Measurement of the drift velocity and transverse diffusion of electrons in liquid xenon with the EXO-200 detector

Abstract

The EXO-200 Collaboration is searching for neutrinoless double $\ensuremath{\beta}$ decay using a liquid xenon (LXe) time projection chamber. This measurement relies on modeling the transport of charge deposits produced by interactions in the LXe to allow discrimination between signal and background events. Here we present measurements of the transverse diffusion constant and drift velocity of electrons at drift fields between 20 V/cm and 615 V/cm using EXO-200 data. At the operating field of 380 V/cm EXO-200 measures a drift velocity of $1.{705}_{\ensuremath{-}0.010}^{+0.014}\phantom{\rule{0.16em}{0ex}}\mathrm{mm}/\ensuremath{\mu}\mathrm{s}$ and a transverse diffusion coefficient of $55\ifmmode\pm\else\textpm\fi{}4\phantom{\rule{0.16em}{0ex}}{\mathrm{cm}}^{2}$/s.