The International Thermonuclear Experimental Reactor (ITER), a global collaboration aimed at achieving practical nuclear fusion energy, has reached a landmark milestone with the successful completion of its Central Solenoid and surrounding superconducting magnet system. This magnet system, the largest and most powerful of its kind ever constructed, is a critical component in ITER’s mission to make fusion energy a viable and sustainable power source.
Located in southern France, ITER’s Central Solenoid stands as the electromagnetic heart of the fusion reactor. Towering at 18 meters tall and weighing 1,000 tons, it is engineered to produce a magnetic field strong enough to confine superheated plasma—a key step in initiating and maintaining nuclear fusion reactions. The system is built using advanced superconducting materials that operate at extremely low temperatures to enable strong, stable magnetic fields with minimal energy loss.
Fusion: The Power of the Stars
Nuclear fusion replicates the energy production method of stars, including our Sun. It involves merging light atomic nuclei—such as isotopes of hydrogen—into heavier elements, releasing enormous amounts of energy in the process. Unlike nuclear fission, which splits atoms and generates long-lived radioactive waste, fusion produces no greenhouse gases and minimal radioactive byproducts, making it an attractive candidate for clean energy.
At the heart of ITER’s design is the tokamak, a donut-shaped device that uses magnetic fields to contain plasma at temperatures exceeding 150 million degrees Celsius—ten times hotter than the core of the Sun. The recently completed Central Solenoid is essential in initiating this plasma current and maintaining its stability, helping to ensure that the plasma remains confined long enough for fusion to occur.
Energy Multiplication: A Major Leap Forward
One of the most compelling aspects of this achievement is the energy amplification goal it supports. ITER aims to demonstrate a fusion gain factor (Q) of 10, meaning it will generate 500 megawatts of fusion power from just 50 megawatts of input energy. This would mark the first time in human history that a fusion device produces more energy than it consumes—an essential threshold for the viability of future fusion power plants.
With the Central Solenoid installation now complete, the path is clearer for future milestones such as the first plasma operation scheduled for late this decade. It also serves as a model for future commercial reactors that could transform the global energy landscape.
A Global Effort for a Shared Future
The ITER project involves 35 countries—including the European Union, United States, China, India, Japan, South Korea, and Russia—working together to solve one of humanity’s most pressing challenges: how to produce abundant, carbon-free energy sustainably. Each member has contributed components, expertise, and funding, making it one of the most ambitious scientific collaborations in history.
With this major engineering feat accomplished, ITER brings the world one step closer to realizing the long-sought dream of fusion energy—a future where electricity can be produced safely, cleanly, and almost without limit.
