It is big and it is superconducting

19 Dec 2007 - Sabina Griffith

The ITER Organization is moving on from design to procurement. On Wednesday, 28th November, the Director General of the ITER Organization, Kaname Ikeda, and the Director for International Affairs Department of the Japan Atomic Energy Agency (JAEA), Toshi Nagaoka, signed the first Procurement Arrangement between the ITER Organization and the Japanese Domestic Agency at the Chateau de Cadarache.

On Tuesday, 18 December, the second Procurement Arrangement was signed by the ITER Principal Deputy Director General Norbert Holtkamp and Didier Gambier, Director of the European Domestic Agency "Fusion for Energy" in Barcelona. Both Procurement Arrangements are part of the TF conductor package for the 18 Toroidal Field (TF) Coils.

"These two first Procurement Arrangements clearly signal that ITER procurements have begun and on a big scale", Kaname Ikeda, ITER Director General, commented. With approximately 400 tons of niobium3-tin (Nb3Sn) superconducting strands, these are two of the largest superconductor procurements in history. "The amount of material that is going to be manufactured is certainly unprecedented in its scale and it signals the first step in the construction of the ITER magnets", Neil Mitchell, responsible officer for the ITER Magnet System said.

The ITER TF coils are designed to have a total magnetic energy of 41 gigajoule and a maximum magnetic field of 11.8 tesla. The Coils will have a total length of 82.2 kilometers and a total weight of 6540 tons. The manufacture of the strands with their 10000 micron-scale filaments is extremely complex and uses cutting-edge technology. They have been developed through a series of tests on different designs. To assist the ITER Organization in developing the specification for this procurement package, an advisory committee was formed to review the technical part of the procurement and to make sure it was correct, complete, and adequately specified the critical items such as the conductor quality control and testing.

About 90% of the ITER components and structures are provided "in kind" by the Members, through the Domestic Agencies. The Japanese contribution to the construction of the ITER superconducting TF magnet system is to supply 25% of the TF Conductors, 9 TF coil winding packs, and almost all of the TF coil structures. Europe will manufacture 20 % of the TF Conductors, 10 % of the TF Magnet Structure and 10 of the TF Coil Winding packs.