Physicists are putting the finishing touches on the Jiangmen Underground Neutrino Observatory (JUNO), which will probe the secret ways of neutrinos, a swarm of ultralight subatomic particles without electric charge, and their antiparticle partners, the antineutrinos.
JUNO, which is scheduled to begin collecting data in the summer of 2025, aims to determine which of the three types of neutrinos is the heaviest. This will be the largest detector of its type in the world.
At the center of the detector, located 700 meters underground in China, is an acrylic sphere about 35 meters wide. It will be filled with a 20,000-ton liquid scintillator that will emit light in response to particles produced when passing antineutrinos interact with protons in the liquid. Tens of thousands of photomultiplier tubes will watch the scintillator for antineutrino-causing glimmers. The water surrounding the sphere will fill a cylindrical pit that will help filter out subatomic particles that are not antineutrinos but can mimic them. Scientists began filling the pit with water on December 18.
Once operational, the detector will scrutinize antineutrinos emitted as abundant byproducts from two nuclear power plants, each about 50 kilometers apart.
Scroll through the slideshow below to see photos of JUNO together.
