Calibration of liquid argon detector with $^{83m}Kr$ and $^{22}Na$ in different drift field

TL;DR

This paper details the calibration of a liquid argon detector using $^{83m}Kr$ and $^{22}Na$, measuring light yields at different drift fields and confirming the decay rate of $^{83m}Kr$ aligns with known values.

Contribution

The study introduces a calibration method using $^{83m}Kr$ and $^{22}Na$ in liquid argon detectors, analyzing light yield variations with electric fields and verifying $^{83m}Kr$ decay rate.

Findings

Light yield of 7.26 photonelectrons/keV for $^{83m}Kr$

Light yield of 7.66 photonelectrons/keV for $^{22}Na$

Decay half-life of $^{83m}Kr$ measured as 1.83 hours

Abstract

$^{83m}Kr$ and $^{22}Na$ have been used in calibrating a liquid argon (LAr) detector.$^{83m}Kr$ atoms are produced through the decay of $^{83}Rb$ and introduced into the LAr detector through the circulating purification system. The light yield reaches 7.26$\pm$0.02 photonelectrons/keV for 41.5keV from $^{83m}Kr$ and 7.66$\pm$0.01 photonelectrons/keV for the 511keV from $^{22}Na$, as a comparison. The light yield varies with the drift electric field from 50 to 200V/cm have been also reported. After stopping fill, the decay rate of $^{83m}Kr$ with a fitted half-life of 1.83$\pm$0.11 h, which is consistent with the reported value of 1.83$\pm$0.02 h.