Self-shielding effect of a single phase liquid xenon detector for direct dark matter search

Abstract Liquid xenon is a suitable material for a dark matter search. For future large scale experiments, single phase detectors are attractive due to their simple configuration and scalability. However, in order to reduce backgrounds, they need to fully rely on liquid xenon’s self-shielding property. A prototype detector was developed at Kamioka Observatory to establish vertex and energy reconstruction methods and to demonstrate the self-shielding power against γ -rays from outside of the detector. 662 keV γ -rays from 137 Cs are attenuated by a factor of about 50 over a distance of 20 cm.