Electro-Mechanical Property Investigation of Striated REBCO Coated Conductor Tapes in Pure Torsion Mode

In superconducting cable applications using the HTS tapes, striation of ReBCO coated conductor (CC) is being considered to reduce ac loss. The striation of ReBCO coating film with laser patterned filaments has been tried. In practical applications, the striated ReBCO CC tapes should also exhibit acceptable tolerance to mechanical stress/strains. However, reports on the electromechanical properties of striated CC tapes in bending or torsion mode are limited. In this study, the critical current degradation behavior of the striated Cu stabilized SmBCO CC tapes in pure torsion mode was investigated using a sample holder which gives torsional deformation to CC tapes. The CC tape has been laser scribed to produce multi-filaments. The Ic/Ic0 and n-value-torsional angle (θ) behaviors in the striated SmBCO CC tapes were examined and compared with the case of non-striated ones. According to the location of the coating film strip striated within the cross-section, there existed some difference in the I_cf degradation behavior indicating that a non-uniform deformation was induced on each striated strip.