BEIJING, March 22 (Xinhua) — Chinese scientists are working on a blueprint for a giant telescope to detect neutrinos, one of the most abundant particles in the universe, from the depths of seas or lakes.
The facility is designed to have a volume of about 30 cubic kilometers, and will be submerged to a depth of more than one kilometer, said Chen Mingjun, chief researcher of the project at the Institute of High Energy Physics under the Chinese Academy of Sciences.
Chen added that the goal of building such an underwater telescope is to detect high-energy neutrinos, as these particles are believed to be produced outside the solar system. So observing neutrinos passing through the telescope will contribute to solving a century-old scientific mystery of the origin of cosmic rays.
And in the early 20th century, scientists discovered that Earth is constantly bombarded by energetic particles from outer space, called cosmic rays. The Large Altitude Air Observatory in the mountains of the Qinghai-Tibet Plateau, China, detected 12 sources of gamma rays in 2021, and they are believed to come from the same sources as cosmic rays.
in this context; One popular hypothesis, Chen said, is that high-energy neutrinos and gamma rays are likely produced simultaneously when high-energy cosmic rays originate.
“If we can observe the two particles together, we will be able to determine the origin of cosmic rays,” Chen said.
When passing through water, neutrinos collide with atomic nuclei and produce secondary particles, which emit light signals that can be picked up by underwater detectors.
Some studies have already hinted at this possibility, and Chen believes that neutrino observations can trace the origin of this mysterious space radiation.
On the reason why scientists built the telescope in the depths of the water, Chen said that from one kilometer under the water, sunlight does not penetrate the darkness, and the process of photosynthesis cannot occur, and there are no fish or microorganisms either.
“Clean water will help increase the chances of detecting neutrino signals,” Chen said.
Similar foreign underwater neutrino monitors include the cubic kilometer-scale IceCube Observatory, located near the South Pole, and the Baikal-GVD Telescope, which currently covers 0.5 cubic kilometers in Lake Baikal.
turn; Chen mentioned that the planned Chinese observatory will be much larger. “It will be a 30 cubic kilometer observatory with more than 55,000 optical units suspended along 2,300 strings,” he said.
In February, Chen’s team completed the first sea trial to test the monitoring system at a depth of 1,800 meters underwater.
Most of Chen’s team spent many years studying cosmic rays. They participated in the Large Altitude Air Observatory Project in the mountains of the Qinghai-Tibet Plateau in China, a giant cosmic ray observatory located 4.41 km above sea level in southwest China’s Sichuan Province.
However, finding extraterrestrial neutrinos in deep waters is more difficult than in mountains, Chen said, adding that his team’s current challenges include developing detectors to meet higher requirements on waterproofing, as well as higher equipment costs and underwater operations.