Qualification study of SiPMs on a large scale for the CMVD Experiment

TL;DR

This study develops a mass testing system for SiPMs used in a cosmic muon veto detector, ensuring each device meets the high efficiency requirements for the CMV experiment at the India-based Neutrino Observatory.

Contribution

It introduces a comprehensive setup for testing SiPM gain and overvoltage, including temperature-dependent characterization, for large-scale detector applications.

Findings

Successful development of a mass testing system for SiPMs.

Detailed temperature-dependent SiPM characterization.

Achievement of SiPM quality control for high-efficiency muon veto.

Abstract

A Cosmic Muon Veto (CMV) detector using extruded plastic scintillators is being designed around the mini-Iron Calorimeter (mini-ICAL) detector at the transit campus of the India based Neutrino Observatory, Madurai for the feasibility study of shallow depth underground experiments. The scintillation signals that are produced in the plastic due to muon trajectories are absorbed by wavelength shifting (WLS) fibres. The WLS fibres re-emit photons of longer wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs detect these photons, producing electronic signals. The CMV detector will use more than 700 scintillators to cover the mini-ICAL detector and will require around 3000 SiPMs. The design goal for the cosmic muon veto efficiency of the CMV is >99.99%. Hence, every SiPM used in the detector needs to be tested and characterised to satisfy the design goal of CMV. A mass testing system was developed for the measurement of gain and choice of the overvoltage ($V_{ov}$) of each SiPMs using an LED driver. The $V_{ov}$ is obtained by studying the noise rate, the gain of the SiPM. This paper describes the experimental setup used to test the SiPMs characteristics along with detailed studies of those characteristics as a function of temperature.