China completes world’s largest fusion magnet, moves closer to artificial Sun

The achievement represents an important step in China’s long-term strategy to produce electricity from fusion power by around 2030, reinforcing its position in the global race to unlock one of science’s most promising carbon-free energy technologies.

The magnet was developed by the Institute of Plasma Physics under the Chinese Academy of Sciences and has now been formally accepted following testing.

The giant D-shaped structure measures 21 metres in length, 12 metres in width and weighs an enormous 582 tonnes.

What is an artificial Sun?

An artificial Sun is a nuclear fusion reactor designed to recreate the same process that powers the Sun.

Instead of burning fuel, fusion reactors combine hydrogen atoms at temperatures exceeding 100 million degrees Celsius, releasing vast amounts of energy without emitting carbon dioxide.

Scientists believe the technology could eventually provide a clean, safe and virtually inexhaustible source of electricity.

Record-breaking magnet designed for fusion reactors

Researchers said the newly completed superconducting magnet is the largest ever built for a fusion reactor.

According to the research team, it has 1.3 times the volume and stores three times more energy than comparable magnets developed for the International Thermonuclear Experimental Reactor (ITER), the world’s largest international fusion research project.

Its primary role is to generate an exceptionally powerful magnetic field capable of containing plasma—a superheated gas reaching temperatures of around 100 million degrees Celsius—inside the reactor without allowing it to come into contact with the reactor walls.

Alongside the giant toroidal magnet, researchers also successfully tested a high-temperature superconducting central solenoid coil, widely regarded as the heart of a fusion reactor.

Comparable to the spark plug in a car engine, the coil helps ignite and sustain the plasma required for nuclear fusion.

Built entirely with domestic technology

China says both the superconducting magnet and the central solenoid coil were developed entirely using domestic materials and manufacturing capabilities, reducing reliance on foreign suppliers for critical fusion technologies.

The six-year research programme has produced 47 patents and established 25 industry standards, according to the development team.

Constructing the magnet demanded exceptional engineering precision.

It has been designed to operate reliably for around 60 years at temperatures approaching minus 269 degrees Celsius while carrying extremely high electrical currents and enduring intense radiation as well as mechanical stress.

Engineers also reduced electrical resistance at key joints to almost zero, allowing electrical currents exceeding 100,000 amperes to pass through with virtually no energy loss—a requirement considered essential for future commercial fusion reactors.

Breakthrough builds on earlier fusion success

The latest development follows another major achievement in China’s fusion research programme.

Earlier this year, the Experimental Advanced Superconducting Tokamak (EAST), commonly known as China’s artificial Sun, established a world record by sustaining plasma at 100 million degrees Celsius for 1,066 seconds.

Researchers said the milestone demonstrated an unprecedented ability to maintain the extreme conditions needed for nuclear fusion over extended periods.

China targets fusion power by 2030

China has outlined a three-stage roadmap to commercialise fusion energy.

The Burning Plasma Experimental Superconducting Tokamak is expected to be completed by the end of 2027, paving the way for the country’s first fusion-based electricity generation around 2030.

The long-term objective is to develop the China Fusion Engineering Demonstration Reactor, which could become the world’s first fusion demonstration power station.

Challenges remain before commercial fusion

Despite the breakthrough, researchers acknowledge that considerable work remains before fusion energy becomes commercially viable.

The project must still progress through full reactor assembly, extensive long-term testing and demonstrate that the technology can consistently produce more energy than it consumes.

Nevertheless, scientists believe each engineering advance brings nuclear fusion closer to becoming a practical source of virtually unlimited, zero-carbon electricity, with the potential to reshape the future of global energy generation.