Superconducting wires and tapes

Technological applications of superconductivity can be divided into two major areas superconducting electronics and superconducting wires and tapes. While the widespread use of high-Tc cuprate superconductors in technology has not yet been realized, steady and... 

Gold Shunt Layers on Superconducting Wires and Tapes... 

IC -Advanced Superconductors manufactures superconductive wire, cable, and tape for MRI diagnostic systems, high-energy physics, and fusion power research. Products are based on NbTi, NbjSn, BSCCO (Bi-Sr-Ca-Cu-O) 2212/Ag, and BSCCO 2223/Ag multi-fUament wire and tape. 

The electronic theory of metallic superconduction was established by Bardeen, Cooper and Schrieffer in 1957, but the basis of superconduction in the oxides remains a battleground for rival interpretations. The technology of the oxide ( high-temperature ) superconductors is currently receiving a great deal of attention the central problem is to make windable wires or tapes from an intensely brittle material. It is in no way a negative judgment on the importance and interest of these materials that they do not receive a detailed discussion here it is simply that they do not lend themselves to a superficial account, and there is no space here for a discussion in the detail that they intrinsically deserve. 

Unlike the alloys and elements discussed previously, it is not immediately clear how a superconducting oxide could be made into a wire. Superconducting oxides are powders. The problem is overcome by making tapes, rather than wires, and using an exterior coating of silver. Silver is used as it is practically the only material which does not react... 

Technology as we have witnessed over the years has been outpacing any other development. Some of the developments in technology such as co-extrusion in copper, sintered material objects of required shapes, use of thin-film techniques to produce a tape for electrical connections and the fabrication of tapes and wires of superconductor Nb3Sn lend hope for future technological developments in superconducting rare earth materials such as borocarbides and YBaaCujOy. 

FIGURE 8.1.13 Jc-H curves of PIT processed Bi-2223 and Bi-2212 superconducting tapes at temperatures of 4.2, 20, and 77 K. Jc-H curves ofconventionalNb-Ti and NbsSn wires are also included for comparison. 

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