RII Track-4: Liquid Xenon Time Projection Chamber R&D on the Large Xenon Test Stand at LLNL

Large, monolithic liquid xenon time-projection chambers have been demonstrated to be among the most powerful tools for low-background rare-event searches. In particular, the direct dark matter search community has embraced them as the leaders of the next generation program that is beginning to take shape. EXO-200 has also demonstrated the potential for such a detector to meet the next generation target for a tonne-scale neutrinoless double-beta decay search. The goal of this fellowship will be to initiate a long-term collaboration between the University of South Dakota (USD) and the Lawrence Livermore National Laboratory (LLNL). This collaboration will leverage the large xenon test facility at LLNL to perform R&D towards a (five) tonne scale liquid-xenon time-projection chamber to eventually search for the neutrinoless double-beta decay of Xe-136 with the nEXO experiment. The primary objective of the LLNL test facility, once we finish construction and commissioning, will be to qualify the electric field for the full diameter of nEXO. However, it can house many of the novel detector systems being prototyped for nEXO including novel charge readout tiles and custom silicon photomultipliers. The test facility will also be used to prototype external xenon handling systems. Immersing the PI in this R&D nexus for nEXO will ensure that the PI will have the expertise to contribute to the ongoing success of the nEXO experiment.