China completes world’s largest 582-tonne superconducting magnet for ‘Artificial Sun’
Developed by the Institute of Plasma Physics (ASIPP) of the Chinese Academy of Sciences in Hefei, the giant magnet is designed to trap heated plasma at a temperature of over 100 million degrees Celsius, about six times hotter than the core of the Sun. This breakthrough supports China’s long-term goal of generating electricity from controlled nuclear fusion by 2030.
World’s largest toroidal field magnet completed
The newly constructed toroidal field (TF) superconducting magnet is among the most important components of the tokamak fusion reactor. Weighing 582 metric tons and measuring 21 meters long, it surpasses all previous fusion magnets in size.
The magnet was developed for the Burning Plasma Experimental Superconducting Tokamak (BEST), China’s next-generation experimental fusion reactor. Engineers recently completed construction, factory acceptance and full parameter testing in Hefei, marking a significant engineering achievement for China’s fusion program. Unlike traditional electromagnets, superconducting magnets operate with almost zero electrical resistance when cooled to extremely low temperatures. This allows them to carry large electrical currents while consuming much less energy.
China has also successfully tested the high-temperature superconducting central solenoid, another critical component often described as the “heart” of the tokamak. The central solenoid produces the plasma current required to initiate and sustain fusion reactions, working with the toroidal field magnet to maintain plasma stability.
How does the new magnet improve upon previous designs?
Chinese researchers say the new toroidal field magnet has a volume about 1.3 times larger than the equivalent magnet designed for the international ITER fusion project in France. It can also store three times more magnetic energy and provide stronger magnetic fields for plasma confinement.
The six-year development program included advances in superconducting conductor fabrication, structural engineering, cryogenic systems and quench protection. Researchers say the project has generated dozens of patents and helped establish new industry standards for large-scale superconducting magnet technology.
China’s ‘Artificial Sun’ program enters next phase
China’s Experimental Advanced Superconducting Tokamak (EAST), commonly known as the “Artificial Sun”, has already broken several world records by maintaining ultra-hot plasma for increasingly longer periods of time. EAST serves as a research platform to test technologies needed for future commercial fusion reactors.
However, the newly completed magnet is aimed at the BEST reactor rather than the EAST. BEST is designed to go beyond experimental research by demonstrating continuously burning plasma and eventually generating electricity through controlled nuclear fusion.
When might fusion power become commercially viable?
China expects the construction of the BEST reactor to be completed by 2027. If development continues as planned, researchers hope to demonstrate electricity generation from controlled nuclear fusion around 2030.
Although commercial fusion remains one of science’s greatest engineering challenges, advances in superconducting magnet technology are bringing researchers closer to using fusion as a practical source of clean energy.
Why is nuclear fusion seen as the future of clean energy?
Unlike traditional nuclear fission, which produces energy by splitting heavy atoms, nuclear fusion produces energy by combining light hydrogen isotopes. The process emits no greenhouse gases during operation and produces far less long-lived radioactive waste than today’s nuclear power plants.
Scientists see fusion as one of the most promising long-term solutions to increasing global energy demand. China’s latest breakthrough highlights the rapid progress being made in the global race to develop commercially viable fusion energy and brings the vision of an “Artificial Sun” that could power cities a step closer to reality.
