Abstract: In a fabrication method of a MgB2 superconducting tape and wire by filling a tube with a MgB2 superconducting powder and forming it into a tape or wire, a fabrication method of a MgB2 superconducting tape (and wire) which is characterized by using a MgB2 superconducting powder having a high critical current density (Jc) owing to its lowered crystallinity and having potential for excellent grain connectivity as the MgB2 superconducting powder. Provided are a fabrication method of a MgB2 superconducting tape and wire which can fabricate a MgB2 superconducting tape and wire having a level of Jc sufficiently high for practical applications and homogeneous quality throughout its length by an ex-situ process employing a material of the composition suitable for its working environment as the sheath material, and a MgB2 superconducting tape and wire thereby fabricated.

Abstract: A superconducting article is disclosed, including a substrate and a chemical vapor deposited thin film superconducting layer overlying the substrate, the superconducting layer having a critical current not less than about 100 A/cm width at 77K and self field. The superconducting article may be a tape, multiple tapes, or a power device, such as a power cable, power generator, or power transformer. Also disclosed are methods for manufacturing same and methods for using same.

Abstract: A method of processing width of a superconducting wire rod is provided, in which slit processing is performed to a superconducting wire rod formed using a wide substrate, without deteriorating the superconducting feature and at high production efficiency. The method includes a step of preparing the superconducting wire rod and a step of cutting the superconducting wire rod by processing portions each having two opposing cutting portions. At least two sets of the processing portions are arranged adjacent to each other with a distance in a width direction of the superconducting wire rod so that the superconducting wire rod is interposed between the two cutting portions. Contacting positions of the cutting portions contacting one surface of the superconducting wire rod are externally positioned in the width direction of the superconducting wire rod relative to contacting positions of the cutting portions contacting the other surface of the superconducting wire rod.

Abstract: The invention provides an improved method of manufacturing an HTS tape coil for an MRI device with enhanced protection, the method comprising attaching high-Q capacitors at each end of an HTS wire, removing substantially all electrically conductive sheathing material on an inner side of the HTS wire, while retaining substantially all electrically conductive sheathing material on an outer side of the HTS wire. The invention also provides an HTS wire made in accordance with the foregoing method.

Abstract: A superconductive element containing magnesiumdiboride (=MgB2), comprising at least one superconductive filament (1) of a size between 5 and 500 micron, which is enclosed in a metallic matrix (2) and also comprising at least one highly conductive ohmic element (4),the superconducting filaments being separated from the matrix (2) and from the conductive ohmic element (4) by a protective metallic layer (3), the superconductive filament being formed by a reaction between boron (B) and magnesium (Mg) powders and boron carbide (=B4C) powders as a first additive is characterized in that one or more additional powder additives containing carbon are present in the reaction of the powder mixtures including Mg, B and B4C. The reaction of the powder mixture to MgB2 is carried out at temperatures between 500 and 760° C. leading to a maximum of the critical current density, Jc, at temperatures at 760° C. and below.

Abstract: A superconducting cable enables the cooling of the superconducting conductor with high efficiency and has a sufficient insulating strength. A method of controlling the temperature of the coolants used in the cable is offered. The superconducting cable comprises a heat-insulated pipe that houses a cable core provided with a superconducting conductor made of a superconducting material. The cable core is also provided with a poorly heat-conductive pipe placed at the outer side of the outer circumference of the superconducting conductor. The inside and outside of the poorly heat-conductive pipe are separately filled with different types of coolants having different purposes. The poorly heat-conductive pipe is filled with a conductor-use coolant for cooling the superconducting conductor so as to maintain it at the superconducting state. The heat-insulated pipe is filled with an insulation-use coolant for performing electric insulation of the superconducting conductor.

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: The present invention provides a method for producing a MgB2 superconductor, comprising compacting and heating a mixture comprising Mg or MgH2 powder and B powder, wherein said mixture comprises SiC powder and an aromatic hydrocarbon, and a MgB2 superconductor having a higher critical current density (Jc) than that of the known MgB2 superconductors added SiC only or added an aromatic hydrocarbon only such as benzene.

