Update on toroidal field coil manufacturing
15 Oct 2010
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Frédéric Savary, Toroidal Field Coil Section Leader
Regular radial plate mockup in preparation for welding at the contractor SIMIC in Italy.
A recently held meeting of the Integrated Product Team for ITER's toroidal field coils highlighted some of the manufacturing milestones reached for the coil structures and the coils themselves. The Chinese Domestic Agency presented the status of their procurement process for the magnet supports for which the call for tender has been launched.
Three contracts are already in place for the fabrication of a full scale prototype for the radial plates. The toroidal field coils use a conductor with a circular outer section that is contained in grooves in so-called "radial plates." There is one radial plate for each double pancake and the conductor is contained in grooves on each side. The radial plates measure 8.7 m x 13.8 m and weigh 5.5 tonnes each. Different manufacturing routes are utilized so that the Domestic Agencies can select the best solution from both the technical and cost point of view before launching into series production.
The manufacturing routes are:
- hot rolled plates, forgings and powder hipped plates for the raw material;
- narrow gap TIG welding, electron beam welding and laser welding for the assembly of the radial plate segments;
- finish machining either before or after assembly and welding of the segments, eventually with a portal machine along the entire perimeter of the radial plate.
Forging of a curved radial plate segment to be delivered to CNIM in France.
One contract has been placed with the company SIMIC S.p.A. in Italy, the second contract is with the company CNIM in France and the third one is with the company Toshiba in Japan. Regarding the winding for the toroidal field double pancakes, the company Toshiba is completing the optimization of the winding parameters with a dummy conductor and will start the fabrication of a 1/3rd scale double pancake winding in a few weeks. This double pancake winding will then be utilized for a vacuum pressure impregnation trial.