Extraction efficiency of drifting electrons in a two-phase xenon time projection chamber

Author(s): Edwards, BNV; Bernard, E; Boulton, EM; Destefano, N; Gai, M; Horn, M; Larsen, N; Tennyson, B; Tvrznikova, L; Wahl, C; McKinsey, DN | Abstract: © 2018 IOP Publishing Ltd and Sissa Medialab. We present a measurement of the extraction efficiency of quasi-free electrons from the liquid into the gas phase in a two-phase xenon time-projection chamber. The measurements span a range of electric fields from 2.4 to 7.1 kV/cm in the liquid xenon, corresponding to 4.5 to 13.1 kV/cm in the gaseous xenon. Extraction efficiency continues to increase at the highest extraction fields, implying that additional charge signal may be attained in two-phase xenon detectors through careful high-voltage engineering of the gate-anode region.