Measurements of charging-up processes in THGEM-based particle detectors

TL;DR

This paper investigates how charging-up of insulating surfaces in THGEM-based detectors causes transient gain variations, with experimental results aligning with model simulations, highlighting the process's impact during initial operation.

Contribution

It provides experimental validation of charging-up effects in THGEM detectors and compares these results with model simulations, clarifying the transient nature of gain stabilization.

Findings

Charging-up causes initial gain variation.

Gain stabilizes after transient charging effects.

Experimental results agree with simulations.

Abstract

The time-dependent gain variation of detectors incorporating Thick Gas Electron Multipliers (THGEM) electrodes was studied in the context of charging-up processes of the electrode's insulating surfaces. An experimental study was performed to examine model-simulation results of the aforementioned phenomena, under various experimental conditions. The results indicate that in a stable detector's environment, the gain stabilization process is mainly affected by the charging-up of the detector's insulating surfaces caused by the avalanche charges. The charging-up is a transient effect, occurring during the detector's initial operation period; it does not affect its long-term operation. The experimental results are consistent with the outcome of model-simulations.