Measurement of photoelectron yield of the CDEX-10 liquid argon detector prototype
- Received Date: 2016-01-31
- Accepted Date: 2016-03-23
- Available Online: 2016-11-05
Abstract: The China Dark Matter Experiment (CDEX) is a low background experiment at China Jinping Underground Laboratory (CJPL) designed to directly detect dark matter with a high-purity germanium (HPGe) detector. In the second phase, CDEX-10, which has a 10 kg germanium array detector system, a liquid argon (LAr) anti-Compton active shielding and cooling system is proposed. To study the properties of the LAr detector, a prototype with an active volume of 7 liters of liquid argon was built and operated. The photoelectron yields, as a critically important parameter for the prototype detector, have been measured to be 0.051-0.079 p.e./keV for 662 keV γ rays at different positions. The good agreement between the experimental and simulation results has provided a reasonable understanding and determination of the important parameters such as the surviving fraction of the Ar2* excimers, the absorption length for 128 nm photons in liquid argon, the reflectivity of Teflon and so on.