Purification Efficiency and Radon Emanation of Gas Purifiers used with Pure and Binary Gas Mixtures for Gaseous Dark Matter Detectors

TL;DR

This paper evaluates various gas purifiers used in gaseous dark matter detectors, focusing on their efficiency in removing impurities and their radon emanation rates to minimize background noise.

Contribution

It provides a comparative analysis of purifier performance and radon emission, identifying options with low radon emanation for improved detector purity.

Findings

Certain purifiers show high O2 and H2O removal efficiency.

Radon emanation rates vary significantly among purifiers.

Absorption of quenchers by purifiers affects gas system performance.

Abstract

Rare event searches require extreme radiopurity in all detector components. This includes the active medium, which in the case of gaseous detectors, is the operating gas. The gases used typically include noble gas mixtures with molecular quenchers. Purification of these gases is required to achieve the desired detector performance, however, purifiers are known to emanate 222 Rn, which is a potential source of background. Several purifiers are studied for their O 2 and H 2 O purification efficiency and Rn emanation rates, aiming to identify the lowest-Rn options. Furthermore, the absorption of quenchers by the purifiers is assessed when used in a recirculating closed-loop gas system.