Design and Strand Tests of a Fusion Cable Composed of Coated Conductor Tapes

The design of a flat cable suitable for future fusion reactors has been carried out. The cable consists of twisted round strands, which are composed of tapes stacked between copper profiles. According to calculations, the strand twist pitch and the cable twist pitch should be at least 1.5 or 2 m long to limit the strain and thus the reduction of the critical current. A 4-m-long strand (Ø6.2 mm) was fabricated on a continuous stacking and soldering line to demonstrate that the scaling up to industrial production is feasible. The strand can carry about 940 A in self-field at 77 K. The critical current evolution under bending strain was measured but it turned out to be rather fragile in “hard” bending direction. Three types of joints between strands were also manufactured and tested at 77 K.