Abstract: The present invention provides a simple, energy efficient and cost effective process for continuous production of high quality MgB2 based superconducting wires, tapes, bulk bodies and powders with better phase purity, microstructure and superconducting properties by introducing some innovative steps namely processing the reactants in evacuated and sealed metal tubes by electrical self-heating cum hot rolling followed by annealing under electrical self-heating, thereby overcoming various deficiencies and shortcomings associated with the prior art.

Abstract: A precursor for producing a Nb3Sn superconducting wire includes a bundle of single-element wires each including a Cu or Cu-based alloy matrix, Nb or Nb-based alloy filaments, at least one Sn or Sn-based alloy core, the Nb or Nb-based alloy filaments and at least one Sn or Sn-based alloy core being arranged in the Cu or Cu-based alloy matrix, an diffusion barrier layer around the periphery of the Cu or Cu-based alloy matrix, the inner diffusion barrier layer being composed of Nb or a Nb-based alloy, and a Cu or Cu-based alloy layer around the periphery of the diffusion barrier layer; an outer diffusion barrier layer around the periphery of the bundle of the single-element wires, the outer diffusion barrier layer being composed of Nb, a Nb-based alloy, Ta, a Ta-based alloy, or a combination thereof; and a stabilizing copper layer around the periphery of the outer diffusion barrier layer.

Abstract: A method of producing a superconducting wire comprises the steps of (a) preparing a superconducting precursor powder by treating a material powder for a superconducting use, (b) packing a first metal pipe with the superconducting precursor powder, and (c) sealing the first metal pipe. In the method, the step of packing the first metal pipe and the step of sealing the first metal pipe are performed in an atmosphere under a reduced pressure to reliably perform a degassing treatment of the superconducting powder. Thus, a method of producing a superconducting wire excellent in superconducting property, particularly a critical current, is offered. A production method of a superconducting multifilament wire is offered. A superconducting apparatus produced through these methods is offered.

Abstract: Critical current densities of internal tin wire having values of at least 2000 at temperature of 4.2 K and in magnetic field of 12 T are achieved by controlling the following parameters in a distributed barrier subelement design: wt % Sn in bronze; atomic Nb:Sn; local area ratio; reactable barrier; and barrier thickness relative to the filament thickness; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.

Abstract: A new type of conductor well-suited for use in a superconducting electromagnet. The conductor comprises a single electrically conductive member at its core. The conductor may include concentric layers of dissimilar materials. This conductor is surrounded by a channel through which coolant—typically liquid helium—can flow. The channel is bounded by a metal conduit of sufficient strength to withstand the Lorentz forces. The metal conduit is covered by an insulator which forces the current into the desired helical path.

Abstract: A method for forming improved superconducting composites having improved Jc values by assembling octagonal or curved octagonal elements which when assembled allow for formation of uniformly continuously spaced voids. The voids are then filled with a metal, alloy, intermetallic substance, or ceramic oxide. The assembly of the octagonal elements and the filling of the voids is performed in a metal can. Accordingly, the flexibility in design of the present invention allows control of the performance of the superconductor and is cost effective.

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 method for the fabrication of an insulated solder bonded multifilamentary superconducting wire composite. An uninsulated wire composite is prepared by using a high melting point solder to join a multifilamentary superconducting composite to a solderable metallic component. A polymer insulation film coating is then applied on top of the wire composite, and the resulting assembly is subjected to heating in a furnace at furnace temperatures and for a period sufficient to cure the insulation but insufficient to melt the solder.

Abstract: A composite superconducting wire and a method of manufacturing the wire is disclosed. Nano-particle dispersion strengthened copper is co-drawn with Niobium rod to produce DSC-1Nb wire. n numbers of DSC-1Nb wires are then stacked in a hollow DSC tube and drawn to form a DSC-n.Nb hexagonal wire. In a separate preliminary process, Tin rod is co-deformed with Copper tube to form a Cu-1Sn wire. m DSC-n Nb wires and 1 Cu-1Sn wires are then wrapped by Niobium foil and placed into a Copper tube. This entire assembly is then drawn to a finished size. The drawn composite is then subjected to heat treatment with a final stage at 650-700° C. for about 100 hours or longer. The new wire has higher electric critical current and higher mechanical strength than the controlled conventional ones.

