Speaker
Description
Radon and its progeny represent a significant source of background in rare-event physics experiments owing to their continuous production within the natural uranium decay chain. To investigate the diffusion of radon daughters into detector materials, we developed a dedicated experimental setup comprising a controlled radon source, a high-electric-field vacuum chamber, and a thin Nylon-6 film. Nylon-6 was chosen as the initial test material because of its extensive use in low-background detectors, with future studies planned for a broader range of polymers. Using this system, we performed controlled measurements of the diffusion behavior of 210Pb and 210Po under varying relative humidity conditions. Significant humidity-dependent diffusion was observed, with markedly different behavior at 40% and 95% relative humidity. These findings indicate that elevated humidity can enhance the migration of radon progeny into detector materials, emphasizing the need for careful environmental control to minimize backgrounds in ultra-low-background experiments.