In a landmark achievement for fusion energy, the International Thermonuclear Experimental Reactor (ITER), with headquarters in French city Saint-Paul-les-Durance, has completed all components for the world’s largest, most powerful pulsed superconducting electromagnet system.
ITER is an international collaboration of more than 30 countries to demonstrate the viability of fusion — the power of the sun and stars — as an abundant, safe, carbon-free energy source for the planet.
The final component was the sixth module of the Central Solenoid, built and tested in the United States. When it is assembled at the ITER site in Southern France, the Central Solenoid will be the system’s most powerful magnet, strong enough to lift an aircraft carrier.
The Central Solenoid will work in tandem with six ring-shaped Poloidal Field (PF) magnets, built and delivered by Russia, Europe, and China.
International reactor completes world’s largest and most powerful pulsed magnet system
The fully assembled pulsed magnet system will weigh nearly 3,000 tonne. It will function as the electromagnetic heart of ITER’s donut-shaped reactor, called a Tokamak.
A ten-fold energy gain
At full operation, ITER is expected to produce 500 megawatts of fusion power from only 50 megawatts of input heating power, a ten-fold gain. At this level of efficiency, the fusion reaction largely self-heats, becoming a “burning plasma.”
By integrating all the systems needed for fusion at industrial scale, ITER is serving as a massive, complex research laboratory for its 30-plus member countries, providing the knowledge and data needed to optimise commercial fusion power.
India among consortium of global powers working on harnessing tech for clean energy /h6>
A global model
ITER’s geopolitical achievement is also remarkable: the sustained collaboration of ITER’s seven members — China, Europe, India, Japan, Korea, Russia, and the United States. Thousands of scientists and engineers have contributed components from hundreds of factories on three continents to build a single machine.
Pietro Barabaschi, ITER Director-General, says, “This achievement proves that when humanity faces existential challenges like climate change and energy security, we can overcome national differences to advance solutions.”
In 2024, ITER reached 100 per cent of its construction targets. With most of the major components delivered, the ITER Tokamak is now in assembly phase. Last month, the first vacuum vessel sector module was inserted into the Tokamak Pit, about three weeks ahead of schedule.
Role of private sector
The past five years have witnessed a surge in private sector investment in fusion energy R&D. In November 2023, the ITER Council recognised the value and opportunity represented by this trend.
They encouraged the ITER Organisation and its domestic agencies to actively engage with the private sector, to transfer ITER’s accumulated knowledge to accelerate progress toward making fusion a reality.
In 2024, ITER launched a private sector fusion engagement project, with multiple channels for sharing knowledge, documentation, data, and expertise, as well as collaboration on R&D. This tech transfer initiative includes sharing information on ITER’s global fusion supply chain, another way to return value to member governments and their companies.
Last month, ITER hosted a public-private workshop to collaborate on the best technological innovation to solve fusion’s remaining challenges.
Contribution of members
Under the ITER Agreement, members contribute most of the cost of building ITER in the form of building and supplying components. This arrangement means that financing from each member goes primarily to their own companies, to manufacture ITER’s challenging technology. In doing so, these companies also drive innovation and gain expertise, creating a global fusion supply chain.
Europe, as the Host Member, contributes 45 per cent of the cost of the ITER Tokamak and its support systems. China, India, Japan, Korea, Russia, and the United States each contribute 9 per cent, but all members get access to 100 per cent of the intellectual property.
India has fabricated the ITER Cryostat, the 30-metre high, 30-metre diameter thermos that houses the entire ITER Tokamak. India has also provided the cryolines that distribute liquid helium to cool ITER’s magnets.
Additionally, India has been responsible for delivering ITER’s cooling water system, the in-wall shielding of the Tokamak, and multiple parts of the external plasma heating systems.
Russia has delivered the 9-meter-diameter ring-shaped Poloidal Field magnet that will crown the top of the ITER Tokamak. Working closely with Europe, Russia has also produced approximately 120 tonnes of Niobium-Titanium (NbTi) superconductors, comprising about 40 per cent of the total required for ITER’s Poloidal Field magnets.
China, under an arrangement with Europe, has manufactured a 10-metre Poloidal Field magnet. It has already been installed at the bottom of the partially assembled ITER Tokamak.
In total, ITER’s magnet systems will comprise 10,000 tonne of superconducting magnets, with a combined stored magnetic energy of 51 Gigajoules. The raw material to fabricate these magnets consisted of more than 100,000 kilometers of superconducting strand, fabricated in 9 factories in six countries.
Step 2. The pulsed magnet system sends an electrical current to ionize the hydrogen gas, creating a plasma, a cloud of charged particles.
Step 3. The magnets create an “invisible cage” that confines and shapes the ionized plasma.
Step 4. External heating systems raise the plasma temperature to 150 million degrees celsius, ten times hotter than the core of the sun.
Step 5. At this temperature, the atomic nuclei of plasma particles combine and fuse, releasing massive heat energy.
