Speaker
Description
Direct dark matter search with liquid xenon such as XENONnT experiment has the best sensitivity to dark matter in the form of Weakly Interacting Massive Particles (WIMPs) today. XLZD experiment, the future direct dark matter search with about 50 tons of xenon, aims to improve the sensitivity to 10 times that of previous experiments and we need to decrease the background rate to achieve the goal. The most common background is the beta decay of the daughter nucleus of Rn-222 emanating from detector components. Then, we proposed a method to prevent the radon from entering the sensitive area with a hermetic chamber made of quartz and fluoroplastic (PTFE) and developed a small chamber with a diameter of 5cm. The hermeticity of the chamber was evaluated by measurement of the ratio of radon concentration in gaseous xenon inside and outside the chamber. As a result, the hermeticity was estimated to meet the requirement of XLZD.
