UV-Transparent Crystal Xenon for Particle Detection: Freezing Process and Scaling Projections

Liquid xenon (LXe) detectors have reached world-leading sensitivities in the ever-going search for WIMP dark matter, though radioactive decays via the radon chain continue to be a leading background. Crystal xenon (CXe) as a medium prevents the diffusion of radon, potentially making radon decays subdominant to neutrinos in a tonne-scale detector such as LUX-ZEPLIN. We present a process for consistently freezing UV-transparent xenon crystals, established through experimental trials in a multi-kilogram-scale detector. We extrapolate measurements of freezing time versus crystal mass to evaluate the feasibility of a future tonne-scale crystal xenon particle detector.