Abstract: A monofilament (100) for producing an Nb3 Sn-containing superconductor wire (33) includes a powder core (1) with an Sn-containing powder, a reaction tube (3) composed of an Nb alloy that includes Nb and at least one further alloy component X. The powder core is disposed within the reaction tube. The monofilament also includes at least two sources (4) for at least one partner component Pk. A respective source includes one or more source structures at a unitary radial position in the monofilament. The source structures are at different radial positions. The alloy component X and the partner component Pk form precipitates XPk on reaction annealing of the monofilament in which Sn from the powder core and Nb from the reaction tube react to produce Nb3 Sn. The powder core is disposed in a moderation tube, which is disposed within the reaction tube. This provides a monofilament with improved current carrying capacity.

Abstract: A monofilament (100) for producing an Nb3Sn-containing superconductor wire (33) includes a powder core (1) with an Sn-containing powder, a reaction tube (3) composed of an Nb alloy that includes Nb and at least one further alloy component X. The powder core is disposed within the reaction tube. The monofilament also includes at least one source (4) for at least one partner component Pk. A respective source includes one or more source structures at a unitary radial position in the monofilament. The alloy component X and the partner component Pk form precipitates XPk on reaction annealing of the monofilament in which Sn from the powder core and Nb from the reaction tube react to produce Nb3Sn. The powder core is disposed in a moderation tube, which in turn is disposed within the reaction tube. This provides a monofilament for a powder-in-tube based Nb3Sn-containing superconductor wire with improved current carrying capacity.

Abstract: A subelement (1) for an Nb3Sn-containing superconductor wire includes an Sn-containing core (2), an inner matrix (5) which includes Cu and surrounds the Sn-containing core (2), a region (7) of mutually abutting Nb-containing rod elements (8, 30), which surrounds the inner matrix (5), where the Nb-containing rod elements (8, 30) are each configured with an Nb-containing core filament (9; 31) and a Cu-containing filament casing (10), an outer matrix (6) which includes Cu and surrounds the region (7) of Nb-containing rod elements (8, 30). The Sn-containing core (2) has a core tube (3) into which an Sn-containing powder (4) has been introduced, the Sn-containing powder (4) being in a compacted state. This provides a subelement for an Nb3Sn-containing superconductor wire which cost-effectively yields an improved superconducting current carrying capacity.

Abstract: For producing an Nb3Sn superconductor wire, restack rod process (RRP) subelements (1a; 60a) are grouped to form a bundle having an approximately circular cross section and are arranged together with filling elements (18a-18c) in an internally and externally round outer tube (19; 52). To the inside the filling elements form a serrated profile (25) for abutment against the hexagonal subelements, and to the outside they form a round profile (24) for direct or indirect abutment in the outer tube. In fabricating the RRP subelements, and before a reshaping with a reduction in cross section, an externally hexagonal and internally round casing structure (9) is provided, into which the remaining parts of the subelements are inserted, in particular, an annular arrangement of hexagonal Nb-containing rod elements (4), which are surrounded externally by an outer matrix (7, 61) and internally by an inner matrix (3).

Abstract: A subelement (1) for an Nb3Sn-containing superconductor wire includes an Sn-containing core (2), an inner matrix (5) which includes Cu and surrounds the Sn-containing core (2), a region (7) of mutually abutting Nb-containing rod elements (8, 30), which surrounds the inner matrix (5), where the Nb-containing rod elements (8, 30) are each configured with an Nb-containing core filament (9; 31) and a Cu-containing filament casing (10), an outer matrix (6) which includes Cu and surrounds the region (7) of Nb-containing rod elements (8, 30). The Sn-containing core (2) has a core tube (3) into which an Sn-containing powder (4) has been introduced, the Sn-containing powder (4) being in a compacted state. This provides a subelement for an Nb3Sn-containing superconductor wire which cost-effectively yields an improved superconducting current carrying capacity.

Abstract: A method for producing an at least two-part structure, such as a semifinished product for a superconducting wire is provided. A first structure and a second structure are separately produced, and the first structure and the second structure are then inserted one into the other. The first structure and the second structure are respectively produced in layers by selective laser melting or selective electron beam melting of a powder. The method produces two-part structures for semifinished products of superconducting wires.

