Abstract
Ag-sheathed Bi-2223 superconducting oxide conductors with a critical current density of 66, 000A/cm2 at 77K, and coils that have generated magnetic fields of about 1.5 Teslas at 4.2K had been successfully developed. The conductors were piled-up bundles of four to six sheets of element tapes and had transport currents of around 200Amps. The so-called CSL (Core Size Limit) prevented us from making single conductors which had the capability of transporting a large current of as high as 200Amps at 4.2K. Until now, it was difficult to fabricate a conductor with high critical current density and the capability of transporting a large amount of current simultaneously. The role of CSL to large scale applications of high temperature superconducting oxides is discussed.
