Toshiba completes ITER coil

In an event on 7 June 2021, members of the Japanese Diet and senior representatives of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) joined with members of QST, ITER Japan and the ITER Organization to celebrate the achievement.

"Toroidal field coils are among the core components of this tokamak machine. The specifications required for each coil are extremely challenging, and we know how difficult it is to produce a first-of-a-kind component of this size and precision. I sincerely appreciate the tremendous effort and capabilities of the Toshiba team to tackle many technical challenges under these difficult circumstances," said ITER Director-General Bernard Bigot in his video address, referring to the difficulties the Covid-19 pandemic situation has placed on international manufacturing and shipping.

A tokamak uses multiple magnetic fields to influence the path of the plasma. The D-shaped toroidal field coils, which completely enclose the vacuum vessel by matching its shape on both the inboard and outboard sides, are relied on for plasma confinement. In the huge ITER device, a set of 18 coils will produce a total magnetic energy of 41 gigajoules, generating an intense field all around the plasma (11.8 tesla at its maximum) to keep it confined in the centre of the vessel away from the walls.

Each coil is made up of a superconducting core wound from 4.57 km of niobium-tin (Nb3Sn) and a surrounding stainless steel coil case. Weighing 360 tonnes each, and measuring 9 x 17 m, they are among the largest components of the ITER machine. Toshiba ESS has developed highly precise processing technology in order to fulfil the requirements of manufacturing ITER toroidal field coils to within an accuracy of millimetres.

QST—with the cooperation of Mitsubishi Heavy Industries, Ltd., Mitsubishi Electric Corporation, Hyundai Heavy Industries, and Toshiba Energy Systems & Solutions Corporation—will supply 9 toroidal field coils (assembly of winding packs and coil structures) plus another 10 coil structures to the ITER Project. Toshiba ESS is under contract with QST to manufacture four toroidal field coils and six structural cases.

*QST—Japan's National Institutes for Quantum and Radiological Science and Technology—is responsible for all components allocated to Japan by the ITER Organization.

Read the Toshiba press release in Japanese or English.