China’s Jiangmen Underground Neutrino Observatory (JUNO) has officially entered its final construction phase, marking a significant milestone in the global pursuit of neutrino research. According to the Institute of High Energy Physics at the Chinese Academy of Sciences, the project is on track to be completed by the end of November.
At the heart of JUNO lies the world’s largest single acrylic sphere, which has now been fully assembled deep underground at a depth of approximately 700 meters. This colossal sphere houses a 20,000-tonne liquid scintillator designed to detect elusive neutrinos, particles that hold the secrets to some of the universe’s most fundamental mysteries. Surrounding the sphere, the installation of the outer stainless-steel grid and 45,000 photomultiplier tubes is progressing smoothly.
JUNO’s primary scientific objective is to determine the neutrino mass hierarchy, a critical question in particle physics that could enhance our understanding of the universe’s formation and evolution. The observatory will also facilitate other cutting-edge research, positioning it as a key international center for neutrino studies upon its completion.
The construction team has surmounted numerous technical challenges to bring JUNO to fruition. Notably, they have developed photomultiplier tubes boasting the highest photon detection efficiency in the world. Additionally, a high-purity, high-seal, and high-efficiency purification system for the liquid scintillator has been created, achieving the world’s longest attenuation length to date. The acrylic sphere itself is engineered to withstand a buoyant force of approximately 3,000 tonnes over long-term operation.
Once operational, JUNO will stand alongside Japan’s Super-Kamiokande and the United States’ Deep Underground Neutrino Experiment, solidifying the Chinese mainland’s leading position in the field of neutrino research. The observatory is expected to attract scientists from around the globe, fostering international collaboration and accelerating advancements in our understanding of the universe.
Reference(s):
cgtn.com
