In-field performances of commercial REBCO tapes below liquid nitrogen temperatures

摘要

We investigated critical current density (J_c) characteristics of commercial REBCO tapes of four manufacturers at temperatures between 30 and 77 K in magnetic fields up to 5 T. We first examined variation in the J_c characteristics of two Zr-doped REBCO tapes (SuperPower) of the same specifications, which are found to be quite different, indicating that the in-field J_c characteristics due to artificial pinning centers vary among spools or along the length of tape. We then investigated in-field performances of four different commercial REBCO tapes (AMSC, Fujikura, SuNAM, SuperPower), calculating performances of coils using their magnetic-field angle dependences of J_c. The REBCO tapes are found to give very different in-field performances depending on the strength and direction of field they experience, and their relative superiority is observed to vary with temperature.