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 tube made of oxygen free copper is filled with a plurality of copper matrix Nb—Ti superconducting lead wires to obtain a composite billet. The resulting billet is subjected to hydrostatic pressure extrusion. Further, ageing heat treatment and wire drawing process are repeated for the composite material three times to prepare a Cu/Nb—Ti superconducting single wire. Then, the resulting Cu/Nb—Ti superconducting single wires are stranded each other to produce a superconducting strand. The superconducting strand is coated with an aluminum alloy to which either a content of 20 to 100 ppm of Cu and Mg or Mg, or a content of 10 to 120 ppm of Si and Cu is added by means of hot extrusion, the strand thus extruded is reduced by 0 to 20% in accordance with cold working to produce an aluminum stabilized superconductor.

Abstract: A composite superconductor having an interior component of multiple filaments of superconducting Bi-2223 sheathed in a Ag or Ag alloy material, and a RE, TI or Hg based superconductor surrounding the interior component.

Abstract: A high temperature oxide superconductor is efficiently protected from the affects of water and acids by forming a passivation layer of a fluoride. The fluoride layer comprises a fluoride composed of one or more elements composing the oxide superconductor and/or one or more elements that can compose an oxide superconductor by replacing at least in part one or more elements composing the oxide superconductor.

Abstract: A method of preparing a metal tube for a length of superconducting wire Inserts superconducting base material into the tube and packs or coils the tube so that a portion of its outer surface would contact another surface. To prevent the portion of the outer surface from sticking to the other surface, the portion is coated with powder material particles suspended in an effectively liquid component before the packing or coiling so that the surfaces do not contact each other. The powder material has a melting point temperature higher than the melting point temperature of the tube and the liquid component evaporates or burns away completely at the temperature that forms the superconducting phase of the superconducting base material.

Abstract: In order to obtain a superconducting wire containing an oxide superconductor, whose critical current density is not much reduced upon application of bending, a plurality of strands 3, comprising oxide superconductors 1 covered with first metal sheaths 2, are filled into a second metal sheath 4, and deformation processing is performed to sectionally apply a compressive load to the second metal sheath, so that the thickness of the oxide superconductor 1 contained in each strand 3 is not more than 5% of the overall thickness of the superconducting wire 6.

Abstract: Superconductor tapes are annealed under uniaxial pressure, such a compressive annealing yielding significant improvement in the resultant critical current density. This thermomechanical processing technique obtains improved critical currents with fewer processing steps.

Abstract: An oxide superconducting wire having a circular or substantially circular sectional shape and exhibiting a high critical current density comparable to that of a tape-shaped wire is provided. The oxide superconducting wire consists of a plurality of filaments extending along the longitudinal direction of the wire in the form of ribbons, and a stabilizer matrix covering the filaments. The aspect ratio of the width to the thickness of each filament is 4 to 40, and the thickness of each filament is 5 to 50 &mgr;m. A section of the wire is in a circular or substantially circular shape. The wire exhibits a critical current density of at least 2000 A/cm2 at a temperature of 77 K with no application of a magnetic field. It is preferable that the plurality of filaments are substantially rotation-symmetrically arranged with respect to the center of the wire.

Abstract: The present invention provides a (Bi,Pb)SCCO-2223 oxide superconductor composite which exhibits improved critical current density and critical current density retention in the presence of magnetic fields. Retention of critical current density in 0.1 T fields (77 K, ⊥ ab plane) of greater than 35% is disclosed. Significant improvements in oxide superconductor wire current carrying capacity in a magnetic field are obtained by subjecting the oxide superconductor composite to a post-processing heat treatment which reduces the amount of lead in the (Bi,Pb)SCCO-2223 phase and forms a lead-rich non-superconducting phase. The heat treatment is carried out under conditions which localize the lead-rich phase at high energy sites in the composite.

Abstract: A superconducting current lead includes a cylindrical support member 3, and superconducting wire material units 1 each of which is fixed onto the support member and each of which is composed of a single tape-like oxide superconducting wire material or a laminated tape-like oxide superconducting wire material, wherein tape surf aces of the superconducting wire material units are disposed in parallel with a circumferential direction in a cylindrical coordinate system, and the cylindrical support member is formed from a low thermal conductivity material.

