Taizhou firm builds world's largest detector for China's neutrino observatory

The acrylic sphere built by Donchamp in Taizhou, Jiangsu. [Photo/Taizhou Daily]

The Jiangmen Underground Neutrino Observatory, a major scientific facility led by the Institute of High Energy Physics of the Chinese Academy of Sciences, began operating on Aug 26 in Jiangmen, Guangdong province.

Its mission is to capture the universe's most elusive particles — neutrinos. At its heart lies the core detector, the world's largest single-piece acrylic sphere, known as the "Eye of Particles", built by Taizhou-based Donchamp (Jiangsu) Materials Technology.

The "Eye of Particles" measures an astonishing 35.4 meters in diameter, dwarfing the previous global record holder in Canada, which is just 12 meters wide. Constructed from 263 precision-bent acrylic panels, each 120 millimeters thick, plus chimney structures, the seamless sphere weighs nearly 600 metric tons. Once submerged at a depth of 44 meters, it will hold 20,000 tons of liquid scintillator, enabling scientists to detect neutrino interactions with unprecedented sensitivity.

The project posed extraordinary challenges for materials science and engineering. Donchamp established dedicated production lines, built high-standard workshops, and introduced advanced facilities including 24-hour constant-temperature workshops. The company overcame critical barriers in seamless bonding, transparency, and large-scale thermoforming, even dedicating over a year to perfecting the panel-bending process.

Installation proved equally formidable. "From June 2022, we mobilized hundreds of workers, transported the components 1,800 kilometers to the site, and battled for 30 months before completing the liquid scintillator filling this August," said Zhang Gaofeng, chief engineer at Donchamp.

Neutrinos, often called the "ghost particles" of the cosmos, are among the most mysterious and fundamental elements of the universe. Studying them has the potential to reshape our understanding of the cosmic model and the material world that sustains human existence, placing JUNO at the cutting edge of international scientific research.