Superconducting power applications are based on the zero resistance. The critical current densities for traditional low temperature Superconductors obtained in a very sharp boundary between the superconducting and the normal state have surely indicated the critical applications under the zero resistance state. In high temperature superconductors, the critical current density derived from the usual criterion accompanies the finite resistivity of around lo-" a-cm. From a viewpoint of power applications, such a low resistive state should be distinguished from the superconducting state. We call the stable low resistive state the semi -superconductivity.
As a semi-superconducting application, a semi-superconductingBitter magnet is introduced using Bi zSrzCaCuzOs disks.Index Term -I--high temperature superconductor, flux flow resistivity, semi-superconductivity