Characteristics of Compressive Strain and Superconducting Property in YBCO Coated Conductor

We have applied compressive stress perpendicular to YBCO coated tapes, and measured the degradation of critical currents. When the tape was pushed from the silver surface of the tape, the performance of the tape hardly decreases. On the other hand, compressing from the hastelloy face, degradation of the tape occurred. We observed the damage of the tapes by a magneto-optical imaging technique. The observed results were consistent with the degradation data. From those results, we think that it is better not to compress strongly from the hastelloy side.