Lattice braided superconductors

A technique has recently been developed for the braiding of large numbers of superconducting wires into fully transposed, rectangular cross section conductors of low aspect ratio. The technique is derived from textile industry lattice braiding used to manufacture square cross section braids which are not, however, fully transposed. The void structure of the lattice braid cross section is superior, for axial forced flow cooling, to folded flat braids and to triplex cables. The lattice braided conductor also has an effective transposition length which is much shorter than its actual transposition length, and, because of the geometry of the wire path through the cross section, axial magnetic field coupling is cancelled out over lengths which can be only fractions of the actual transposition length. A prototype braid sample has been fabricated from insulated superconducting wire which exhibits the advantages expected. Application of this type of conductor to large force-cooled and/or pulsed coils is discussed.