Abstract: A process for increasing the resistivity of a HTS oxide composite sheath including heating a superconductive HTS oxide composite, the composite including a sheath including silver, in the presence of mercury at temperatures sufficient to form a silver--mercury alloy is provided together with a HTS oxide composite which includes a high temperature superconductor oxide core surrounded by a metallic sheath, the metallic sheath including silver and mercury.Also provided is a process for preparing a HTS oxide composite having an enhanced transport critical current density including placing the HTS oxide composite within a sealed, evacuated container, and, heating the HTS oxide composite for time and at temperatures sufficient for enhancement of transport critical current density in comparison to the transport critical current density of the HTS oxide composite prior to the heating.

Abstract: Process for producing an elongated superconductor with a bismuth phase having a high transition temperature and a superconductor produced according to this process. An elongated superconductor with at least one conductor core made of high-T.sub.c Bi-containing superconductor material with the 2212 or 2223 phase is to be manufactured. For this purpose, the cross section of a structure made of Ag matrix material and a precursor of the superconductor material is reduced. Subsequently the raw conductor thus obtained is annealed in an oxygen-containing atmosphere. According to this invention, a temperature variation between a higher temperature (T1) and a lower temperature (T2) is provided for the annealing. The higher temperature (T1) is at most 7 K above the decomposition temperature (Tz), and the lower temperature (T2) is at most 9 K below the decomposition temperature (Tz).

Abstract: An unsegregated metal oxide/silver composite wire is provided having a plurality of metal oxide filaments disposed within a matrix comprising silver, wherein the filaments are comprised of at least copper, and an intermediate region comprising copper oxide and silver in contact with and surrounding each of the metal oxide filaments. The intermediate region has a thickness of no greater than three microns. Each of the metal oxide filaments extends continuously for the length of the wire, and each of the metal oxide filaments is separated from adjacent filaments by the matrix.

Abstract: A multifilamentary superconducting composite article comprising multiple substantially electrically decoupled domains, each including one or more fine, preferably twisted filaments of a desired superconducting oxide material. In a preferred embodiment, the article comprises a matrix, which substantially comprises a noble metal, a conductive jacketing layer surrounding the matrix, a plurality of discrete filament decoupling layers, each comprising an insulating material, disposed within the matrix to separate the matrix into a plurality of substantially electrically decoupled domains; a plurality of filaments, each comprising a desired superconducting oxide, which are disposed within and essentially encapsulated by the matrix and chemically isolated thereby from the decoupling layers, each of the electrically decoupled domains containing at least one filament.

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 high temperature superconductor composite material, which is suitable for production of filaments, wires, coils and other shaped products, has a ceramic powder of a material selected from the group consisting of, for example, YBa.sub.2 Cu.sub.3 O.sub.7-x and Bi.sub.2 Sr.sub.2 Ca.sub.2 Cu.sub.3 O.sub.10 ; a solution of a material selected from the group consisting of rubber silicone or lacquer silicone in a substance selected from the group consisting of toluene or acetone; and an ultra-fine silver powder dope, and is produced by using an emulsion mixture of the three major components with ultrasonic homogenization of the mixture, primer cladding of a glue-exterior layer on a silver core filament, high temperature superconductor coating of the silver core by chemical adhesion, and polymerization of the coating applied by low temperature heating, whereafter the composition is treated by magnetic treatment, gamma irradiation, and microwave supported fast heating.

Abstract: An a.c. cable has at least one cable core (15) with two concentric conductor arrangements (8, 9) used as forward and return conductors. At least one of the conductor arrangements (8, 9) contains a plurality of conductor layers (L.sub.j and L.sub.j ') made of stranded normally conducting or superconducting individual conductors (3). The individual conductors preferably feature high-T.sub.c superconducting materials. The wire angles (.alpha..sub.j, .alpha..sub.j ') in the individual conductor layers (L.sub.j and L.sub.j ') should be selected so as to minimize losses. A calculation formula for the wire angles (.alpha..sub.j, .alpha..sub.j ') is given for this purpose.

