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arXiv · 2112.02892

Low Radioactive Material Screening and Background Control for the PandaX-4T Experiment

Abstract

PandaX-4T is a ton-scale dark matter direct detection experiment using a dual-phase TPC technique at the China Jinping Underground Laboratory. Various ultra-low background technologies have been developed and applied to material screening for PandaX-4T, including HPGe gamma spectroscopy, ICP-MS, NAA, radon emanation measurement system, krypton assay station, and alpha detection system. Low background materials were selected to assemble the detector. Surface treatment procedures were investigated to further suppress radioactive background. Combining measured results and Monte Carlo simulation, the total material background rates of PandaX-4T in the energy region of 1-25 keV$\rm{}_{ee}$ are estimated to be (9.9 $\pm$ 1.9) $\times \ 10^{-3}$ mDRU for electron recoil and (2.8 $\pm$ 0.6) $\times \ 10^{-4}$ mDRU for nuclear recoil. In addition, $^{nat}$Kr in the detector is estimated to be <8 ppt.

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Zhicheng Qian, Lin Si, Abdusalam Abdukerim, Zihao Bo, Wei Chen, Xun Chen, Yunhua Chen, Chen Cheng, Yunshan Cheng, Xiangyi Cui, Yingjie Fan, Deqing Fang, Changbo Fu, Mengting Fu, Lisheng Geng, Karl Giboni, Linhui Gu, Xuyuan Guo, Ke Han, Changda He, Jinrong He, Di Huang, Yanlin Huang, Zhou Huang, Ruquan Hou, Xiangdong Ji, Yonglin Ju, Chenxiang Li, Mingchuan Li, Shu Li, Shuaijie Li, Qing Lin, Jianglai Liu, Xiaoying Lu, Lingyin Luo, Wenbo Ma, Yugang Ma, Yajun Mao, Yue Meng, Xuyang Ning, Ningchun Qi, Xiangxiang Ren, Nasir Shaheed, Changsong Shang, Guofang Shen, Wenliang Sun, Andi Tan, Yi Tao, Anqing Wang, Meng Wang, Qiuhong Wang, Shaobo Wang, Siguang Wang, Wei Wang, Xiuli Wang, Zhou Wang, Mengmeng Wu, Weihao Wu, Jingkai Xia, Mengjiao Xiao, Xiang Xiao, Pengwei Xie, Binbin Yan, Xiyu Yan, Jijun Yang, Yong Yang, Chunxu Yu, Jumin Yuan, Ying Yuan, Dan Zhang, Minzhen Zhang, Peng Zhang, Tao Zhang, Li Zhao, Qibin Zheng, Jifang Zhou, Ning Zhou, Xiaopeng Zhou, Yong Zhou. 2021-12-06. Low Radioactive Material Screening and Background Control for the PandaX-4T Experiment. https://doi.org/10.1007/jhep06(2022)147

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