Since the discovery of high temperature superconducting oxides, much study has been done to understand the electronic structure of the oxides and to examine various aspects of the superconducting properties. Recent progress in the theoretical study of the high temperature superconducting oxides is reviewed.
An overview of the physical properties of high-Tc superconductors is given. Present status of experimental studies on electronic properties in the normal state, superconducting properties such as isotope effect, energy gap, penetration depth and coherence length, and static and dynamic properties of the flux line are presented.
A 40A/mm2-24kA high-rigidity large forced-cooled (NbTi)3Sn superconducting coil named DPC-TJ was developed under the collaboration between Japan Atomic Energy Research Institute and Toshiba Corporation. The purpose of the DPC-TJ program is to demonstrate the realizability of the high average-current-density with a large coil wound by a large Nb3Sn superconductor which meets the requirements of the conductor for the next thermonuclear fusion machine. The DPC-TJ coil was fabricated as a first coil of the preformed-armor type, which was thought out in this program as a fabrication method that enables the high-rigidity and the high-current-density simultaneously without difficulty. In this paper, the outline of the DPC-TJ program is described laying stress on the development of the DPC-TJ coil.