When completed, the central solenoid will be the largest and most powerful pulsed superconducting magnet ever built. At nearly 60 feet high and weighing 1,000 tons, the central solenoid will have a stored magnetic energy of 6.4 gigajoules and a maximum field of 13 tesla. Positioned along the central axis of the ITER tokamak, it will enable a powerful pulsed current of 15 megaamperes to be induced in the plasma for 300–500 seconds. The central solenoid will work in conjunction with the poloidal field magnets to control and shape the fusion plasma.
The modules: According to General Atomics, the construction of the six independent coil packs, or modules, that make up ITER’s central solenoid was a 15-year-long project, representing a major technical achievement for the United States. Completed inside the company’s Magnet Technologies Center near San Diego, Calif., each module required more than two years to fabricate, followed by testing, and then shipment to France, where they will be stacked to form the superconducting magnet.
The six modules, plus a spare, were wound from niobium-tin superconducting cable produced in Japan. According to the ITER Organization, five of the modules have arrived at ITER so far, while the sixth, completed in April, is en route. The seventh, spare module was displayed during a celebration of the project’s completion held August 28 at the Magnet Technologies Center.
General Atomics said the project underscores the ingenuity of California’s fusion engineering community, particularly in San Diego, and marks a major U.S. contribution to one of the most ambitious energy science projects in history.
Quotables: “This achievement is more than just a technical triumph,” said Wayne Solomon, vice president of Magnetic Fusion Energy for the General Atomics Energy Group. “It’s proof that General Atomics can deliver on the most complex challenges in energy while helping establish San Diego as a leading regional hub for fusion research and technology.”
“The central solenoid is unlike anything that has ever been built,” explained Nikolai Norausky, program manager of the Central Solenoid Project at General Atomics. “We’re talking about orders of magnitude of scale. We had to develop a modern supply chain. Often our suppliers were dealing with the largest, or the heaviest, or the most precise aspects of their technologies. And we had to bring all that in to develop the manufacturing know-how, and the tooling, in order to produce the central solenoid magnets.”
