Recent developments of various superconducting cables for accelerators

Hitachi Cable, Ltd. has produced many types of superconducting cables for detector magnets, dipole and quadrupole magnets, and others. For example, they are Al stabilized Nb-Ti composite cables for the colliding beam detector magnets and Rutherford type cables for dipole and quadrupole magnets. Through these developments, Hitachi has contributed to the completion of many projects in high energy physics. In a few years, Hitachi Cable has developed high J/sub c/ and very fine filament Nb-Ti superconducting wires. Features of the developed superconducting composites are as follows: (1) high critical current density of 2610 A/mm2 at 5T was attained by the moderate heat-treated and high homogenized 3-4μmphi filaments Nb-46.5%Ti composites; and (2) the most typical feature in wire production is the application of hydrostatic extrusion; this decreases the formation of compounds between Cu and Nb-Ti and no multiple necking in filaments because of the extrusion at relatively low temperature