Effect of hole geometry on charge sharing and other parameters in GEM-based detectors

TL;DR

This study investigates how different hole geometries in GEM detectors affect charge sharing, efficiency, and gain, using numerical simulations and experimental comparisons to optimize detector performance.

Contribution

It provides a detailed numerical analysis of how hole geometry influences key parameters in GEM detectors, linking fabrication techniques to detector response.

Findings

Hole geometry significantly impacts charge sharing and efficiency.

Numerical simulations generally align with experimental data.

Optimizing hole geometry can improve detector performance.

Abstract

Gas Electron Multipliers (GEM) are among the more prominent Micro-Pattern Gaseous Detectors (MPGDs) and widely used in high energy particle physics experiments and various related applications. Adoption of different production techniques lead to holes of varying geometries in GEM foils. Since the response of a GEM-based detector is closely related to the hole geometry through the influence of the latter on charge sharing and transport through GEM foils, attempts have been made to relate hole configurations to different figures of merit of a detector. Numerical simulations have been performed to study the effects of hole geometry on important parameters such as charge sharing, collection efficiency, extraction efficiency, gain, possibility of transition from avalanche to streamer modes for single, double and triple layer GEM detectors. The numerical estimates have been compared to available experimental data. The comparisons, although not always in agreement, are found to be generally encouraging.