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China has achieved a major milestone in its pursuit of commercial nuclear fusion by completing the construction and testing of a colossal 582-ton superconducting magnet designed for its next-generation “Artificial Sun” programme, according to Xinhua News Agency. Measuring 21 metres in length, the toroidal-field magnet is the largest of its kind ever built for a controlled fusion reactor. Developed by the Institute of Plasma Physics (ASIPP) under the Chinese Academy of Sciences in Hefei, the magnet is designed to confine plasma heated to more than 100 million degrees Celsius, a temperature around six times hotter than the Sun’s core. According to the project’s roadmap, the breakthrough is expected to support China’s long-term goal of demonstrating electricity generation from controlled nuclear fusion around 2030.
The giant magnet powering China’s next-generation ‘Artificial Sun’
The newly completed magnet is a toroidal-field (TF) superconducting magnet, one of the most critical components of a tokamak fusion reactor. Weighing 582 metric tons and stretching 21 metres long, it is larger than any comparable magnet built for a fusion facility.The magnet was developed for China’s Burning Plasma Experimental Superconducting Tokamak (BEST) project, the country’s next-generation experimental fusion reactor. Engineers completed construction, factory acceptance and full-parameter testing in Hefei, marking one of the biggest engineering achievements in China’s fusion programme.
Why does a fusion reactor need such a massive magnet?
Nuclear fusion requires hydrogen plasma to be heated to temperatures exceeding 100 million°C, far hotter than the centre of the Sun. At such extreme temperatures, no known material can physically contain the plasma.Instead, powerful superconducting magnets generate intense magnetic fields that suspend the plasma inside a doughnut-shaped vacuum chamber called a tokamak. The toroidal-field magnet prevents the superheated plasma from touching the reactor walls, allowing fusion reactions to continue safely while minimising damage to the reactor.
How superconducting technology makes fusion possible
Unlike ordinary electromagnets, superconducting magnets operate with virtually zero electrical resistance when cooled to extremely low temperatures. This enables them to carry enormous electrical currents while consuming far less energy.China also successfully tested a high-temperature superconducting central solenoid, another key component often described as the “heart” of a tokamak. The central solenoid generates the plasma current needed to initiate and maintain fusion reactions, working together with the toroidal-field magnet to keep the plasma stable throughout the experiment.
What makes this magnet different from previous designs?
According to Chinese researchers, the new toroidal-field magnet has a volume approximately 1.3 times larger than the equivalent magnet designed for the international ITER fusion project in France. It also stores three times more magnetic energy, allowing it to generate stronger magnetic fields for plasma confinement.The six-year development programme involved breakthroughs in superconducting conductor manufacturing, structural engineering, cryogenic technology and quench protection. Researchers say the project has resulted in dozens of patents and new industry standards for large-scale superconducting magnet technology.
How China’s ‘Artificial Sun’ programme has evolved
China’s Experimental Advanced Superconducting Tokamak (EAST), widely known as the “Artificial Sun”, has already achieved several world records by sustaining ultra-hot plasma for increasingly longer periods. EAST serves as a research platform where scientists test technologies required for future commercial fusion reactors.The newly completed magnet is intended for the BEST reactor rather than the current EAST machine. BEST aims to move beyond laboratory experiments by demonstrating sustained burning plasma and eventually producing electricity from controlled nuclear fusion.
When could fusion electricity become a reality?
China expects construction of the BEST experimental reactor to be completed by 2027. If development progresses as planned, researchers hope to demonstrate electricity generation from controlled fusion by around 2030.Although commercial fusion power remains one of the world’s greatest scientific and engineering challenges, each advance in superconducting magnet technology brings researchers closer to producing a virtually limitless source of clean energy with minimal long-lived radioactive waste and no carbon emissions during operation.
Why fusion is considered the future of clean energy
Unlike conventional nuclear fission, which splits heavy atoms to release energy, nuclear fusion combines light hydrogen isotopes to produce enormous amounts of power. The process generates no greenhouse gas emissions during operation and produces significantly less long-lived radioactive waste than existing nuclear power plants.Scientists around the world consider fusion one of the most promising long-term solutions to growing global energy demand. China’s latest achievement demonstrates the rapid pace of progress in the global race to make fusion a practical source of electricity, bringing the vision of an “Artificial Sun” capable of powering cities one step closer to reality.
