Abstract: An arrangement for electrically conductively connecting two electrical units by means of a bipolar high voltage direct current transmission, in which between the units are arranged at least two electrical direct current cables constructed as superconductive cables. The superconductive cables are mounted separately from each other in a cryostat (1,2) suitable for conducting a cooling agent which has at least one metal pipe provided with a thermal insulation. The cryostats (1,2) are connected with at least one of their ends to a cooling plant (7) supplying the cooling agent and a pipeline (3) is placed parallel to the two cryostats (1,2). The pipeline (3) is connected at both its ends to the two cryostats (1,2) through valves (15,16,17) which are closed during uninterrupted operation and, in the case of an interruption at one of the superconductive cables, the pipeline (3) serves with the then open valves for conducting the cooling agent intended for the cryostat of the impaired cable.

Abstract: A superconducting cable line includes a heat insulation pipe for a fluid for transporting liquid hydrogen, a superconducting cable housed in the heat insulation pipe for a fluid, and heat exchange means for performing a heat exchange between liquid hydrogen and a refrigerant of the cable. The superconducting cable includes a cable core inside a heat insulation pipe for a cable and is housed in the heat insulation pipe for a fluid to form a low temperature environment around the cable and a double heat insulation structure including the heat insulation pipe. Therefore, since heat intrusion into the superconducting cable is reduced and the refrigerant is cooled with liquid hydrogen, the line can reduce energy for cooling the refrigerant.

Abstract: High-current, compact, flexible conductors containing high temperature superconducting (HTS) tapes and methods for making the same are described. The HTS tapes are arranged into a stack, a plurality of stacks are arranged to form a superstructure, and the superstructure is twisted about the cable axis to obtain a HTS cable. The HTS cables of the invention can be utilized in numerous applications such as cables employed to generate magnetic fields for degaussing and high current electric power transmission or distribution applications.

Abstract: A termination for a superconductive cable (1) is provided, consisting of a pressure-tight metal inner container (2) in which there is a liquid refrigerant and into which the cable protrudes, and a metal outer container (3) which is separated from the inner container by an intermediate space (4) in which vacuum insulation is applied. A first rupture diaphragm (6) is applied in the wall of the inner container (2) and a second rupture diaphragm (7) is applied in the wall of the outer container (3) level with the first rupture diaphragm (6). An evacuated relief space (8), which contains superinsulation and is sealed from the intermediate space (4) with the vacuum insulation by a pressure-tight wall (9), is provided between the two rupture diaphragms (6, 7).

Abstract: A superconducting cable having improved transmission efficiency facilitates the laying operation and reduces heat intrusion. The superconducting cable comprises a first pipe 105 within which are accommodated a refrigerant passage section 101, a superconducting member 102 and an electrical insulating section 103, and a second pipe 106 arranged on the outer side of the first pipe. A vacuum heat insulating section 104 is provided between the first and second pipes. The second pipe is formed of a ferromagnetic material.

Abstract: A composite conductor suitable as a connecting conductor that includes a superconductor and is capable of reducing the generation of Joule heat in a joint part between the system side and power-supply sides of a superconductor apparatus. A composite conductor 10 includes a superconductor 12 provided continuously in the flowing direction of the electric current, and a metal conductor 11 joined with the superconductor 12 and provided at least at a joint part with mating conductors 50, 60 to be joined, wherein the electric current is fed and received between the metal conductor 11 and the mating conductors 50, 60 by joining the metal conductor 11 and the mating conductors 50, 60, and wherein the superconductor 12 is arranged in the metal conductor 11 so as to be approximately parallel to the joint surface (joint interface) between the metal conductor 11 and the mating conductors 50,60.

Abstract: A flexible conductor core for superconducting power cable, characterized by a central tubular element on which the superconducting tapes are placed, in the shape of a spiral or helix, in at least two layers with a calculated angle of lay length, being one of the sections of the layers of the superconducting tapes laid in a direction opposite to the other section, wherein the laying length of all the layers varies from a maximum Pmax1 (1000 cm) and Pmax2 (1000 cm) in the intermediate layers to a Pmin1 (2 cm) and Pmin2 (2 cm) in the external layers, while the laying angle of the tapes of all the layers varies from ?max1 (45°) to ?min1 (0°)

Abstract: In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

Abstract: A high voltage power cable termination with a current lead, a power cable having a first tube and an outer conductor, e.g., a superconductor, whose electrically conducting properties improve at low temperatures, arranged around the first tube and intended in use to be cooled to low temperatures by cryogenic fluid flowing through the first tube, a joint for electrically connecting one end of the current lead to the conductor at one end of the cable at or adjacent to one of the first tube, and a second tube communicating with the first tube at or adjacent to the joint for conveying cryogenic fluid to or from the first tube. The first and the second tube are arranged so that, in use, no cryogenic fluid conveyed by the tubes contacts the conductor or the current lead at the joint. The invention also relates to electrical apparatus, e.g., a high voltage induction device, having such a termination.

