GB1175091A - Superconducting Apparatus - Google Patents

Abstract

1,175,091. Superconducting devices. FORD MOTOR CO. 27 Feb., 1967 [24 March, 1966], No. 9177/67. Heading H1K. Two superconducting elements in a cryogenic environment are interconnected by a superconducting " weak link," and an inductive member is located adjacent the elements, to induce a current therein. As shown in Fig. 1, the " weak link " comprises two pointed superconducting screws connecting two segments of an annular superconductor. The screws may be of niobium while the elements of the annulus are of vanadium. Insulating separators, e.g. of plastics or a suitable adhesive, isolate the main parts of the elements from each other. The superconducting annulus is inserted into an insulating cylinder, Fig. 1, and then into a cutaway cylindrical container which incorporates means for adjusting the linking screws so as to vary the extent of the superconducting linkage. Alternative " weak links " may be provided by evaporated insulating films to permit tunnelling between the two superconducting elements, or by small metallic bridges between the elements. Such bridges may be formed by evaporation through an insulating film or through a mask so as to provide a small bridge linking large evaporated superconducting films, or by mechanical removal of part of an evaporated superconducting film. A further form of link consists of two crossed superconducting wires. The device may be used with separate input and output inductance coils, in which case a sinusoidal current in the input coil produces a series of voltage pulses in the output coil, Fig. 4 (not shown), as a result of quantum jumps in the flux through the superconducting loop controlled by the critical current in the " weak link." Hysteresis in the flux in the superconducting loop permits the device to be used as a memory element. A single coil, either inside or outside the cryogenic environment, may serve as both inductive input and output for amplification or oscillation applications, Fig. 7 (not shown).