Abstract: A superconducting conductor comprises a first fraction of prior-tinned strands (1, 3, 5, 7, 9, etc. . . . ) and an additional fraction of non-prior-tinned strands (2, 4, 6, 8, 10, etc., . . . ). The strands of the first fraction and of the additional fraction alternate regularly and are maintained in a coherent assembly after being assembled with transposition by heating to melt the layer of tin on the prior-tinned strands, with the tin from said layer then solidifying, thus providing substantially point adherence between the previously tinned strands while leaving channels (11, 12, etc. . . . ) inside the superconducitng conductor for cooling liquid circulation. The invention is also to a method of manufacturing such a superconducting conductor.

Abstract: A lead interface for a superconducting device has a segment of normal conducting lead electrically connected to a segment of superconducting lead coiled within a dewar. The superconducting lead is adapted to be cooled to below the superconductor critical temperature by circulating a cooling fluid through an internal fluid chamber which runs the length of the superconducting coil and into an intermediate disk having an internal spiral fluid chamber. When the superconducting device is on standby, a superconducting switch is closed and the superconducting segment of the interface is left uncooled. To charge or discharge the superconducting device, the superconducting segment of the interface is cooled prior to opening the superconducting switch.

Abstract: A superconductive wire having an elongated flexible sheath bent into a nonlinear shape and formed with an inwardly extending longitudinal formations which can be grooves. A sintered body of a ceramic superconductive materials fills the sheath and conforms to the shape, the body having formations complementarily interfitting with the formations of the sheath. At least one of the grooves can be formed with a channel through which a cooling medium can be circulated or the grooves can receive a conductive strand or a support rod.

Abstract: A holder for protection and handling of a brittle electrical conductor element, such as a ceramic superconductor, limited in its ability to withstand tensile and compression forces exerted thereon and bending along its axial length beyond a predetermined arcuate path. The holder has a flexible housing which encompasses and protects the superconductor element. A helically disposed strengthening element is integral with the housing. The strengthening element resists tensile forces exerted on the housing in an axial direction and resists radially imposed forces on the housing isolating the superconductor element from these forces. The strengthening element also provides for limited arcuate bending of the housing for limiting the bending beyond a predetermined arcuate path.

Abstract: An electric cable for shielding the conductor therein from tensile stresses during bending of the conductor in a predetermined lateral direction. An elongated duct having a pair of opposed sidewalls and a floor therebetween holds the conductive element, while an elongated lid of relatively substantial thickness is mounted in the opening to the duct between the free ends of the sidewalls. The lid fills the duct from the opening between the free ends of the sidewalls to the neutral surface produced by lateral bending of the cable in the direction of the floor of the duct. Bonding material secures the lid and duct in a fixed longitudinal relationship, and a suitable flowable filler encases the conductor in the resulting tubular housing. The cable disclosed has particular application to the preservation of the integrity of superconductor materials used as the conductor in the cable. Preferably, the duct and lid are made of soft and hard copper, respectively.

Abstract: An electronic system having components operating at low temperature at various locations within the system, cryogenic fluid and electrical power are distributed by means of the same conduit. In one embodiment, the conduit consists of a supply section and a return section with each section comprising a channel for conveying cryogenic fluid having superconducing walls for conveying electrical power. In another embodiment of the invention, the conduit comprises a copper rod having channels formed therein for the transport of cryogenic fluid and a channel for supporting a rod of superconducing material therein. The superconducing rod conducts electrical current to a subsystem while being cooled by cryogenic fluid in nearby channels and the cryogenic fluid is used at its destination for cooling purposes.

Abstract: A cryogenically coolable inductive coil including: a multicomponent conductor comprising a plurality of components, each component including a cable of conductive material having a longitudinal axis about which the cable is twisted, the cable being wrapped helically and being compacted, after wrapping, to minimize voids in the cable and to give the component a polygonal profile, the components being disposed parallel, and adjacent, to one another with mutually facing sides of adjacent components being in contact with one another; and an electrical insulating and support structure at least partially surrounding the conductor for supporting stresses induced in the conductor due to magnetic fields created by the flow of current through the conductor, the conductor and the structure being wound to form the coil.