Abstract: A superconducting cable (1) for high power with at least one phase comprises a superconducting core (2) wherein a plurality of elements (3) are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material (8). Thanks to the distribution of the superconducting material into several coaxial conductive elements (3), the cable (1) allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field.

Abstract: In a dielectric resonator, a superconductor is formed on two neighboring surfaces of a cubic dielectric body, and the superconductors formed on each two neighboring surfaces are connected by a silver electrode formed in the vicinity of the edge where the neighboring two surfaces join.

Abstract: A superconducting wire having a fine line made of an oxide superconductor which has metal material dispersed therein, the outer periphery of which being coated with a conductive material; and a manufacturing method for the superconducting wire, comprising a process for drawing a metal pipe; filled with an oxide superconductor so as to product the fine line and a process for heating the fine line at a temperature which is higher than the melting point of the metal material constituting the metal pipe.

Abstract: Method of maintaining a superconducting cryolink at low temperature by a flow of liquid nitrogen produced by a liquefier feeding one end of a link section, wherein the section is fed by a single liquefier and nitrogen is drawn off from at least one intermediate point of the link section.

Abstract: A high temperature superconducting cable comprises a cryogenic core, with a superconducting material either inside the cryogenic core or wrapped around the core. A space maintained at a vacuum and functioning as a cryostat surrounds the core; within this space are a separator and superinsulation. A conventional dielectric at room temperature surrounds the superinsulation, and a conventional ground shield surrounds the conventional dielectric. This cable does not require a cryogenic dielectric and is of suitable size and nature to be used in retrofitting conventional cable pipes.

Abstract: A superconducting cable for high power with at least one phase includes a superconducting core wherein a plurality of elements are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material. As a result of the distribution of the superconducting material into several coaxial conductive elements, the cable allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field. The conductive elements are connected at the ends to yield a mean exploitation efficiency of 100%.

Abstract: A superconducting current lead is provided, in which a plurality of unit conductors serving as current paths and each formed from a tape-like oxide superconducting wire are disposed on a cylindrical support member 4 so that a tape surface of the superconducting wire material is made parallel with a circumferential direction in a cylindrical coordinate system, and magnetic members 3 are disposed between the plurality of unit conductors.

Abstract: A self-protected modular high temperature superconducting (HTS) down-lead that is capable of carrying large currents from a room temperature power source to a superconducting device operating at cryogenic temperatures. This down-lead incorporates a safety lead capable of carrying current and absorbing heat to protect the HTS material of the lead in the event of catastrophic failure of the HTS elements. The lead is in continuous contact with the HTS material and provides protection from interrupts and excess current. The down-lead is modular in design, and parts are easily replaced. Further, the down-lead is cooled through conduction in the middle stage, and gas cooled in the upper and lower stages by independent gas sources.

Abstract: An Nb.sub.3 Al multi-filamentary superconducting wire capable of realizing both stabilization of a superconducting state and increase in capacity is provided. The Nb.sub.3 Al multi-filamentary superconducting wire includes a core formed of copper or copper alloy and located at the center of the wire; a multi-filamentary superconductor layer located around the core and having filaments containing Nb and Al as constituent elements embedded in a matrix formed of copper or copper alloy; and a high resistance layer located around the multi-filamentary superconductor layer, and is characterized in that a sectional area of the core is at least 15% of the total sectional area of the core and the matrix and that the core and the matrix are formed of copper or copper alloy of at least 99.9% purity.

Abstract: A sheathed twisted superconductor with a high critical temperature is made from a billet obtained by assembling square cross-section single strands in a square cross-section metal tube. The multistrand obtained by drawing the billet through a roller die is twisted with a particular lay and rolled using rollers the diameter of which is much greater than the twist lay. The sheathed twisted superconductor obtained by this method is intended for variable current applications.

Abstract: A new design for an aluminum stabilized superconductor which embeds the superconducting cable within a high purity aluminum stabilizer. This stabilizer is, in turn, partially surrounded by an aluminum alloy sheath. The aluminum alloy sheath is constructed and arranged so that at least one exterior surface of the stabilizer is open for exposure to a coolant. Preferably, this open exterior surface of the stabilizer will be knurled for greater cooling efficiency.

