Measurement of photoelectron yield of the CDEX-10 liquid argon detector prototype

【摘要】 The China Dark Matter Experiment（GDEX） 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） antiCompton 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.更多还原

【Abstract】 The China Dark Matter Experiment（GDEX） 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） antiCompton 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.更多还原