China Unveils World’s Largest Fusion Reactor Magnet in Breakthrough for ‘Artificial Sun’ Project

On June 27, 2026, the Institute of Plasma Physics at the Chinese Academy of Sciences in Hefei announced a major milestone in fusion energy: the successful completion and full-parameter testing of two critical superconducting magnets. The first is the world's largest toroidal field (TF) superconducting magnet, and the second is a high-temperature superconducting central solenoid (CS) coil. Both achieved 100% domestic production and reached internationally leading performance, marking a decisive step in China's quest for a working fusion reactor.

The Two Magnets: Specs and Performance

Toroidal Field (TF) Superconducting Magnet

• Dimensions: 21 meters long, 12 meters wide, 3.3 meters tall; total weight of 582 metric tons.
• Comparison with ITER: Its volume is 1.3 times that of the ITER TF magnet, and its energy storage capacity is three times greater than ITER's, making it the largest such magnet ever built for a fusion reactor.
• Engineering achievement: The magnet was designed and fabricated over six years, successfully passing a comprehensive expert review on Saturday. It is designed to operate stably for 60 years under ultra-low temperatures, high currents, intense radiation, and high stress.

High-Temperature Superconducting Central Solenoid (CS) Coil

• Testing results: Completed full-condition parameter testing on the same day, with measured data showing stable current of 60 kA, stored energy of 6.03 MJ, maximum magnetic field change rate of 5.1 T/s, and joint resistance of 0.87 nΩ.
• Performance ranking: Key indicators and core performance reached internationally leading levels.

100% Domestic Production

Both magnets achieved full domestic production of core technologies. Every critical component and manufacturing process was developed within China, from superconducting materials and structural design to fabrication processes and cryogenic insulation. The project generated 47 patents and established 14 standards.

Significance for the CFETR Roadmap

These magnets were developed as part of China's "artificial sun" program under the Comprehensive Research Facility for Fusion Technology (CRAFT), which is the preconstruction technology platform for the China Fusion Engineering Test Reactor (CFETR).

CFETR is China's next-step fusion device, designed to bridge the gap between the ITER experimental reactor and a demonstration fusion power plant (DEMO). It is planned in two phases: Phase I targets a fusion power gain Q ≈ 10 and 500 MW of fusion power in pulsed mode, while Phase II targets steady-state operation with higher power.

The institute stated that these successive breakthroughs "have further solidified the foundation for China's construction of fusion reactors" and will "significantly enhance the country's capabilities in independent R&D and engineering construction of fusion reactors."

Context: A Year of Chinese Fusion Milestones

This magnet announcement follows several other notable Chinese fusion achievements in 2026. In January, scientists operating the Experimental Advanced Superconducting Tokamak (EAST) in Hefei reported pushing plasma densities 30% to 65% higher than a long-accepted theoretical limit, using a process called plasma-wall self-organization. Later in June, the China National Nuclear Corporation generated a plasma current of more than 1 million amps for the first time. Together, these advances show a rapidly maturing domestic fusion program with a clear construction roadmap toward a demonstration power plant by the 2040s–2050s.