Abstract: In the present invention, a superconducting (sc) ceramic filament is enclosed in a silver sheath which is sealed therearound by applying silver powder between the surfaces of said sheath, pressing the surfaces and powder into contact and then applying sufficient heat to fuse them together, which heat is below the melting point of the surfaces and powder and then sintering the so enclosed ceramic filament, which upon cooling, forms a superconductor.

Abstract: The present invention relates to a superconducting cable conductor which contains a carrying element, on which is wound at least one layer comprising two or more superconducting conductor elements, the individual conductor elements of each layer being arranged next to one another, and the superconducting conducting elements are formed from a tape-type substrate coated with a superconducting material based on rare earth barium cuprate, preferably based on yttrium barium cuprates.

Abstract: This invention relates to an oxide superconducting wire comprising oxide superconducting filaments, a high-density ceramic layer uniformly surrounding each of the filaments, and a silver sheath that directly covers the ceramic layer. The ceramic layer becomes non-superconducting when the filaments are cooled to an operating temperature of oxide superconductors. The oxide superconductors can be isolated by the ceramic that acts as a highly resistive material or an insulator. A high normal resistance is achieved, and thereby AC loss is reduced remarkably.

Abstract: Method of producing superconducting cables by using cold plastic deformation operations only including the step of obtaining a bar-like semi-finished product of prefixed dimension through the steps of: forming round-section, mono- or multifilament, superconducting copper bars of relatively long length; assembling the bars about a cylindrical copper core of substantially the same length, using assembly templates, the templates having through holes arranged in a circle to support the bars, and a central through seat for supporting the core; tying the bars onto an outer lateral surface of the core; sliding onto one end of the bar/core assembly a number of metal supporting rings, while sliding the templates off the opposite end thereof; sliding a copper tube onto the bar/core assembly while cutting the ties in axial sequence and sliding off the supporting rings; and subjecting the assembly to a number of drawing operations.

Abstract: A superconducting material useful for forming electrolytic devices is made by establishing multiple niobium or tantalum components in a primary billet of a ductile material; working the primary billet through a series of reduction steps to form the niobium or tantalum components into elongated elements; cutting and restacking the resulting elongated elements with a porous confining layer to form a secondary billet, working the secondary billet through a series of reduction steps including twisting and final rolling to thin ribbon cross-sections with greater than 5:1 Aspect Ratios; cutting the resulting elongated billet into sections; and leaching the core and sheath at least in part.

Abstract: A method for winding on embedded b-zero coil maintains the integrity of superconducting main coil and the b-zero wire during coil winding and during normal operation of a superconducting MRI magnet. The b-zero coil is co-wound with an aluminum overwrap while the aluminum overwrap is being wound onto the superconducting MRI coil. The two-wire geometries are selected such that the height or thickness of the aluminum overwrap is greater than or equal to the height or thickness of the b-zero coil wire. The b-zero coil wire sits in a cavity that is created by adjacent turns.

Abstract: By rapidly heating a precursor wire having a multifilamentary structure in which multiple composite cores in which a composite compound of an Nb—Ga compound and Nb is embedded in Nb are embedded in Nb, Ta, Nb-base alloy or Ta-base alloy as a matrix material to a temperature range of 1400 to 2100° C. in 2 seconds, quenching the precursor wire at a rate of 5000° C./second or larger, and subjecting the precursor wire to additional heat treatment at a temperature range of 600 to 850° C. for 1 to 400 hours, a superconducting wire having a multifilamentary structure in which multiple composite cores in which a composite compound containing Nb3Ga of a stoichiometric composition embedded in Nb are embedded in Nb, Ta, Nb-base alloy or Ta-base alloy as a matrix material is obtained.

Abstract: Superconducting cable (1) comprising: a) a layer (20) of tapes comprising superconducting material, b) a tubular element (6) for supporting said layer (20) of tapes comprising superconducting material, c) a cooling circuit, adapted to cool the superconducting material to a working temperature not higher than its critical temperature, characterized in that said tubular element (6) is composite and comprises a predetermined amount of a first material having a first thermal expansion coefficient and a second material having a thermal expansion coefficient higher than that of said first material, said thermal expansion coefficients and said amounts of said first and second material being predetermined in such a way that said tubular element has an overall thermal shrinkage between the room temperature and said working temperature of the cable such as to cause a deformation of said tapes comprising superconducting material lower than the critical deformation of the same tapes.

