China has completed and tested the world's largest superconducting fusion magnet, a key component for nuclear fusion reactors, in a major step toward its goal of generating electricity from fusion power by around 2030.
The toroidal field superconducting magnet was developed by the Institute of Plasma Physics under the Chinese Academy of Sciences. The D-shaped structure measures 21 metres in length, 12 metres in width and weighs 582 tonnes.
Researchers said it is the largest fusion reactor superconducting magnet ever built, with 1.3 times the volume and three times the stored energy of comparable magnets developed for the International Thermonuclear Experimental Reactor (ITER), the world's largest fusion project.
The magnet generates the powerful magnetic field needed to confine plasma, a superheated gas at about 100 million degrees Celsius, inside a fusion reactor without allowing it to come into contact with the reactor walls.
The research team also successfully tested a high-temperature superconducting central solenoid coil, a critical component that helps ignite and sustain the plasma required for fusion reactions.
China said both technologies were developed entirely using domestic materials and manufacturing capabilities, eliminating reliance on foreign suppliers for key fusion components. The six-year programme resulted in 47 patents and 25 industry standards.
Engineers designed the magnet to operate for 60 years at temperatures close to minus 269 degrees Celsius while carrying electrical currents exceeding 100,000 amperes and withstanding intense radiation and mechanical stress. They also reduced electrical resistance at critical joints to nearly zero to minimise energy loss.
The achievement builds on China's progress in fusion research. Earlier this year, its Experimental Advanced Superconducting Tokamak (EAST), known as China's artificial Sun, sustained plasma at 100 million degrees Celsius for 1,066 seconds, setting a world record.
China plans to complete its Burning Plasma Experimental Superconducting Tokamak by the end of 2027 and aims to begin generating electricity from fusion power around 2030. It also plans to build the China Fusion Engineering Demonstration Reactor, which could become the world's first fusion demonstration power station.
Researchers said major challenges remain, including reactor assembly, long-term testing and demonstrating that fusion reactors can consistently generate more energy than they consume.