The Daya Bay Reactor Neutrino Experiment, the first-generation neutrino oscillation experiment in China started in 2003, has now officially been decommissioned. The instrument, located at the Institute of High Energy Physics (IHEP), was designed to measure the mixing angle θ13, which it successfully achieved in 2012.

Guests look at four neutrino detectors at the Daya Bay Reactor Neutrino Experiment in Shenzhen, Guangdong Province, during a decommissioning ceremony held on December 12, 2020. [IMAGE: XINHUA]

Chinese scientists have decommissioned the Daya Bay Reactor Neutrino Experiment in Shenzhen, Guangdong Province. In doing so, they have bid farewell to a major scientific instrument that was responsible for one of China’s biggest discoveries in physics — a discovery which in turn may help explain why the universe is the way it is.

Launched in 2011, the instrument has finished all of its research missions and produced valuable data with unprecedented precision. “The Daya Bay Reactor Neutrino Experiment laid the foundation of China’s international cooperation in neutrino-related particle physics and paved the theoretical groundwork for new neutrino observatories being built in China and around the world,” said Wang Yifang, Director of the Chinese Academy of Sciences’ Institute of High Energy Physics.

The results from Daya Bay in 2012 sent a shock wave through the world’s physics community, with the journal Science hailing it as one of the biggest breakthroughs of the year. Lee Tsung-Dao, a Nobel laureate in physics, said in a congratulatory letter that it represented a major achievement in physics with key significance for basic research.

“While there have been numerous breakthroughs in our understanding of neutrinos in the past few decades, there are still many questions left unanswered,” Wang said. “Answering them may fundamentally change how we understand particle physics and the evolution of the universe.”

China’s next-generation neutrino detector－ the Jiangmen Underground Neutrino Observatory, or JUNO － is being built 700 meters underground in Jiangmen, Guangdong Province. The instrument is expected to be completed around 2022. Around 680 researchers from 18 countries and regions are participating in the project.

The new machine aims to detect and measure neutrinos with unprecedented precision and energy resolution, hoping to uncover more insights and solve more mysteries about the perplexing elementary particle.

Source: China Daily