Abstract: The present invention provides an oxide superconducting wire including a component provided in the form of a tape and a metal tape. The component in the form of a tape has an oxide superconducting member and a metal coating member formed mainly of silver and coating a surface of the oxide superconducting member. The metal tape, bonded in a heat treatment (e.g., fusion- or diffusion-bonded) to a surface of the component in the form of a tape, does not contain any superconducting material and it is formed mainly of silver and it also contains at least one component other than silver.

Abstract: A method for increasing the critical temperature, Tc, of a high critical temperature superconducting (HTS) film (104) grown on a substrate (102) and a superconducting structure (100) made using the method. The HTS film has an a-b plane parallel to the surface of the substrate and a c-direction normal to the surface of the substrate. Generally, the method includes providing the substrate, growing the HTS film on the substrate and, after the HTS film has been grown, inducing into the HTS film a residual compressive strain the a-b plane and a residual tensile strain into the c-direction.

Abstract: A superconductor composite material consists of sintering products of interaction of superconductor ceramics with silicone material. The superconductor composite material can also include at least one metal, metal oxide or halogen element dope that interacts with superconductor ceramics and silicone residuals at sintering high temperature. The suspension or slurry of superconductor ceramics, silicone and dope powders can be used for coating of the particular substrate. Such coating employs modified forming methods including dip coating, painting, slip casting, cladding, printing, and spraying in order to produce continuous superconductor filament, wire, tape, coil, large size screen, and small chip or electronic element. The condensed suspension is used for extrusion, injection molding, and pressing continuous and short superconductor tubes, rods, beams, rails as well as disks, rings and other bulk shaped materials.

Abstract: A novel process of the production and processing of high quality, high Tc BSCCO or (Bi,Pb)SCCO superconductors starts with fabrication of a forming a bundle including a plurality of billets, each billet containing at least one filament comprising a dominant amount of an tetragonal BSCCO phase with selected intermediate phases, and substantially surrounded by a constraining metal. The bundle is thermomechanically consolidated to form a multifilamentary precursor article by applying pressure and heat to the bundle under conditions cooperatively selected to cause interdiffusion of said constraining metal at the interfaces between said metal and said filaments and substantially complete elimination of voids in said bundle, and the consolidation step is completed before any high strain longitudinal deformation is performed on the bundle.

Abstract: High-Tc superconducting ceramic oxide products and macroscopic and microscopic methods for making such high-Tc superconducting products. Completely sealed high-Tc superconducting ceramic oxide provides are made by a macroscopic process including the steps of pressing a superconducting ceramic oxide powder into a hollow body of a material inert to oxygen; heat treating the superconducting ceramic oxide powder packed body under conditions sufficient to sinter the ceramic oxide powder; and then sealing any openings of the body. Optionally, a waveform or multiple pulses of alternate magnetic filed can be applied during the heat treatment.

Abstract: The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

Abstract: A method for producing a high-Tc superconductor having a strip shape and having at least one superconductive conductor core by forming a conductor initial product and annealing. The forming is in this case intended to include at least two flattening steps. A flattening step which follows a preceding flattening step is intended to result in the percentage thickness reduction in the cross section of the at least one conductor core being greater than that from the preceding flattening step. The strip conductor produced in this way advantageously has a plurality of conductor cores that are embedded in a Ag material and are composed of a bi-cuprate.

Abstract: A niobium-based superconductor is manufactured by establishing multiple niobium components in a billet of a ductile metal, working the composite billet through a series of reduction steps to form the niobium components into elongated elements, each niobium element having a thickness on the order of 1 to 25 microns, surrounding the billet prior to the last reduction step with a porous confining layer of an acid resistant metal, immersing the confined billet in an acid to remove the ductile metal from between the niobium elements while the niobium elements remain confined by said porous layer, exposing the confined mass of niobium elements to a material capable of reacting with Nb to form a superconductor.

