Abstract: Disclosed is a splicing method of two second-generation ReBCO high temperature superconductor coated conductors (2G ReBCO HTS CCs), in which, with stabilizing layers removed from the two strands of 2G ReBCO HTS CCs through chemical wet etching or plasma dry etching, surfaces of the two high temperature superconducting layers are brought into direct contact with each other and heated in a splicing furnace in a vacuum for micro-melting portions of the surfaces of the high temperature superconducting layers to permit inter-diffusion of ReBCO atoms such that the surfaces of the two superconducting layers can be spliced to each other and oxygenation annealing for recovery of superconductivity which was lost during splicing.

Abstract: A device and method for making a persistent joint allowing end terminations of superconducting MgB2 wire to be joined with a superconducting bridge. Superconducting electromagnetic coils may be joined in series or joining of coil assemblies to current sources and the two ends of a persistent switch. The device includes wire filaments with end preparation exposing reacted MgB2, inserted into a block and surrounded with Mg+B and/or MgB2 in powder, solid, slurry or sol-gel form and subsequently reacted to establish a bridge of superconducting MgB2 electrically connecting the superconducting MgB2 wires. Autonomous operation of the superconducting background magnet coils in magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) devices are allowed, or similar devices where autonomous operation of an MgB2 based superconducting magnet is required. The low resistant joint will also be beneficial for other superconducting applications such as fault current limiters, motors, generators, etc.

Abstract: A junction box is provided which allows serial connection of the individual conductors of at least one high temperature superconductor (HTS) wire bundle. The junction box includes an electrical interface device disposed within a junction box housing. The interface device is configured receive both ends of each conductor of each HTS wire bundle, and to provide a superconductive electrical connection between respective first ends of conductors to respective second ends of other wire bundle conductors to form at least one superconductive multi-turn electromagnetic winding.

Abstract: A method for superconductingly connecting two or more wires (1, 2), each comprising at least one filament (3a-3d) that contains MgB2 or a mixture of Mg and B, wherein a superconducting connection is realized through exposed end regions (4a) of the filaments (3a-3d) via an MgB2 matrix, is characterized in that a bulk boron powder (4) is provided into which the exposed end regions (4a) of the filaments (3a-3d) of the wires (1, 2) project, the boron of the bulk boron powder (4) being present in amorphous modification. The bulk powder (4) is then compacted together with the projecting exposed end regions (4a) of the filaments (3a, 3b) to form a compressed element (8) and the compressed element (8) is infiltrated with molten magnesium (10) from the surface (13) of the compressed element (8). The method improves the quality, in particular, the current-carrying capacity and the critical magnetic field strength of a superconducting connection of MgB2 superconducting wires.

Abstract: A method for connecting two or more superconducting wires (1, 2), each comprising at least one filament (3a-3b) that contains MgB2, wherein the superconducting connection is realized through exposed end regions (13) of the filaments (3a-3d) via a superconducting matrix, is characterized in that a bulk powder (4) of a high-temperature superconductor (HTS) powder with a transition temperature of Tc>40K is provided, into which the exposed end regions (13) of the filaments (3a-3d) project, wherein the Boron of the Boron powder of the bulk powder (4) is in amorphous modification, and the bulk powder (4) is compacted together with the projecting exposed end regions (13) of the filaments (3a-3d) to form a compressed element (8). The method improves the quality, in particular, the current carrying capacity and the critical magnetic field strength of a superconducting connection of two MgB2 wires.

Abstract: A connection arrangement for connecting together two superconductor cables, each having a central conductor comprising at least one superconductive part, a dielectric layer surrounding said central conductor, a shield surrounding said dielectric layer and a cryogenic enclosure surrounding said shield, the connection arrangement has an electrical splicing device for splicing together the central conductors and stripped dielectric layers of the corresponding shields. This connection arrangement has a covering made of semi-conductive material that is placed between the two shield ends and an electrical connection device for connecting together the two shield ends, the connection device surrounding the covering, being contained in the cryogenic enclosure, and comprising two junction elements each electrically and mechanically joined to a respective one of the shield ends, and an electrical splicing arrangement for splicing together the two junction elements.

Abstract: A two-sided joint for splicing two laminated wires together, while preserving the mechanical integrity of the wire is disclosed. The two-sided joint can splice two laminated HTS wires having tapered ends and includes a bottom strap and a top strap. Under one aspect, a laminated, spliced superconductor wire includes a superconductor joint, which includes first and second superconductor wires, each wire including a laminate layer, a substrate layer overlaying the laminate layer, a buffer layer overlaying the substrate layer, a superconductor layer overlaying the buffer layer, a gap layer overlaying the superconductor layer, and a laminate layer overlaying the gap layer, a first HTS strap in electrical connection with the second laminate layer of the first laminate wire and the second laminate layer of the second laminate wire, and a backing strap proximate to the first laminate layer.

Abstract: A cabled conductor comprises a plurality of transposed strands each comprising one or more preferably twisted filaments preferably surrounded or supported by a matrix material and comprising textured anisotropic superconducting compounds which have crystallographic grain alignment that is substantially unidirectional and independent of the rotational orientation of the strands and filaments in the cabled conductors. The cabled conductor is made by forming a plurality of suitable composite strands, forming a cabled intermediate from the strands by transposing them about the longitudinal axis of the conductor at a preselected strand lay pitch, and, texturing the strands in one or more steps including at least one step involving application of a texturing process with a primary component directed orthogonal to the widest longitudinal cross-section of the cabled intermediate, at least one such orthogonal texturing step occurring subsequent to said strand transposition step.

