Abstract:
A tape-type superconductor (1), comprising an elongated substrate (2), in particular a metal tape, and a continuous superconducting layer (3), in particular of a HTS type material, deposited on the substrate (2), is characterized in that Ic∥/Ic⊥≧1.5, with Ic∥ being the width density of critical current of the continuous superconducting layer (3) in parallel to the substrate (2) and in parallel to the elongated direction of the substrate (2), and with Ic⊥ being the width density of critical current of the continuous superconducting layer (3) in parallel to the substrate (2) and perpendicular to the elongated direction of the substrate (2). The tape-type superconductor has reduced ac losses.
Abstract:
A tape-type superconductor (1), comprising an elongated substrate (2), in particular a metal tape, and a continuous superconducting layer (3), in particular of a HTS type material, deposited on the substrate (2), is characterized in that Ic∥/Ic⊥≧1.5, with Ic∥ being the width density of critical current of the continuous superconducting layer (3) in parallel to the substrate (2) and in parallel to the elongated direction of the substrate (2), and with Ic⊥ being the width density of critical current of the continuous superconducting layer (3) in parallel to the substrate (2) and perpendicular to the elongated direction of the substrate (2). The tape-type superconductor has reduced ac losses.
Abstract:
A high temperature superconductor (=HTS) coated conductor (1), comprising an HTS layer (11) deposited epitaxially on a substrate (2), wherein the HTS layer (11) exhibits a lattice with a specific crystal axis being oriented perpendicular to the substrate plane (SP), in particular wherein the HTS layer material is of ReBCO type and the c-axis (c) is oriented perpendicular to the substrate plane (SP), wherein the HIS layer (11) comprises particle inclusions (4), in particular wherein the particle inclusions (4) may be used to introduce pinning of magnetic flux, is characterized in that at least a part (4a) of the particle inclusions (4) are formed of the same material as the HTS layer (11), and/or of chemical fractions of the material of the HTS layer (11), such that the average stoichiometry of said part (4a) of the particle inclusions (4) corresponds to the stoichiometry of the HTS layer (11), and that the particle inclusions of said part (4a) are discontinuities of the lattice of the HTS layer (11). A more simple method for producing a HTS coated conductor with reduced losses, and with improved critical current and critical magnetic field is thereby provided.
Abstract:
A method for producing a high temperature superconductor (=HTS) coated conductor (12), wherein a buffer layer (2; 22) and an HTS layer (4; 24; 65) are deposited on a substrate (1; 21), with the following steps: a) after depositing the buffer layer (2; 22), the surface (2a) is locally roughened, resulting in a roughened surface (13), b) a non-superconducting, closed intermediate layer (3; 23) is deposited on top of the roughened surface (13), c) and the HTS layer (4; 24; 65) is deposited on top of the intermediate layer (3; 23). A simple method for producing a HTS coated conductor with reduced losses, and with improved critical current and critical magnetic field is thereby provided.
Abstract:
A method for producing a high temperature superconductor (=HTS) coated conductor (12), wherein a buffer layer (2; 22) and an HTS layer (4; 24; 65) are deposited on a substrate (1; 21), with the following steps: a) after depositing the buffer layer (2; 22), the surface (2a) is locally roughened, resulting in a roughened surface (13), b) a non-superconducting, closed intermediate layer (3; 23) is deposited on top of the roughened surface (13), c) and the HTS layer (4; 24; 65) is deposited on top of the intermediate layer (3; 23). A simple method for producing a HTS coated conductor with reduced losses, and with improved critical current and critical magnetic field is thereby provided.
Abstract:
A high temperature superconductor (=HTS) coated conductor (1), comprising an HTS layer (11) deposited epitaxially on a substrate (2), wherein the HTS layer (11) exhibits a lattice with a specific crystal axis being oriented perpendicular to the substrate plane (SP), in particular wherein the HTS layer material is of ReBCO type and the c-axis (c) is oriented perpendicular to the substrate plane (SP), wherein the HIS layer (11) comprises particle inclusions (4),in particular wherein the particle inclusions (4) may be used to introduce pinning of magnetic flux, is characterized in that at least a part (4a) of the particle inclusions (4) are formed of the same material as the HTS layer (11), and/or of chemical fractions of the material of the HTS layer (11), such that the average stoichiometry of said part (4a) of the particle inclusions (4) corresponds to the stoichiometry of the HTS layer (11), and that the particle inclusions of said part (4a) are discontinuities of the lattice of the HTS layer (11). A more simple method for producing a HTS coated conductor with reduced losses, and with improved critical current and critical magnetic field is thereby provided.
Abstract:
A cryostat (1) with a magnet coil system including superconductors for the production of a magnet field B0 in a measuring volume (3) has a plurality of radially nested solenoid-shaped coil sections (4, 5, 6) and which are electrically connected in series, at least one of which being an LTS section (5, 6) with a conventional low temperature superconductor (LTS) and at least one of which being an HTS section (4) including a high temperature superconductor (HTS), wherein the magnet coil system is located in a helium tank (9) of the cryostat (1) along with liquid helium at a helium temperature TL. The apparatus is characterized in that a chamber (11) is provided within which the HTS sections (4) are held having an internal portion with a sufficiently low pressure such that helium located therein at a temperature of TL is gaseous. The cryostat in accordance with the invention can be utilized to maintain HTS coil sections over a long period of time in a reliable fashion.
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 magnetic resonance apparatus comprising a superconducting magnet coil disposed in a cryostat, and a refrigerator for cooling same comprising a compressor (1) for compressing a working gas, and a high-pressure line (2) and a low-pressure line (3) disposed between the compressor (1) and a control valve (5), which periodically connects the high-pressure line (2) and the low-pressure line (3) to at least one connecting line (6) between the control valve (5) and a cold head (4) of the refrigerator, thereby producing pressure pulses through the switched working gas, wherein the control valve (5) and/or connecting line (6) and cold head (4) components are rigidly mechanically coupled to the cryostat, is characterized in that at least one of the above-mentioned lines (2, 3, 6) is branched on the compressor side upstream of the rigidly coupled components, and is symmetrically joined at one of the coupled components in such a manner that the pressure pulses through the working gas are vectorially compensated for at the component where the branched line is joined, thereby minimizing vibrations of the cryostat. The inventive magnetic resonance apparatus greatly reduces transmission of oscillations to the magnet coil and thereby the number and strength of artefacts in the spectra or images acquired with this magnetic resonance apparatus, to ensure high-quality magnetic resonance recordings.
Abstract:
A superconducting magnet coil configuration has at least one section containing a superconducting strip conductor which is wound in several layers like a solenoid in a cylindrical winding chamber (1) between two end flanges (2, 3), characterized in that the radially innermost layers of the section consist of metallic low-temperature superconductors (LTS) (LTS layers (8)) and radially adjacent layers of the section are formed from high-temperature superconductor (HTS) material (HTS layers (9)). The invention proposes a magnet coil configuration using HTS material which has a notch structure for correcting inhomogeneities and homogenizing a compact high-field magnet, wherein the mechanical load on the HTS strip conductor is minimized.