The world’s biggest superconducting magnet for a nuclear fusion reactor has passed final tests as part of China’s CRAFT (Comprehensive Research Facility for Fusion Technology) project, overcoming one of the hardest engineering challenges in nuclear fusion.
The assembly comprises two coils: a toroidal-field magnet that acts as a magnetic cage, and a central solenoid that serves as the igniter. The results, achieved by researchers at the Chinese Academy of Sciences Institute of Plasma Physics (ASIPP) clear a major engineering hurdle on the path to confining a plasma.
The magnetic cage, known as the CRAFT toroidal field coil, is a core component of the reactor. It uses a strong magnetic field to prevent the container from melting as the plasma inside reaches hundreds of millions of degrees.
The magnetic field is like an invisible railway, guiding charged particles along prescribed paths and holding them safely away from the vessel walls, preventing erosion and structural damage from high-energy collisions.
At 21 metres long, 12 metres wide, and 3.3 metres high, the toroidal-field magnet weighs 582 tonnes. It has 1.3 times the volume and triple the energy storage of its counterpart at the International Thermonuclear Experimental Reactor (ITER) in southern France.
ASIPP researcher Wu Yu told CCTV that “16 of these coils will eventually be assembled to form the complete magnetic field, each carrying 100 kiloamperes and generating 6.5 tesla at the centre”. Institute director Song Yuntao said the coil took six years to complete and had the highest energy storage capacity of its type in the world. Its speciality steel, insulation and superconducting wires were all made in China.
The igniter tested at the same time, is a high-temperature superconducting central solenoid coil. Its main roles are to induce and drive the plasma current and to dynamically adjust the plasma confinement configuration. “The central solenoid magnet operates under the most complex conditions of any magnet in the reactor, and its performance directly determines whether a fusion device can be successfully ignited and stably sustained,” said ASIPP Deputy Director Qin Jinggang.
He added that, while the coil’s rated design current was 46.5kA, it passed testing at 60kA. This is six times the capacity of China’s Experimental Advanced Superconducting Tokamak (EAST) device, which has been operating since 2006.
China’s path to a superconducting tokamak began in the late 1970s, when the Soviet Union built the world’s first such device, the T-7. Russia gave the T-7 to China and in 1994 converted it into the HT-7. Then, in 2006, China completed EAST, the world’s first fully superconducting tokamak.
The CRAFT megaproject, located in Hefei, Anhui Province, spans a massive specialised research campus. Hefei also hosts EAST and the Burning Plasma Experimental Superconducting Tokamak (BEST) as well as the planned China Fusion Engineering Test Reactor (CFETR) BEST is scheduled to finish assembly by 2027 to demonstrate actual net-energy “burning plasma”. The engineering design wog CEFTR was fully completed in 2020. Full-scale construction is expected to begin in the late 2020s, with an ambitious target to deliver its first electricity to the power grid by 2035.
EAST and BEST are situated on Science Island (Shushan District), a specialised research peninsula on Shushan Lake managed by the Hefei Institutes of Physical Science. While the CRAFT facility is conceptually part of this ecosystem, its massive 40-hectare footprint was too large for the island itself. It is located a short drive away in Hefei’s “Future Big Science City” district to accommodate its heavy industrial scale.
EAST is an academic testing bed. It works to solve pure physics questions about plasma behaviour. CRAFT does not generate electricity but is the vital technological bridge in China’s multi-decade fusion roadmap. By proving components work under real-world stress, CRAFT directly feeds into the engineering design of BEST and the future CFETR, which are engineering demonstration facilities.
The technology developed at CRAFT acts as the industrial blueprint and manufacturing foundation for the BEST (Burning Plasma Experimental Superconducting Tokamak) reactor. Currently entering its final assembly phases in Hefei with a targeted 2027 completion date, BEST is China’s intermediate “bridge” reactor. It transitions the program from the basic plasma physics of the EAST reactor to a machine specifically built to achieve a 5x net energy gain (generating five times more energy than it consumes).
Unlike earlier test reactors that just study plasma behaviour using external power, BEST is designed to study “burning plasma”, where the fusion reaction itself provides the majority of the heat to keep the reaction going.
