| 摘要 |
PCT No. PCT/CH88/00071 Sec. 371 Date Dec. 5, 1988 Sec. 102(e) Date Dec. 5, 1988 PCT Filed Mar. 31, 1988 PCT Pub. No. WO88/08208 PCT Pub. Date Oct. 20, 1988.An extruded superconductor (1) comprises a conductor core composed of thin metal filaments, for example of niobium-titanium or niobium-tin, and a high-purity aluminium sheath (2) which acts as a stabilizer. A marked reduction in the electrical conductivity perpendicular to the longitudinal axis of the conductor is achieved by means of structures (3) in the form of cross-sectionally distributed layers, ribbon-like strips or closely aligned longitudinal single filaments or fibres or bundles of fibres made of a material of low conductivity embedded coaxially in the aluminium sheath. The layers of low conductivity material embedded coaxially in the aluminium sheath may be closed concentric circular sheaths surrounding the conductor core, at a distance from the core and from one another or ribbon-like strips made of the low conductivity material arranged in a star-shaped configuration about the conductor core. |
