Single Electron Spectra in RPWELL-based detectors

TL;DR

This study investigates single-photo-electron spectra in RPWELL gaseous detectors, revealing Polya-like charge distributions that enhance single-electron detection efficiency across various gas mixtures and configurations.

Contribution

It provides new insights into the shape of single-electron spectra in RPWELL detectors and demonstrates how these spectra can improve detection efficiency.

Findings

Discharge-free operation over a broad dynamic range (10^4 to 10^6 gain).

Polya-like charge spectra observed, differing from exponential distributions.

Gas mixture and electric field influence the Polya spectrum and detection efficiency.

Abstract

Single-electron avalanche distributions in gaseous multipliers affect their efficient detection and that of single UV-photons. In this work, we investigated the shape of single-photo-electron spectra in single- and double-stage Resistive Plate WELL (RPWELL) detector configurations, operated in $\mathrm{Ne/CH_{4}}$ and $\mathrm{Ar/CH_{4}}$. Discharge-free operation was reached over a broad dynamic range, with charge gains of \numrange[range-phrase = -]{e4}{e6}. Compared to the usual exponential ones, the observed Polya-like charge spectra pave the way towards higher single-electrons detection efficiencies. The latter were evaluated here, using experimental data combined with numerical simulations. The effects of the gas mixtures, electric field configuration and detector geometry on the Polya spectra and their related "$\theta$" parameter are presented.