Abstract: A ceramic wire superconducting cable is provided having porous expanded polytetrafluoroethylene insulation, a superconductive ceramic tape "conducting" layer having openings at prescribed intervals and a high strength polytetrafluoroethylene fiber protective layer. The components covering the cable are porous permitting liquid nitrogen to permeate and directly contact with the superconductive cable.

Abstract: A superconducting transmission line system for transferring electrical power over long distances. The system includes a superconducting transmission line extending from a first location where power is supplied to the line to a second location where electrical power is taken from the line. The line includes an inner tube, and a superconducting core positioned inside the tube and spaced from the inner surface of the tube. The core and the inner tube define a passageway for a cryogenic liquid, the boiling temperature of which is above the superconducting transition temperature of the core. The transmission line system also includes a number of spaced supports holding the transmission line with the portion of the transmission line extending between a pair of adjacent supports being lower than the parts of the line held by the pair of adjacent supports. A regenerator for the cryogenic liquid is mounted on each of the pair of supports.

Abstract: A composite hyperconductor for use at cryogenic temperatures and particularly well suited for AC applications employs at least one filament of conductor having an extremely low electrical resistance at cryogenic temperatures, a strengthening matrix surrounding the conductor, and a barrier for electrically insulating the conductor from the matrix while providing for efficient heat transfer therebetween and/or serving as a diffusion barrier to prevent contamination of the high purity conductor during processing. The preferred composite hyperconductor for space applications comprises an ultra high purity aluminum conducting filament, a aluminum alloy matrix and a boron nitride barrier.

Abstract: A cryogenically coolable inductive coil including: a multicomponent conductor comprising a plurality of components, each component including a cable of conductive material having a longitudinal axis about which the cable is twisted, the cable being wrapped helically and being compacted, after wrapping, to minimize voids in the cable and to give the component a polygonal profile, the components being disposed parallel, and adjacent, to one another with mutually facing sides of adjacent components being in contact with one another; and an electrical insulating and support structure at least partially surrounding the conductor for supporting stresses induced in the conductor due to magnetic fields created by the flow of current through the conductor, the conductor and the structure being wound to form the coil.

Abstract: A two stage cryocooler sleeve is provided having a second stage heat exchanger system capable of achieving lower temperatures than the first stage heat exchanger. A current lead comprising a ceramic superconductor having a critical temperature greater than the operating temperature of the first stage is tapered. The broader end is thermally coupled to the first stage heat exchanger and the narrow end coupled to the second stage heat exchanger. The tapered ceramic lead reduces the heat conduction from the first heat exchanger to said second heat exchanger.

Abstract: A superconducting magnet arrangement for magnetic resonance systems including a cryomagnetic dewar containing magnetic coils in a helium vessel surrounded by a nitrogen vessel. A separate support structure is used to support the vessels in the dewar.

Abstract: A sealing system for the sealing passage of cables or tubes, consisting of a rectangular frame, parallelepipedal blocks of resilient material, each block consisting of two identical halves, and featuring a bore adapted to the dimensions of the cables, compression means for compressing the blocks within the frame and retaining means, whereby the half blocks feature at least one groove transverse to the longitudinal axis of the bore on the outer surfaces parallel to said axis and the frame features corresponding grooves while the blocks are locked in place by the said retaining means that may rest in a groove of a half block.

Abstract: A holder for mounting a split type zero-phase current transformer on an electric wire or cable. The holder has a cylindrical portion made from a flexible material such as a rubber and is provided with a slit extending over the entire axial length thereof. At least one protrusion protrudes inwardly from the inner surface of the cylindrical portion. This holder can be used for a large variety of diameters of electric wire or cable in mounting the split type zero-phase current transformer on such electric wire or cable.

