Preparation of neutron-activated xenon for liquid xenon detector calibration

We report the preparation of neutron-activated xenon for the calibration of liquid xenon (LXe) detectors. Gamma rays from the decay of xenon metastable states, produced by fast neutron activation, were detected and their activities measured in a LXe scintillation detector. Following a 5-day activation of natural xenon gas with a 252Cf ( 4 × 10 5 n / s ) source, the activities of two gamma ray lines at 164 and 236 keV, from 131mXe and 129mXe metastable states, were measured at about 95 and 130 Bq/kg, respectively. We also observed three additional lines at 35, 100 and 275 keV, which decay away within a few days. No long-lifetime activity was observed after the neutron activation.