title: The characteristics of a low background germanium gamma ray spectrometer at China JinPing Underground Laboratory.
abstract: A low background germanium gamma ray spectrometer, GeTHU, has been installed at China JinPing Underground Laboratory (CJPL). The integral background count rate of the spectrometer was 0.629 cpm between 40 and 2700 keV, the origins of which were studied by Monte Carlo simulation. Detection limits and efficiencies were calculated for selected gamma peaks. Some samples of rare event experiments were measured and (137)Cs contamination was found in boric acid. GeTHU will be mainly used to measure environmental samples and screen materials in dark matter and double beta decay experiments.
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Yuhao
authors.initials: Y
authors.lastname: Mi
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China. Electronic address: mahao@tsinghua.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Su
authors.affiliation: Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yue
keywords: CJPL; Germanium spectrometer; Low-background