New Techniques for Superconducting Cables

This paper presents experimental results of tests on new techniques of constructing superconducting cables; those fabricated from braided elemental and high field alloying superconductors. Braided superconducting cables are feasible for small size, packaged delay lines. Tests were facilitated by the use of. a tunnel diode pulse generator operating at 4.2°K. Cables fabricated with a braided niobium outer conductor and a solid niobium inner conductor, lengths of 200 feet to 1500 feet, show an output 10%-90% risetime of less than 3 ns at 4.2°K. When compared to the same length of RG-213U a marked improvement is observed. Similar cables constructed of a solid Nb-25%Zr inner conductor, lengths of 263 feet and 900 feet, exhibit an output 10%-90% risetime of 0.65 ns. These results indicated that the risetime was not a function of length as is the case in ordinary cables.