Thermal Stability of Conductor Joint for JT-60SA Central Solenoid

Broader Approach activities accompany the ITER project, and these activities have been carried out between the EU and Japan. The type of the joint between the conductors of the JT-60 Super Advanced (JT-60SA) central solenoid (CS) is a butt joint. The butt joint is a compact joint, but it has limited stability because of poor helium cooling. In this paper, the butt joint of the JT-60SA CS is analyzed, for the temperature rise at the butt joint, by using the FEM simulation software COMSOL Multiphysics. As a result, when the plasma disruption occurs, the butt joint of the CS in the JT-60SA has enough high T CS margin even if the mass flow decreases from 6.0 to 4.0 g/s. These analyzed results become the fundamental data to evaluate the thermal stability of the coils and to protect coil systems from quench.