The enhancement of current in superconductor wires by modifying and changing the surface region microstructure

The electromagnetic characteristics of superconductor are briefly analyzed and described, when a magnetic field is applied to the superconductor, flux lines penetrate it from the surface. The flux lines are pinned by pinning centers on the surface of the superconductor, and cannot penetrate deeply from the surface and the density of the flux lines will be higher near the surface and lower in the inner region, with the participation of surface barrier effect and Meissner effect, which indicates the enhancement of pining in the core of the superconducting wire is useless and blocks the transport current. Based on this knowledge, the new multilayer structure wire is design, and the core of the wire is the high-density superconductor crystal covered by doping or changing microstructure layer with thickness as the penetration depth, outer part of the superconducting region is modified, by nanoparticle surface decorating, electron and heavy ion irradiation and extension to surface. Furthermore the Columnar defects, located near the surface, which suppress the surface barrier but create gigantic surface pinning, and the other pining centers have not this property. Then the superconducting region is wrapt by the normal metal.