China’s world’s largest ghost particle detector is about to operate

A scientific facility in southern China designed to measure neutrinos, the mysterious ghost particles, has begun filling with ultra-pure water, marking the final key milestone before research begins, according to CGTN. Ultrapure water, filtered through multiple stages of the water filtration system, began pouring into the detector at the Jiangmen Underground Neutrino Observatory (Juno) in Guangdong province on December 18 at a rate of about 100 tons per hour. hours, according to the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences, the unit in charge of the project.

To measure the mass of different types of ghost particles created by two nearby nuclear power plants, Juno’s main component is a giant spherical underground detector. The machine will contain 20,000 tons of liquid scintillator and suspended in 35,000 tons of pure water at a depth of 700 meters below ground.

The liquid filling process will be conducted in two phases and take eight months, according to IHEP. During the first two months, ultra-pure water will be poured both inside and outside the giant sphere. Over the next six months, the ultra-pure water inside the sphere will be replaced by a liquid scintillator.

Ghost particles, the smallest and lightest of the 12 elementary particles that make up the physical world, are difficult to detect because they have no charge, have extremely small mass, and move nearly at the speed of light. Although most particles will pass through the detection fluid without leaving a trace, some will interact with the fluid, triggering two flashes of light that can be recorded by thousands of light-sensitive optical tubes.

In October, the spherical detector, approximately 35 m in diameter and supported by a 41.1 m diameter stainless steel structure, was fully installed. Workers proceed to assemble the outer metal shell and optical tube. Once filled with water, the facility will begin collecting scientific data from August next year. Juno will become the world’s first new generation neutrino detector to go into operation, ahead of two other international facilities, the Deep Underground Neutrino Experiment in the US and the Hyper-Kamiokande observatory in Japan, both scheduled to operate in 2027 – 2028.

The $376 million project in China is the result of collaboration between 750 researchers from 74 institutes in 17 countries and regions.