BEST is a heavy, dense machine that requires tens of thousands of components to fit together with near-zero margins for error. CRAFT’s Remote-Handling Test Platform and heavy-duty robotic engineering systems are what allow the mechanical assembly of BEST to happen ahead of schedule. The heavy-duty fusion robotics mastered at CRAFT provide the millimetre-level installation precision required to build out the 6,000-tonne machine and will eventually handle maintenance inside the radioactive core once operational.
Elsewhere in China, construction has begun on the second phase of China Fusion Energy Co’s Fusion Technology Research and Development Centre at the innovation city of Tianfu in Chengdu District, Sichuan Province. China Fusion, established in July 2025, is a subsidiary of China National Nuclear Corporation (CNNC). To create a fully operational corporate entity, CNNC restructured an existing tier-two subsidiary, renaming it China Fusion Energy Co. Seven leading state-owned nuclear and energy firms immediately backed the platform with an initial multi-billion-yuan capital injection.
The Tianfu centre will focus on fusion reactor materials research and development, key subsystem testing and validation, and key component development. The priority task will be to solve technological problems in thermonuclear reactors. The total planned area is approximately 500 acres and construction will be carried out in stages. The first phase, completed and commissioned in May 2026, focuses on addressing radiation damage to structural materials in fusion reactors. It is planned to build a complex installation for irradiating materials from thermonuclear reactors designed to provide critical support in performance assessment and engineering applications of key materials.
Developments in Hefei and Chengdu are two branches of the same national roadmap. The projects relate to one another as consecutive steps. The Hefei Hub (housing EAST, CRAFT, and BEST) is the academic and engineering birthplace. China Fusion Energy was specifically created to take the breakthroughs proven in Hefei and scale them into actual commercial power plants connected to the national grid.
While the corporate headquarters and digital R&D for China Fusion are expanding in places like Shanghai and Chengdu, the physical technology is deeply intertwined. For example, Sichuan Heavy Industry Fusion is a direct capital shareholder in China Fusion. This means the heavy industrial manufacturing plants in Sichuan will be the ones mass-producing the massive 400-tonne Dewar bases, cryostats, and vacuum chambers originally conceptualised and tested at the CRAFT facility in Hefei.
In Hefei, BEST is scheduled to finish assembly by 2027 to demonstrate actual net-energy “burning plasma”. The expansion of the fusion technology research centre in Tianfu prepares the industrial supply chain, commercial financing, and system designs so that the moment BEST proves net-energy production, CNNC can immediately begin building the full-scale pilot reactors (CFETRs) to deliver electricity to the grid by the 2030s. In short: Hefei invents and tests the core technology, while the new Chengdu facility is building the corporate and industrial infrastructure required to replicate that technology at a mass-factory scale.
While Hefei’s EAST and BEST reactors test heavy engineering hardware, CNNC operates its own next-generation fusion research platform – Huanliu-3 (HL-3) in Chengdu. It is housed inside the Southwestern Institute of Physics directly affiliated with CNNC. While both HL-3 and EAST are both high-level tokamaks, they are built by different entities to focus on completely separate technical challenges.
EAST is designed to prove that a reactor can hold a magnetic field completely stable for long periods of time without the plasma breaking down or melting the container. HL-3 is designed to recreate the absolute peak conditions needed to trigger real fusion, generating maximum plasma current and pushing core temperatures past 150m degrees Celsius.
EAST was built earlier and used imported or internationally co-developed diagnostic equipment during its early life cycle. HL-3 is China’s first entirely home-grown, next-generation tokamak. It is equipped with highly specialised diagnostic tech, helping to perfect the parts that CNNC will mass-produce. EAST is an academic testing bed. It works to solve pure physics questions about plasma behaviour. HL-3 is the direct precursor to a working commercial power plant. It is testing exotic advanced magnetic fields and new divertor configurations specifically to figure out how to efficiently remove excess heat when connected to an actual electrical grid.
China Fusion was established to serve as the unified “national team” driving the commercialisation, overall system design, and digital R&D needed to turn laboratory physics into grid-connected electricity.
