Construction and on-site performance of the LHAASO WFCTA camera
F. Aharonian, Q. An, Axikegu, Lixin Bai, Y. X. Bai, Y. W. Bao, D. Bastieri, Xiao-Jun Bi, Y. J. Bi, H. Cai, J. T. Cai, Z. Cao, Z. Cao, Jin Chang, Jin Chang, X. Chang, B. M. Chen, J. Chen, Lin Chen, Lin Chen, Lin Chen, M. J. Chen, M. L. Chen, Q. H. Chen, Shaw H. Chen, S. Z. Chen, T. L. Chen, X. L. Chen, Yong Chen, Na Cheng, Y. D. Cheng, S. W. Cui, Xiaohong Cui, Y. D. Cui, B. Z. Dai, H. L. Dai, Zi-Gao Dai, Danzengluobu Danzengluobu, D. della Volpe, B. D′Ettorre Piazzoli, X. Dong, J. H. Fan, Yi-Zhong Fan, Z. X. Fan, J. Fang, Ke Fang, C. F. Feng, Li Feng, S. H. Feng, Y. L. Feng, B. S. Gao, C. D. Gao, Q. Gao, Wei Gao, M. M. Ge, Li‐Sheng Geng, G. Gong, Q. B. Gou, M. H. Gu, J. G. Guo, Xueling Guo, Yi-Qing Guo, Y. Y. Guo, Y. A. Han, H. H. He, Hao-Ning He, Junjiang He, S. L. He, Xinyu He, Yan He, M. Heller, Y. K. Hor, C. Hou, Xianglin Hou, H. B. Hu, S. Hu, S. C. Hu, X. Hu, Dezhi Huang, Q. Huang, Wenhao Huang, X. T. Huang, Zhongjie Huang, Fei Ji, X. L. Ji, H. Y. Jia, K. Jiang, Z. J. Jiang, Chao Jin, D. Kuleshov, K. Levochkin, Bing Li, C. Li, C. Li, F. Li, Hao Li, H. C. Li, H. Y. Li, J. Li, K. Li
Abstract
Abstract The focal plane camera is the core component of the Wide Field-of-view Cherenkov/fluorescence Telescope Array (WFCTA) of the Large High-Altitude Air Shower Observatory (LHAASO). Because of the capability of working under moonlight without aging, silicon photomultipliers (SiPM) have been proven to be not only an alternative but also an improvement to conventional photomultiplier tubes (PMT) in this application. Eighteen SiPM-based cameras with square light funnels have been built for WFCTA. The telescopes have collected more than 100 million cosmic ray events and preliminary results indicate that these cameras are capable of working under moonlight. The characteristics of the light funnels and SiPMs pose challenges (e.g. dynamic range, dark count rate, assembly techniques). In this paper, we present the design features, manufacturing techniques and performances of these cameras. Finally, the test facilities, the test methods and results of SiPMs in the cameras are reported here.