Abstract: For producing an Nb3Sn superconductor wire, restack rod process (RRP) subelements (1a; 60a) are grouped to form a bundle having an approximately circular cross section and are arranged together with filling elements (18a-18c) in an internally and externally round outer tube (19; 52). To the inside the filling elements form a serrated profile (25) for abutment against the hexagonal subelements, and to the outside they form a round profile (24) for direct or indirect abutment in the outer tube. In fabricating the RRP subelements, and before a reshaping with a reduction in cross section, an externally hexagonal and internally round casing structure (9) is provided, into which the remaining parts of the subelements are inserted, in particular, an annular arrangement of hexagonal Nb-containing rod elements (4), which are surrounded externally by an outer matrix (7, 61) and internally by an inner matrix (3).

Abstract: A measurement current (i) is injected into an active part (4) of an HTS superconductor. The active part is cooled, but not reservoirs (1, 2) from/to which the superconductor is wound. Only a fraction of the active part is exposed to a magnetic field for testing the electrical properties of the superconductor. Buffer devices (20a, 20b) prevent current sharing from outside the active part. The measurement current is injected where the residual magnetic field is at least 3 times lower than the magnetic field for testing, and/or the local critical current at the current injection locations is at least three times higher than the critical current at the magnetic field for testing. The electrical properties, e.g. the critical current, are tested by determining an integral of a voltage drop (U) across the active part, e.g. between two voltage pick-up elements (15a, 15b), as a function of measurement time (?).

Abstract: A monofilament (100) for producing an Nb3Sn-containing superconductor wire (33) includes a powder core (1) with an Sn-containing powder, a reaction tube (3) composed of an Nb alloy that includes Nb and at least one further alloy component X. The powder core is disposed within the reaction tube. The monofilament also includes at least one source (4) for at least one partner component Pk. A respective source includes one or more source structures at a unitary radial position in the monofilament. The alloy component X and the partner component Pk form precipitates XPk on reaction annealing of the monofilament in which Sn from the powder core and Nb from the reaction tube react to produce Nb3Sn. The powder core is disposed in a moderation tube, which in turn is disposed within the reaction tube. This provides a monofilament for a powder-in-tube based Nb3Sn-containing superconductor wire with improved current carrying capacity.

Abstract: A method for producing a semifinished product for a superconducting wire is provided herein. The semifinished product includes at least one NbTi-containing structure, such as a NbTi-containing rod structure. The NbTi-containing structure may be produced in layers by selective laser melting or selective electron beam melting of a powder that contains Nb and Ti. In the production of at least some layers of the NbTi-containing structure, during the production of an irradiated area provided for a material deposition of a respective layer, at least one process parameter of the selective laser melting or electron beam melting is varied in one or a plurality of first zones of the irradiated area as compared to one or a plurality of second zones of the irradiated area. The present techniques simplify introduction of artificial pinning centers into the NbTi-material of a superconducting wire or a semifinished product for such a superconducting wire.

Abstract: An NMR spectrometer (131) with an NMR magnet coil (91) having windings of a conductor with a superconducting structure (1), which have a plurality of band-segments (2, 2a, 7a-7e, 8a-8d, 15) made of band-shaped superconductor. Each band-segment (2, 2a, 7a-7e, 8a-8d, 15) has a flexible substrate (3) and a superconducting layer (4) deposited thereon, wherein the band-segments (2, 2a, 7a-7e, 8a-8d, 15) each have a length of 20 m or more. At least one of the band-segments (2, 2a, 7a-7e, 8a-8d, 15) forms a linked band-segment (2, 2a), and each linked band-segment (2, 2a) is connected to at least two further band-segments (7a-7e) in such a way that the combined further band-segments (7a-7e) overlap with at least 95% of the total length (L) of the linked band-segment (2, 2a). The magnet coil generates particularly high magnetic fields in a sample volume and has a low drift.

Abstract: A method for producing an at least two-part structure, such as a semifinished product for a superconducting wire is provided. A first structure and a second structure are separately produced, and the first structure and the second structure are then inserted into one another. The first structure and the second structure are respectively produced in layers by selective laser melting or selective electron beam melting of a powder. The method produces two-part structures for semifinished products of superconducting wires.

Abstract: A method for producing a semifinished product for a superconducting wire is provided herein. The semifinished product includes at least one NbTi-containing structure, such as a NbTi-containing rod structure. The NbTi-containing structure may be produced in layers by selective laser melting or selective electron beam melting of a powder that contains Nb and Ti. In the production of at least some layers of the NbTi-containing structure, during the production of an irradiated area provided for a material deposition of a respective layer, at least one process parameter of the selective laser melting or electron beam melting is varied in one or a plurality of first zones of the irradiated area as compared to one or a plurality of second zones of the irradiated area. The present techniques simplify introduction of artificial pinning centers into the NbTi-material of a superconducting wire or a semifinished product for such a superconducting wire.

