Electron train backgrounds in liquid xenon dark matter search detectors are indeed due to thermalization and trapping

Understand

Electron emission from liquid into gaseous xenon is a cornerstone of dark matter search detectors such as ZEPLIN, XENON, LUX and LZ.

• The probability of emission is a function of the applied electric field E, and electrons which fail to pass from the liquid into the gas have been previously hypothesized to become thermalized and trapped.
• This article shows, for the first time, quantitative agreement between an electron emission model and existing data.
• The model predicts that electrons in the liquid must surmount a typical potential barrier phi_b=0.34+-0.01 eV in order to escape into the gas.