging results of a bubble-assisted Liquid Hole Multiplier with SiPM readout in liquid xenon

First imaging results in liquid xenon of a Liquid Hole Multiplier (LHM) coupled to a quad-Silicon Photomultiplier (SiPM) array are presented. Ionization electrons deposited in the noble liquid by 5.5 MeV alpha particles, are collected into the holes of a Thick Gas Electron Multiplier (THGEM) electrode having a xenon gas bubble trapped underneath. They drift through the liquid-gas interface, inducing electroluminescence within the bubble. The resulting photons are detected with a Hamamatsu VUV4 quad-SiPM array—providing the deposited energy with a charge-only RMS resolution of 6.6%. The image reconstruction resolution was estimated to be ~200 μm (RMS).