Experimental results of 40-kA Nb3Al cable-in-conduit conductor for fusion machines

A 40-kA [Nb.sub.3]Al cable-in-conduit conductor has been developed for the toroidal field coils of fusion reactors, because [Nb.sub.3]Al has excellent mechanical performance. This conductor consists of 405 copper-stabilized multifilamentary strands inserted into a CuNi circular conduit. The [Nb.sub.3]Al strands are fabricated by the Jelly-roll process with a diameter of 1.22 mm. This conductor could be operated up to a current of 46 kA at an external field of 11.2 T. Accordingly, [Nb.sub.3]Al promises to soon become a useful superconductor for large-scale high-field applications, such as fusion machines.