Speaker
Description
Neutrinoless double beta decay (0vbb) is a lepton-number-violating process that is forbidden in the Standard Model. The observation of 0vbb would imply that neutrinos are their own anti-particles, and provide an important step towards explaining the asymmetry of matter and anti-matter in the universe. nEXO is a proposed next-generation 0vbb experiment containing 5000 kg of isotopically enriched Xe-136 in a time projection chamber (TPC), detecting both ionization charge and scintillation light. Ionization electrons produced by charged particles drift along the electric field towards the anode where it is read out by arrays of crossed strips, deposited on 10 cm*10 cm dielectric tiles. The signal pre-processing, digitization and read-out steps are carried out at cryogenic temperatures by a follow-up novel System-on-Chip CRYO ASIC deployed on the back side of the tiles. nEXO requires a high precision of reconstruction of the electron energy to effectively discriminate signals from backgrounds. In this study, we focus on bench-top and cold tests at SLAC for the CRYO ASIC motherboard and the charge readout module prototype, and also the liquid xenon testing of the charge module prototype using a 28 kg LXe TPC at Stanford. These tests aim to characterize the noise and signal response performance of the charge module, and elucidate the reconstruction and physics potential of nEXO.
