Groundbreaking Neutrino Experiment Poised for Launch as Completion Draws Near

Scientists are finalizing the Jiangmen Underground Neutrino Observatory, or JUNO, which will explore the elusive characteristics of neutrinos, a category of exceptionally light subatomic particles devoid of electric charge, along with their antiparticle counterparts, antineutrinos.

Scheduled to commence data collection in summer 2025, JUNO intends to ascertain which of the three varieties of neutrinos possesses the greatest mass. It will stand as the most substantial detector of its kind globally.

At the center of the detector, situated 700 meters below ground in China, is a spherical acrylic structure approximately 35 meters in diameter. It will be filled with 20,000 metric tons of liquid scintillator, which generates light in reaction to particles created when an antineutrino collides with a proton within the liquid. Tens of thousands of photomultiplier tubes will monitor the scintillator for flashes induced by antineutrinos. Encircling the sphere, a cylindrical pit will be filled with water to assist in filtering out subatomic particles that are not antineutrinos but may resemble them. Scientists began the process of filling this pit with water on December 18.

When fully operational, the detector will analyze antineutrinos emitted abundantly as by-products from two nuclear power stations, located approximately 50 kilometers away.

To view some images of JUNO being constructed, browse through the slideshow below.