R&D towards a Hydrogen-Doped Liquid Xenon TPC at LBNL

WIMP dark matter direct detection experiments, such as LUX-ZEPLIN (LZ) and XENONnT, use liquid xenon as the medium of detection. While these experiments have high sensitivity for dark matter candidates with mass greater than O(10 GeV/c²), these detectors lose sensitivity to candidates lighter than O(10 GeV/c²) due to poor kinematic matching with the xenon nucleus. HydroX aims to address this issue by doping liquid xenon with a light element, such as hydrogen, in order to give greater sensitivity for dark matter candidates with mass in the O(1 GeV/c²) range. This talk will describe the current progress of HydroX R&D at LBNL, where a test setup is being used to characterize the scintillation and ionization signal response from doped liquid xenon.