Abstract: A method of manufacturing a sintered body, which is a method of manufacturing a sintered body containing Mg and B, comprises the arrangement and heat treatment steps of arranging Mg powder (3a, 3b) and B powder (2) without mixing the Mg powder and the B powder with each other and heat-treating the Mg powder (3a, 3b) and the B powder (2) after the arrangement step. The temperature in the heat treatment step is at least 651° C. and not more than 1107° C. Thus, the critical current density can be improved.

Abstract: Laminated, biaxially textured superconductors include Ir-based buffer layers and/or substrates.

Abstract: Disclosed is a method of manufacturing a continuous disk winding. A high-temperature superconducting wire is lapped using Kapton films to insulate the high-temperature superconducting wire. The high-temperature superconducting wire is wound on a bobbin by a predetermined number of turns to form a layer of windings. An annular disk having a slit formed therein is fitted onto the bobbin. The slit is formed along the circumference of the disk and to be inclined from the inner side of the disk towards the outer side thereof. The high-temperature superconducting wire is inserted into the slit of the disk to pass through the annular disk smoothly along the inclined slit and wound again by the predetermined number of turns to form a next layer of windings. The above steps of fitting an annular disk, and inserting and winding the high-temperature superconducting wire are repeated to form multiple layers of windings.

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 low AC loss electrical conductor includes a plurality of single-filament superconducting strands longitudinally wound about one another. An insulative housing surrounds the plurality of single-filament superconducting strands.

Abstract: A method for manufacturing clad superconducting wire for use in superconducting coils, such wire having improved resistance to electromagnetic forces by using composite superconducting wires that are clad with selected high-stiffness high-strength materials.

Abstract: A method of forming a superconducting conductor is disclosed. The method provides translating a substrate tape through a deposition chamber and along a helical path, where the helical path has multiple windings of the substrate tape and each winding of the substrate tape extends along a feed path and a return path. The method further provides depositing a HTS layer overlying the substrate tape within a deposition chamber, wherein the deposition chamber houses the substrate tape along the feed path but not the return path.

Abstract: Disclosed herein is method for making a wire comprising contacting a first end of a first superconducting wire with a second end of a second superconducting wire, wherein the superconducting wire comprises a superconducting filament having a superconducting composition comprising magnesium diboride; heating the first end of the first superconducting wire with the second end of the second superconducting wire at a point to form a joint, wherein the superconducting filament having the superconducting composition is in continuous electrical contact with any other part of the superconducting filament after the formation of the joint.

Abstract: A method of producing an electrical connection structure between at least two superconducting lines. The method comprises adding metal powder or alloy powder to a superconducting material comprising magnesium diboride, intervening the superconducting material between at least two superconducting lines, and heating said superconducting lines and said superconducting material to a temperature lower than the melting point of said superconducting material prior to the addition of said metal powder or alloy powder thereto, but higher than the melting point of said metal powder or alloy powder.

Abstract: A low alternating current loss superconducting cable is provided, including a plurality of superconducting tapes spirally wound around a longitudinally extending core. The tapes are provided in a path between about 5° and 85° relative to the longitudinal axis of the core such that the tape completely covers the surface of the core. The tapes are generally parallel to each other and include first and second tapes that are adjacent to each other. The first and second tapes partially overlap each other.

Abstract: Processes for the fabrication of MgB2 powder and wires are provided. Powders are produced by mechanically alloying magnesium- and boron-containing precursors under controlled conditions to avoid secondary phase and impurity formation. Powders are also prepared by vapor phase reaction of volatile magnesium- and boron-containing precursors. Wires, tapes, films and coatings are provided.

Abstract: A superconducting cable comprising at least a superconducting conductor and a cryostat, including a thermal insulation and an inner tube, with a protecting element between the superconducting conductor and the inner tube, to prevent damages to the superconducting material by the inner tube of the cryostat.

