Study on cosmogenic activation in germanium detectors for future tonne-scale CDEX experiment

• Published in: Science China. Physics, mechanics & astronomy Vol. 62; no. 1; p. 11011
• Main Authors: Ma, JingLu, Yue, Qian, Lin, ShinTed, Wong, Henry Tsz-King, Hu, JinWei, Jia, LiPing, Jiang, Hao, Li, Jin, Liu, ShuKui, Liu, ZhongZhi, Ma, Hao, Tang, WeiYou, Tian, Yang, Wang, Li, Wang, Qing, Wang, Yi, Yang, LiTao, Zeng, Zhi
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 2019; Springer; Springer Nature B.V
• Subjects: Activation analysis; Astronomy; Beta decay; Classical and Continuum Physics; Crystal growth; Dark matter; Dark matter (Astronomy); Detectors; Experiments; Fabrication; Germanium; Isotopes; Laboratories; Neutrinos; Neutrons; Observations and Techniques; Physics; Physics and Astronomy; Radioisotopes; Sea level; Sensors; Solar neutrinos; Spectra; germanium detectors; cosmogenic activation; background level; production rate; dark matter
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-018-9215-0

A study on cosmogenic activation in germanium was carried out to evaluate the cosmogenic background level of natural and 70Ge depleted germanium detectors. The production rates of long-lived radionuclides were calculated with Geant4 and CRY. Results were validated by comparing the simulated and experimental spectra of CDEX-1B detector. Based on the validated codes, the cosmogenic background level was predicted for further tonne-scale CDEX experiment. The suppression of cosmogenic background level could be achieved by underground germanium crystal growth and high-purity germanium detector fabrication to reach the sensitivity requirement for direct detection of dark matter. With the low cosmogenic background, new physics channels, such as solar neutrino research and neutrinoless double-beta decay experiments, were opened and the corresponding simulations and evaluations were carried out.