Patent ID: 7514634

Claim:
A superconductor element comprising Nb 3 Sn, the conductor element having at least one superconductor filament which is obtained after drawing via a solid diffusion reaction of an initial filament structure, the initial filament structure comprising: a thermally and electrically highly conducting metal or a copper matrix; a sleeve of a metallic material embedded in said matrix, said sleeve having a room temperature expansion coefficient α sheet <17*10 −6 K −1 , an elastic limit R p0.2 >300 Mpa, and a cross sectional reduction A>20%, said metallic material being chemically inert to diffusing tin up to a reaction temperature of the solid diffusion reaction; an elongated hollow tube of niobium or a niobium alloy, said tube having an inner surface and an outer surface, said outer surface cooperating with an inner surface of said sleeve, wherein said sleeve directly and completely surrounds said outer tube surface as a diffusion barrier during the solid diffusion reaction, said sleeve structured and dimensioned to have a thickness d sleeve after drawing of 3 μm<d sleeve <15 μm for mechanical reinforcement of the conductor element, wherein a cross sectional area of said sleeve is >11% of an overall cross sectional area of the filament; and a powder material disposed within said tube in contact with said tube inner surface, said powder material comprising NbSn 2 .