Charging-up and reverse charging-up phenomena in a double-mask triple GEM detector

TL;DR

This paper investigates charging-up and reverse charging-up phenomena in a double-mask triple GEM detector, revealing how gain varies and stabilizes under irradiation with detailed experimental analysis.

Contribution

It provides new insights into the gain variation and stabilization mechanisms of GEM detectors under irradiation, including the reverse charging-up effect.

Findings

Charging-up causes gain increase during high radiation exposure.

Reverse charging-up leads to gain relaxation when irradiation rate decreases.

Detailed measurements elucidate gain stabilization behavior in GEM detectors.

Abstract

The Gas Electron Multiplier (GEM) detectors are widely used in high-energy physics (HEP) experiments as tracking devices because of their excellent position resolution and to handle high particle rates capability. Charging-up effect is a well known phenomenon in GEM detectors because of the presence of the dielectric medium -- Kapton in the foil. Charging-up of GEM foil takes place when it is exposed to high radiation after application of high voltage. A new phenomenon of reverse charging-up, a complementary behaviour is also observed when the irradiation rate is reduced, where the gain relaxes gradually towards its initial value. In this study, the charging-up and reverse charging-up effects are investigated for a double-mask triple GEM chamber operated with an Argon and Carbon dioxide (70/30) gas mixture. The measurements provide a detailed understanding of the gain variation under irradiation and its stabilisation behaviour. The experimental setup, methodology and results are presented in this article.