Development of Nb/sub 3/Al multifilamentary superconductors

Nb/sub 3/Al/Cu multifilamentary strands fabricated by the Jelly-roll process, and cable-in-conduit conductors have been developed for fusion magnets. The recent strand has achieved a high critical density of 800 A/mm/sup 2/ (12 T, 4.2 K) with a feasible heat treatment condition for large coils or conductors. The improved strands have were also confirmed to good bending and tensile strain tolerance. A cable-in-conduit Nb/sub 3/Al superconductor with 1152 strands was also developed. It has a titanium conduit and center tube, conforming to the current design for ITER magnets.>