Studies of THGEM-based detector at low-pressure Hydrogen/Deuterium, for AT-TPC applications

TL;DR

This study evaluates the performance of THGEM detectors in low-pressure Hydrogen and Deuterium, focusing on gain, stability, and ion-back flow, to enhance their application in active-target TPCs for nuclear physics.

Contribution

It provides new insights into the gain limits and stability of THGEM detectors in low-pressure hydrogen/deuterium, relevant for nuclear physics applications.

Findings

Maximum gain above 10^4 at 200 Torr and higher pressures.

Gain limited to around 10^3 at pressures below 200 Torr.

Results inform avalanche behavior in low-pressure noble gases.

Abstract

We study the performance of single- and double- THick Gas Electron Multiplier (THGEM) detectors in pure Hydrogen and Deuterium at low pressures, in the range of 100-450 Torr. The effect of the pressure on the maximum achievable gain, ion-back flow and long-term gain stability are investigated for single and double cascade detectors. In particular, it was found that maximum achievable gains above 10^4, from single-photoelectrons avalanche, can be achieved for pressures of 200 Torr and above; for lower pressure the gains are limited by avalanche-induced secondary effects to a values of around 103. The results of this work are relevant in the field of avalanche mechanism in low-pressure, low-mass noble gases, in particular for applications of THGEM end-cap readout for active-target Time Projection Chambers (TPC) in the field of nuclear physics and nuclear astrophysics.