Gain stabilization and consistency correction approach for multiple SiPM-based gamma-ray detectors on GECAM

TL;DR

This paper presents a gain stabilization and correction method for SiPM-based gamma-ray detectors on GECAM, significantly improving gain stability and uniformity through adaptive bias voltage adjustments during in-flight conditions.

Contribution

It introduces an adaptive bias voltage system and an iterative correction approach to stabilize and unify SiPM detector gains in space applications.

Findings

Gain variation within 2% during in-flight tests.

Gain non-uniformity reduced from 17% to 0.6%.

Effective in both ground and space conditions.

Abstract

Each satellite of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM, mission) consists of 25 SiPM based gamma-ray detectors (GRDs). Although SiPM based GRD has merits of compact size and low bias-voltage, the drift of the SiPM gain with temperature is a severe problem for GRD performance. An adaptive voltage supply source was designed to automatically adjust the SiPM bias voltage to compensate the temperature effects and keep the gain stable. This approach has been proved to be effective during both the on-ground and in-flight tests. The in-flight measured variation of the SiPM gain is within 2%. To reduce the gain non-uniformity of GRDs, an iterative bias voltage adjustment approach is proposed and implemented. The gain non-uniformity is reduced from 17% to 0.6%. In this paper, the gain stabilization and consistency correction approach are presented and discussed in detail.