Emanation and Diffusion of Radon Through Gasket Materials for SuperCDMS SNOLAB

The SuperCDMS SNOLAB experiment, currently under construction, will attempt to directly detect dark matter particles. Shielding surrounding the experiment’s detectors will reduce interactions of particles from radioactivity and cosmic rays. A gas purge will remove radon from gaps in the shielding to reduce backgrounds further. Gaskets used to seal this purge volume must allow sufficiently low radon diffusion through them while emanating little radon into the purge volume. I will describe measurements of radon diffusion through gaskets made of EPDM, Zip-A-Way, and Silicone, inferred from the time dependence of radon concentration in a volume separated from a high-radon volume by the gasket in question. Results of these diffusion measurements and of the radon emanation measurements will be given in the presentation.