Sensitivity analysis of gamma spectroscopy system with dual high-purity germanium detectors
YAO Yukun,
ZHANG Tao,
CHENG Chen,
SHEN Xun,
LIU Jianglai,
MENG Yue,
QIAN Zhicheng,
SI Lin,
WANG Siguang,
WU Mengmeng
Affiliations
YAO Yukun
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
ZHANG Tao
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
CHENG Chen
School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
SHEN Xun
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
LIU Jianglai
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
MENG Yue
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
QIAN Zhicheng
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
SI Lin
(Institute of Nuclear and Particle Physics, Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Key Laboratory for Particle Physics and Cosmology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China)
WANG Siguang
School of Physics, State Key Laboratory of Nuclear Physics and Technology and Center for High Energy Physics, Peking University, Beijing 100871, China
WU Mengmeng
School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
BackgroundIn rare decay experiments, for instance dark matter and neutrino experiments, rays produced by the radioavtive decay in detector material induce extra experiment background, the energy deposition would contaminate the concerned region. Accurately measuring radioactivity of detector materials, better understanding background source, and controlling experimental background are extremely important to improve sensitivity for those detections. With high energy resolution, flexibility for sample geometry and non-destructive processing for samples, high-purity germanium (HPGe) γ spectroscopy is a widely used ultra-low radioactive technology. The PandaX collaboration set up two high-purity germanium γ spectroscopies, so-call JP1 and JP2, in Jinping underground laboratory.PurposeThis study aims to improve the sensitivity of γ spectroscopies, precisely measure materials with lower radioactivity and screen lower radioactive material for dark matter and neutrino experiments by designing a gamma spectroscopy system with dual high-purity germanium detectors based on the existing JP1.MethodsTwo approaches, i.e., enhancing efficiency and suppressing background were adopted to improve the sensitivity of both HPGe detectors, and the Monto Carlo method was employed to analyze the efficiency and background source of JP1, hence the improved result of dual high-purity germanium detectors was estimated.ResultsFor different nuclides concerned in dark matter and neutrino experiments, the minimum detectable activity of dual high-purity germanium γ spectroscopy system is expected to improve by factor of 2~4. This new system can also measure the radioactivity with γ-γ coincidence method to improve the sensitivity for small size samples.ConclusionsDual high-purity germanium γ spectroscopy can improve sensitivity of factor 2~4 and apply to developing a new γ-γ coincidence method.
