China’s Underground Neutrino Experiment: A Global First Begins Operations

On August 26, 2025, the Jiangmen Underground Neutrino Experiment (JUNO), a decade-long endeavor by Chinese scientists, officially began operations 700 meters beneath Jiangmen, Guangdong, to capture the universe’s elusive “ghost particles”—neutrinos. This marks the world’s first ultra-large-scale, ultra-high-precision neutrino-dedicated scientific facility to go live.

Located 700 meters underground near Jiangmen city, the JUNO detector targets neutrinos generated by the Taishan and Yangjiang nuclear power plants 53 kilometers away, measuring their energy spectra with unprecedented accuracy.

What Are Neutrinos, and How Are They Detected?

Neutrinos are cosmic time capsules, offering clues to the universe’s past and keys to its future. Detecting them is a formidable challenge, as they rarely interact with matter—billions pass through our bodies every second, unnoticed. The key lies in photomultiplier tubes (PMTs), dubbed “golden eyes” by scientists.

These tubes detect the faint fluorescence emitted when neutrinos strike a scintillator, a glow one-hundred-billionth the brightness of a phone screen. The metal film inside the tubes, just tens of nanometers thick, was once a closely guarded foreign technology. Chinese scientists, through millions of trials, independently mastered its production, breaking the monopoly and slashing PMT costs by over half.

JUNO employs 45,000 such tubes, and this breakthrough saved hundreds of millions of yuan, enabling a cost-effective yet cutting-edge facility. With these precise “eyes,” humanity stands poised to decipher the universe’s hidden language and unravel its deepest mysteries.

Source: CCTV News