Abstract: An NMR spectrometer (131) with an NMR magnet coil (91) having windings of a conductor with a superconducting structure (1), which have a plurality of band-segments (2, 2a, 7a-7e, 8a-8d, 15) made of band-shaped superconductor. Each band-segment (2, 2a, 7a-7e, 8a-8d, 15) has a flexible substrate (3) and a superconducting layer (4) deposited thereon, wherein the band-segments (2, 2a, 7a-7e, 8a-8d, 15) each have a length of 20 m or more. At least one of the band-segments (2, 2a, 7a-7e, 8a-8d, 15) forms a linked band-segment (2, 2a), and each linked band-segment (2, 2a) is connected to at least two further band-segments (7a-7e) in such a way that the combined further band-segments (7a-7e) overlap with at least 95% of the total length (L) of the linked band-segment (2, 2a). The magnet coil generates particularly high magnetic fields in a sample volume and has a low drift.

Abstract: A semi-finished wire (1) for a Nb3Sn superconducting wire (45) has a multiplicity of elements containing Nb packed against each other (6). The elements containing Nb (6) each have a rod containing Nb (7) and an enclosure containing Cu (8) surrounding the latter. The semi-finished wire also has a structure containing Sn (5) and a matrix containing Cu (4) in which the structure containing Sn (5) is disposed and on and/or in which the elements containing Nb (6) are disposed. The enclosures containing Cu (8) of the elements containing Nb (6), contain Sn. The semi-finished wire is suitable for manufacturing an Nb3Sn superconducting wire with which further improved superconducting current-carrying capacity is achieved.

Abstract: An inductive fault current limiter (1) has a normally conducting primary coil assembly (2) with a multiplicity of turns (3) and a superconducting, short-circuited secondary coil assembly (4), wherein the primary coil assembly (2) and the secondary coil assembly (4) are at least substantially coaxial with respect to each other and at least partially interleaved in each other. The primary coil assembly (2) has a first coil section (2a) and a second coil section (2b), wherein the turns (3) of the first coil section (2a) of the primary coil assembly (2) are disposed radially inside the secondary coil assembly (4) and the turns (3) of the second coil section (2b) of the primary coil assembly (2) are disposed radially outside the secondary coil assembly (4). The fault current limiter has an increased inductance ratio.

Abstract: A superconducting structure (1) has a plurality of linked band-segments (2), with each linked band-segment (2) having a substrate (3) and a superconducting layer deposited onto it (4). The linked band-segments (2) are joined to one another by superconducting layers (4) that face each other. Each linked band-segment (2) is joined to two additional band-segments (7a, 7b) in such a way that the superconducting layers (4) of the two additional band-segments (7a, 7b) and of the linked band-segment (2) face each other. The additional band-segments (7a, 7b) together substantially overlap the total length (L) of the linked band-segment (2). This provides for a superconducting structure, which exhibits high superconductivity and which is very suitable for long distances.

Abstract: An inductive fault current limiter (1), has a normally conducting primary coil assembly (2) with a multiplicity of turns (3), and a superconducting, short-circuited secondary coil assembly (4). The primary coil assembly (2) and the secondary coil assembly (4) are disposed at least substantially coaxially with respect to each other and at least partially interleaved in each other. The secondary coil assembly (4) has a first coil section (4a) disposed radially inside the turns (3) of the primary coil assembly (2) and a second coil section (4b) disposed radially outside the turns (3) of the primary coil assembly (2). The fault current limiter has an increased inductance ratio.

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: An inductive fault current limiter (1), has a normally conducting primary coil assembly (2) with a multiplicity of turns (3), and a superconducting, short-circuited secondary coil assembly (4). The primary coil assembly (2) and the secondary coil assembly (4) are disposed at least substantially coaxially with respect to each other and at least partially interleaved in each other. The secondary coil assembly (4) has a first coil section (4a) disposed radially inside the turns (3) of the primary coil assembly (2) and a second coil section (4b) disposed radially outside the turns (3) of the primary coil assembly (2). The fault current limiter has an increased inductance ratio.