摘要 |
A multifilament superconducting strand for use at industrial frequencies and made from an initial billet comprising a superconducting core niobium-titanium alloy surrounded by an anti-diffusion barrier layer which is in turn surrounded by a copper based matrix material, with the strand being made from the billet by successive stages of extrusion, wire-drawing, and assembly, wherein the strand includes 5x105 to 5x106 filaments each constituted by the superconducting core reduced to a diameter in the range 50 nm to 150 nm, the filaments being separated from one another by a distance lying in the range 30 nm to 100 nm, which distance is occupied by the anti-diffusion layer and the matrix material. The matrix material contains in excess of 8% manganese when the anti-diffusion layer is made of niobium, or alternatively, the anti-diffusion layer may be of an iron-containing alloy with the matrix containing copper and nickel.
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