A study of liquid argon detector's $n$/$\gamma$ discrimination capability with PMT or SiPM readout

TL;DR

This study compares the pulse shape discrimination capabilities of liquid argon detectors using PMTs and various SiPMs, highlighting the superior performance of J-60035 SiPM despite some drawbacks, informing photosensor selection.

Contribution

It provides a simulation-based comparison of PSD capabilities of LAr detectors with different photosensors, identifying the J-60035 SiPM as the most effective option.

Findings

J-60035 SiPM achieves highest PSD capability.

AP effects are more significant than CT effects.

SiPMs can outperform PMTs in PSD performance.

Abstract

Liquid Argon (LAr) is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection. Argon provides excellent Pulse Shape Discrimination (PSD) capability which could separate the electron recoil backgrounds from the expected nuclear recoil signals. This essay simulated the PSD capability of an LAr detector when PMTs or three kinds of SiPMs are used as photosensors based on the experimental data. The results show that the J-60035 SiPM could help the LAr detector achieve the highest PSD capability event though SiPM's After-Pulse (AP) and Cross-Talk (CT) deteriorate its PSD capability. In addition, the results also show that the effect from AP is greater than CT. This is instructive for selecting photosensors for LAr detectors.