Abstract: A superconducting circuit including a superconducting joint that joints a niobium titanium superconducting wire having a structure where a filament made of niobium titanium alloy is arranged in a matrix made of copper or copper alloy and other superconducting wire, in which a volume ratio or a surface density of an ?-Ti precipitation in the niobium titanium alloy of the filament in the superconducting joint is smaller than the volume ratio or the surface density of the ?-Ti precipitation in the niobium titanium alloy of the filament in the niobium titanium superconducting wire in a portion other than the superconducting joint.

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: A Nb3Sn superconducting coil can be formed from a wire including multiple unreacted strands comprising tin in contact with niobium. The strands are wound into a cable, which is then heated to react the tin and niobium to form a cable comprising reacted Nb3Sn strands. The cable comprising the reacted Nb3Sn strands are then mounted in and soldered into an electrically conductive channel to form a reacted cable-in-channel of Nb3Sn strands. The cable-in-channel of reacted Nb3Sn strands are then wound to fabricate a superconducting coil. The Nb3Sn superconducting coil can be used, for example, in a magnet structure for particle acceleration. In one example, the superconducting coil is used in a high-field superconducting synchrocyclotron.

Abstract: A superconductive element containing Nb3Sn, in particular a multifilament wire, comprising at least one superconductive filament (8) which is obtained by a solid state diffusion reaction from a preliminary filament structure (1), said preliminary filament structure (1) containing an elongated hollow pipe (2) having an inner surface (3) and an outer surface (4), wherein said hollow pipe (2) consists of Nb or an Nb alloy, in particular NbTa, wherein the outer surface (4) is in close contact with a surrounding bronze matrix (5) containing Cu and Sn, and wherein the inner surface (3) is in close contact with an inner bronze matrix (5) also containing Cu and Sn, is characterized in that the inner bronze matrix (5) of the preliminary filament structure (1) encloses in its central region an elongated core (6) consisting of a metallic material, said metallic material having at room temperature (=RT) a thermal expansion coefficient ?core<17*10?6K?1, preferably ?core?8*10?6 K?1, said metallic material having at RT a

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: A multi-filament superconducting wire in which the filaments comprise zirconia-stabilized ultra-fine grain Nb3Sn. The superconducting wire is formed by wire-drawing a preform comprising a metallic matrix and at least one niobium alloy rod having zirconium and oxygen in solid solution and heat treating the drawn wire in the presence of tin to yield at least one continuous filament comprising ultra-fine grain Nb3Sn having semi-coherent ZrO2 precipitates disposed therein. The ZrO2 precipitates serve to stabilize the ultra-fine grain microstructure of the Nb3Sn at temperatures up to 1100° C. and allows Nb3Sn to maintain the ultra-fine grain microstructure when heat treated at temperatures that are greater than those previously used. By using higher temperatures to form Nb3Sn, the time required for heat treatment can be significantly reduced.

Abstract: An Nb3Sn-based superconductive wire which, when used in a superconductive magnet, manifests sufficient strength also against force along the radius direction in operating the magnet and reveals little deterioration in properties due to mechanical strain ascribable to the force along the radius direction is provided. An Nb3Sn-based superconductive wire comprising a bronze/filament aggregate obtained by placing a lot of niobium (Nb) or niobium alloy filaments in a copper (Cu)-tin (Sn)-based alloy matrix, wherein said niobium or niobium alloy filament constituting the bronze/filament aggregate 3? is a composite filament 5 obtained by combining with a filament reinforcing material having mechanical strength under temperature not more than room temperature after thermal treatment for producing an Nb3Sn-based superconductive compound, larger than the mechanical strength of the niobium or niobium alloy.

Abstract: This invention provides a production method of Nb3Al superconducting multifilamentary wire based on rapid-heating, quenching and transformation method, capable of producing a high-performance Nb3Al superconducting multifilamentary wire by improving critical temperature thereof, upper critical field and critical current density. Upon a first stage heat treatment of beating a composite, in which bcc phase Nb—Al supersaturated solid solution is dispersed in Nb matrix, the bcc phase Nb—Al supersaturated solid solution ordered in temperature rise process is made disordered at an initial phase thereof and a non-reacting portion located adjacent is heated using a reaction heat generated when transforming this disordered bcc phase to A15 phase. Then, disordering of the bcc phase is promoted while propagating a high-temperature transformation region so as to automatically progress high-temperature beat treatment.

Abstract: A high-performance Nb3Al extra-fine multifilamentary superconducting wire is produced simply and inexpensively through the improvement of critical values, Tc, Hc2 and Jc, without the addition of third elements such as Ge, Si and Cu. A first rapid heating and quenching treatment is applied to an Nb/Al composite wire having an atomic ratio of Al to Nb from 1:2.5 to 1:3.5 and having an extra-fine multifilamentary structure to form a BCC alloy phase comprising Nb with Al supersaturatedly dissolved therein wherein the treatment comprises heating the composite wire up to a temperature not lower than 1900° C. within two seconds and then introducing it into a molten metal at a temperature not higher than 400° C. to rapidly quench it.

