Thick GEM versus thin GEM in two-phase argon avalanche detectors

Understand

The performance of thick GEMs (THGEMs) was compared to that of thin GEMs in two-phase Ar avalanche detectors, in view of their potential application in coherent neutrino-nucleus scattering, dark-matter search and in other rare-event experiments.

• The detectors comprised a 1 cm thick liquid-Ar layer followed by either a double-THGEM or a triple-GEM multiplier, operated in the saturated vapor above the liquid phase.
• Three types of THGEMs were studied: those made of G10 and Kevlar and that with resistive electrodes (RETHGEM).
• Only the G10-made THGEM showed a stable performance in two-phase Ar with gains reaching 3000.