JT-60SA TF magnet assembly

JT-60SA will be the world’s largest superconducting tokamak when it is assembled in 2020 in Naka, Japan (R = 3 m, a = 1.2 m). It is being constructed jointly by institutions in the EU and Japan under the Broader Approach agreement. The assembly of its 400-tonne toroidal field (TF) magnet, designed for an on-axis field of 2.25 T, was completed in July 2018. Consideration of its assembly throughout the design process, with associated consultation and testing, allowed high positional accuracy and hence respect for magnetic field tolerances to be achieved.