2025/05/30 by Ziliang Chu, Diru Wu, Chu, Ziliang +9 · 1 citation
Computer Science · Engineering · #Embedded Systems and FPGA Applications #Engineering Applied Research #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Instrumentation and Detectors (physics.ins-det) #Internet of Things and Social Network Interactions
paper · pdf · doi:10.48550/arxiv.2505.24142
openalex publication_date 2025/05/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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 SF6-based leak test system, opting against the typical helium-based system due to helium's ability to penetrate the PMT glass. After a few hours of accumulating leaking SF6 from the underwater boxes, a leak rate detection limit of 2.3×10-9~Pa⋅m3/s in terms of SF6 was achieved, corresponding to 1.65×10-8~Pa⋅ m3/s helium equivalent. This meets the sensitivity requirement of 1×10-7~Pa⋅m3/s. This system was critical in identifying and replacing a few cases of leaking underwater boxes before installation.