SiPM array of Xenoscope, a full-scale DARWIN vertical demonstrator

Abstract

The DARWIN project aims to build and operate a next-generation observatory for dark matter and neutrino physics, featuring a time projection chamber with a proposed active target of 40 t of liquid xenon. As an R&D facility to test fundamental components of the future detector, Xenoscope, a full-scale vertical demonstrator with ∼400 kg of liquid xenon and up to 2.6 m electron drift length, was built at the University of Zurich. Its main objective is to demonstrate electron drift over unprecedented distances in liquid xenon—first in a purity monitor setup with charge readout, followed by a dual-phase time projection chamber. In this second phase, an array of 48 VUV4 MMPCs from Hamamatsu (model S13371-6050CQ-02) with a 12-channel readout will be placed above the liquid xenon column and operated as a light readout for the secondary proportional scintillation signals coming from extracted electrons in the time projection chamber. This work presents the design and development of the silicon photomultiplier array of Xenoscope, covering the structural and electronic design, sensor characterisation at cryogenic temperature and signal simulation.