First demonstration of THGEM/GAPD-matrix optical readout in two-phase Cryogenic Avalanche Detector in Ar

TL;DR

This paper demonstrates a novel optical readout method using THGEM and GAPD matrices in a two-phase cryogenic detector with argon, achieving high spatial resolution and promising applications in neutrino and dark matter research.

Contribution

First implementation of THGEM/GAPD optical readout in a two-phase cryogenic argon detector, showing effective avalanche detection and spatial resolution.

Findings

Achieved ~80 photoelectrons per 20 keV X-ray in liquid argon.

Measured spatial resolution of 2.5 mm (FWHM).

Demonstrated potential for neutrino and dark matter experiments.

Abstract

The multi-channel optical readout of a THGEM multiplier coupled to a matrix of 3x3 Geiger-mode APDs (GAPDs) was demonstrated in a two-phase Cryogenic Avalanche Detector (CRAD) in Ar. The GAPDs recorded THGEM-hole avalanches in the Near Infrared (NIR). At an avalanche charge gain of 160, the yield of the combined THGEM/GAPD-matrix multiplier amounted at ~80 photoelectrons per 20 keV X-ray absorbed in the liquid phase. A spatial resolution of 2.5 mm (FWHM) has been measured for the impinging X-rays. This technique has potential applications in coherent neutrino-nucleus scattering and dark matter search experiments.