Abstract: A superconducting conductor, having an excellent repeated temperature property with no reduction of critical current density against a temperature cycle, comprises an oxide superconductor and an fiber reinforced plastic ("FRP"), serving as a support member, which is composed with the oxide superconductor for integrally moving with the oxide superconductor in thermal expansion and thermal shrinkage. The oxide superconductor is bonded to the FRP with an adhesive agent, or wound on and fixed to the same with a Teflon tape or the like.

Abstract: A pseudo rod, fabricated from several plate sections joined together at their edges and having a cross-section resembling a polygon approximates a rod having a circular cross section. Using multiple plates joined at their edges permits growing a crystalline material on the planar faced substrates and if the plates are crystalline material, the crystalline material grown thereon can have improved current carrying capability.

Abstract: An electrical conductor particularly suited for use as a downlead to low temperature devices includes a ceramic honeycomb body having longitudinal channels wherein films of substantially single crystals of a ceramic superconductor are grown. The maximum current carrying capacity of the ceramic superconductor may be oriented parallel to the channels. Square channels arranged in alternating rows of oppositely directed current provide desirable magnetic field cancellations and permit high current flows. A method for making the electrical conductor and a method of extruding the ceramic honeycomb body are also disclosed.

Abstract: A superconductive transmission line is formed of mixed metallic oxide ceramic material, particularly Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x drawn epitaxially upon a substrate. The superconductive material has basal crystallographic planes in alignment with copper oxide of the ceramic material. The planes are parallel to the substrate. The transmission line is constructed of a plurality of electrically conductive elements, each of which is formed of the superconductive material. The conductive elements are arranged with the crystalline planes parallel to an axis of the transmission line, along which axis power is to flow. Thereby, magnetic fields induced by currents flowing in the conductive elements intersect the conductive elements perpendicularly to the basal crystallographic planes to maximize the current which can flow while retaining linearity between magnetization and applied magnetic field.

Abstract: A superconductor protected against partial transition includes superconductor strands around at least one non-superconductor central strand or at least one non-superconductor central core electrically insulated from the superconductor strands. At least at both ends of the superconductor, the central strand or said central core is electrically connected to the superconductor strand. The central strand or the central core comprises at least one non-superconductor metal filament whose resistivity at 4.2.degree. K. is less than 10.sup.-9 .OMEGA..m embedded in a metal alloy matrix whose resistivity at that temperature is greater than 10.sup.-8 .OMEGA..m.

Abstract: An improved transmission system for electrical energy comprising a plurality of ball members interspersed by mating members enclosed within at least one protective outer wrapping, with the ball members and the mating members being in contact with adjacent members and being formed of material which is electrically conductive at superconductor temperatures and each having an axial opening extending therethrough to permits passage of a suitable coolant fluid, such as liquid helium.

Abstract: A transmission line using superconductors instead of conventional conductors substantially reduces ohmic losses compared to conventional conductors. The superconductors are cooled by refrigerant flowing through a hollow superconducting inner conductor. The refrigerant is transported to the inner conductor using a novel connector.

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 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: 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: 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 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 composite superconducting wire using ceramic superconductor material in which one or more elongated superconductor material are accomodated in one or more grooves formed on an elongated reinforcing member so that a long size superconductor wire can be provided. Various methods of producing such composite superconductor wire are also disclosed.

Abstract: A superconducting electrical conductor comprises a porous substrate of bonded fibers which are coated by ceramic oxide superconducting material of the perovskite type so that its critical temperature of superconductivity is at or above the boiling point of liquid nitrogen. To form electrical cable, the conductor is encased within an inner tube. An outer tube surrounds the inner tube and defines an evacuated annular space therewith. This provides a thermal barrier between substrate, which will be bathed by liquid nitrogen, and the ambient. Electrical and heat insulation surrounds the outer tube.Joint connectors in the form of multiple rigid rods, each coated by superconducting material and held in a perforated frame, are used to connect facing ends of the substrate to form an electrical connection from one length of conductor to the next.

Abstract: A ceramic type superconductive layer (2) is formed on the outer peripheral surface of an optical fiber (1), and a stabilizing layer (3) is formed so that it contacts the outer peripheral surface of the superconductive layer (3). The diameter of the optical fiber is, for example, not more tha 100 .mu.m. The superconductive layer may be formed with a spirally extending groove (7) which divides the superconductive layer.