Numerical and experimental study on critical current of quasi-isotropic superconducting strand stacked by REBCO and copper tapes with different stacking patterns

Abstract

In order to improve the transmission capacity of the second generation REBCO tape, many structures of superconducting strand/cable stacked with REBCO tapes were proposed. Quasi-isotropic superconducting strands (Q-IS) stacking REBCO & copper tapes alternately and stacking REBCO tapes outside with copper tapes inside are proposed in this paper. The critical current of Q-IS strand is simulated based on H-formulation, and strand samples are fabricated and tested. Critical current densities of Q-IS strand in the two stacking patterns are analyzed, indicating that the second stacking pattern can improve the critical current density of a single REBCO tape more than the first pattern. Another kind of Q-IS strand with REBCO tapes placed on a copper former is also proposed, and this kind of strand can be twisted to improve the engineering current density and reduce the AC loss, which can be used in power transmission, large superconducting magnets, fusion application and so on.