Abstract: The inventive method of manufacturing an oxide superconducting wire comprises a step (S1, S2) of preparing a wire formed by covering raw material powder of an oxide superconductor with a metal and a step (S4, S6) of heat-treating the wire in a pressurized atmosphere, and the total pressure of the pressurized atmosphere is at least 1 MPa and less than 50 MPa. Thus, formation of voids between oxide superconducting crystals and blisters of the oxide superconducting wire is suppressed while the partial oxygen pressure can be readily controlled in the heat treatment, whereby the critical current density can be improved.

Abstract: Based on its superconductive properties relating to “nonlineanty,” a conventional HTS strip is divisible into three “domains,” namely, a medial domain and two lateral domains. The nonlinearity associated with the conventional strip's medial domain is considerably greater than that which is associated with its lateral domains. Similarly divisible into a medial domain and two lateral domains, the present invention's HTS strip uniquely exploits these physical distinctions by causing more (e.g., most) of the current that it conducts to be conducted by its lateral domains. Various inventive designs accomplish this through narrowing or interruption/punctuation (e.g., via holes and/or trenches) or degradation, or some combination thereof, of the medial domain. By thus “re-proportioning” current conduction as compared with a conventional strip, an inventive strip succeeds in “re-proportioning” the associated nonlinearities.

Abstract: A method of making an oxide superconductor article includes converting an oxide superconducting precursor into an oxide superconductor by thermo-mechanical processing using intermediate rolling deformation and heat treatment (including liquid-phase sintering and low temperature baking) and applying an additional heat treatment after the material is fully processed (including optional liquid-phase sintering and low temperature baking) to decompose any secondary phase remaining at the grain boundaries and to promote diffusion of the secondary phase into the oxide grain, where they form 2223 phase. The material has a better superconducting grain connectivity and improved superconducting transport property.

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: An ion source impinging on the surface of the substrate to be coated is used to enhance a MOCVD, PVD or other process for the preparation of superconducting materials.

Abstract: The present invention is a high-throughput, ultraviolet (UV) assisted metalorganic chemical vapor deposition (MOCVD) system for the manufacture of HTS-coated tapes. The UV-assisted MOCVD system of the present invention includes a UV source that irradiates the deposition zone and improves the thin film growth rate. The MOCVD system further enhances the excitation of the precursor vapors and utilizes an atmosphere of monatomic oxygen (O) rather than the more conventional diatomic oxygen (O2) in order to optimize reaction kinetics and thereby increase the thin film growth rate. In an alternate embodiment, a microwave plasma injector is substituted for the UV source.

Abstract: A method of heat treating a coil (14) for use as a superconducting coil. The coil (14) is heated in a furnace, the temperature of the furnace being controlled to perform a predetermined heating cycle. A current is passed through the coil (14) for at least a portion of the heating cycle so as to further heat the coil by resistance heating.

Abstract: In one embodiment, the invention comprises a system for manufacturing a superconductive electrical conductor. A channel (140) is formed in a mold (130) that is formed from a ceramic material having a negative heat coefficient of expansion. A material (142) having a positive heat coefficient of expansion that develops superconductivity characteristics upon the application of heat is deposited in the channel. Heat is applied to the mold (130) with the material (142) that develops superconductivity characteristics deposited in the channel to develop the superconductivity characteristics in the deposited material. In a particular embodiment, the negative heat coefficient of expansion and said positive heat coefficient of expansion are complementary, such that change with heat in dimensions of the channel (140) formed in the mold (130) and change with heat in dimensions of the material (142) deposited in the channel (140) are substantially the same. In a more particular embodiment the channel forms a coil (22).

