Nuclear Fusion: Tokamak JT-60SA becomes superconducting

The start-up phase of the JT-60SA (tokamak) machine built to support ITER, the most important Big Science project on nuclear fusion energy, is proceeding as planned.

The tokamak (complex fusion device) JT-60SA has recently become superconducting and has currently reached an operating temperature of – 269 ° C, roughly equivalent to the temperature of the space.

The superconducting system represents the heart of the reactor of the Broader Approach research project, the agreement between Europe and Japan aimed at a faster execution of the world research program on nuclear fusion. To date, it is the largest superconducting tokamak in the world and it will remain so until ITER is completed.

The Italian companies, supervised and coordinated by ENEA, have provided a significant contribution in the fabrication of the high-tech components for the project. Among these, Walter Tosto has manufactured the toroidal field (TF) coils to contain the superconducting magnetic system.

After the completion of the tokamak assembly in Naka in March 2020, the joint Japanese and European team is preparing to obtain the “first plasma”.

The machine was started up on 10 October 2020. The process began with the evacuation of all the air from the vacuum vessel. This phase, which lasted about three weeks, subsequently paved the way for the slow cooling of the magnets to bring them, starting from an initial temperature of 27 ° C, to the operating temperature of – 269 ° C. The goal was achieved in the last few days and the current temperature can be viewed from the website http://www.jt60sa.org/jt60sa_tmon/.