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

Abstract: In a method for manufacturing Nb.sub.3 Al phase by a diffusion reaction of Nb.sub.2 Al phase and Nb phase, a part of the Nb.sub.2 Al phase is remained and dispersed in the Nb.sub.3 Al phase homogeneously as for magnetic flux pinning centers for a high magnetic field. As for a method for dispersing the Nb.sub.2 Al phase homogeneously, a Nb.sub.3 Al group superconducting precursory composition obtained by dispersing Nb particles and Nb.sub.2 Al ultrafine particles by a mechanical alloying method is used, and further, by a conventional method for generating Nb.sub.3 Al phase by a diffusion reaction of Nb and an aluminum alloy, A Nb.sub.3 Al group superconductor can be achieved.

Abstract: A method for making triniobium tin superconductor with improved critical current density is disclosed where an annealed niobium-base substrate is passed through a tin alloy bath containing tin, copper, and bismuth, to coat the substrate with tin and then annealing the coated substrate to form triniobium tin superconductor. A tin alloy bath containing up to twenty weight percent copper and up to one weight percent bismuth is disclosed.

Abstract: A component 10 for making Al5 Nb.sub.3 Sn superconducting wire is of plane-filling cross-section after removing temporary additions 6, 7. It consists of a central pillar 1 of aluminium (later replaced by tin) surrounded by a two-deep array of polygonal copper columns 2/2a containing niobium rods. Many (e.g. 61) components 10 are stacked together and extruded. The niobium rods adopt and retain a uniform distribution with minimum intervening material. On heat-treatment of the whole, the tin diffuses over a relatively short path and hence consistently into the rods, whereby there is formed a kilofilament Nb.sub.3 Sn wire.

Abstract: A superconducting tunnel junction radiation sensing device includes first and second superconductor electrodes and a tunnel barrier layer interposed therebetween. The tunnel barrier layer is made up of a thin-wall portion and a thick-wall portion each formed of a semiconductor or an insulator, and each having opposite surfaces respectively contacting the first and second superconductor electrodes, and each extending adjacent each other in a same horizontal plane between the first and second electrodes. The thick-wall portion has a vertical thickness which is at least twice that of the thin-wall portion. Furthermore, the thickness of the thin-wall portion is such that a tunnel effect is enabled therethrough form the first electrode to the second electrode, and the thickness of the thick-wall portion is such that a tunnel effect is substantially prohibited therethrough from the first electrode to the second electrode.

Abstract: A high current amplifier, three terminal device, comprising a Josephson tunnel junction and a Schottky diode is configured so that the Josephson junction and Schottky diode share a common base electrode which is made very thin. Electrons which cross the Schottky barrier are supplied to the Josephson junction to obtain the amplified output current.

Abstract: Superconductors formed by powder metallurgy have a matrix of niobium-titanium alloy with discrete pinning centers distributed therein which are formed of a compatible metal. The artificial pinning centers in the Nb-Ti matrix are reduced in size by processing steps to sizes on the order of the coherence length, typically in the range of 1 to 10 nm. To produce the superconductor, powders of body centered cubic Nb-Ti alloy and the second phase flux pinning material, such as Nb, are mixed in the desired percentages. The mixture is then isostatically pressed, sintered at a selected temperature and selected time to produce a cohesive structure having desired characteristics without undue chemical reaction, the sintered billet is reduced in size by deformation, such as by swaging, the swaged sample receives heat treatment and recrystallization and additional swaging, if necessary, and is then sheathed in a normal conducting sheath, and the sheathed material is drawn into a wire.

Abstract: A Type II superconducting filament is formed by surrounding a Type II superconducting alloy ingot with layers of a fine grain Type II superconducting alloy sheet, a barrier layer and a copper extrusion can. The composite is then reduced to a filament by hot and cold working.

Abstract: In one embodiment this invention provides a process for decreasing the resistivity of an electrical conductor.The process involves the application of high temperature and an external field to a conductor to induce a current flow and physicochemical transition in the conducting matrix.

Abstract: A flexible Nb-containing superconductor-laminated aromatic polyimide material useful for superconducting wires and circuits, comprising an Nb-containing superconductor layer formed on an aromatic imide polymer substrate, which preferably comprise a polymerization-imidization product of an aromatic tetracarboxylic acid component comprising, as a major ingredient, a biphenyltetracarboxylic dianhydride with an aromatic diamine component comprising, as a major ingredient, an aromatic diamine having a one benzene ring structure.

Abstract: A superconductive material with a superconducting critical temperature of at least 77.degree. K. comprising 20 at. % Nb, 10 at. % Si, 10 at. % Al and 60 at. % O is provided by simultaneous vapor-phase physical deposition or sputtering of Nb, Si and Al onto a heated sapphire substrate under oxygen-containing atmosphere, followed by a rapid quenching or post-oxidization of Nb-Si-Al ternary system composition having an Nb/Si/Al atomic ratio of 2/1/1. The high critical temperature allows abundantly existing, cheap available liquid nitrogen to be used as a cryogen for developing superconductivity.