Abstract: In one embodiment, the invention comprises a system for manufacturing a superconductive electrical conductor. A channel (140) is formed in a mold (130) that is formed from a ceramic material having a negative heat coefficient of expansion. A material (142) having a positive heat coefficient of expansion that develops superconductivity characteristics upon the application of heat is deposited in the channel. Heat is applied to the mold (130) with the material (142) that develops superconductivity characteristics deposited in the channel to develop the superconductivity characteristics in the deposited material. In a particular embodiment, the negative heat coefficient of expansion and said positive heat coefficient of expansion are complementary, such that change with heat in dimensions of the channel (140) formed in the mold (130) and change with heat in dimensions of the material (142) deposited in the channel (140) are substantially the same. In a more particular embodiment the channel forms a coil (22).

Abstract: A high temperature superconducting cable includes a tubular support and a plurality of superconducting tapes. The superconducting tapes include a superconducting material enclosed in a metal covering, spirally wound onto the tubular support to form at least an electroinsulated, thermally-insulated, and refrigerated superconducting layer. The superconducting tapes also include at least a metal strip coupled to the metal covering. A process for manufacturing high temperature superconducting cables is also disclosed.

Abstract: Method of manufacture a wide bore, high field superconducting magnet. The superconducting magnet has a plurality of superconducting coils impregnated with epoxy and nested within each other. An innermost one of the nested coils has a bore therethrough that defines a bore width of the magnet. The bore width is greater than approximately 100 millimeters. The nested coils are electrically connected in series and cooled to an operating temperature less than approximately 4 degrees K. The magnet also has external reinforcements on the coils that are applied prior to impregnating the coils with epoxy. An active protection circuit protects the coils in response to a quench in the magnet. The protection circuit includes heater elements positioned in thermal contact with the coils prior to impregnating the coils with epoxy. The magnet further has lead supports for supporting the lead wires with epoxy that extend from the coils.

Abstract: The present invention concerns the improvement of the supercurrent carrying capabilities, i.e. the increase of critical current densities, of bicrystalline or polycrystalline superconductor structures, especially of high-Tc superconductors. By providing an appropriate predetermined dopant profile across the superconductor structure, in particular within or in the vicinity of the grain boundaries, the space-charge layers at the grain boundaries are reduced and thereby the current transport properties of the superconductor significantly improved. Simultaneously, the influence of magnetic fields on the critical current densities is significantly reduced, which in turn enhances the overall supercurrent carrying capabilities while keeping the supercurrent transport properties of the grains at good values.

Abstract: A Nb3Al superconducting wire and method for fabricating the same wherein Nb and Al powders in combination, or Nb—Al alloy powders are encapsulated in a metal tube, preferably copper or copper-alloy (e.g., CuNi), and the resultant composite is processed by conventional means to fine wire. Multifilamentary composites are produced by rebundling of the powder-filled wires into metal tubes followed by conventional processing to wire of a desired size. It is required for the use of Nb and Al powders in combination that the Nb and Al powder particle size be less than 100 nm. In the use of Nb—Al alloy powders, it is preferred, but not required, that the powder particle size be similarly of a nanometer scale. The use of nanometer-scale powders is beneficial to wire fabrication, allowing the production of long wire piece-lengths. At final wire size, the wires produced by practice of the present invention are heat treated at temperatures below the melting point of copper (1083° C.

Abstract: There is disclosed a continuous process for the formation of a superconducting wire utilizing magnesium diboride powder. The process provides a long length, low cost strand of superconducting wire which can be used in a monofilament or multifilament form.

Abstract: By a method for constructing a superconducting multiphase cable comprising N phases, the phases are divided into n groups with N phases in each group, all the groups have a common screen. The individual groups may be geomtrically formed with coaxial or flat phases. The individual phases in each group may further be divided into individual conductors such as tapes. The insulation between the individual conductors in the groups may be separately insulated from each other or have a common insulation. In a particularly appropriate embodiment, the number of groups is 1 and implemented with a flat or concentric geometry. In this way, a compact superconducting power cable is provided, which is relatively inexpensive in production and has few working operations while maintaining good electrical properties.

