Toward a High-Current Conductor Made of HTS CrossConductor Strands

Abstract

Over the last decade, several approaches for the fabrication of high-current cables from second-generation high-temperature superconductor (HTS) REBCO tapes were investigated, among them Roebel cable, conductor on round core, and several twisted stacked tape cable types. We introduced a novel type of stacked HTS tape arrangement, which is called HTS CrossConductor or HTS CroCo, aiming for high engineering critical current densities j <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> that can be scaled to application-relevant lengths of conductors. Measurements of the critical current of a triple-HTS CroCo superstrand at T = 77 K and self-field conditions and at T = 4.2 K, as well as in fields up to B = 12 T, show the expected current calculated from the individual tape critical currents. Twisting experiments of the triple-HTS CroCo superstrand indicate a critical bending strain of around 0.6%. Based on these results, a Rutherford cable design for a cable with a critical current of 80 kA is suggested.