THGEM operation in Ne and Ne/CH₄

Abstract

The operation of Thick Gaseous Electron Multipliers (THGEM) in Ne and Ne/CH 4 mixtures, features high multiplication factors at relatively low operation potentials, in both single-and double-THGEM configurations. We present some systematic data measured with UV-photons and soft x-rays, in various Ne mixtures. It includes gain dependence on hole diameter and gas purity, photoelectron extraction efficiency from CsI photocathodes into the gas, long-term gain stability and pulse rise-time. Position resolution of a 100x100 mm 2 X-ray imaging detector is presented. Possible applications are discussed.

First Tests of MICROMEGAS and GEM-Like Detectors Made of a Resistive Mesh

“…Recently, several groups working with such detectors fully confirmed our earlier results [12]- [14]. Unfortunately, the position resolution of RETGEM (similarly to TGEM) is limited by the hole's diameter and pitch and is about 0.7-1 mm [15], [16].…”

“…Unfortunately, as noted in the introduction, the position resolution of the RETGEM is quite modest (0.7-1 mm) [15], [16] due to the large hole's diameters and pitch.…”

Status and perspectives of gaseous photon detectors

“…Ne-based mixtures are preferred to other noble gases, since Ne has the largest first Townsend coefficient and the detector can be operated at considerably lower voltages [59]. For example, a gain of 10 5 has been measured at a ΔV THGEM of 200 V in a double THGEM flushed with Ne and irradiated by 5.9 keV X-rays, to be compared with the 1000 V needed in pure Ar to achieve the same gain (Fig.…”

A novel fast-neutron detector concept for energy-selective imaging and imaging spectroscopy

“…The thickness of both the converter layer and coating was increased, from 0.1 mm to 0.24 mm for the polyethylene layers and from 0 to 0.08 mm for the energy-selective Hafnia coating. The gas gap between the neighbor foils is 0.5 mm in each stack and it is filled with Ne-based mixtures (i.e., Ne/5%CF 4 or Ne/5%CH 4 )-Ne mixtures are known to provide a relative high electron multiplication gain as well as high dynamic, 20 allowing the ionization of the escaping proton to be detected by the position-sensitive gaseous detector. It follows that the full converter structure is composed of 215 foils, arranged on a 30 cm long.…”