Coupling Time Constant Measurements of Spirally-Twisted Striated Coated Conductors With Finite Transverse Conductance Between Filaments

Striation is effective for AC loss reduction of coated conductors, but it must be associated with twisting. Instead of direct twisting like in low Tc metallic superconductors, we spirally-twisted “striated and copper-plated coated conductor”, in which filaments are electrically connected. The thickness of the plated-copper was varied to examine its influence on filament decoupling. The magnetization losses of these conductors were measured along a transverse magnetic field with a small amplitude, where the coupling loss was dominant. From the frequency dependence of the measured magnetization loss, the coupling time constants of samples with different copper thicknesses, different spiral pitches, and different core diameters were determined. This study demonstrates filament decoupling by spiral twisting the striated and copper-plated coated conductors.