DarkSide-20k - URANIA Project

Princeton University, Princeton NJ

Investigators

Abstract

Gravitational effects that cannot be explained by visible matter are well-documented, though their source remains unknown. A well-motivated explanation for these observations is the existence of an as-yet-undiscovered elementary Weakly Interacting Massive Particle (WIMP). The motion of galactic halo WIMPs relative to a detector on Earth could result in WIMP-nucleus elastic collisions detectable by a low-background, low-threshold detector capable of unambiguously identifying a small number of nuclear recoils over the course of a very large exposure. This award supports the DarkSide-20k (DS-20k) detector, a liquid argon time projection chamber designed to achieve leading sensitivity to high-mass (above 30 GeV/c2) WIMP dark matter, by providing funding for the URANIA plant, in Cortez, CO, for the high-volume extraction of low-radioactivity argon gas from an underground source (UAr). The funds will be used for pieces of infrastructure that are the direct responsibility of the US NSF-funded groups. Scientific broader impacts of the project include the discovery of a novel, commercially viable helium source that today supplies 15% of the US production and the production of hundreds of tonnes of low-radioactivity UAr for DS-20k. The extraction facility could continue to produce underground argon for other interested particle physics experiments that require UAr to achieve their scientific objectives, as well as for other technical uses including nuclear test ban verification and radiometric dating. Constructing DS-20k will require that large amounts of UAr be procured in timely fashion. This will be accomplished by URANIA, an argon extraction and purification plant capable of extracting 250 kg/day of UAr. The URANIA plant itself is funded by the Italian Agency (INFN) and will be built by a contracted vendor following specifications established by the URANIA Project team. The preparation of the extraction facility site, as well as the installation and commissioning of the plant, falls under the responsibility of the NSF-supported groups and is funded by this award. These are the critical components of the project that require the technical expertise of the U.S. groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.