Muon flux measurement at China Jinping Underground Laboratory

• Published in: Chinese physics C Vol. 45; no. 2; p. 25001
• Main Authors: Guo, Zi-yi, Bathe-Peters, Lars, Chen, Shao-min, Chouaki, Mourad, Dou, Wei, Guo, Lei, Hussain, Ghulam, Li, Jin-jing, Liu, Qian, Luo, Guang, Luo, Wen-tai, Qi, Ming, Shao, Wen-hui, Tang, Jian, Wan, Lin-yan, Wang, Zhe, Xu, Ben-da, Xu, Tong, Xu, Wei-ran, Yang, Yu-zi, Yeh, Minfang, Zhao, Lin
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 01.02.2021
• Subjects: angular distribution; CJPL; cosmic-ray muon ux; liquid scintillator; neutrino detector
• DOI: 10.1088/1674-1137/abccae
• ISSN: 1674-1137

China Jinping Underground Laboratory (CJPL) is ideal for studying solar, geo-, and supernova neutrinos. A precise measurement of the cosmic-ray background is essential in proceeding with R&D research for these MeV-scale neutrino experiments. Using a 1-ton prototype detector for the Jinping Neutrino Experiment (JNE), we detected 264 high-energy muon events from a 645.2-day dataset from the first phase of CJPL (CJPL-I), reconstructed their directions, and measured the cosmic-ray muon flux to be cm s . The observed angular distributions indicate the leakage of cosmic-ray muon background and agree with simulation data accounting for Jinping mountain's terrain. A survey of muon fluxes at different laboratory locations, considering both those situated under mountains and those down mine shafts, indicates that the flux at the former is generally a factor of larger than at the latter, with the same vertical overburden. This study provides a convenient back-of-the-envelope estimation for the muon flux of an underground experiment.