Effects of lateral-tailoring of coated conductor for ac loss Reduction of superconducting power transmission cables

The effects of removing low-Jc edges of coated conductors by a laser for ac loss reduction were studied in two-layer superconducting power transmission cables. By removing the low-Jc edges, narrower coated conductor with more uniform Jc distribution can be obtained. The original 5 mm-wide coated conductors as well as the edge-removed 4 mm-wide and 3 mm-wide coated conductors were assembled spirally around cyrindrical formers in two layers to form a cable. The measured ac losses were compared with the ac losses calculated using a numerical model where the spiral structure is neglected. For ac loss calculations, we used the lateral Jc distribution of the coated conductor measured by the magnetic knife method or those which are assumed based on the losses of the critical current by the edge removal.