Development of a comprehensive PMT optical model for the JUNO experiment
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Shandong University（山东大学）；Joint Institute for Nuclear Research（俄罗斯杜布纳联合核子研究所）；Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University（中山大学中法核工程与技术学院）；School of Physics, Sun Yat-sen University（中山大学物理学院）
Y. Ren, X. Yang, Y. Wang, Z. Deng, Z. Qin, A. Olshevskiy, W. Wang, N. Anfimov, Z. Wang, G. Cao
There are 17,612 20-inch photomultiplier tubes (PMTs) installed at the Jiangmen Underground Neutrino Observatory (JUNO). Developing a precise optical model for the PMTs is crucial for enhancing the accuracy of detector simulations and refining the energy response model at JUNO. In this study, we established a comprehensive PMT optical model based on prior studies, taking into account the non-uniformity of photon detection efficiency (PDE) across the PMT surface and the variances in PDE as well as reflections among different PMTs. By collecting reflectance data from 669 PMTs and utilizing PDE data from mass testing systems, we estimated the thickness maps of the photocathode (PC) and the anti-reflective coating (ARC) for each PMT. We also determined the collection efficiency (CE) by decomposing PDE with consideration of the optical processes occurring within the PMTs. The refractive index and extinction coefficient of both the PC and ARC, along with the escape factor, were evaluated over a broad wavelength range of 300~nm to 700~nm, covering the entire spectrum of interest for JUNO. Compared to the prediction from a simplified PMT optical model, which assumes uniform PC and ARC across all PMTs of the same type, the further developed PMT optical model yields much more reflectance for HPK PMTs and less for NNVT PMTs, and the change in PDE is at the level of a few percent. This comprehensive PMT optical model also provides a valuable reference for other PMT-based applications.
Long-Delayed Afterpulse Measurement of JUNO 20-inch Photomultiplier Tubes
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；Nanjing University（南京大学）；University of Science and Technology of China（中国科学技术大学）；China Center of Advanced Science and Technology（中国高等科学技术中心）
Realistic Detector Geometry Modeling and Its Impact on Event Reconstruction in JUNO
Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）
Machine-Learning based photon counting for PMT waveforms and its application to the improvement of the energy resolution in large liquid scintillator detectors
Design, waterproofing, and mass production of the 3-inch PMT frontend system of JUNO
Institute of High Energy Physics（中国科学院高能物理研究所）；Univ. Bordeaux, CNRS, LP2I, UMR 5797（波尔多大学）；Guangxi University（广西大学）；IPHC, Université de Strasbourg, CNRS/IN2P3（斯特拉斯堡大学）；Pakistan Institute of Nuclear Science and Technology（巴基斯坦核科学与技术研究所）；Sun Yat-Sen University（中山大学）；The University of Liverpool（利物浦大学）；INFN Catania and Dipartimento di Fisica e Astronomia dell Università di Catania（卡塔尼亚大学）；Joint Institute for Nuclear Research（杜布纳联合核子研究所）；INFN Sezione di Milano and Dipartimento di Fisica dell Università di Milano（米兰大学）
Embedded underwater front-end electronics for the 3-inch photomultipliers in the JUNO experiment
Univ. Bordeaux, CNRS, LP2I（波尔多大学）；Institute of High Energy Physics（高能物理研究所）；Millennium Institute for SubAtomic Physics at the High-energy Frontier (SAPHIR), ANID（前沿高能子原子物理学千年研究所）；Department of Physics and Astronomy, University of California, Irvine（加州大学尔湾分校物理与天文学系）；IPHC, Université de Strasbourg, CNRS/IN2P3（斯特拉斯堡大学）；Sun Yat-Sen University（中山大学）；The University of Liverpool（利物浦大学）；INFN Catania and Dipartimento di Fisica e Astronomia dell Università di Catania（卡塔尼亚大学）；Joint Institute for Nuclear Research（联合核研究所）
