Towards THGEM UV-photon detectors for RICH: on single-photon detection efficiency in Ne/CH4 and Ne/CF4

TL;DR

This paper investigates the efficiency of UV-photon detection using THGEM detectors with CsI photocathodes in Ne-based gas mixtures, demonstrating high gain and full collection efficiency suitable for RICH applications.

Contribution

It provides new measurements of photoelectron extraction and collection efficiencies in Ne/CH4 and Ne/CF4, showing high detector gains at low voltages for UV photon detection.

Findings

Full collection efficiency achieved in tested gases.

High detector gains (>10^5) at low voltages.

Potential suitability for RICH photon detection.

Abstract

The article deals with the detection efficiency of UV-photon detectors consisting of Thick Gas Electron Multipliers (THGEM) coated with CsI photocathode, operated in atmospheric Ne/CH4 and Ne/CF4 mixtures. We report on the photoelectron extraction efficiency from the photocathode into these gas mixtures, and on the photoelectron collection efficiency into the THGEM holes. Full collection efficiency was reached in all gases investigated, in some cases at relatively low multiplication. High total detector gains for UV photons, in excess of 10^5, were reached at relatively low operation voltages with a single THGEM element. We discuss the photon detection efficiency in the context of possible application to RICH.