Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • On site | 28 who "truly shined"

    The new ITER Star Awards recognize exemplary performance and commitment. Every year, during the annual assessment campaign, ITER staff may be recognized for exe [...]

    Read more

  • MT-28 Conference | Superconducting magnets as a catalyst

    Many passers-by paused for a moment and picked up their cell phones to capture the scene. It was indeed rare to see dancers on the square outside of the Pavillo [...]

    Read more

  • Fusion world | TCV tokamak turns 30

    The Swiss TCV tokamak (for Tokamak à Configuration Variable, or 'variable configuration' tokamak) has been exploring the physics of nuclear fusion for 30 years [...]

    Read more

  • Image of the week | Port cell with a view

    A visit to ITER would not be complete without a peek into the Tokamak pit where the machine is being progressively assembled. For several years, one of the equa [...]

    Read more

  • Visit | Chinese Minister reaffirms "full support"

    ITER Director-General Pietro Barabaschi and the Chinese Minister of Science and Technology (MOST) Wang Zhigang share a common academic background. They both tra [...]

    Read more

Of Interest

See archived entries

Industrial milestone

US ITER ready to deliver first central solenoid module

This week the "beating heart" of ITER—the central solenoid, the largest of ITER's magnets—will take the first step in the final lap of a decade-long journey. Over the next few days, it will be loaded onto a special heavy transport vehicle at General Atomics near San Diego, California, bound for the port of Houston, where it will be re-loaded onto a ship bound for Marseille. By early September, it will reach its final destination, the ITER worksite, where it will meet the rest of the superconducting "ITER magnet family" and take its place in the machine.

The General Atomics fabrication team poses in front of the first two modules of the central solenoid. Module 1, at right, is packaged for shipment. Module 2, at left, will be shipped later this summer. Courtesy General Atomics. (Click to view larger version...)
The General Atomics fabrication team poses in front of the first two modules of the central solenoid. Module 1, at right, is packaged for shipment. Module 2, at left, will be shipped later this summer. Courtesy General Atomics.
Creating the magnetic cage that will shape and control the ITER fusion plasma calls for three primary magnet arrays: the D-shaped vertical array of "toroidal field coils," the horizontal layer of ring-shaped "poloidal field coils," and the central solenoid positioned in the central axis.

The unique role of the central solenoid is to direct a pulse of current in the plasma that circulates around the torus—hence the "beating heart" moniker. But this is no normal heartbeat. The size and strength of ITER's central solenoid—a stack of six modules, plus support structures, that together boast a height of 18 metres, a weight of more than a thousand tonnes, and a magnetic field strength of 13 Tesla at its core—will enable a current of 15 million amperes in 400-second pulses, more powerful and more sustained than any previous tokamak.

To manufacture this behemoth, General Atomics created the Magnet Technologies Center as a fit-for-purpose facility. After a four-year collaboration with US ITER on the design and tooling, fabrication of the first module started in 2015.

Each module required more than two years of precision fabrication, carefully winding more than 5 kilometres of steel-jacketed niobium-tin superconducting cable into precise flat discs, then splicing together enough discs to create the full module. Five weeks of heat treatment followed: baking the module evenly in a giant convection-style furnace. Delicately stretching the module coils—much like a giant Slinky toy—allowed the individual turns to be wrapped in fiberglass-Kapton insulation to avoid electrical shorting across the windings. And finally, with the module inserted into a special mould, 3,800 litres of epoxy resin were injected under vacuum, saturating the insulation material, eliminating bubbles, and fusing the module into a structural whole.

In February, the first module passed a demanding series of tests; but it waited on standby as the second module was run through a similar series, as an extra precaution to allow any lessons learned to be applied.

And now, freshly wrapped for travel over land and sea, Module 1 is heading off to take its place as the first of its kind at ITER. Six more modules (one as a spare) will follow in a series, all of them to be installed in 2023-2024. And not so long after that, ITER's scientists will stand by anxiously as their colossal newborn generates its first heartbeat.

To view the making of the central solenoid, see this video from General Atomics.

Read more about the fabrication process in this booklet.



return to the latest published articles