Why would you put a flashlight in a dark matter detector?

TL;DR

This paper investigates the impact of external crosstalk in silicon photomultipliers used in liquid xenon dark matter detectors, highlighting potential challenges and discussing mitigation strategies for future experiments.

Contribution

It provides the first measurement of external crosstalk effects in SiPMs within a liquid xenon TPC and explores implications for dark matter detection.

Findings

External crosstalk can significantly affect detector performance.

Measurement results inform design considerations for future experiments.

Potential solutions to mitigate crosstalk are discussed.

Abstract

Silicon photomultipliers (SiPMs) are solid-state, single-photon sensitive, pixelated sensors whose usage for scintillation detection has rapidly increased over the past decade. It is known that the avalanche process within the device, which renders a single photon detectable, can also generate secondary photons which may be detected by a separate device. This effect, known as external crosstalk, could potentially degrade the science goals of future xenon dark matter experiments. In this article, we measure the effect of external crosstalk in a dual-phase, liquid xenon time projection chamber fully instrumented with SiPMs. We then consider the implications for a future xenon dark matter experiment utilizing SiPMs and discuss possible solutions.