Item

Abstract

The DARWIN experiment is a proposed dark matter search that is set to employ liquid
xenon to detect scattering events originating from hypothetical dark matter particles
(WIMPs). Being a rare-event search, the experiment requires an ultra-low background
to reach its target sensitivity. The radioactive isotope ²²²Rn emanating from the
detector materials currently poses the most serious threat to the background level as
it has the potential to mimic signals of the searched-for WIMP interactions. In this
thesis, electrodeposited copper coatings are investigated for their potential application
for reducing this background source. For this purpose, thoriated tungsten welding
electrodes are coated using a variety of different coating parameters. It was shown
that while some reduction factor > 1 was generally achieved, the reduction factors
are often inconsistent and the electrodeposition process not very well understood at
this stage. Additionally, it was found that the activity remaining after the coating
process is likely diffusion-driven.