Abstract: The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

Abstract: A multifilamentary oxide superconducting wire having a low aspect ratio and a relatively high critical current density, and being suitable for a stranded wire. In order to produce such a wire, a tape-shaped, multifilamentary oxide superconducting wire prepared by the powder-in-tube process is cut along its length. The resulting multifilamentary oxide superconducting wires have a width smaller than that of the tape-shaped wire. The resulting wires typically have an aspect ratio of one to two. The filaments of the resulting wires are in the shape of a ribbon extending in the longitudinal direction, and arranged substantially parallel to each other and in layers. The filaments have an aspect ratio greater than two. The filaments inside include a filament having a portion substantially not covered with the stabilizer.

Abstract: A modified powder-in-tube process produces a superconductor wire having a significantly greater current density than will a superconductor wire of the same nominal superconductor composition produced using conventional draw-swage-extrude-roll deformation. In the process disclosed, a superconductor precursor is placed within a ductile tube, the tube with the powder therein is then deformed into a cross-section substantially corresponding to that of the end product, and the deformed tube is then subject to a plurality of heat treatments to convert the precursor into the desired superconducting ceramic oxide phase. Before the last of the heat treatments, the tube is isostatically pressed to densify and texture the superconductor precursor oxide in the tube.

Abstract: The present invention provides a method to prepare a (Bi,Pb)SrCaCuO-2223 superconducting wire with improved critical current density at reduced cost. In general, the basic method according to the present invention comprises the steps of: (a) preparing a starting precursor powder with the oxygen content adjusted to the value of the final 2223 phase; (b) filling the starting powder into a metal sheath; (c) performing deformation processing on the metal sheath to form a composite wire and develop texture in the 2212 superconducting phases; (d) sealing said metal sheath so that a fixed oxygen content is maintained; (e) performing sintering to obtain the (Bi,Pb)SrCaCuO-2223 phase. The method uses metals other than a silver-based material in the sheath material, thus significantly reducing the materials cost of the (Bi,Pb)SrCaCuO-2223 superconducting wire.

Abstract: A method of manufacturing an aluminum-stabilized superconducting wire, which comprises the step of hot-extrusion-coating an entirety or a part of an outer circumference of a superconducting wire (11) which includes a superconducting filament embedded in a copper or copper alloy matrix, with a stabilizer (13) made of a precipitation-type aluminum alloy, is provided. The precipitation-type aluminum alloy is an Al—Ni alloy containing 100 to 25000 ppm of Ni, and the stabilizer made of the precipitation-type aluminum alloy is subjected, prior to the hot extrusion coating step, to an aging-heat treatment in which it is heated at a temperature of 250° C. to 500° C. for 10 minutes or more.

Abstract: A superconducting magnet comprised of a reinforced and stabilized superconducting wire material which is wound into an electromagnetic coil. The superconducting wire material comprises a compound superconducting substance, and a reinforcing, stabilizing agent which covers said compound superconducting substance. The superconducting magnet can be produced without requiring a specifically designed heat treatment furnace, and is light in weight and capable of generating a high magnetic field.

Abstract: A method of producing an Nb—Sn compound superconducting wire precursor includes forming composite filament materials, each filament including a niobium material of an Nb-based metal and a titanium material of pure Ti enveloped in the niobium material; forming a composite rod in which composite filament materials are arranged in a matrix of a Cu-based metal but not in contact with one another, the matrix containing Sn diffused by heat treatment to combine with the niobium material to form a compound; and drawing the composite rod.

Abstract: A novel process of the production and processing of high quality, high Tc (Bi,Pb)SCCO superconductors starts with fabrication of a precursor article including selected intermediate phases with desired chemical and structural properties. The precursor fabrication includes introducing the reacted mixture having a dominant amount of the tetragonal BSCCO phase into a metal sheath, and sealing the reacted mixture within said sheath, heating the mixture at a second selected processing temperature in an inert atmosphere with a second selected oxygen partial pressure for a second selected time period, the second processing temperature and the second oxygen partial pressure being cooperatively selected to form a dominant amount of an orthorhombic BSCCO phase in the reacted mixture.

