In-beam gamma rays of CSNS Back-n characterized by black resonance filter

• Published in: Nuclear science and techniques Vol. 35; no. 10
• Main Authors: Wang, Jin-Cheng, Ren, Jie, Jiang, Wei, Ruan, Xi-Chao, Liu, Ying-Yi, Yang, Hao-Lan, Xu, Kuo-Zhi, Pan, Xin-Yi, Sun, Qi, Bao, Jie, Huang, Han-Xiong, Bai, Hao-Fan, Bai, Jiang-Bo, Cao, Ping, Chen, Qi-Ping, Chen, Yong-Hao, Duan, Wen-Hao, Fan, An-Chuan, Fan, Rui-Rui, Feng, Chang-Qing, Gu, Min-Hao, Han, Chang-Cai, Han, Zi-Jie, He, Guo-Zhu, He, Yong-Cheng, Hong, Yang, Hu, Yi-Wei, Jiang, Zhi-Jie, Kang, Ling, Lan, Chang-Lin, Li, Bo, Li, Feng, Li, Qiang, Li, Xiao, Li, Yang, Liu, Jie, Liu, Rong, Liu, Shu-Bin, Liu, Yi-Na, Luan, Guang-Yuan, Ning, Chang-Jun, Qiu, Yi-Jia, Ren, Wen-Kai, Ren, Zhi-Zhou, Song, Zhao-Hui, Sun, Kang, Tan, Zhi-Xin, Tang, Jing-Yu, Tang, Sheng-Da, Wang, Li-Jiao, Wang, Peng-Cheng, Wang, Zhao-Hui, Wen, Zhong-Wei, Wu, Xiao-Guang, Wu, Xuan, Wu, Ze-Peng, Xia, Cong, Xie, Li-Kun, Yi, Han, Yu, Tao, Yu, Yong-Ji, Zhang, Guo-Hui, Zhang, Hang-Chang, Zhang, Qi-Wei, Zhang, Xian-Peng, Zhang, Yu-Liang, Zhang, Zhi-Yong, Zhao, Mao-Yuan, Zhou, Zhi-Hao, Zhu, Ke-Jun, Zou, Chong
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.10.2024
• Subjects: Beam Physics; Nuclear Energy; Particle Acceleration and Detection; Particle and Nuclear Physics; Physics; Physics and Astronomy; In-beam gamma rays; Back-n; Black filter resonance technique; scintillator
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1007/s41365-024-01553-8

The back-streaming white-neutron beamline (Back-n) of the China Spallation Neutron Source is an essential neutron-research platform built for the study of nuclear data, neutron physics, and neutron applications. Many types of cross-sectional neutron-reaction measurements have been performed at Back-n since early 2018. These measurements have shown that a significant number of gamma rays can be transmitted to the experimental stations of Back-n along with the neutron beam. These gamma rays, commonly referred to as in-beam gamma rays, can induce a non-negligible experimental background in neutron-reaction measurements. Studying the characteristics of in-beam gamma rays is important for understanding the experimental background. However, measuring in-beam gamma rays is challenging because most gamma-ray detectors are sensitive to neutrons; thus, discriminating between neutron-induced signals and those from in-beam gamma rays is difficult. In this study, we propose the use of the black resonance filter method and a CeBr 3 scintillation detector to measure the characteristics of the in-beam gamma rays of Back-n. Four types of black resonance filters, 181 Ta, 59 Co, nat Ag, and nat Cd, were used in this measurement. The time-of-flight (TOF) technique was used to select the detector signals remaining in the absorption region of the TOF spectra, which were mainly induced by in-beam gamma rays. The energy distribution and flux of the in-beam gamma rays of Back-n were determined by analyzing the deposited energy spectra of the CeBr 3 scintillation detector and using Monte Carlo simulations. Based on the results of this study, the background contributions from in-beam gamma rays in neutron-reaction measurements at Back-n can be reasonably evaluated, which is beneficial for enhancing both the experimental methodology and data analysis.