Critical Current Degradation Behavior in YBCO Coated Conductors Under Torsional Strain

Abstract

The Ic degradation behaviors of a YBCO coated conductor (CC) tape (RABiTS/MOD) was investigated using a sample holder which gives torsional angles to HTS tapes. The Ic degradation in YBCO CC tape under torsional strains occurred gradually which is a characteristic feature under torsion. Uniform torsional deformation was induced in the YBCO CC tape evident from the consistent Ic degradation behavior at each subsection along the longitudinal direction of the tape. Similar with the tension case, the reversible behavior of Ic under torsional loading was found. The irreversible strain, epsivirr.t., was ~0.6%. The critical strain defined by the 95% Ic retention criterion was 1.4% which was located within the irreversible limit. The n-value-thetas behavior in the YBCO CC tape was similar to the Ic/Ic0-thetas behavior.