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Abstract

For current and future experiments searching for rare events, background control
and reduction are of crucial concern. Liquid xenon detectors searching for
dark matter such as XENON1T are among these detectors. One of the largest
contributions to its background is due to ²²²Rn emanated from detector materials.
Radon mitigating properties of surface coatings applied by plasma deposition,
sputtering and electrodeposition were investigated in this work. The most promising
result was achieved by the application of an electrodeposited copper coating,
which reduced the ²²⁰Rn emanation rate by two orders of magnitude. In this
case the ²²²Rn emanation rate also showed a significant reduction.
The impact and stability of the coating layers under operating conditions in a
liquid xenon dual phase TPC will be tested in the Heidelberg Xenon system. In
preparation for this, data analysis for a first successful calibration of the detector
in single-phase mode using a ^83mKr source, are presented.