KAIPING, China (AP) — A massive detector located beneath a granite hill in southern China is nearing completion, set to begin tracking mysterious ghostly particles known as neutrinos. The Jiangmen Neutrino Underground Observatory, soon to be operational, is one of the three largest global projects aimed at detecting neutrinos, elusive cosmic particles with an incredibly small mass.
This observatory, located 700 meters (2,297 feet) underground, is designed to minimize interference from cosmic rays and radiation that might otherwise disrupt its sensitivity. It is set to become fully operational next year, pushing the boundaries of particle detection, according to physicist Andre de Gouvea from Northwestern University. He emphasized that if successful, the project could offer groundbreaking insights into the universe’s formation.
Neutrinos are created during cosmic events such as the Big Bang, and they travel through space with little interaction with matter. They are emitted by stars like the Sun and are produced during particle collisions, such as those occurring in particle accelerators. Despite their abundance, the particles are notoriously difficult to detect, as they rarely interact with other matter.
Scientists have been aware of neutrinos for almost a century but have only begun to scratch the surface in understanding their properties. The process of detecting these particles involves capturing the faint flashes of light or charged particles produced when a neutrino interacts with other matter.
To increase their chances of detecting neutrinos, scientists need to build extraordinarily large detectors, a strategy that has been applied in the construction of the Jiangmen facility. With a price tag of $300 million, the detector has taken over nine years to construct. Once completed, it will be filled with a special liquid that emits light when neutrinos pass through it, and surrounded by purified water to further minimize interference.
The facility will primarily study antineutrinos, the antimatter counterpart to neutrinos, to better understand their behavior. These antineutrinos are produced by nuclear reactors located over 50 kilometers (31 miles) away, and their interactions within the detector will result in detectable light flashes.
The Jiangmen Neutrino Detector will address a long-standing mystery about neutrinos, specifically their mass. Neutrinos oscillate between three different states, and scientists aim to identify the heaviest and lightest among them. This is a critical step in understanding the fundamental properties of matter.
Two other large neutrino detection projects, Japan’s Hyper-Kamiokande and the U.S.-based Deep Underground Neutrino Experiment (DUNE), are also under construction and are expected to begin operation by 2027 and 2031, respectively. Together with the Jiangmen facility, these projects will verify each other’s findings and contribute to a deeper understanding of neutrino physics.
Wang Yifang, the lead scientist of the Jiangmen project, stated that the collaboration between the various observatories will allow scientists to gain a more comprehensive understanding of the fundamental principles of physics. He highlighted the potential of neutrinos to provide crucial answers about the universe’s early evolution.
Neutrinos play a key role in answering some of the most profound questions in physics, such as why the universe is predominantly composed of matter rather than antimatter. The results from these experiments could shed light on the fundamental imbalances that occurred during the universe’s early moments, offering insights into its development and expansion.
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