Ionization and scintillation of nuclear recoils in gaseous xenon

TL;DR

This study demonstrates the simultaneous detection of ionization and scintillation from nuclear recoils in gaseous xenon at 14 bar, showing potential for dark matter detection through recoil discrimination.

Contribution

First demonstration of combined ionization and scintillation measurement from nuclear recoils in gaseous xenon at high pressure.

Findings

Successful discrimination between electronic and nuclear recoils using ionization to scintillation ratio.

Recoil spectra consistent with Monte Carlo simulations.

Encourages further research into gaseous xenon for dark matter detection.

Abstract

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope $\alpha$-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.