EyesonSci | World's largest transparent spherical neutrino detector starts filling ultrapure water

GUANGZHOU, Dec. 18 (Xinhua) -- The world's largest transparent spherical detector started filling with ultrapure water Wednesday, signifying that the construction of the neutrino research facility has reached its last critical stage.

The ultrapure water, which has been filtered through multiple stages of the water purification system, is injected at a flow rate of 100 tonnes per hour into the detector pool of the Jiangmen Underground Neutrino Observatory (JUNO), according to the Institute of High Energy Physics under the Chinese Academy of Sciences, the project's leading institution.

The core of JUNO is a liquid scintillator detector immersed in a 44-meter-deep cylindrical pool in the underground hall buried deep in a granite layer of a hill in Kaiping, Jiangmen City, in south China's Guangdong Province. The detector is supported by a stainless steel mesh shell with a diameter of 41.1 meters, which holds an acrylic sphere with a diameter of 35.4 meters to be filled with 20,000 tonnes of liquid scintillator.