According to CCTV reports, today,The Jiangmen Neutrino Experiment (JUNO) successfully completed the infusion of 20,000 tons of liquid scintillator and officially started taking data..The Jiangmen Neutrino Experiment has become the first large scientific facility in the world dedicated to ultra-large-scale and ultra-high-precision neutrinos.
This large scientific device can begin to solve a major problem in the field of particle physics in the next decade: neutrino mass sequencing, and assist scientists in conducting cutting-edge research on neutrinos from the sun, supernovae, atmosphere and earth, opening a new window to explore unknown physics.
According to reports,The Jiangmen Neutrino Experiment Detector is located 700 meters underground near Jiangmen City, Guangdong Province. It can detect neutrinos produced by Taishan and Yangjiang nuclear power plants 53 kilometers away and measure their energy spectra with unprecedented precision..
Wang Yifang, spokesperson of the Jiangmen Neutrino Cooperation Group, said in an interview: "It is a breakthrough progress to complete the perfusion of the Jiangmen neutrino detector and start running and taking numbers."
According to his introduction,This is the first time in the world that such a large-scale and ultra-high-precision neutrino-specific large-scale scientific device has been operated., will make it possible to answer fundamental questions about the nature of matter and the universe.
Additional information:
The Jiangmen Neutrino Experiment was conceived by the Institute of High Energy Physics of the Chinese Academy of Sciences in 2008. It received support from the Strategic Priority Science and Technology Project (Type A) of the Chinese Academy of Sciences in 2013, and was supported by the Guangdong Provincial People's Government in the same year. Construction of tunnels and underground laboratories was launched in 2015.
In December 2021, the laboratory construction was completed and the installation and construction of the detector in the underground laboratory began. In December 2024, the construction of the main body of the detector was completed and the filling of ultrapure water and liquid scintillator began.
During the filling process,The project team first completed the filling of more than 60,000 tons of ultrapure water within 45 days, controlling the liquid level difference between the inner and outer organic glass balls to centimeters, and the flow deviation did not exceed 0.5%, effectively ensuring the safety and stability of the main structure of the detector.
After half a year of meticulous operation, 20,000 tons of liquid scintillator was accurately injected into a 35.4-meter-diameter organic glass ball, and the replacement of the original pure water was simultaneously completed.
What is particularly critical is that the special requirements of ultra-high cleanliness, transparency and extremely low radioactive background for ultrapure water and liquid scintillator are all met.
At the same time, the project team completed the debugging and optimization of the detector, ensuring that the detector immediately entered the formal operation and counting stage after the perfusion was completed.
JUNO's core detector is a liquid scintillator detector (central detector) with an effective mass of 20,000 tons, which is placed in the center of a 44-meter-deep pool in the underground experimental hall.
The stainless steel lattice shell with a diameter of 41.1 meters serves as the main support structure, carrying many key components including a 35.4-meter-diameter plexiglass sphere, 20,000 tons of liquid scintillator, 20,000 20-inch photomultiplier tubes, 25,000 3-inch photomultiplier tubes, front-end electronics, cables, antimagnetic coils and light isolation panels.
Photomultiplier tubes all over the inner wall of the detector work together to detect the scintillation light produced by the interaction between neutrinos and liquid scintillation, and convert it into an electrical signal for output.
JUNO is designed to have a service life of up to 30 years and can later be upgraded to become the world's most sensitive neutrino-free double-beta decay experiment.
