Tootfinder

A highly sensitive SF$_6$-based leak test system for JUNO 3-inch PMT underwater electronics boxes
Ziliang Chu, Diru Wu, Miao He, Jilei Xu, Xiaoping Jing, Jian Wang
https://arxiv.org/abs/2505.24142

A highly sensitive SF$_6$-based leak test system for JUNO 3-inch PMT underwater electronics boxes
A total of 25600 3-inch photomultiplier tubes (PMTs), along with their corresponding frontend electronics, have been installed at the Jiangmen Underground Neutrino Observatory (JUNO). These electronics are housed in 200 stainless steel boxes that operate underwater. To verify the sealing integrity of the underwater boxes following integration, we developed an SF$_6$-based leak test system, opting against the typical helium-based system due to helium's ability to penetrate the PMT glass. After a…