The Jiangmen Underground Neutrino Observatory (JUNO) has entered its final phase of construction, marking a significant milestone in China's pursuit of advanced neutrino research. The Institute of High Energy Physics at the Chinese Academy of Sciences announced that key components of the observatory are nearing completion, with all installation tasks expected to be completed by the end of November.
The innermost acrylic sphere, a critical element of JUNO's core detector, has been fully assembled. This sphere houses a 20,000-tonne liquid scintillator used to detect elusive neutrinos. Encasing this sphere is an outer stainless-steel grid, which is currently being fitted with 45,000 photomultiplier tubes designed to capture the faintest flashes of light resulting from neutrino interactions. The acrylic sphere is engineered to withstand a buoyant force of approximately 3,000 tonnes, ensuring stability during long-term operations deep underground.
Located about 700 meters below the surface, JUNO's design presents unique engineering challenges. The team has surmounted several technical hurdles, including the development of photomultiplier tubes with the highest photon detection efficiency in the world. They have also established a high-purity, high-seal, and high-efficiency purification system for the liquid scintillator, achieving the longest attenuation length globally to date.
Upon its completion, JUNO will stand alongside Japan's Super-Kamiokande and the United States' Deep Underground Neutrino Experiment (DUNE), positioning China at the forefront of international neutrino research. JUNO's primary scientific mission is to determine the neutrino mass hierarchy—a fundamental question in particle physics. The observatory is also poised to contribute to other groundbreaking research areas, enhancing our understanding of the universe.
JUNO's advancements not only reflect China's growing capabilities in high-energy physics but also signify the nation's commitment to collaborative international scientific endeavors. As a major facility in neutrino observation, JUNO is set to attract scientists from around the world, fostering global partnerships and driving forward the boundaries of knowledge.
Reference(s):
cgtn.com
