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

TL;DR

This paper investigates the performance of THGEM and THGEM/G-APD multipliers in gaseous and two-phase xenon at cryogenic temperatures, demonstrating stable operation, high gains, and optical readout capabilities for potential detector applications.

Contribution

First demonstration of THGEM multipliers in two-phase Xe with detailed comparison to other noble gases and analysis of optical readout using G-APDs at cryogenic temperatures.

Findings

Stable operation of double-THGEM in two-phase Xe with gains up to 600

Detection of NIR avalanche scintillations with G-APDs at cryogenic temperatures

Comparison of two-phase Xe detector performance with Ar and Kr detectors

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 4pi. The results are compared with those of two-phase Ar avalanche detectors. The advantages, limitations and possible applications are discussed.