Measurement of the 232Th(n,f) cross section in the 1–200 MeV range at the CSNS Back-n

• Published in: Nuclear science and techniques Vol. 34; no. 8; pp. 1 - 12
• Main Authors: Ren, Zhi-Zhou, Yang, Yi-Wei, Chen, Yong-Hao, Liu, Rong, Ye, Bang-Jiao, Wen, Jie, Guo, Hai-Rui, Han, Zi-Jie, Chen, Qi-Ping, Wen, Zhong-Wei, Sun, Wei-Li, Yi, Han, Liu, Xing-Yan, Ye, Tao, Bai, Jiang-Bo, An, Qi, Bao, Jie, Bao, Yu, Cao, Ping, Chen, Hao-Lei, Chen, Zhen, Cui, Zeng-Qi, Fan, Rui-Rui, Feng, Chang-Qing, Gao, Ke-Qing, Gao, Xiao-Long, Gu, Min-Hao, Han, Chang-Cai, He, Guo-Zhu, He, Yong-Cheng, Hong, Yang, Hu, Yi-Wei, Huang, Han-Xiong, Huang, Xi-Ru, Jiang, Hao-Yu, Jiang, Wei, Jiang, Zhi-Jie, Jing, Han-Tao, Kang, Ling, Li, Bo, Li, Chao, Li, Jia-Wen, Li, Qiang, Li, Xiao, Li, Yang, Liu, Jie, Liu, Shu-Bin, Long, Ze, Luan, Guang-Yuan, Ning, Chang-Jun, Niu, Meng-Chen, Qi, Bin-Bin, Ren, Jie, Ruan, Xi-Chao, Song, Zhao-Hui, Sun, Kang, Sun, Zhi-Jia, Tan, Zhi-Xin, Tang, Jing-Yu, Tang, Xin-Yi, Tian, Bin-Bin, Wang, Li-Jiao, Wang, Peng-Cheng, Wang, Zhao-Hui, Wu, Xiao-Guang, Wu, Xuan, Xie, Li-Kun, Yang, Xiao-Yun, Yu, Li, Yu, Tao, Yu, Yong-Ji, Zhang, Guo-Hui, Zhang, Lin-Hao, Zhang, Qi-Wei, Zhang, Xian-Peng, Zhang, Yu-Liang, Zhang, Zhi-Yong, Zhou, Lu-Ping, Zhou, Zhi-Hao, Zhu, Ke-Jun
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.09.2023; Department of Engineering and Applied Physics,University of Science and Technology of China,Hefei 230026,China%Institute of High Energy Physics,Chinese Academy of Sciences(CAS),Beijing 100049,China; State Key Laboratory of Particle Detection and Electronics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,China%Northwest Institute of Nuclear Technology,Xi'an 710024,China%Institute of High Energy Physics,Chinese Academy of Sciences(CAS),Beijing 100049,China; Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China; State Key Laboratory of Particle Detection and Electronics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,China%Institute of High Energy Physics,Chinese Academy of Sciences(CAS),Beijing 100049,China; University of Chinese Academy of Sciences,Beijing 100049,China; Spallation Neutron Source Science Center,Dongguan 523803,China; University of Chinese Academy of Sciences,Beijing 100049,China%State Key Laboratory of Particle Detection and Electronics,University of Science and Technology of China,Hefei 230027,China; Spallation Neutron Source Science Center,Dongguan 523803,China%Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China%Institute of Applied Physics and Computational Mathematics,Beijing 100088,China%Department of Modern Physics,University of Science and Technology of China,Hefei 230026,China; State Key Laboratory of Particle Detection and Electronics,University of Science and Technology of China,Hefei 230027,China%Key Laboratory of Nuclear Data,China Institute of Atomic Energy,Beijing 102413,China%State Key Laboratory of Particle Detection and Electronics,University of Science and Technology of China,Hefei 230027,China; School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230027,China%State Key Laboratory of Nuclear Physics and Technology,School of Physics,Peking University,Beijing 100871,China%Institute of High Energy Physics,Chinese Academy of Sciences(CAS),Beijing 100049,China; State Key Laboratory of Particle Detection and Electronics,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing,China; Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,China%Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621900,China%Institute of High Energy Physics,Chinese Academy of Sciences(CAS),Beijing 100049,China
• Subjects: Beam Physics; Nuclear Energy; Particle Acceleration and Detection; Particle and Nuclear Physics; Physics; Physics and Astronomy; Fast-fission ionization chamber; Th(n,f) cross section; Back-n white neutron source; 232Th(n,f)cross section
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1007/s41365-023-01271-7

The 232 Th(n,f) cross section is very important in basic nuclear physics and applications based on the Th/U fuel cycle. Using the time-of-flight method and a multi-cell fast-fission ionization chamber, a novel measurement of the 232 Th(n,f) cross section relative to 235 U in the 1–200 MeV range was performed at the China Spallation Neutron Source Back-n white neutron source (Back-n). The fission event-neutron energy spectra of 232 Th and 235 U fission cells were measured in the single-bunch mode. Corrected 232 Th/ 235 U fission cross-sectional ratios were obtained, and the measurement uncertainties were 2.5–3.7% for energies in the 2–20 MeV range and 3.6–6.2% for energies in the 20–200 MeV range. The 232 Th(n,f) cross section was obtained by introducing the standard cross section of 235 U(n,f). The results were compared with those of previous theoretical calculations, measurements, and evaluations. The measured 232 Th fission cross section agreed with the main evaluation results in terms of the experimental uncertainty, and 232 Th fission resonances were observed in the 1–3 MeV range. The present results provide 232 Th(n,f) cross-sectional data for the evaluation and design of Th/U cycle nuclear systems.