Abstract: A device for use as an adjunct in assuring that a manufactured wire is substantially free of internal flaws. A plurality of successively adjacent wire bending stations are provided, where each station includes means for bending the wire into bending planes which are different for each of the stations. The wire is passed through the successive stations, whereby the different bending planes at each station subject the wire at each station to tensile bending strain at portions of the wire cross-section which are different for each station. As a result the probability is increased that a given internal flaw in the wire will be exposed to the tensile bending strain condition as the wire passes through the successive stations, increasing likelihood of breakage of the wire at the flaw or of flaw magnification to improve detection of the flaw during subsequent wire inspections.

Abstract: A method for successfully heat treating magnet coils of braided Bi2Sr2Ca1Cu2Ox (Bi-2212) strand. The Bi-2212 coil is fabricated using standard round wire powder-in-tube techniques, and braided with a ceramic-glass braid with integrated carbonaceous binder. The coil is heated in an atmosphere controlled furnace below the high current density phase reaction sequence to burn off the carbonaceous binder and evacuated to remove unwanted gases from the inner windings. The oxygen environment is then reintroduced and the coil is heat treated to the high Jc reaction temperature and then processed as normal. As the local atmosphere around the surface of the wire, particularly the concentration of oxygen, is critical to a successful reaction sequence, high current Bi-2212 coils can thereby be obtained.

Abstract: In a method of manufacturing a copper clad aluminum channel superconductive conductor, an electrically conductive wire comprising a metal or alloy core is formed with a longitudinally extending groove in a surface thereof. A wire made of a material that exhibits superconducting properties within a defined temperature range is soldered into the groove.

Abstract: Critical current densities of internal tin wire having values of at least 2000 A/mm2 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: In a method of manufacturing a copper clad aluminum channel superconductive conductor, an electrically conductive wire comprising a metal or alloy core is formed with a longitudinally extending groove in a surface thereof. A wire made of a material that exhibits superconducting properties within a defined temperature range is soldered into the groove.

Abstract: A method for fabrication of nanometer scale metal fibers, followed by optional further processing into cables, yarns and textiles composed of the primary nanofibers. A multicomponent composite is first formed by drilling a billet of matrix metal, and inserting rods of the metal desired as nanofibers. Hexed or round rods can also be inserted into a matrix metal can. The diameter of this composite is then reduced by mechanical deformation methods. This composite is then cut to shorter lengths and reinserted into another billet of matrix metal, and again the diameter is reduced by mechanical deformation. This process of large scale metal stacking followed by mechanical deformation is repeated until the desired fiber size scale is reached, the fibers being contained in the matrix metal. After size reduction, the composite metal wires may be further processed into built up configurations, depending on intended application, by stranding, cabling, braiding, weaving, knitting, felting, etc.

Abstract: Critical current densities of internal tin wire to the range of 3000 A/mm2 at temperature of 4.2 K and in magnetic field 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; barrier thickness relative to the filament thickness; additions of a dopant such as Ti or Ta to the Nb3Sn; and the design for restacking and wire reduction to control the maximum filament diameter at the subsequent heat reaction stage.

Abstract: A method for decreasing the effective magnetic filament sizes for high current internal tin Nb3Sn superconductors. During processing composite rods preferably comprised of copper clad Ta rods of approximately the same dimensions as the hexes in the designed filament billet stack are used as dividers in the subelement. Along with the Ta rods, Ta strips are strategically situated against the Nb or Nb alloy barrier tube which surrounds the subelement. The use of Ta as a spacer instead of copper prevents any reasonable likelihood of bridging of the superconducting phases formed after final reaction.

Abstract: A method for increasing the copper to superconductor ratio of a superconductor core wire by forming a copper-based strip about the core wire which at least partially encloses the core wire in contact therewith by deforming the strip longitudinally into a U shape nested about the wire; and soldering the wire and strip in the assembly of step (a) to form a strong mechanical, electrical and thermal bond therebetween.

Abstract: An improvement is disclosed in the method for producing a multifilament (Nb, Ti)3Sn superconducting wire by the steps of preparing a plurality of Nb or Nb alloy rods where Nb or Nb alloy monofilaments are encased in copper or copper alloy sheaths; packing the Nb or Nb alloy rods within a copper containing matrix to form a packed subelement for the superconducting wire; providing sources of Sn, and sources of Ti within said subelement; assembling the subelements within a further copper containing matrix; and diffusing the Sn and Ti into the Nb or Nb alloy rods to form (Nb, Ti)3Sn. The method is improved by diffusing the Ti into the Nb from a minor number of Ti dopant source rods which are distributed among the Nb or Nb alloy rods.

Abstract: A method for producing a superconductor having a high copper to superconductor composition (Cu/SC) ratio by cross-sectional area. An assembly is prepared formed of one or more fine filaments of a superconductor composition or of a precursor component for a superconductor alloy composition, which filaments are embedded in a copper-based matrix. The assembly is electroplated with copper to increase the Cu/filament ratio in the resulting product, and thereby increase the said Cu/SC ratio to improve the stability of the final superconductor.

Abstract: The centers of a plurality of copper tubes are filled with an alloy of tin with a minor amount of aluminum and drawn to form Cu-Sn wires which are cabled around a core Nb wire; a plurality of these strands are provided in a copper tube, or a copper foil or finely wound copper wire and drawn to produce a multifilament wire; heat treatment is applied to cause the tin to diffuse and form the intermetalic Nb.sub.3 Sn at the surface of the Nb filaments to produce the ultimate superconducting wire product. The addition of a small quantity of Al to the Sn facilitates processing and improves the final product properties.

Abstract: A superconductor of the cable-in-conduit type which employs forced flow of liquid helium, comprises a flat-sided housing having an essentially rectangular cross-section, within the housing a metal support bar cabled with multifilamentary superconducting subcables alternated with stainless steel cables or wires. The superconductor provides a large heat transfer surface owing to the multifilamentary superconducting subcables which have a void volume in the range of about 30-35%, as well as mechanical support owing to the stainless steel cables or wires.

Abstract: The centers of a plurality of copper tubes are filled with tin and drawn to form Cu-Sn wires which are cabled around a core Nb wire; a plurality of these strands are provided in a copper tube, or a copper foil or finely wound copper wire; and a plurality of said tubes are packed into a copper can to form a billet which is drawn to produce a multifilament wire; and heat treatment is applied to cause the tin to diffuse and form the intermetallic Nb.sub.3 Sn at the surface of the Nb filaments to produce the ultimate superconducting wire product.