Special Seminar - Development of a single vacuum ultra-violet photon-sensing solution for the nEXO experiment and beyond | Giacomo Gallina | University of British Columbia


Silicon PhotoMultiplier (SiPM) technology represents an unprecedented attempt to create an ideal solid-state photon detector combining the low-light detection capabilities of the previous device generations with all the benefits of a solid-state sensor. For this reason, large-scale low-background cryogenic experiments, such as Darkside-20k and the next-generation Enriched Xenon Observatory experiment (nEXO), are migrating to a SiPM-based light detection system. nEXO aims to probe the boundaries of the standard model of particle physics by searching for neutrino-less double beta decay of Xe136. The nEXO experiment follows the same detection concept as the EXO-200 experiment, but uses 5 tonnes of Liquid Xenon (LXe) inside a vacuum cryostat that will be located in a water shield at SNOLAB. Decays in the Xenon produce both light and ionization and it is important to measure both to achieve sufficient energy resolution and thus background rejection. In particular, electrons from the ionization drift in an applied electric field toward anode pads where they are measured. The light flash is simultaneously detected by an array of SiPMs. The goal of this talk is to show the latest results of the SiPM characterisation in order to choose the best SiPM technology for the nEXO experiment. Moreover I
will introduce the first results towards the development of a new generation of SiPM back-illuminated sensor to dramatically improve energy and timing resolution of future noble liquid detectors (e.g. nEXO and Darkside-20k), significantly enhancing their background rejection capabilities relative to the current generation of dark matter and double beta decay experiments.

 

Via Zoom: https://princeton.zoom.us/j/96979435241