SiPM module for the ACME III electron EDM search

TL;DR

This paper presents the design and performance evaluation of a large-area SiPM module optimized for detecting fluorescent light in the ACME III electron EDM search, replacing traditional PMTs to improve sensitivity.

Contribution

Development and characterization of an optimized 16-channel SiPM module tailored for the ACME III experiment's photon detection needs.

Findings

SiPM dark count rate is low and well-suppressed

Optical crosstalk is minimized, ensuring high signal fidelity

Module performance meets the requirements for ACME III sensitivity

Abstract

This report shows the design and the performance of a large area Silicon Photomultiplier (SiPM) module developed detection of fluorescent light emitted from a 10 cm scale volume. The module was optimized for the planned ACME III electron electric dipole moment (eEDM) search, which will be a powerful probe for the existence of physics beyond the Standard Model of particle physics. The ACME experiment searched for the eEDM with the world's highest sensitivity using cold ThO polar molecules (ACME II). In ACME III, SiPMs will be used for detection of fluorescent photons (the fundamental signal of the experiment) instead of PMTs, which were used in the previous measurement. We have developed an optimized SiPM module, based on a 16-channel SiPM array. Key operational parameters are characterized, including gain and noise. The SiPM dark count rate, background light sensitivity, and optical crosstalk are found to all be well suppressed and more than sufficient for the ACME III application.