VUV-sensitive Silicon Photomultipliers for Xenon Scintillation Light Detection in nEXO

TL;DR

This paper reports on the development and testing of VUV-sensitive Silicon Photomultipliers for xenon scintillation detection in the nEXO experiment, demonstrating improved efficiency and potential for precise energy measurements in neutrino research.

Contribution

It introduces a new generation of VUV-sensitive SiPMs with enhanced photon detection efficiency suitable for large-scale xenon detectors like nEXO.

Findings

Improved photon detection efficiency at 175 nm meeting nEXO criteria

Measurements in gaseous xenon and dry nitrogen setups

Projected energy resolution and light collection performance

Abstract

Future tonne-scale liquefied noble gas detectors depend on efficient light detection in the VUV range. In the past years Silicon Photomultipliers (SiPMs) have emerged as a valid alternative to standard photomultiplier tubes or large area avalanche photodiodes. The next generation double beta decay experiment, nEXO, with a 5 tonne liquid xenon time projection chamber, will use SiPMs for detecting the $178\,\text{nm}$ xenon scintillation light, in order to achieve an energy resolution of $\sigma / Q_{\beta\beta} = 1\, \%$. This paper presents recent measurements of the VUV-HD generation SiPMs from Fondazione Bruno Kessler in two complementary setups. It includes measurements of the photon detection efficiency with gaseous xenon scintillation light in a vacuum setup and dark measurements in a dry nitrogen gas setup. We report improved photon detection efficiency at $175\,\text{nm}$ compared to previous generation devices, that would meet the criteria of nEXO. Furthermore, we present the projected nEXO detector light collection and energy resolution that could be achieved by using these SiPMs.