Abstract: The invention provides 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 wire having a stacked structure comprising (a) a substrate composed of an electrically conductive material, (b) an oxide superconductor material, and (c) an electrically conductive material which is substantially not reactive with said oxide superconductor material (b), wherein said electrically conductive material (c) is impregnated in said oxide superconductor material (b) by way of heat fusion such that gaps among crystal grains contained in said oxide superconductor material (b) are filled with said electrically conductive material (c). And a process for the production of said superconducting wire.

Abstract: This invention relates to an oxide superconducting wire comprising (1) oxide superconducting filaments, (2) a high-density ceramic layer uniformly surrounding each of the filaments, and (3) a silver sheath that directly covers the ceramic layer. The ceramic layer becomes non-superconducting when the filaments are cooled to an operating temperature of oxide superconductors. The oxide superconductors can be isolated by the ceramic that acts as a highly resistive material or an insulator. A high normal resistance is achieved, and thereby AC loss is reduced remarkably.

Abstract: A multifilamentary superconductor composite having a high fill factor is formed from a plurality of stacked monofilament precursor elements, each of which includes a low density superconductor precursor monofilament. The precursor elements all have substantially the same dimensions and characteristics, and are stacked in a rectilinear configuration and consolidated to provide a multifilamentary precursor composite. The composite is thereafter thermomechanically processed to provide a superconductor composite in which each monofilament is less than about 50 microns thick.

Abstract: An oxide superconducting wire of an anisotropic oxide superconductor comprises a core part of the wire and a superconducting layer enclosing the core part so that specific crystal axes of the oxide superconductor are oriented toward the core part. A method of producing a wire of an anisotropic oxide superconductor comprises the steps of arranging a metal sheath around a metal rod for forming a core part of the wire and charging powder of the oxide superconductor in a clearance between the metal sheath and the metal rod for preparing a composite material, and plastically working the composite material so that the metal sheath is larger in reduction of area than the metal rod.

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 supported superconductor device which is useful as a superconducting current lead or as a high voltage current regulator. The device is formed of a tubular support, with a layer of ceramic, glassy or glass ceramic material adhered to the inner wall of the tubular support, the layer of material embedding a superconducting layer centrally arranged within the material of the first layer, the material of the first layer having a minimum expansion coefficient and being reinforced with pore filling material.

Abstract: An aspected multifilamentary oxide article is provided having a plurality of aspected filaments including a metal oxide and extending continuously for the length of the article. A constraining member substantially surrounds each filament, wherein each of the filaments has an average transverse cross-sectional thickness less than about 35 &mgr;m and an average variation in cross-section along its length of less than about 10%. The article exhibits superior filament uniformity, hardness, and oxide density and texture.

Abstract: A multifilamentary oxide superconducting wire having a low aspect ratio and a relatively high critical current density, and being suitable for a stranded wire, is provided. In order to produce such a wire, a tape-shaped, multifilamentary oxide superconducting wire prepared by the powder-in-tube process is cut along its length. The resulting multifilamentary oxide superconducting wires have a width smaller than that of the tape-shaped wire. The resulting wires typically have an aspect ratio of one to two. The filaments of the resulting wires are in the shape of a ribbon extending in the longitudinal direction, and arranged substantially parallel to each other and in layers. The filaments have an aspect ratio greater than two. The filaments include a filament having a portion substantially not covered with the stabilizer.

Abstract: Provided is an insulated oxide superconducting cable conductor having a high critical current and a high critical current density. The insulated oxide superconducting cable conductor comprises an elongated former, a plurality of tape-shaped multifilamentary oxide superconducting wires which are wound on the former at a bending strain factor of not more than 0.5%, and a spirally wound tape-shaped insulating material covering the tape-shaped multifilamentary oxide superconducting wires. The tape-shaped multifilamentary superconducting wires are superposed on the former in layers, whereby stabilizing materials of the superposed superconducting wires are in contact with each other. The tape-shaped insulating material consists essentially of a material which is contracted at a thermal contraction rate of at least three times that of the tape-shaped multifilamentary wires by cooling from a temperature of 298 K to that of 77 K.

