Image Courtesy: CCTV
China has successfully completed full-performance testing of what it says is the world’s largest superconducting magnet system, a major milestone in its pursuit of commercial nuclear fusion. The achievement validates two of the most critical components needed for future fusion reactors, where powerful magnetic fields are used to confine plasma that can reach temperatures exceeding 100 million degrees Celsius.
The breakthrough was achieved by researchers at the Institute of Plasma Physics under the Chinese Academy of Sciences, who completed the development, acceptance, and testing of a toroidal-field superconducting magnet and a high-temperature superconducting central solenoid coil. Both systems were developed using domestically produced technologies and materials as part of China’s Comprehensive Research Facility for Fusion Technology (CRAFT).
The toroidal-field magnet serves as the reactor’s primary magnetic confinement system, preventing superheated plasma from coming into contact with the reactor walls. Measuring 21 meters long, 12 meters wide, and 3.3 meters high, the magnet weighs 582 tonnes. Chinese researchers say it has 1.3 times the volume and three times the energy storage capacity of the equivalent component developed for the International Thermonuclear Experimental Reactor (ITER) in France.
The high-temperature superconducting central solenoid, tested alongside the toroidal magnet, is responsible for initiating and controlling the plasma current inside the reactor. Although designed to operate at 46.5 kiloamperes, the system reportedly passed testing at 60 kiloamperes, demonstrating performance beyond its rated specifications.
Institute deputy director Qin Jinggang said the central solenoid operates under the most demanding conditions in a fusion reactor and plays a critical role in achieving stable plasma ignition. Researchers also noted that the complete reactor will eventually use 16 toroidal-field coils, each carrying 100 kiloamperes and generating a magnetic field of 6.5 tesla at the reactor’s center.
The project highlights China’s growing capabilities in manufacturing advanced superconducting technologies entirely with domestic materials, including specialty steel, insulation, and superconducting wires. Building on decades of investment in fusion research, including the EAST “artificial sun” reactor, the CRAFT facility is expected to accelerate the development of technologies needed for future commercial fusion power plants.
