AC Loss of High-Tc Superconductors

Applications where high-Tc superconductors hold a good promise to find practical use include high-Tc superconducting power cables. High hopes ride on these new materials for excellent qualities as means of power tranmission, such as high capacity, low voltage and low power loss. As the lower critical field of high-Tc superconductors is considerably smaller than that of metal superconductors, so the surface current density of the former is very low. This poses, however, a technical problem very hard to solve as to how to reduce AC loss. Measurements of AC loss in high-Tc superconducting tapes by the magnetization method have shown that quantitative evaluation in the Bean model provides for satisfactory approximation of AC loss in high-Tc superconducting tapes.