Subscribe options

Select your newsletters:

Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Component delivery| A jewel in a box

    Sailing under the flag of Germany, the Regine is a mighty ship, strengthened for heavy cargo and equipped on its portside with two 750-tonne on-board cranes. Ha [...]

    Read more

  • Education | Make your own tokamak with 3D printing!

    It's not Lego, but it is definitely 'hands-on.' To offer a tangible device to illustrate the workings of magnetic confinement fusion in a tokamak, the ITER Orga [...]

    Read more

  • Worksite | Europe's Fusion for Energy is building the ITER installation

    Anyone driving to ITER can take full measure of the enormity of the project a few kilometers before reaching the destination. Gigantic cranes can be seen from a [...]

    Read more

  • Disruption mitigation | Experts in plasma disruptions gather online

    On 20-23 July, 120 international experts participated in the 1st IAEA Technical Meeting on Plasma Disruptions and their Mitigation, jointly organized by the Int [...]

    Read more

  • Start of assembly | World dignitaries celebrate a collaborative achievement

    Due to the constraints imposed by the COVID-19 pandemic, the crowd in the ITER Assembly Hall was small. But thanks to live broadcasting and video feed, the audi [...]

    Read more

Of Interest

See archived entries

Pre-compression rings

An iron fist - in reverse

Knowing that the large electromagnetic forces at work during machine operation would cause stress over time to ITER's largest magnet set, engineers devised a compression system to "push back." The resilience of the solution—large composite "pre-compression" rings that will encircle the tips of the toroidal field coil cases at top and bottom—is about to be tested at a dedicated facility. 

This unusual test bench has 36 actuators exerting a force of 1,000 tonnes each. They will operate simultaneously to subject the toroidal field coil magnet system's pre-compression rings to ITER-like forces in order to test their resistance and durability. (Click to view larger version...)
This unusual test bench has 36 actuators exerting a force of 1,000 tonnes each. They will operate simultaneously to subject the toroidal field coil magnet system's pre-compression rings to ITER-like forces in order to test their resistance and durability.
At a brand-new facility at CNIM (La Seyne-sur-Mer, France) everything is ready for the arrival of an exceptional test bench, capable of applying stresses similar to those of ITER operation to the toroidal field coil pre-compression rings and measuring millimetric deformation.

The tool, developed by Douce Hydro (France) in collaboration with CNIM, will subject the rings to a combined circumferential force of 36,000 tonnes while maintaining a positional accuracy of 0.1 mm. The test on each ring will last a few hours and will be supplemented by other tests to confirm creep and fatigue performance.

The ITER Organization is procuring the test facility and tooling through a contract awarded to the CNIM/Douce Hydro consortium, while the European Domestic Agency has developed the conceptual design of the test facility and is responsible for technical progress.

Neil Mitchell, ITER Magnet Division head, cites the collaboration as "an excellent example of ITER Organization and the European Domestic Agency working as a single team to construct the facility within budget and to schedule."

At a newly created facility at CNIM, representatives of ITER, the European Domestic Agency, manufacturer Douce Hydro and host CNIM stand before the test bench where nine pre-compression rings will be tested (three upper, three lower and three spare). (Click to view larger version...)
At a newly created facility at CNIM, representatives of ITER, the European Domestic Agency, manufacturer Douce Hydro and host CNIM stand before the test bench where nine pre-compression rings will be tested (three upper, three lower and three spare).
The European Domestic Agency is responsible for the fabrication of nine pre-compression rings (three top, three bottom and three spare). Weighing roughly 3 tonnes each, with an inner diameter of 5 metres, they are made of a fiberglass composite that consists of more than one billion minuscule glass fibres glued together using epoxy resin. This material—the result of an in-depth R&D program—has proved to be the best material for withstanding high loads and avoiding the circulation of current.

The first full-scale prototype should be delivered to the test facility by the European Domestic Agency before the end of the year.  Eventually all nine of the pre-compression rings will be proof tested before installation.

Read the original report on the European Domestic Agency website.


return to the latest published articles