Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Fusion machines | The second-hand market

    Whatever their size, fusion devices are fine pieces of technology that are complex to design and expensive to build. As research progresses and experimental pro [...]

    Read more

  • Manufacturing in China | A set of clamps to resist all loads

    China is providing an extensive array of supports and clamps for ITER's superconducting magnet systems—in all, more than 1,600 tonnes of equipment. On 9 June, t [...]

    Read more

  • Power electronics | Coaxial cables arrive from Russia

    Thirty-eight reels of cable on 13 specially equipped trailers ... the recent convoy of electrotechnical equipment shipped by the Russian Domestic Agency was the [...]

    Read more

  • Conference|Lions and mammoths and cave bears—oh my!

    Separated by less than 200 kilometres in space—but by 36,000 years in time—the ITER Tokamak and the Chauvet Cave may seem to have little in common. But to scien [...]

    Read more

  • Neutral beam test facility | First ITER test bed enters operation

    For all those who had contributed to designing and building the world's largest negative ion source, it was a deeply symbolic moment. ITER Director-General Bern [...]

    Read more

Of Interest

See archived articles

Magnetic system

Nine rings to fight the force

Work on the pre-compression rings of the ITER magnet system progresses in Europe, where work on a full-scale prototype is underway. These technically challenging components—made of composite materials—are designed to push back against the electromagnetic forces of the ITER machine and reduce the fatigue on the structures of the toroidal field magnets.

At Airbus Defence and Space in Madrid, a pre-compression ring ''slice'' undergoes testing. Well-established aerospace techniques have been useful for the prototype activities on ITER's pre-compression rings, which are certainly the largest composite structures ever designed for use in a cryogenic environment. © AIRBUS D&S Spain (Click to view larger version...)
At Airbus Defence and Space in Madrid, a pre-compression ring ''slice'' undergoes testing. Well-established aerospace techniques have been useful for the prototype activities on ITER's pre-compression rings, which are certainly the largest composite structures ever designed for use in a cryogenic environment. © AIRBUS D&S Spain
The electromagnetic forces acting on the machine structure during operation will be huge—to the order of several hundred meganewtons (MN). Caused by electromagnetic interaction between the toroidal field coil current and the magnetic field generated by the poloidal field coils, these out-of-plane forces will cause stress to the toroidal field coils and, over time, fatigue.

Six pre-compression rings, installed at the top and bottom of the toroidal field coils, will be used to pull the 18 coils tightly together. Measuring five metres in diameter and weighing approximately three tonnes, the pre-compression rings will reduce the fatigue on the magnet structures caused by electro-magnetic forces—consequently prolonging their operational lifetime. Three other rings will be manufactured as spares.

A lengthy R&D program carried out in Europe identified a glass-fibre/epoxy composite as the best material for withstanding high loads and avoiding the circulation of current; the fiberglass composite rings, consisting of more than a billion miniscule glass fibres, will be glued together by a high performances epoxy resin.

Work is underway at Airbus Defence and Space (Airbus D&S) in Madrid, Spain, on a full-size prototype—part of advanced qualification activities that precede the start of production. Development of the spare pre-compression rings is taking place at CNIM in Toulon, France, where a small-scale mockup is underway.

Read the full article on the European Domestic Agency website.


return to the latest published articles