Patent attributes
A superconductor element comprising Nb3Sn, in particular, multi-filament wire, which contains at least one superconducting filament (1) which is obtained after drawing through solid diffusion reaction from an initial filament structure which comprises a longitudinal hollow tube (3) of niobium (Nb) or an Nb alloy, in particular, NbTa or NbTi, with an inner surface (8) and an outer surface (9), wherein the tube (3) is embedded into a thermally and electrically highly conducting metal matrix (2), in particular, of copper (Cu), wherein the tube (3) is filled with a material (4) which contains tin (Sn) is characterized in that, for mechanical reinforcement of the conductor element and as a diffusion barrier during solid diffusion reaction, the outer surface (9) of the tube (3) is directly and completely surrounded by a sleeve (7) made from a metallic material which has, at room temperature, a thermal expansion coefficient αsheet<17*10−6K−1, preferably αsheet<8*10−6K−1, an elastic limit Rp0.2>300 MPa and a cross-sectional reduction A>20%, wherein the metallic material is selected to be chemically inert to diffusing tin (Sn) up to a reaction temperature T of the solid diffusion reaction.
