Fabrication and Electromagnetic Characterization of Ultrasmall Diameter REBCO Wires

Using ultrathin RE-Ba-Cu-O (REBCO, RE = rare earth) superconductor tapes, we have fabricated of a multilayer round wire with an outer diameter of 1.6 mm on a flexible copper former of 0.8 mm diameter with a critical current of 283 A at 77 K, self-field. A single-layer round wire's angular dependence of critical current in a magnetic field shows near isotropic characteristics. The critical current of a single-layer round wire has been measured over a temperature range of 30-77 K in magnetic fields up to 9 T.