Speaker
Description
Large liquid xenon experiments have become one of the leading detector technologies applied in rare event searches, such as direct dark matter detection or the search for the neutrinoless double beta decay.
Significant background sources to these searches arise from progeny isotopes of the radioactive noble gas $^{222}$Rn, which can emanate from detector surfaces. In particular for the next generation detectors such as XLZD, additional radon mitigation methods will be required to reach their designed sensitivity goals.
A novel radon mitigation technique based on electrochemically deposited surface coatings has recently been developed at the Max-Planck-Institut für Kernphysik (MPIK) in Heidelberg, achieving a thousandfold reduction in radon emanation from stainless steel samples. This work aims to apply and validate this method in a large-scale liquid xenon detector for the first time, while assessing its compatibility with the ultra-high purity requirements of LXe detectors and evaluating its long-term stability under cryogenic operating conditions. The coating will be performed in collaboration with MPIK and will be validated in Xenoscope, a 2.6-m-long dual-phase TPC operated at the University of Zurich, which provides a representative environment for large-scale LXe detectors.
In this contribution, recent results from Xenoscope will be presented, alongside with the status and plans of applying surface coatings to the detector.