International Round Robin Test For Critical Current Measurement Of Re-Ba-Cu-O Superconducting Tapes

VAMAS TWA 16 promoted an international round robin test (RRT) on critical current (I-c) measurement of RE-Ba-Cu-O (REBCO; RE = rare earth) superconductors to establish the transport Ic measurement method in liquid nitrogen bath without an external magnetic field. Ten laboratories from five countries participated in the RRT and tested commercially available REBCO superconductors. I-c and measurement conditions were reported. In parallel, intrinsic I-c nonuniformity of the superconductors were evaluated by reel-to-reel scanning Hall-probe microscopy for 10-m conductors. Statistical analyses of I-c provided uncertainty of the measurement method. Combined standard uncertainty was analyzed considering the intrinsic nonuniformity of I-c. The analysis indicated that the intrinsic nonuniformity has the largest contribution to the uncertainty of I-c.