Mass testing and characterization of 20-inch PMTs for JUNO
Angel Abusleme, Thomas Adam, S. Ahmad, Rizwan Ahmed, S. Aiello, M. Akram, Abid Aleem, Tsagkarakis Alexandros, Fengpeng An, Qi An, Giuseppe Andronico, Н. Анфимов, V. Antonelli, Tatiana Antoshkina, Burin Asavapibhop, J. P. A. M. de André, Didier Auguste, Weidong Bai, Nikita Balashov, W. Baldini, Andrea Barresi, D. Basilico, E. Baussan, Marco Bellato, Antonio Bergnoli, Thilo Birkenfeld, Sylvie Blin, David Blum, S.C. Blyth, Anastasia Bolshakova, M. Bongrand, Clément Bordereau, D. Breton, A. Brigatti, R. Brugnera, Riccardo Bruno, A. Budano, José Busto, Ilya Butorov, J. Busenitz, Barbara Caccianiga, Hao Cai, X. Cai, Yanke Cai, Zhiyan Cai, Riccardo Callegari, Antonio Cammi, Agustín Campeny, Chuanya Cao, Guofu Cao, Jun Cao, R. Caruso, C. Cerna, Chi Kuen Chan, J. F. Chang, Yun Chang, Guo-Ming Chen, Pingping Chen, Po-An Chen, Shaomin Chen, Xurong Chen, Yixue Chen, Yu Chen, Zhiyuan Chen, Zikang Chen, Jie Cheng, Yaping Cheng, Yu Cheng, Alexey Chetverikov, D. Chiesa, P. Chimenti, A. Chukanov, Gérard Claverie, Catia Clementi, Barbara Clerbaux, Marta Colomer Molla, Selma Conforti Di Lorenzo, Daniele Corti, F. Dal Corso, Olivia Dalager, C. De La Taille, Zhi Deng, Ziyan Deng, Wilfried Depnering, M. Fernández Díaz, Xuefeng Ding, Yayun Ding, Bayu Dirgantara, Sergey Dmitrievsky, Tadeáš Dohnal, Dmitry Dolzhikov, Georgy Donchenko, J. Dong, E. Doroshkevich, M. Dracos, Frédéric Druillole, Ran Du, Shuxian Du, S. Dusini, Martin Dvořák
Abstract
Abstract Main goal of the JUNO experiment is to determine the neutrino mass ordering using a 20 kt liquid-scintillator detector. Its key feature is an excellent energy resolution of at least 3% at 1 MeV, for which its instruments need to meet a certain quality and thus have to be fully characterized. More than 20,000 20-inch PMTs have been received and assessed by JUNO after a detailed testing program which began in 2017 and elapsed for about four years. Based on this mass characterization and a set of specific requirements, a good quality of all accepted PMTs could be ascertained. This paper presents the performed testing procedure with the designed testing systems as well as the statistical characteristics of all 20-inch PMTs intended to be used in the JUNO experiment, covering more than fifteen performance parameters including the photocathode uniformity. This constitutes the largest sample of 20-inch PMTs ever produced and studied in detail to date, i.e. 15,000 of the newly developed 20-inch MCP-PMTs from Northern Night Vision Technology Co. (NNVT) and 5000 of dynode PMTs from Hamamatsu Photonics K. K.(HPK).