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arXiv · 2201.02961

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

Renmingjie Li·Shukui Liu·Shinted Lin·Litao Yang·Qian Yue·Changhao Fang·Haitao Jia·Xi Jiang·Qianyun Li·Yu Liu·Yulu Yan·Kangkang Zhao·Lei Zhang·Changjian Tang·Haoyang Xing·Jingjun Zhu
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Abstract

The ultralow detection threshold, ultralow intrinsic background, and excellent energy resolution of p-type point-contact germanium detector 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.

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Renmingjie Li, Shukui Liu, Shinted Lin, Litao Yang, Qian Yue, Changhao Fang, Haitao Jia, Xi Jiang, Qianyun Li, Yu Liu, Yulu Yan, Kangkang Zhao, Lei Zhang, Changjian Tang, Haoyang Xing, Jingjun Zhu. 2022-09-21. Identification of the anomalous fast bulk events in a p-type point contact germanium detector. https://doi.org/10.1007/s41365-022-01041-x

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