Abstract: A superconducting ceramic includes a laminate and a superconducting ceramic tape joined to the laminate. The laminate and superconductor tape are joined such that the tape is under a compressive stress. The compressive stress is of a greater amount than the compressive stress which results from differences in thermal expansion of the tape and the laminate. The greater compressive stress can be achieved by putting the laminate under a greater tension than the superconducting ceramic tape during joining of the superconducting ceramic tape to the laminate.

Abstract: Articles according to the invention comprise a superconductive cuprate (e.g., YBa.sub.2 Cu.sub.3 O.sub.7) body containing elongate grains measuring at least about 10 .mu.m along the long axis and having an aspect ratio of at least 10:1. Bodies according to the invention can have relatively high critical current density, as compared to analogous non-textured bodies.

Abstract: In order to provide a flexible oxide superconducting cable conductor which is reduced in ac loss, tape-shaped multifilamentary superconducting wires covered with a stabilizing metal are spirally wound on a flexible former. Each of the multifilamentary superconducting wires has a plurality of filaments. The filament contains an oxide superconductor. The superconducting wires are preferably wound on the former at a bending strain of not more than 0.3 %. In winding on the former, a prescribed number of tape-shaped multifilamentary superconducting wires are wound on a core member in a side-by-side manner, to form a first layer. Then, an insulating layer is provided on the first layer. This insulating layer can be formed by an insulating tape. A prescribed number of tape-shaped superconducting multifilamentary wires are wound on the insulating layer in a side-by-side manner, to form a second layer. The insulating layer is adapted to reduce ac loss of the conductors.

Abstract: Disclosed is an AC oxide superconductor round wire including a metal matrix, and a plurality of superconductor filaments embedded in the metal matrix, wherein the superconductor filaments are twisted at a twist pitch L.sub.p satisfying the following relation.2L.sub.c1 <L.sub.p .ltoreq.2L.sub.c2L.sub.c1 =2{(2.rho..multidot.d.sub.f .multidot.J.sub.c)/(.mu..sub.o .multidot.dH/dt)}.sup.1/2L.sub.c2 =2{(2.rho..multidot.d.sub.b .multidot.J.sub.cb)/(.mu..sub.o .multidot.dH/dt)}.sup.

Abstract: An oxide superconducting wire having a circular or substantially circular sectional shape and exhibiting a high critical current density comparable to that of a tape-shaped wire is provided. The oxide superconducting wire consists of a plurality of filaments extending along the longitudinal direction of the wire in the form of ribbons, and a stabilizer matrix covering the filaments. The aspect ratio of the width to the thickness of each filament is 4 to 40, and the thickness of each filament is 5 to 50 .mu.m. A section of the wire is in a circular or substantially circular shape. The wire exhibits a critical current density of at least 2000 A/cm.sup.2 at a temperature of 77 K with no application of a magnetic field.

Abstract: A method of fabricating a low-inductance, in-line resistor includes the steps of: depositing a superconductive layer 12 on a base layer 14; patterning an interconnect region 16 on the superconductive layer 12; and converting the interconnect region 16 of the superconductive layer 12 to a resistor material region 18. The resistor region 18 and the superconductive layer 12 are substantially in the same plane. The method can further include the steps of depositing a conductive layer 22 on the resistor region 18 and on the photo-resist layer 20, and lifting off the photo-resist layer 20 to leave the conductive layer 22 on the resistor region 18. As such, the conductive layer 22 provides a low sheet resistivity for the resistor region 18.

Abstract: A superconducting oxide composite structure including a superconducting oxide member, a metal layer surrounding the superconducting oxide member, and an insulating layer of a complex oxide formed in situ adjacent to the superconducting oxide member and the metal layer is provided together with a method of forming such a superconducting oxide composite structure including encapsulating a superconducting oxide member or precursor within a metal matrix layer from the group of: (i) a reactive metal sheath adjacent to the superconducting oxide member or precursor, the reactive metal sheath surrounded by a second metal layer or (ii) an alloy containing a reactive metal; to form an intermediate product, and, heating the intermediate product at temperatures and for time sufficient to form an insulating layer of a complex oxide in situ, the insulating layer to the superconducting oxide member or precursor and the metal matrix layer.

