Understanding Radon Mitigation through Vacuum Swing Absorption

Radon is a noble gas that undergoes radioactive decay which can be problematic for dark matter search experiments. Therefore, filtration is needed in order to prevent radon daughters from attaching themselves to the detector during assembly. The filtration process involves flowing outside air (relatively high in radon) through large tanks of carbon. The filtration system at the South Dakota School of Mines and Technology has shown radon reduction over 3000x, with concentrations as low as 20 mBq/m³. This same system has been used as a radon mitigation model for both the LZ and SuperCDMS experiments. In order for further understanding and optimization of radon mitigation, a smaller “Table-Top” system is being commissioned. This system will be used to study the effects of radon passing through carbon under various parameters such as tank volume, flow rate, temperature, pressure, and relative humidity.