Speaker
Description
The liquid xenon time projection chamber (LXe TPC) is a well-established particle detection technology commonly used in rare event searches such as dark matter (DM) direct detection. LZ is a LXe TPC expected to improve on the current best WIMP sensitivity by almost two orders of magnitude by the time its nominal data-taking finishes around 2027. If DM lies beyond LZ’s detection capabilities, further improvement by an order of magnitude will be required to either claim a discovery or reach the point where solar neutrinos become the dominant, irreducible background (the “neutrino fog”), stymieing progress. Continuing the paradigm of building larger detectors beyond LZ would be costly, and may not be effective at reaching the neutrino floor due to a less exotic but more prevalent background, radon emitted from internal detector components. We propose to address this through crystallizing the xenon. Once solid, the xenon will no longer admit external Rn into the bulk, allowing existing Rn to decay away. These decays can also be efficiently vetoed using the time structure of the decay sequence and the fixed position of daughter isotopes. In this talk, I will present recent results from a crystalline/vapor two phase TPC test stand which establish the viability of this new detector technology, and suggest its implementation as a possible future upgrade to LZ.
