Calibration of liquid argon detector with 83mKr and 22Na in different drift fields

Abstract

Liquid noble gases are widely used as targets in low background search experiments, particularly in direct dark matter search experiments. 83mKr is an excellent low-energy internal calibration source for future larger liquid noble gas detectors. To calibrate liquid argon detector with 83mKr in different drift fields and to study the correlation between light yield and drift fields. A dual-phase LAr prototype detector was designed to study the 83mKr responses in liquid argon. 83mKr atoms are produced through the decay of 83Rb and introduced into the LAr detector through the circulating purification system. We report that the light yield reaches 7.26 ± 0.02 pe/keV for 41.5 keV from 83mKr and 7.66 ± 0.01 pe/keV for 511 keV from 22Na, as a comparison. After stopping the fill, the rate decays of 83mKr are with a fitted half-life of 1.83 ± 0.11 h, which is consistent with the reported value of 1.83 ± 0.02 h. The light yield that varies with the drift electric field from 0 to 200 V/cm has also been reported.