Construction and measurements of a vacuum-swing-adsorption radon-mitigation system

TL;DR

This paper details the design, construction, and measurement of a vacuum-swing-adsorption radon-mitigation system used in a cleanroom to significantly reduce radon levels, thereby decreasing background noise in sensitive physics experiments.

Contribution

It introduces a novel vacuum-swing-adsorption radon-mitigation system and demonstrates its effectiveness in achieving ultra-low radon levels in a cleanroom environment.

Findings

Radon filter reduces radon levels by approximately 20 times.

Achieved radon activity levels below 2 Bq/m$^3$ in the cleanroom.

System meets the stringent requirements for low-background physics experiments.

Abstract

Long-lived alpha and beta emitters in the $^{222}$Rn decay chain on (and near) detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double-beta decay, and in screening detectors. In order to reduce backgrounds from radon-daughter plate-out onto the wires of the BetaCage during its assembly, an ultra-low-radon cleanroom is being commissioned at Syracuse University using a vacuum-swing-adsorption radon-mitigation system. The radon filter shows ~20$\times$ reduction at its output, from 7.47$\pm$0.56 to 0.37$\pm$0.12 Bq/m$^3$, and the cleanroom radon activity meets project requirements, with a lowest achieved value consistent with that of the filter, and levels consistently < 2 Bq/m$^3$.