JT-60SA assembly of the Toroidal Field coils has started

With the placement of the first two, of the total 18, Toroidal Field (TF) coils in the tokamak, the complex process of assembling this magnet has started at the JT-60SA site in Naka, Japan. This is a major achievement resulting from a fruitful collaboration between Japanese ITER Domestic Agency QST and F4E. “The technical challenges in developing and assembling these superconducting magnets that are amongst the largest in the world should not be underestimated. Indeed, each TF coil is eight metres high, five metres wide, and weighs 30 tonnes”, said Johannes Schwemmer, F4E Director. The TF coils are the backbone of the JT-60SA machine, one of the three projects within the Broader Approach Agreement between Europe and Japan. They are large “D” shaped superconducting magnets whose main task will be to create the main magnetic field needed to confine the plasma.

A ceremony to mark this auspicious event was hosted by F4E and QST and held at the JT-60SA site in mid-January. Attended by several high-level Japanese politicians such as the Research State Minister Mr Mizuochi and Members of the House of Representatives, the event attendees also included the top management from QST, Drs Hirano, Nakamura, Shimada, Tajima, Mori, Kurihara, Ishida and Kamada. In attendance from Europe were F4E Director Johannes Schwemmer, Pietro Barabaschi, Home Team Project Manager for Europe’s contribution to the BA project, and Head of F4E’s Broader Approach JT-60SA Unit Enrico Di Pietro. Gerassimos Thomas, Deputy Director General in the Directorate-General for Energy at the European Commission was present and the EU Voluntary Contributors CEA (France) and ENEA (Italy) were represented by CEA Administrator General Daniel Verwaerde and ENEA President Federico Testa.

“JT-60SA’s impressive progress while staying within schedule and the cost envelope is largely due to the exceptionally effective collaboration that F4E and QST have been able to forge. I also have the highest appreciation for our partners in Europe, namely CEA, ENEA, CIEMAT, Consorzio RFX and KIT”, said Johannes Schwemmer during his speech at the event. All parties are now looking forward to the operation of the JT-60SA facility which will begin in 2019.

During the ceremony, another achievement was also celebrated: the completion of the JT-60SA cryoplant commissioning and F4E’s transfer of ownership of JT-60SA’s cryogenic system to QST. A powerful refrigerator producing helium at temperatures close to absolute zero in order to cool the superconducting magnets when confining the plasma, the JT-60SA cryoplant presently ranks among the largest helium refrigerators in the world. In the next three years the cryogenic plant will be progressively integrated with the cryodistribution system and magnets system.