China Builds World’s Largest Fusion Superconducting Magnet
Chinese researchers have achieved a major breakthrough in superconducting magnet technology for fusion reactors, successfully completing development and acceptance testing of two critical magnet systems — the Toroidal Field (TF) superconducting magnet and the High-Temperature Superconducting (HTS) Central Solenoid Coil. Both systems achieved 100% domestic localization of core technologies, marking a significant step forward in China’s pursuit of clean nuclear fusion energy.
A Magnet of Unprecedented Scale
The TF superconducting magnet, developed at the Institute of Plasma Physics (IPP) under the Chinese Academy of Sciences in Hefei, Anhui Province, is now the world’s largest fusion reactor superconducting magnet. Measuring 21 meters long, 12 meters wide, and 3.3 meters tall, the colossal component weighs 582 tons. According to Xinhua News Agency, its volume is 1.3 times that of the ITER TF magnet, while its energy storage capacity is three times greater.
This achievement is the culmination of six years of intensive design, development, and testing. The project has generated 47 authorized patents and established 14 technical standards, with all performance indicators leading among international counterparts.
Two Critical Systems, One Breakthrough
Superconducting magnets are among the most critical components of tokamak fusion reactors. They generate the powerful magnetic fields needed to confine plasma heated to over 100 million degrees Celsius — hotter than the core of the sun. The TF magnet creates the toroidal (ring-shaped) magnetic field that confines the plasma via Lorentz force, preventing high-energy particles from damaging the vacuum chamber walls.
Simultaneously, the HTS Central Solenoid Coil completed full-parameter testing with impressive results. Test data showed a stable current of 60 kiloamps, energy storage of 6.03 megajoules, a maximum magnetic field change rate of 5.1 teslas per second, and a joint resistance of just 0.87 nano-ohms. As China Daily reported, key indicators and core performance have reached internationally leading levels.
The central solenoid coil’s core function is to induce and drive plasma current while dynamically regulating the plasma confinement configuration. To meet the extreme operating conditions, the project team developed innovative solutions including a stress-distributed reinforced support structure and a high-low temperature hybrid magnet design, overcoming more than ten key technical challenges.
Complete Domestic Supply Chain
Perhaps the most strategically significant aspect of this breakthrough is the 100% domestic localization achieved across both magnet systems. From superconducting materials and structural design to complete manufacturing processes, the entire supply chain is now Chinese-developed and controlled. The China Nuclear Power Network noted that every critical link in the full chain of the magnet systems has achieved domestic自主可控 (independent controllability).
This supply chain independence reduces reliance on foreign suppliers for critical fusion components — a significant consideration as global competition in fusion energy intensifies.
The CRAFT Facility: Kuafu Chases the Sun
These achievements were realized at the Comprehensive Research Facility for Fusion Technology (CRAFT), nicknamed “Kuafu” after the Chinese mythological giant who chased the sun. Located in Hefei, Anhui Province, CRAFT is a National Major Science and Technology Infrastructure facility approved under China’s 13th Five-Year Plan. Its core mission is to develop and master key technology systems for future fusion reactor host systems.
Earlier milestones at CRAFT included the delivery of the TF magnet coil box in October 2025, which the Chinese Academy of Sciences reported as the world’s largest toroidal field coil box at the time, and the successful passage of CRAFT’s first performance process test in December 2025.
China’s Fusion Energy Roadmap
These magnet breakthroughs directly support China’s ambitious fusion energy roadmap. The country has a clearly defined strategy for magnetic confinement fusion development:
- Experimental devices (EAST, HL-2M, HL-3) — ongoing, with EAST holding the world record for plasma confinement time at over 1,000 seconds
- Compact Fusion Energy Experimental Device (BEST) — planned for completion by 2027, aiming for 5× energy gain
- China Fusion Engineering Demonstration Reactor (CFEDR) — engineering design underway, targeting construction of the world’s first fusion demonstration power station
- Prototype Fusion Power Plant (PFPP) — targeted for approximately 2050
As the project team leader stated, according to Xinhua: “The successive breakthroughs of the two core superconducting magnets have further consolidated the superconducting engineering foundation for China’s construction of fusion reactors, and have effectively enhanced the independent R&D and engineering construction capabilities for fusion reactor construction.”
Global Context and Implications
China is now a leading contender in the global fusion race. The ITER project, the world’s largest international fusion collaboration being built in France, has faced repeated delays, with first plasma now projected for 2034. Meanwhile, private fusion companies globally have attracted billions in investment, and national programs in the United States, United Kingdom, Japan, and South Korea remain active.
A Guangming Daily feature article from June 2025 traced China’s fusion journey from the early HT-6 and HT-7 devices through EAST’s world-record plasma confinement to the current CRAFT and BEST projects, highlighting how China has transformed from a follower to a core force in fusion research.
What’s Next
While these magnet breakthroughs represent a significant engineering milestone, integrating them into a complete, operational fusion reactor remains a substantial challenge. Commercial fusion power generation remains a long-term goal, with most experts projecting the 2030s or 2040s at the earliest.
However, with 47 patents, 14 technical standards, and a fully domestic supply chain now established, China has laid a formidable foundation for the next phase of its fusion program. The CFEDR demonstration reactor, once built, would represent the world’s first attempt at a grid-connected fusion power station — a milestone that would reshape the global energy landscape.
For now, the world’s largest fusion reactor superconducting magnet sits in Hefei, a testament to six years of scientific and engineering perseverance, and a powerful symbol of China’s accelerating ambitions in the quest for clean, limitless energy.