Abstract: The invention relates a powder in tube type method of making an HTc superconductive multifilament strand having a silver-based matrix, in which:

Abstract: A cabled conductor is provided for use in a cryogenically cooled circuit including refrigeration having a predetermined operating temperature and efficiency. The conductor includes multiple conductor strands cabled about the longitudinal axis of the conductor at a preselected cabling period, each strand including a composite of superconducting ceramic in intimate contact with conductive matrix material. Each filament has high performance regions in which the filament material is well-textured with its preferred direction aligned perpendicular to the widest longitudinal cross-section of the conductor alternating with poorly superconducting regions which are at least about half the diameter of a filament in length and in which the superconducting ceramic filament is strained by transposition in excess of its critical strain limit. In the poorly superconducting regions, the conductive matrix material provides an alternate current path.

Abstract: A method for preparing a BSCCO-2223 oxide superconducting article includes annealing an oxide superconductor article comprised of BSCCO-2223 oxide superconductor at a temperature selected from the range of about 500° C.≦T≦787° C. and an annealing atmosphere having an oxygen pressure selected from within the region having a lower bound defined by the equation, PO2(lower)≧3.5×1010exp(−32,000/T+273) and an upper bound defined by the equation, PO2(upper)≦1.1×1012exp(−32,000/T+273). The article is annealed for a time sufficient to provide at least a 10% increase in critical current density as compared to the critical current density of the pre-anneal oxide superconductor article. An oxide superconductor having the formula Bi2−yPbySr2Ca2Cu3O10+x, where 0≦x≦1.5 and where 0≦y≦0.6 is obtained, the oxide superconductor characterized by a critical transition temperature of greater than 111.0 K, as determined by four point probe method.

Abstract: A process for producing a multifilamentary conductive tape of the type including a plurality of layers of a high-temperature superconducting material, incorporated in a mutually spaced relationship within a metal matrix, includes the steps of: a) submitting to plastic deformation individual metal tubes including a precursor of a superconducting material, so as to obtain a plurality of elementary tapes structurally independent from one another; b) coupling the tapes so obtained by means of a heat treatment at a temperature and for a time sufficient to establish a stable mutual connection between said tapes. The multifilamentary tape so obtained or possibly the independent tapes, are then subjected to at least one sintering step, which may be followed by one or more cycles of plastic deformation and sintering. Advantageously, the process of the invention allows to increase the fill factor of the tape, with a corresponding increase in the critical current in superconductivity conditions.

Abstract: The invention relates a powder in tube type method of making an HTc superconductive multifilament strand having a silver-based matrix, in which: a first envelope is filled with powder reagents for an HTc superconductor; the resulting billet is drawn down into a monofilament strand; the monofilament strand is cut up into lengths and a secondary envelope is filled with the resulting lengths, thereby making a multifilament billet which is drawn down into a multifilament strand; the multifilament strand is cut up into lengths and a new envelope is filled with the resulting lengths, thereby making a new multifilament billet which is drawn down into a new multifilament strand; and it is shaped and subjected to heat treatment; according to the invention, at least one face of the monofilament strand is electrically insulated; and during the first multifilament step the secondary envelope is filled with the resulting insulated lengths.

Abstract: A long oxide superconducting wire for a coil or a cable, manufacturing method thereof, an oxide superconducting coil and a cable conductor which have high operational frequency are provided. The wire is a tape-like oxide superconducting wire including a plurality of filaments of oxide superconductor embedded in a matrix, and each filament is twisted spirally along the longitudinal direction of the tape wire. By winding the wire in a coil, an oxide superconducting coil is obtained. When a plurality of such wires are collected, an oxide superconducting cable conductor can be obtained.

Abstract: An oxide superconducting stranded wire having inter-strand insulation and high critical current is provided. A wire including an oxide superconducting material and a matrix covering the material and consisting essentially of silver or a silver alloy is coated with a paint containing, as a main component, an organometallic polymer such as a silicone polymer or aluminum primary phosphorus in a paint reservoir, and the paint is baked in a baking furnace via a drying furnace. A plurality of such wires with the baked paint are twined into a stranded wire, which is then heated up to a temperature necessary for sintering the oxide superconducting material. The stranded wire thus obtained through the step of sintering may have high critical current. A heat-resisting insulating coating layer may be formed by baking the paint.