SiPM cross-talk in liquid argon detectors

TL;DR

This paper investigates SiPM cross-talk in liquid argon detectors, highlighting its impact on light yield and noise, and provides a parametrization model for SiPMs at cryogenic temperatures to improve detector performance.

Contribution

It introduces a detailed characterization of optical cross-talk in SiPMs at 87 K and develops a parametrization model for future detector optimization.

Findings

Light yield up to 32 photo-electrons per keV with 12 primary photo-electrons.

Generalized Fano factor exceeds 2 at 5 V over-voltage.

Parametrization of optical cross-talk for FBK NUV-HD-Cryo SiPMs at cryogenic temperature.

Abstract

SiPM-based readouts are becoming the standard for light detection in particle detectors given their superior resolution and ease of use with respect to vacuum tube photo-multipliers. However, the contributions of detection noise such as the dark rate, cross-talk, and after-pulsing may impact significantly their performance. In this work, we present the development of highly reflective single-phase argon chambers capable of light yields up to 32 photo-electrons per keV, with roughly 12 being primary photo-electrons generated by the argon scintillation, while the rest are accounted by optical cross-talk. Furthermore, the presence of compound processes results in a generalized Fano factor larger than 2 already at an over-voltage of 5 V. Finally, we present a parametrization of the optical cross-talk for the FBK NUV-HD-Cryo SiPMs at 87 K that can be extended to future detectors with tailored optical simulations.