Abstract: According to an aspect, a tape-type high temperature superconducting wire is provided by applying compression work to a wire manufactured by drawing so that an oxide high temperature superconductor is divided into a plurality of superconductors by a stabilizing material of substantially equal thickness. According to another aspect, a high temperature superconducting wire is provided by packing a material which becomes a superconductor portion into a metal sheath which becomes the stabilizing material and applying drawing work thereto, followed by bundling an assembly of these wire in a metal sheath and applying drawing work thereto. The thickness of the superconductor portion is approximately 10% or less than the thickness of the wire. The critical current density is hardly decreased in the high temperature superconducting wire even if subjected to bending work.

Abstract: A bulk high temperature superconductor single crystal having the formula MBa.sub.2 Cu.sub.3 O.sub.7-x wherein M is selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er, and Yb; and, x has a number value from about 0.1 to about 1.0; are produced by a novel process incorporating: i) starting powders produced by combustion spray pyrolysis, ii) a novel setter powder, and/or iii) a monitored isothermal growth process.

Abstract: This invention permits superconducting ceramics, as well as other ceramic materials, to be spray deposited onto indefinitely large sheets of metallic substrate from a carboxylic acid salt solution. Elemental metal precursors of the superconductor are introduced into the solution as carboxylic acid salts. The deposit formed on the malleable metallic substrate is then thermomechanically calcined to form c-axis textured metal-superconductor composite sheet structures. These composite sheet structures can be formed by pressing together two ceramic-substrate structures, ceramic face-to-face, to form a metal-ceramic-metal sheet structure, or by overlaying a metal sheet over the deposited structure. Once the structure has been thermomechanically calcined, the c-axis of the superconductor is oriented parallel to the vector defining the plane of the metal sheet, i.e., perpendicular to the surface of the plane.

Abstract: A superconducting conductor fabricated from a plurality of wires, e.g., fine silver wires, coated with a superconducting powder. A process of applying superconducting powders to such wires, to the resulting coated wires and superconductors produced therefrom.

Abstract: In application to a superconducting magnet which is cooled by a cryogenic refrigerator, provided is a superconducting coil which can maintain a cooled state and enables a stable operation and continuous driving even if a ramping speed is increased. First and second superconducting conductors are connected with each other. Respective tape-like superconducting multifilamentary wires are electrically connected with each other through solder, to form joint bodies. The respective joint bodies are insulated from each other by interposition of an insulating material therebetween.

Abstract: In order to provide a crystal oriented high quality thallium group superconducting wire having a high critical current density, thallium group superconducting film is formed on oxide single crystal fiber having plane facets and polygonal cross section in the thallium group superconducting wire, wherein c-axis of the thallium group superconducting film is oriented perpendicularly, and a- and b-axis are oriented in parallel to the longitudinal direction of the above fiber, respectively, and resulting to obtain a high quality thallium group superconducting wire with Jc of 10.sup.5 A/cm.sup.2 or more at 77K.

Abstract: The present invention provides a method of producing high-strength and high-conductance copper and silver materials comprising the steps of combining a predetermined ratio of the copper with the silver to produce a composite material, and melt spinning the composite material to produce a ribbon of copper and silver. The ribbon of copper and silver is heated in a hydrogen atmosphere, and thereafter die pressed into a slug. The slug then is placed into a high-purity copper vessel and the vessel is sealed with an electron beam. The vessel and slug then are extruded into wire form using a cold hydrostatic extrusion process.

Abstract: A process for manufacturing superconducting magnetic coils from strain-tolerant, superconducting multi-filament composite conductors is described. The method involves winding the precursor to a multi-filament composite conductor and an insulating material or its precursor around a mandrel in order to form a coil, and then exposing the coil to high temperatures and an oxidizing environment. The insulating material or its precursor is chosen to permit exposure of the superconductor precursor filaments to the oxidizing environment, and to encase the matrix-forming material enclosing the filaments, which is reversibly weakened during processing.

