![\"Schematic](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/01\/schematic-view-of-the-juno-detector-arxiv-1200x727.jpg\"\/)
Schematic view of the JUNO detector. \u00a9Arxiv<\/p>\nAfter 17 years of planning and construction, China\u2019s Jiangmen Underground Neutrino Observatory (JUNO) has finally opened its scientific eye. In just two months of operation, this massive detector has already delivered physics results with unprecedented precision, showing signs it could solve a long-standing puzzle in particle physics.<\/p>\n
The 20,000-ton spherical detector, buried 700 meters beneath the surface in Guangdong province, is engineered to study neutrinos, those elusive quantum particles that pass through our bodies by the trillions every second without leaving a trace. With its record-breaking size and sensitivity, JUNO could soon clarify the mysterious mass ordering of these particles and put long-debated theories to rest.<\/p>\n
A Laboratory Like No Other<\/p>\n
The detector itself is a marvel of modern engineering. At the heart of JUNO lies a 35.4-meter-wide acrylic sphere filled with liquid scintillator, a substance that emits light when a neutrino interacts with it. This central sphere is surrounded by 43,212 photomultiplier tubes, devices sensitive enough to detect a single photon. A 35-kiloton water Cherenkov detector and a plastic scintillator layer form additional protection, shielding the core from cosmic rays and background noise.<\/p>\n
Schematic view of the JUNO detector. \u00a9Arxiv<\/p>\n
The facility is located precisely 52.5 km from the Yangjiang and Taishan nuclear power plants, a carefully chosen distance that optimizes the detection of reactor antineutrinos, which are JUNO\u2019s main target. According to the Chinese Academy of Sciences, the detector <\/a>began collecting data on August 26, 2025, and has since maintained a duty cycle of97.8%, reflecting excellent stability during its early science runs.<\/p>\n Breakthrough Precision in Early Results<\/p>\n JUNO\u2019s mission is to determine neutrino mass hierarchy, the order of the masses of the three neutrino types: electron, muon, and tau. Although researchers have long known these particles have different masses, their precise ordering remains one of physics\u2019 major unsolved questions. JUNO aims to resolve it using high-precision measurements of neutrino oscillations.<\/p>\n![\"Left](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/01\/left-pmt-timing-resolution-extracted-with-a-laser-run-right-pmt-time-offset-difference-measured-in-d.jpeg\"\/)
Left: PMT timing resolution extracted with a laser run. Right: PMT Time offset difference measured in different runs taken on 10 October 2025 and 17 October 2025. \u00a9Arxiv<\/p>\n