Cosmic Ray Test of Mini-drift Thick Gas Electron Multiplier Chamber for Transition Radiation Detector

TL;DR

This paper reports on the cosmic ray testing of a thick gas electron multiplier chamber with a mini-drift design, demonstrating high efficiency, good spatial resolution, and stable operation suitable for electron identification in collider experiments.

Contribution

It introduces a mini-drift THGEM chamber with a thick ionization gap for transition radiation detection, showing promising performance metrics.

Findings

Efficiency >94% at -3.65 kV

Spatial resolution ~220 μm

Stable gain uniformity and operation

Abstract

A thick gas electron multiplier (THGEM) chamber with an effective readout area of 10$\times$10 cm$^{2}$ and a 11.3 mm ionization gap has been tested along with two regular gas electron multiplier (GEM) chambers in a cosmic ray test system. The thick ionization gap makes the THGEM chamber a mini-drift chamber. This kind mini-drift THGEM chamber is proposed as part of a transition radiation detector (TRD) for identifying electrons at an Electron Ion Collider (EIC) experiment. Through this cosmic ray test, an efficiency larger than 94$\%$ and a spatial resolution $\sim$220 $\mu$m are achieved for the THGEM chamber at -3.65 kV. Thanks to its outstanding spatial resolution and thick ionization gap, the THGEM chamber shows excellent track reconstruction capability. The gain uniformity and stability of the THGEM chamber are also presented.