Identification of anomalous fast bulk events in a p-type point-contact germanium detector  

作　　者：Ren-Ming-Jie Li Shu-Kui Liu Shin-Ted Lin Li-Tao Yang Qian Yue Chang-Hao Fang Hai-Tao Jia Xi Jiang Qian-Yun Li Yu Liu Yu-Lu Yan Kang-Kang Zhao Lei Zhang Chang-Jian Tang Hao-Yang Xing Jing-Jun Zhu 

机构地区：[1]College of Physics,Sichuan University,Chengdu 610065,China [2]Key Laboratory of Particle and Radiation Imaging(Ministry of Education)and Department of Engineering Physics,Tsinghua University,Beijing 100084,China

出　　处：《Nuclear Science and Techniques》2022年第5期53-67,共15页核技术（英文）

基　　金：supported by the National Key Research and Development Program of China(No.2017YFA0402203);the National Natural Science Foundation of China(No.11975162);the SPARK project of the research and innovation program of Sichuan University(No.2018SCUH0051)。

摘　　要：The ultralow detection threshold,ultralow intrinsic background,and excellent energy resolution of ptype point-contact germanium detectors are important for rare-event searches,in particular for the detection of direct dark matter interactions,coherent elastic neutrino-nucleus scattering,and neutrinoless double beta decay.Anomalous bulk events with an extremely fast rise time are observed in the CDEX-1B detector.We report a method of extracting fast bulk events from bulk events using a pulse shape simulation and reconstructed source experiment signature.Calibration data and the distribution of X-rays generated by intrinsic radioactivity verified that the fast bulk experienced a single hit near the passivation layer.The performance of this germanium detector indicates that it is capable of single-hit bulk spatial resolution and thus provides a background removal technique.

关 键 词：p-type point-contact germanium detector Dark matter Pulse shape analysis Anomalous fast bulk events 

分 类 号：TL81[核科学技术—核技术及应用]