China Plans to Construct the World’s Largest Detector for Tracking Neutrinos in Space

SPACE — China is building detectors deep beneath the surface of the ocean to hunt for ghost particles. Ghost particles or neutrinos are the most elusive subatomic particles in the world.

Why is it so hard to catch? Neutrinos have no electric charge and almost zero mass. That is, neutrinos hardly interact with other types of matter.

Every second, tens of trillions of these ghostly neutrinos flow through Earth (and our bodies) without interacting with anything else. Occasionally, these neutrally charged particles will collide with atomic nuclei, emitting sparks of light that are nearly undetectable.

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Some neutrinos come from nuclear reactions inside the sun, in which atoms coalesce deep within the star. The fusion reaction releases neutrinos, which drift away from the sun within seconds.

Some neutrinos come from nuclear fission, such as in a nuclear reactor. According to the Department of Energy, even the decaying potassium in bananas can release neutrinos.

Scientists also recently saw neutrinos in the Large Hadron Collider for the first time.

However, some neutrinos come from outside the solar system. These high-energy neutrinos may come from black holes, supernovas, pulsars, or other events that scientists have yet to observe. It is these high-energy neutrinos that scientists from the Chinese Academy of Sciences are trying to find.

The new detector to be built by China is equipped with 55,000 sensors installed at a depth of 1 kilometer. According to Chen Mingjun, to Xinhua Net, sunlight can not penetrate too deep. Installing the sensor in that location will help the sensor detect neutrinos and distinguish them from solar neutrinos.

“Clean water will help increase the chances of detecting the neutrino signal,” Chen said, quoted from Live Science.

Scientists had to build neutrino detectors in areas with large amounts of transparent material in order to better see the unexpected flashes of light that reveal neutrinos.

Currently, existing ghost particle detectors include the National Science Foundation’s IceCube Neutrino Observatory in Antarctica, which covers about 1 cubic kilometer with 5,160 sensors nearly a mile beneath the ice. Down there, the ice is clear enough for sensors to detect tiny flashes of light.

In the future, China’s detector will not be the only underwater neutrino detector. There are several other detectors used for ghost particle hunting. However, this Chinese property will be the largest.

Currently, Russia is also building the Baikal Gigaton Volume Detector (Baikal-GVD) in Siberia’s Lake Baikal, the deepest lake in the world.

Next, there will be the upcoming European Cubic Kilometer Neutrino Telescope. This is a multi-agency collaboration that will hunt for neutrinos in the Mediterranean.

There’s also the Pacific Ocean Neutrino Experiment, another multi-agency collaboration working on detectors in the Pacific Ocean, off the coast of British Columbia in Canada.

However, the Chinese detector will be much larger. Its 55,000 sensors will cover about 30 cubic km.

One of the special purposes of this detector is to find out whether high-energy gamma rays and neutrinos might have come from the same intergalactic source.

In 2021, the Chinese Large High Altitude Air Shower Observatory detected gamma rays that the researchers hypothesized to originate from the same place as cosmic rays, or high-velocity subatomic particles from outside the solar system. If the researchers detect neutrinos coming from the same source, scientists can determine the origin of the cosmic rays.