Radon Plate-Out Backgrounds in Rare-Event Searches

The decays from radioisotopes in the radon decay chain negatively impact the sensitivity and performance of rare-event search detectors. Detector components exposed to radon gas can experience radon-daughter plate-out. This process occurs when radon decay products land on a detector material and then undergo additional decay, leading to long-living radioisotopes being embedded into the material surface. In this work, we use the SRIM (Stopping and Range of Ions in Matter) program to simulate radon plate-out in various detector materials. In addition, we use a dedicated database that was used to track detector materials to build a radon exposure model and estimate the plate-out rates in the Super Cryogenic Dark Matter Search (SuperCDMS) experiment.