Abstract: A method for fabricating a cable-in-conduit-conductor for use in superconductor application is described. The system utilizes a work surface with drum means provided at each end. A superconductor cable is fed from a supply source at one end. After the cable is pulled through a tube on the work surface, the leading edge of the cable is bent around one of the drums and returned to the opposite end of the table. This naked length of cable is once again bent around one of the drums and then pulled through another tube on the table. This process is repeated until an acceptable length of superconductor cable is present. Tension means are used in conjunction with a tube mill which compresses the tube-cable combination into a viable cable-in-conduit conductor (CICC). Notably, as this tension-compression is occurring, the naked lengths of cable are eliminated and each separate tube section is joined together to create a uniform CICC.

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 superconducting laminated oxide substrate, which comprises a laminate a layer of a superconducting oxide crystal substrate made of a superconducting oxide single crystal or a superconducting oxide polycrystal and a layer of a reinforcing crystal substrate, prevents cracks from occurring in the superconducting oxide crystal substrate due to the heat treatment conducted for the purpose of forming an insulation film or a conductor film, and provides easy connectivity between electrodes and wiring formed on substrates located at upper and lower positions.

Abstract: It is an object to provide a process for producing a superconducting wire without defects, such as deterioration of characteristics and deformation, in which a superconducting wire having a length of 1 km or more and a high critical electric current density is easily subjected to heat treatment. The first invention comprises a step of inserting a metallic sheath wire, which is formed by filling a superconducting material in a metallic sheath, into a metallic tube having an inner diameter larger than an outer diameter or a width of the metallic sheath wire; and a step of conducting heat treatment under such a condition in that the superconducting wire is wound to overlap a cylindrical fixture to prevent contact with each other while controlling the interior of the metallic tube. The second invention uses a ceramic board on the heat treatment of a pancake formed by winding the metallic sheath wire on a core.

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: Coatings especially for superconductive strip conductors, as well as methods of applying the coatings, are addressed. Exemplary coatings include aluminum oxide in an aqueous suspension, with aluminum oxide particles contained in the suspension having size typically between 0.5-10 &mgr;m.

Abstract: A process is provided for preparing solid superconducting mixed-metal oxides whereby the superconductor can be formed into any predetermined shape by way of viscous sol precursors. The superconductors are also formed by this process into homogeneous phases.

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 or a high temperature liquid metal 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 diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.

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: Powder of not more than 1 &mgr;m in mean particle diameter is prepared to contain a mixture of superconducting phases mainly composed of 2212 phases of Bi—Sr—Ca—Cu or (Bi, Pb)—Sr—Ca—Cu and non-superconducting phases which is obtained by calcining and pulverizing raw material powder at least once, this powder is heat treated at a high temperature and thereafter coated with a metal to prepare a round wire by deformation processing, thereafter a tape type or flat type wire is prepared by deformation processing, then the wire is heat treated under conditions for allowing phase transformation of the 2212 phases of main superconducting phases to 2223 phases with facilitation of grain growth, thereafter the as-formed 2223 phases are highly densified by deformation processing or pressurization, and the wire is again heat treated so that the 2223 phases are strongly bonded with each other and the non-superconducting phases are finely dispersed.

Abstract: A reinforced superconducting coil and method for the reinforcement of such coil utilizing composite superconducting wires clad with high-strength material are disclosed.

Abstract: A process of preparing superconducting magnesium diboride powder by heating an admixture of solid magnesium and amorphous boron powder or pellet under an inert atmosphere in a Mg:B ratio of greater than about 0.6:1 at temperatures and for time sufficient to form said superconducting magnesium diboride. The process can further include exposure to residual oxygen at high synthesis temperatures followed by slow cooling. In the cooling process oxygen atoms dissolved into MgB2 segregated to form nanometer-sized coherent Mg(B,O) precipitates in the MgB2 matrix, which can act as flux pinning centers.

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 or a high temperature liquid metal 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.