Abstract: This invention relates to a practical superconducting conductor based upon biaxially textured high temperature superconducting coatings. In particular, methods for producing flexible and bend strain-resistant articles and articles produced in accordance therewith are described which provide improved current sharing, lower hysteretic losses under alternating current conditions, enhanced electrical and thermal stability and improved mechanical properties between otherwise isolated films in a coated high temperature superconducting (HTS) wire. Multilayered materials including operational material which is sensitive to bend strain can be constructed, in which the bend strain in the region in which such operational material is located is minimized. The invention also provides a means for splicing coated tape segments and for termination of coated tape stack ups or conductor elements.

Abstract: Methods for implementing production of an oxide superconductor joined member, excellent in electric current transmission performance, without a need of going through particularly complex steps, are provided. When joining together oxide superconductors by use of a solder composed of an oxide superconducting material, a finally solidified portion of the solder is positioned in a region where a transmission path of electric current flowing between oxide superconductor base materials as joined together is not obstructed by, for example, disposing the solder on a face of the oxide superconductor base materials, other than butting surfaces of the oxide superconductor base materials, so as to straddle both the base materials like bridge-building. Current flow is also not obstructed by, for example, shaping junction faces of the oxide superconductor base materials such that at least portions of the butting surfaces thereof are in the shape of sloped open faces, parting from each other.

Abstract: A connection structure for superconducting conductors which can simply connect superconducting conductors with each other with small connection resistance and no sophisticated technology is provided. In a connection structure for multifilamentary superconducting conductors, superconducting wires forming the superconducting conductors respectively are joined with each other through solder.

Abstract: A bulk superconductor including a plurality of units each composed of a substrate and a superconductive layer of R--Ba--Cu--O, where R is selected from La, Nd, Sm, Eu, Gd, Y, Dy, Ho, Er, Tm, Yb and mixtures thereof, formed on the substrate. The units are arranged in a row or in a matrix such that the superconductive layers of respective units are superconductively joined with each other.

Abstract: A superconductive article is made from interconnected superconductive, metallic tapes. The tapes preferably are mechanically joined and electrically interconnected by a plurality of superconductive interconnections that extend between the tapes. The interconnections are formed by overlapping the edges of two tapes and forming a plurality of superconductive welds between the tapes in the overlapping regions. Articles of this invention may be formed from superconductive tapes made from Nb.sub.3 Sn having superconductive interconnections that also include Nb.sub.3 Sn.

Abstract: A conductor splice and splice support structure and method of assembly for use with cable-in-conduit superconductor cable of the type having a plurality of spaced sub-cables each including stabilizer and superconductor strands in an annular tube. Two transition ramp members, each having a cross section varying from a first end conforming to the cable configuration to a second end having an enlarged, oval, configuration have a plurality of surface grooves each sized to hold one sub-cable. Between the two transition ramp members is provided a main support member having grooves aligned with the transition members grooves. The main support member grooves are sized to hold two overlapping sub-cables. Preferably, a braid of superconductor material is placed around the overlapping sub-cable ends. The space within the grooves surrounding the sub-cables is preferably filled with solder.

Abstract: A low resistance splice for electrically connecting the ends of two superconducting cables and a method for making the splice. Two cables formed from superconducting material are positioned in close proximity, either overlapping or axially aligned and extending in opposite directions away from the splice. At least one strand of superconducting material is wrapped over both cables in a pressure relationship assuring good electrical contact between cable ends and strands. Solder is melted and applied to hold the strands against the cables. Where the cables overlap, solder may be used at the overlap interface to add mechanical strength. The strands may be in the form of a helical winding around overlapping cable ends or in the from of a braided tube surrounding and pressed against either overlapping or axially aligned cables. In the axial embodiment, the cables with the strand wrap may be pressed into a slot and the slot filled with solder to hold the cables and strands in position.

Abstract: A superconducting joint includes a niobium-tin superconducting composite member, a niobium-tin superconducting wire diffusion bonded to the superconducting composite, a spacer diffusion bonded to the superconducting wire, a support diffusion bonded to the spacer and a superconducting member in electrical contact with the superconducting composite. According to the method of the invention, a wire comprising unreacted niobium and tin is machined to form a tapered end having a first tapered surface exposing the wire interior and an opposing surface. A complementary spacer having the taper substantially similar to that of the wire is assembled with the wire so that the tapered wire and the tapered spacer in surface contact with one another such that the spacer occupies the area of the wire removed by machining and the exposed tapered surface remains still exposed.

Abstract: This invention relates to a superconducting joint which is more commonly referred to as, a pigtail joint, for use in superconducting magnets. Such structures of this type, generally, exhibit total superconducting behavior at temperatures below the transition value of the superconducting joint and have high electrical resistance at temperatures above the transition point of the superconducting joint.

Abstract: A superconducting electrical conductor comprises a porous substrate of bonded fibers which are coated by ceramic oxide superconducting material of the perovskite type so that its critical temperature of superconductivity is at or above the boiling point of liquid nitrogen. To form electrical cable, the conductor is encased within an inner tube. An outer tube surrounds the inner tube and defines an evacuated annular space therewith. This provides a thermal barrier between substrate, which will be bathed by liquid nitrogen, and the ambient. Electrical and heat insulation surrounds the outer tube.Joint connectors in the form of multiple rigid rods, each coated by superconducting material and held in a perforated frame, are used to connect facing ends of the substrate to form an electrical connection from one length of conductor to the next.