Construction and Measurements of an Improved Vacuum-Swing-Adsorption Radon-Mitigation System

TL;DR

This paper details the design, construction, and measurement of an improved vacuum-swing-adsorption radon mitigation system that significantly reduces radon levels in a cleanroom environment, enhancing detector surface cleanliness.

Contribution

It introduces an upgraded radon mitigation system with better components and larger beds, achieving over 300-fold reduction in radon levels compared to previous designs.

Findings

Radon levels reduced from 58.6 Bq/m^3 to 0.13 Bq/m^3

System employs improved pump and larger carbon beds

Achieved >300x radon reduction in the cleanroom

Abstract

In order to reduce backgrounds from radon-daughter plate-out onto detector surfaces, an ultra-low-radon cleanroom is being commissioned at the South Dakota School of Mines and Technology. An improved vacuum-swing-adsorption radon mitigation system and cleanroom build upon a previous design implemented at Syracuse University that achieved radon levels of $\sim$0.2$\,$Bq$\,$m$^{-3}$. This improved system will employ a better pump and larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit and aged water for humidification. With the rebuilt (original) radon mitigation system, the new low-radon cleanroom has already achieved a $>$$\,$300$\times$ reduction from an input activity of $58.6\pm0.7$$\,$Bq$\,$m$^{-3}$ to a cleanroom activity of $0.13\pm0.06$$\,$Bq$\,$m$^{-3}$.