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.
@article{arxiv.1511.05816,
title = {Studies of THGEM-based detector at low-pressure Hydrogen/Deuterium, for AT-TPC applications},
author = {Marco Cortesi and John Yurkon and Wolfgang Mittig and Daniel Bazin and Saul Beceiro-Novo and Andreas Stolz},
journal= {arXiv preprint arXiv:1511.05816},
year = {2015}
}