Abstract: In order to make it possible to produce superconducting coils with small overall height, they are made from a plurality of coil subunits, optionally with a plurality of layers for each coil subunit, in particular in the case of the low-voltage coil of a transformer. The coil subunits contain as electrical conductor a high-temperature superconductor, around which a fibrous glass is spun and which is embedded in a glass-fiber reinforced epoxy resin or in a plastic. The coil subunits are placed around a transformer core in a cryostat.

Abstract: A superconductive lead assembly for a superconductive device (e.g., magnet) cooled by a cryocooler coldhead having first and second stages. A first ceramic superconductive lead has a first end flexibly, dielectrically, and thermally connected to the first stage and a second end flexibly, dielectrically, and thermally connected to the second stage. A jacket of open cell material (e.g., polystyrene foam) is in general surrounding compressive contact with the first ceramic superconductive lead, and a rigid support tube generally surrounds the jacket. This protects the first ceramic superconductive lead against shock and vibration while in the device. The rigid support tube has a first end and a second end, with the second end thermally connectable to the second stage.

Abstract: A superconducting switch comprising a portion of cable including a resistive central strand that is non-superconducting having a plurality of super-conducting strands or of superconductors twisted thereabout, and separated from the central strand by electrical insulation, the cable as a whole being insulated from the external cooling medium by thermal insulation. The central strand is electrically connected to the superconducting strands or the superconductors at each end of a portion of cable. A portion of the length of the resistive central strand extends outside the cable at a point along the length of the portion of said cable and is coupled to a control device situated outside the cooling medium, wherein the control device injector an electrical current into the circuit formed by the resistive central strand that is connected at its ends to the superconducting strands or to the superconductors.

Abstract: An oxide superconducting coil is formed by winding a superconducting multifilamentary wire consisting essentially of a plurality of filaments consisting essentially of an oxide superconductor and a stabilizing material, consisting of silver or a silver alloy, covering the filaments. Superconducting phases of the filaments are substantially rendered monophasic, and c-axes thereof are strongly oriented along the thickness of the wire. Crystal grains of the superconductor forming the filaments are in the form of flakes extending longitudinally along the wire, while the same are bonded to each other. In a section of the wire, a ratio obtained by dividing a sectional area occupied by the silver or the silver alloy by that occupied by the filaments is not more than 3. In a magnetic field of at least 10 T, the coil exhibits a critical current value which is at least 60% of that exhibited by the wire itself forming the coil.

Abstract: In a high-temperature superconductive conductor winding (1) comprising a tape-shaped high-temperature superconducting wire (2) which is combined with a metal 5 and wound into the form of a double pancake coil, the length of a throughout portion (5) provided between pancakes (4, 6) is at least four times the width of the tape-shaped high-temperature superconducting wire. Thus, it is possible to suppress generation of shearing stress at 10 the throughout portion (5), thereby preventing reduction of the critical current density caused by such shearing stress.

Abstract: A composite lead is provided which electrically links and conducts a current between about 75-80K. and liquid helium temperature of about 4.5K. The composite lead may be employed singly or in multiples concurrently to provide conduction of electrical current from normal conductors and semi-conductors at room temperature to superconductors operating at 4.5K. In addition, a variety of organizationl arrangements and assemblies are provided by which the mechanical strength and electrical reliability of the composite lead is maintained.

Abstract: A multifilamentary oxide superconducting wire includes a metal matrix and a plurality of flat oxide superconductor filaments arranged in the metal matrix such that wide directions thereof are radially arranged in a section of the metal matrix. A method of manufacturing a multifilamentary oxide superconducting wire includes the steps of filling a raw material of an oxide superconductor in a through hole of a metal member to form a composite billet, subjecting the composite billet to a diameter reduction process to form a composite wire having a fan-like section, arranging composite wires so that larger arcs of the composite wires are located on the outer side, thus forming form a composite wire arrangement, covering the composite wire arrangement with a metal member to form a metal-covered composite wire arrangement, and performing a predetermined heating process of the metal-covered composite wire arrangement, thus forming the raw material into an oxide superconductor.