Operation of a 1-Liter-Volume Gaseous Argon Scintillation Counter

TL;DR

This paper presents a gaseous argon scintillation counter designed for detecting small nuclear recoil energies below 10 keVee, including calibration, response analysis, and optimization for low-energy measurements.

Contribution

It introduces a novel 1-liter gaseous argon detector with optimized response and software for low-energy nuclear recoil detection, validated against simulations and calibration sources.

Findings

Successful calibration with X-ray and gamma sources

Optimized detector response for low-energy nuclear recoils

Agreement between experimental data and simulations

Abstract

We have built a gas-phase argon ionization detector to measure small nuclear recoil energies (< 10 keVee). In this paper, we describe the detector response to X-ray and gamma calibration sources, including analysis of pulse shapes, software triggers, optimization of gas content, and energy- and position-dependence of the signal. We compare our experimental results against simulation using a 5.9-keV X-ray source, as well as higher-energy gamma sources up to 1332 keV. We conclude with a description of the detector, DAQ, and software settings optimized for a measurement of the low-energy nuclear quenching factor in gaseous argon. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344. Funded by Lab-wide LDRD. LLNL-JRNL-415990-DRAFT.