Description
Next generation liquid nobel gas detectors for the search of weakly interacting massive particles (WIMPs) aim to increase their sensitivity down to the neutrino fog. To achieve this ambitious goal, it is imperative to further reduce detector backgrounds dominated by LXe intrinsic isotopes of 85Kr and 222Rn ten-times below the unshieldable solar and atmospheric neutrino background. Already the XENONnT experiment achieved world leading low background levels for 222Rn (< 1 µBq/kg) and 85Kr (0.2 ppt) through their removal via cryogenic distillation, paired with stringent material selections.
In the ERC Advanced Grand project LowRad the technical foundations for the next generation cryogenic krypton and radon removal systems are developed. This includes among other things a krypton concentrator and a cryogenic heat pump. The concentrator aims to reduce the krypton enriched off-gas losses during krypton distillation by another factor 1000 making a continuous online distillation during data taking feasible. The cryogenic heat pump tackles the 20 kW heating and cooling power demands of future radon removal systems, which is required to reduce the 222Rn background to less than 0.1 µBq/kg, or less than 1 atom in 100 mol xenon. On this poster we will present the status of these two systems currently developed.
Acknowledging the support of the ERC AdG project "LowRad" (101055063).