Abstract: A self sealing motor lead wire grommet comprising a pair of identical molded plastic grommet members insertable into a slot or notch of the shell of an electric motor. The grommet members each have wire receiving notches in their inner abutting edges and grooves along their other edges for receiving a portion of the shell adjacent the slot. In the preferred embodiment the outer grommet member is inserted in the slot and is engaged by the end shield of the motor. Consequently, when the end shield is secured in position on the shell, both grommet members are clamped together in tight engagement with the shell and the end shield, and the lead wires are clamped in their respective wire receiving notches between the abutting grommet members thereby to close or seal the lead wire pass-through slot in the motor and to seal the lead wires to the grommet members.

Abstract: The interior of a tube provided for low temperature operation is shielded from the exterior through a plurality of metal ribbons helically looping around the tube in an intertwined relationship and each carrying a welded on conduit for low temperature liquid whereby one of these conduits serves as a primary or outgoing conductor, and the two others serve as return paths; suitable spacers are provided to position the system in a concentric relation; inner and outermost tubes are preferably corrugated and the immediate interior of the outermost tube is filled with superinsulation.

Abstract: A method and apparatus for making a fast transition of the entire superconducting winding of an electrical apparatus, which is arranged in a vacuum chamber and is cooled by a cryogenic medium, from the superconducting operating state into the normal-conducting state by heating the entire winding in case of a disturbance of a section of the winding which causes that section to become normal-conducting is disclosed. A predetermined quantity of a gas which is at a higher temperature and which would be frozen at the superconducting operating temperature is introduced into the vacuum chamber such that the superconducting parts of the winding are heated above the critical transition temperature characteristic for superconduction. The pressure in the spaces containing the cryogenic medium can also be increased by a predetermined value such that boiling of the cryogenic medium is suppressed when the superconducting parts are heated to at least the critical transition temperature.

Abstract: The present invention relates to a high current capacity superconductor having a high current density and high stability suitable as a superconductive coil for a large superconductive magnet. In a composite superconductor (1) having superconductive wires (2) and an electrically and thermally highly conductive stable metal (4) electrically coupled in the longitudinal direction, a high current capacity composite superconductor characterized by having an inorganic compound film (5) on the surface of the stabilizing metal (4).

Abstract: A grommet assembly has a two-piece grommet comprising a shank and a flange at a rearward end of the shank for locating the shank in a panel aperture. The shank has a rigid projection at one side which is spaced from the flange to form a slot for receiving an edge portion of the panel and pivoting the shank into the aperture. The shank also has a flexible arm opposite the rigid projection which has spaced projections for engaging the backside of the panel when the shank is pivoted into the aperture. The assembly includes a gasket for sealing against the face of the panel and a U-shaped retainer which is mounted on the shank after insertion for securely fastening the grommet assembly to the panel and insuring a good face seal at the gasket.

Abstract: A conductor support is provided for use with high voltage electrical devices having mounting walls with apertures formed therein through which electrical conductors pass. The conductor support is formed of first and second channel members sequentially inserted in the mounting wall aperture. The first channel member includes walls bendable toward and away from each other, corresponding to collapsed and expanded configurations of the first channel member, respectively. The first channel member is collapsed to take on a reduced cross sectional area, and is inserted through the aperture of the mounting wall. The first channel member includes retaining members, such as notches or grooves, for engaging the mounting wall. After insertion, the first channel member is expanded to bring the retaining members into engagement with the mounting wall.

Abstract: An insulator for an electrical heating element includes an inner section and an outer section removably disposed thereabout. The electrical heating element is removably and loosely received within at least one of the sections. Several of these insulators can be used to make a new and improved electrical heating element assembly.

Abstract: A boltless device for spacing two overhead parallel conductors, the device including a rigid, hollow arm structure adapted to extend between the conductors. First resilient bushing means are located at each end of the rigid arm structure and adapted to engage the respective conductors. A second, outside, resilient bushing means is adapted to engage the conductors in opposed relation to the first bushing means, and two resilient metal clips are adapted to be clipped to the respective ends of the rigid arm structure and around the outside bushing means to secure both bushing means and the arm structure of the overhead conductors. The clips each have a shape that conforms to an outside shape and surface of the second bushing means such that the clips engage the outside surface the full distance thereof when each clip is secured to the arm structure.