On the low-temperature performances of THGEM and THGEM/G-APD multipliers in gaseous and two-phase Xe¹

Abstract

The performances of THGEM multipliers in two-phase Xe avalanche mode are presented for the first time. Additional results on THGEM operation in gaseous Xe at cryogenic temperatures are provided. Stable operation of a double-THGEM multiplier was demonstrated in two-phase Xe with gains reaching 600. These are compared to existing data, summarized here for two-phase Ar, Kr and Xe avalanche detectors incorporating GEM and THGEM multipliers. The optical readout of THGEMs with Geiger-mode Avalanche Photodiodes (G-APDs) has been investigated in gaseous Xe at cryogenic temperature; avalanche scintillations were recorded in the Near Infrared (NIR) at wavelengths of up to 950 nm. At avalanche charge gain of 350, the double-THGEM/G-APD multiplier yielded 0.07 photoelectrons per initial ionization electron, corresponding to an avalanche scintillation yield of 0.7 NIR photons per avalanche electron over 4π. The results are compared with those of two-phase Ar avalanche detectors. The advantages, limitations and possible applications are discussed.

Two-phase Cryogenic Avalanche Detectors with THGEM and hybrid THGEM/GEM multipliers operated in Ar and Ar+N2

“…The experimental setup was similar to that used in our previous measurements with twophase Ar and Xe detectors [16], [21]. It includes a 9 l volume cryogenic chamber of 24 cm internal diameter, cooled with liquid nitrogen.…”

“…In one particular measurement, THGEM(G10) electrodes of a fourth type, similar to that of our previous works [7], [16], [21], were used. These were produced by Print Electronics (Israel) and had the same geometrical parameters as that of the THGEM(G10) of Table 1, except of the active area which was smaller, of 2.5×2.5 cm 2 .…”

Study of infrared scintillations in gaseous and liquid argon. Part II: light yield and possible applications

“…electroluminescence under higher electric fields at which the avalanche multiplication occurs in the noble gas medium. This technique consists of optically recording avalanche-induced scintillations emitted from the holes of GEMs [13] or THGEMs [14]: at room temperature -using CCD cameras [15] and large area APDs [16]; at cryogenic temperatures -using CCD cameras [17], [18] and Geiger-mode APDs (GAPDs or SiPMs, [19]) [20], [21], [22], [23].…”

Optical readout: a tool for studying gas-avalanche processes

“…Alternatively, it has been used to efficiently identify defects in large area GEMs and Micro-Strip Gas Chambers (MSGC) [5]. Lately, it has been proposed to optically record avalanches from Thick Gas Electron Multiplier (THGEM [9]) holes in liquid argon [10] and in the vapor phase of liquid xenon [11], with G-APD sensors. In a recent work [12] it has been proposed to optically record avalanche-and electroluminescencephotons from cascaded hole-multipliers in the noble liquid itself, with gaseous photomultipliers [13].…”