Speaker
Description
The Jiangmen Underground Neutrino Observatory (JUNO) is a new-generation neutrino experiment equipped with a total of 20,348 20-inch photomultiplier tubes (PMTs), which include 17,596 PMTs for the central detector and 2,752 PMTs for the VETO detector. Following over a decade of construction, JUNO commenced its scientific operation in August 2025. This poster presents a comprehensive overview of the 20-inch PMT instrumentation, covering key aspects including performance testing, high voltage divider integration, waterproof potting, underwater implosion protection, and on-site installation. Special emphasis is placed on the on-site PMT testing/installation process implemented in the most recent several years.
In addition, the operational status of the 20-inch PMTs since their start of physics operation in August 2025 is summarized. This includes an analysis of the PMTs’ basic performance, statistics of the good and bad PMT channels, and a description of the PMT operational stability, as well as other operation-related characteristics.