We present the results of our recent studies of a Thick Gaseous Electron Multiplier (THGEM)-based detector, operated in Ar, Xe and Ar:Xe (95:5) at various gas pressures. Avalanche-multiplication properties and energy resolution were investigated with soft x-rays for different detector configurations and parameters. Gains above 10E4 were reached in a double-THGEM detector, at atmospheric pressure, in all gases, in almost all the tested conditions; in Ar:Xe (95:5) similar gains were reached at pressures up to 2 bar. The energy resolution dependence on the gas, pressure, hole geometry and electric fields was studied in detail, yielding in some configurations values below 20% FWHM with 5.9 keV x-rays.
@article{arxiv.0712.0485,
title = {Operation of a Thick Gas Electron Multiplier (THGEM) in Ar, Xe and Ar-Xe},
author = {R. Alon and J. Miyamoto and M. Cortesi and A. Breskin and R. Chechik and I. Carne and J. M. Maia and J. M. F. dos Santos and M. Gai and D. McKinsey and V. Dangendorf},
journal= {arXiv preprint arXiv:0712.0485},
year = {2009}
}