Study of charging up effect in a triple GEM detector

TL;DR

This paper investigates the charging up effect in a triple GEM detector made of polyimide foil, analyzing how external radiation influences detector gain through experimental measurements with an Fe55 X-ray source.

Contribution

It provides a detailed experimental study of the charging up effect in a triple GEM detector using a specific gas mixture and continuous irradiation.

Findings

Charging up affects detector gain under irradiation.

Experimental data characterizes the charging up behavior.

Methodology for measuring charging up effects is detailed.

Abstract

The advancement of Micro Pattern Gaseous Detector technology offers us different kinds of detectors with good spatial resolution and high rate capability and the Gas Electron Multiplier (GEM) detector is one of them. Typically GEM is made up of a thin polyimide foil having a thickness of 50 micrometers with 5 micrometers copper cladding on top and bottom sides. The presence of polyimide changes the gain of the detector under the influence of external radiation and the phenomenon is referred to as the charging up effect. The charging up effect is investigated with a double mask triple GEM detector prototype with Ar/CO$_2$ gas mixture in 70/30 ratio under continuous irradiation from a strong Fe$^{55}$ X-ray source. The detailed method of measurements and the test results are presented in this article.