The ITER Organization has announced the completion of its massive magnet system, a process spanning two decades of design, fabrication, and delivery. The final component, the last of six Poloidal Field (PF) coils, was recently lowered into the tokamak pit at the Saint-Paul-lès-Durance facility in France. This event marks the culmination of a complex international manufacturing effort, with components supplied by member nations including China, Europe, Japan, Russia, and the United States. The fully assembled system, comprising 18 Toroidal Field (TF) coils, the six PF coils, and the central solenoid, weighs approximately 10,000 tons and forms the magnetic cage essential for plasma confinement. Source: ITER

The magnet system is engineered to generate extreme magnetic fields required to shape and control the plasma within the tokamak. The central solenoid, built by General Atomics in the U.S., is designed to produce a peak field of 13 Tesla, inducing a powerful current of 15 million amperes within the plasma. The D-shaped TF coils, each standing 17 meters high, will generate the primary toroidal field for confinement. The PF coils, positioned outside the TF coil ring, are responsible for shaping the plasma and maintaining its stability away from the reactor walls. The successful installation of these components is a prerequisite for initiating integrated machine commissioning and proceeding toward first plasma operations. Source: ITER

The magnet system is engineered to generate extreme magnetic fields required to shape and control the plasma within the [tokamak](/glossary/tokamak).

This milestone is critical for the ITER project's primary scientific goal: demonstrating a net energy gain from a sustained fusion reaction. The machine is designed to produce 500 MW of thermal fusion power from a 50 MW input of heating power, achieving a plasma energy gain factor, or Q_plasma, of 10. This would be a significant advance over the current record held by the Joint European Torus (JET), which produced 59 MJ of total fusion energy for a Q of 0.67 in 1997. The ITER tokamak will confine a plasma volume of 840 cubic meters, an order of magnitude larger than any previous fusion experiment, providing a unique platform to study burning plasma physics at a scale relevant to a future power plant. Source: ITER

Despite this hardware achievement, the project's timeline has been subject to significant revisions. The original target for first plasma was 2025, but this has been pushed back by at least a decade due to a combination of manufacturing delays, logistical challenges across the international consortium, and necessary repairs to key components like the vacuum vessel thermal shields. The new baseline schedule is still under review by the ITER Council. While the completion of the magnet system is a major step forward, the path to first plasma and subsequent deuterium-tritium (D-T) operations remains long, with extensive system integration, vacuum testing, and commissioning phases yet to be completed. Source: ITER