Measurements of proportional scintillation and electron multiplication in liquid xenon using thin wires

TL;DR

This study measures proportional scintillation and electron multiplication in liquid xenon using thin wires, providing key parameters for enhancing dark matter detectors with improved sensitivity and simplified design.

Contribution

First comprehensive measurement of electron multiplication thresholds and scintillation gain in liquid xenon with thin wires, aiding practical detector development.

Findings

Maximum scintillation gain of 287 photons per electron

Electron multiplication threshold at 725 kV/cm

Proportional scintillation threshold at 412 kV/cm

Abstract

Proportional scintillation in liquid xenon has a promising application in the field of direct dark matter detection, potentially allowing for simpler, more sensitive detectors. However, knowledge of the basic properties of the phenomenon as well as guidelines for its practical use are currently limited. We report here on measurements of proportional scintillation light emitted in liquid xenon around thin wires. The maximum proportional scintillation gain of $287^{+97}_{-75}$ photons per drift electron was obtained using 10 $\mu$m diameter gold plated tungsten wire. The thresholds for electron multiplication and proportional scintillation are measured as $725^{+48}_{-139}$ and $412^{+10}_{-133}$ kV/cm, respectively. The threshold for proportional scintillation is in good agreement with a previously published result, while the electron multiplication threshold represents a novel measurement. A complete set of parameters for the practical use of the electron multiplication and proportional scintillation processes in liquid xenon was also obtained for the first time.