Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Worksite | First pillars for the crane hall

    For the overhead cranes to deliver machine components into the Tokamak assembly pit, the rails that carry them need to be extended some 80 metres beyond the tem [...]

    Read more

  • Transport | 300 tonnes of equipment on its way to ITER

    A specially designed assembly tool and elements of the cryostat and vacuum vessel thermal shields are part of the shipments travelling now from Korea to ITER. W [...]

    Read more

  • Fusion world | A new tokamak in town

    After EAST in China and WEST in France, another of the cardinal points of the compass has been chosen to name a tokamak. Introducing NORTH—the NORdic Tokamak de [...]

    Read more

  • Opportunities | Bringing the ITER Business Forum to Washington

    Every second year, a two-day ITER Business Forum is held to invite existing and potential suppliers for the ITER Project—laboratories, universities, and compani [...]

    Read more

  • World Energy Congress | Fusion "at a time of transition"

    In the United Arab Emirates, Abu Dhabi is often referred to as a tourism hotspot that combines luxury and ancient traditions. In September, Abu Dhabi was in the [...]

    Read more

Of Interest

See archived entries

Europe

Fabrication begins on unique composite rings

After lengthy development, prototyping and test phases, the composite rings designed to help ITER's toroidal field coils cope with huge out-of-plane forces have been cleared for fabrication.

European contractor CNIM has designed the manufacturing process and tooling for winding, bonding, curing, dry machining, and inspecting the pre-compression rings. The first production unit is underway. © CNIM (Click to view larger version...)
European contractor CNIM has designed the manufacturing process and tooling for winding, bonding, curing, dry machining, and inspecting the pre-compression rings. The first production unit is underway. © CNIM
In ITER, the electromagnetic interaction between the toroidal field coil current and the magnetic field generated by the poloidal field coils will create huge stresses on the toroidal field coils. Pre-compression rings will be installed at the top and bottom of the coil structures to "push back" with a centripetal force of thousands of tonnes, suppressing any deflection and greatly reducing cyclic fatigue stresses.

ITER's pre-compression rings are among the largest and most highly stressed composite structures to be designed for a cryogenic environment. Five metres in diameter, with a cross-section of 33.7 cm x 28.8 cm, the rings are made of a composite that consists of more than one billion minuscule glass fibres glued together using epoxy resin.

Prototypes produced by European Domestic Agency contractor CNIM (Toulon, France) have responded well to the demanding tests underway since January, opening the way for fabrication to start on the first production unit. CNIM will manufacture nine pre-compression rings in all (three top, three bottom and three spare).

Dimensional measurements are performed before final machining. The five-metre-in-diameter, three-tonne components will be installed in sets of three at the top and bottom of the toroidal field coil structures to ''push back'' against deflection. (Three other rings will be manufactured as spares.) © CNIM (Click to view larger version...)
Dimensional measurements are performed before final machining. The five-metre-in-diameter, three-tonne components will be installed in sets of three at the top and bottom of the toroidal field coil structures to ''push back'' against deflection. (Three other rings will be manufactured as spares.) © CNIM
CNIM has partnered with Exel Composites (Finland) for the raw material—a pultruded laminate delivered in lengths of 2.8 km (2 mm thick) on spools. Each laminate profile is wound into one ring on specialized winding tooling, with alternate layers of 0.12 mm-thick epoxy tape applied. The completed ring is cured and then machined to the required final dimensions.

Winding started in late February and the first curing operations took place in March. All nine pre-compression rings are expected to be completed by mid-2020.

See the full report on the European Domestic Agency website.


return to the latest published articles