China Completes World’s Largest Superconducting Magnet for Fusion Energy
The Institute of Plasma Physics at the Chinese Academy of Sciences has completed the world’s largest toroidal field (TF) superconducting magnet for a fusion device. The component, developed for the Comprehensive Research Facility for Fusion Technology (CRAFT) project, weighs 582 tonnes and measures 21 meters in length. According to the institute, the magnet has successfully passed rigorous development approval and full-parameter testing, achieving 100% domestic production, marking a transition toward independent supply chains for fusion reactor components.
How do these magnets enable fusion power?
Fusion reactors, often called “artificial suns,” rely on powerful magnetic fields to confine plasma heated to temperatures exceeding 100 million degrees Celsius. The TF magnet is a critical component of a tokamak fusion reactor, responsible for generating the powerful magnetic fields that confine plasma. By generating a stable, high-intensity magnetic field, it prevents the superheated plasma from touching the reactor walls.
The recent breakthrough at CRAFT involved six years of dedicated design, research and testing, resulting in 47 authorized patents and 14 established technical standards. Alongside the TF magnet, researchers successfully tested a high-temperature superconducting central solenoid coil. Operating at a stable current of 60 kiloamperes with 6.03 megajoules of energy storage, the solenoid is responsible for inducing and driving the plasma current and adjusting its shape.
What sets this development apart from international projects?
The primary technical shift highlighted by the Chinese Academy of Sciences is the move toward full localization of core technologies. The CRAFT project demonstrates that China can now independently manufacture the most critical, largest-scale magnets required for reactor construction.
| Feature | CRAFT TF Magnet | ITER TF Magnet |
|---|---|---|
| Volume | Baseline | Less than CRAFT volume |
| Energy Storage | Baseline | Fraction of CRAFT capacity |
What happens next for fusion energy?
The successful testing of these magnets provides the necessary hardware for the next phase of the CRAFT facility. With core technologies localized, the focus shifts to integrating these magnets into a full-scale tokamak testbed. The ability to produce these magnets domestically is expected to accelerate the timeline for China’s domestic fusion reactor programs.
Frequently Asked Questions
Why is fusion energy considered “limitless”?
Fusion mimics the process that powers the sun, using isotopes of hydrogen (deuterium and tritium) found in seawater. Unlike fission, it produces minimal long-lived radioactive waste and carries no risk of a meltdown.
What is a tokamak?
A tokamak is a device that uses magnetic fields to confine plasma in a donut-shaped (toroidal) vacuum chamber to facilitate nuclear fusion.
What does “full localization” mean for this project?
It means that both magnet systems have achieved full localization of their core technologies, a move that significantly reduces reliance on foreign supply chains and underscores China’s growing independent research and manufacturing capabilities.
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