The ITER fusion energy project, a collaboration of more than 30 partner countries, has completed and delivered its massive toroidal field coils after two decades of design, production, fabrication, and assembly on three continents. The delivery ceremony was attended by representatives from the partner countries, including Japan and Italy. These coils are crucial components in ITER, an experimental fusion mega-project aimed at developing a safe, abundant, and environmentally responsible energy source.
The toroidal field coils, nineteen in total, are giant magnets that will be placed around the ITER vacuum vessel, a donut-shaped chamber called a tokamak. Inside the vessel, hydrogen nuclei will be fused together to release enormous energy from the fusion reaction. The fuel for this reaction is deuterium and tritium. By running an electrical current through the gas, it becomes an ionized plasma—a cloud of nuclei and electrons.
ITER uses niobium-tin and niobium-titanium as the material for its giant coils. When energized with electricity, the coils become electromagnets. When cooled with liquid helium to -269°C (4 Kelvin), they become superconducting. Three different arrays of magnets are employed in ITER: the eighteen D-shaped toroidal field magnets confine the plasma inside the vessel, the poloidal field magnets control the position and shape of the plasma, and the central solenoid uses a pulse of energy to generate a powerful current in the plasma.
The completion and delivery of the toroidal field coils is a significant milestone for ITER. Over 40 companies were involved in their creation, with key contributions from both European and Japanese companies. Each completed coil is massive, measuring about 17 meters tall and 9 meters across, and weighing around 360 metric tons. Together, these coils will operate as a single magnet, the most powerful ever made. They will generate a total magnetic energy of 41 gigajoules, with ITER’s magnetic field being about 250,000 times stronger than that of the Earth.
Fusion research, through projects like ITER, is essential for the development of a sustainable, clean energy source that could potentially meet the world’s energy needs in the future. The success of ITER could revolutionize the energy sector and contribute significantly to reducing carbon emissions and combating climate change.
