Development of 10 kA class Nb3Al superconducting cable by Jelly-role process

This paper reports on a multifilamentary Cu/Nb3Al composite strand developed, with a non-copper critical current density of more than 400 A/mm2 at 12 T, by Jelly-roll process. A 10 kA cable-in-conduit conductor was fabricated to demonstrate the applicability to fusion magnets. The cable had 324 strands, and a circular CuNi seamless pipe was used as the conduit. The strand diameter was 0.88 mm and the filament diameter was 28 μm. The heat treatment was performed at 820 degrees C for 2 hr