229 results about "Superconducting wire" patented technology

The invention belongs to the technical field of superconducting wires, and relates to a niobium-tin composite superconducting wire and a preparation method thereof. The invention provides a Nb3Sn composite superconducting wire. The Nb3Sn composite superconducting wire sequentially comprises an Nb3Sn superconducting wire core, a barrier layer, a stable layer, a transition layer, a substrate layer and a functional layer from inside to outside, the transition layer is formed by mixing copper and a dielectric polymer, and the copper content is continuously decreased in a gradient manner from inside to outside; the substrate layer is the dielectric polymer; the functional layer is a plurality of protruding metal microstructures. According to the invention, the functional layer with the broadband electromagnetic stealth function is integrated on the basis of the Nb3Sn superconducting wire rod, so that the radar cross section is obviously reduced while the Nb3Sn superconducting wire rod bears high-density superconducting current and generates a strong magnetic field, and the technical problem that a high-field superconducting magnet system is easy to detect in an electromagnetic environment is solved.

The present invention relates to the technical field of superconducting materials. Disclosed are a MgB2 superconducting wire and a preparation method therefor. The preparation method comprises: melting Mg, Cu and Ti to obtain a Mg alloy ingot, processing the Mg alloy ingot to obtain a Mg alloy rod, loading the Mg alloy rod and B powder into a Nb tube to obtain a composite rod, processing the composite rod to obtain a single-core wire, loading the single-core wire into an oxygen-free copper tube, then loading into a monel tube in a densely-packed manner, and performing cold-forming treatment to obtain a multi-core composite wire; and performing high-temperature phase-forming heat treatment on the multi-core composite wire to prepare the MgB2 superconducting wire. In the present application, the Mg alloy rod containing Cu and Ti metal elements is used as a Mg source for preparing a MgB2 multi-core wire, so as to improve the plastic deformation ability of the Mg alloy rod in the wire treatment processes, and improve the grain boundary coupling, thereby improving the current carrying performance of the MgB2 superconducting wire.

The invention discloses a superconducting wire performance testing device which is characterized by comprising a sample rod, a conductor critical current testing framework, a conductor mechanical performance testing framework and a Dewar. During performance testing, the sample rod and the conductor critical current testing framework are detachably connected and located in the Dewar; or the sample rod and the conductor mechanical property testing framework are detachably connected and located in the Dewar. The testing device provided by the invention can be used for both critical current testing and mechanical performance testing.

The invention belongs to the technical field of superconducting material processing, and discloses a multi-barrier-layer MgB2 superconducting wire and a preparation method thereof. A plurality of groups of interlayers of the wire are composed of Cu / Ni / Nb, outer-layer copper serves as a stabilizer, Ni serves as a low-cost outer barrier layer, Ni and the outer-layer copper are mutually diffused in the hot extrusion process to form a stable Cu-Ni compound, and Nb foil is added into the Ni layer to serve as an inner barrier layer so as to restrain the diffusion problem of a small amount of Ni-Mg. According to the multi-barrier-layer MgB2 superconducting wire, Nb is greatly replaced by Cu / Ni, the raw material cost is remarkably reduced, the barrier layers are mutually diffused in the hot extrusion process to achieve metallurgical bonding, uniform deformation of the wire in the subsequent machining process is facilitated, the possibility of damage of the barrier layers is reduced, the current-carrying performance of the wire is improved, the Jc of the multi-barrier-layer MgB2 superconducting wire under 4.2 K and 3T is 5199-6271 A / mm < 2 >, and the service life of the multi-barrier-layer MgB2 superconducting wire is prolonged. And the current-carrying performance is obviously improved, and the application prospect is wide.

An example method described herein includes operating a first component of a circuit. The method also includes, while operating the first component, supplying a current to a superconducting wire that is thermally-coupled to the first component, and determining whether the superconducting wire has transitioned between a superconducting state to a non-superconducting state in response to the current. The method further includes measuring a temperature of the first component based on whether the superconducting wire transitioned between the superconducting state to the non-superconducting state in response to the current, and adjusting operation of the first component in accordance with a determination that the temperature exceeds a predetermined threshold temperature.

The present invention provides: a MgB2 superconducting wire that has a barrier layer of highly uniform thickness covering a MgB2 core and that reduces MgB2 filament defects and is suitable for thinning and lengthening; a MgB2 superconducting wire manufacturing method for manufacturing the same; a superconducting coil using the same; and a magnetic generator including the superconducting coil. A MgB2 superconducting wire (200) comprises: a core material (210); a MgB2 filament (220) in which a MgB2 core (221) is covered with a barrier layer (222); and a metal sheath (230). The MgB2 filament (220) has a barrier layer (222) thickness on the outer peripheral side of the wire not more than three times the barrier layer (222) thickness on the core side of the wire. The method for manufacturing the MgB2 superconducting wire includes a step for forming a single core wire, a step for forming an embedded material, a surface reduction processing step, and a heat treatment step. The embedded material is formed by arranging the single core wire in a recess formed in the outer surface of the core material or by incorporating a spacer in a gap.

The invention belongs to the technical field of superconducting materials, and discloses an internal tin method Nb3Sn superconducting wire integrated with a piezoelectric sensing function and a preparation method of the internal tin method Nb3Sn superconducting wire. According to the method, a piezoelectric functional layer and a dielectric layer are prepared on the surface of a SnAl alloy rod, a CuAg alloy rod is installed after drilling to form a composite rod, the composite rod is inserted into an inner tin method Nb3Sn / CuNb composite pipe to be drawn into a subcomponent, then the subcomponent is bundled and installed into a Ta pipe and an oxygen-free copper pipe, and the wire is prepared through multiple times of stretching. The piezoelectric functional layer can convert micro strain into measurable electric signals, in-situ real-time monitoring of mechanical stress and the like in the wire rod is achieved, the CuAg alloy bar can stabilize the tensile strength of the wire rod and promote generation of an Nb3Sn phase, and on the premise that the superconducting performance is not affected, the operation reliability and safety of the high-field magnet under the extreme working condition are improved.

The invention discloses a ductile niobium-titanium alloy material, a preparation method and application of the ductile niobium-titanium alloy material to preparation of a central conductor. The ductile niobium-titanium alloy material comprises, by weight, 44.5%-47.5% of Nb, 47.0%-50.0% of Ti, 1.0%-2.0% of Zr, 0.8%-2.0% of Mo, 0.2%-0.6% of V, 0.1%-0.3% of Al, 0.05%-0.12% of Si, 0.015%-0.025% of C, smaller than or equal to 0.035% of O, smaller than or equal to 0.01% of N, smaller than or equal to 0.25% of Fe + impurities and the balance Ti. The preparation process comprises the steps of double-vacuum melting, double-stage pre-homogenization heat treatment, gradient temperature control thermal machining and double-stage aging heat treatment, a fine grain beta matrix + dispersed alpha phase + nano MC carbide synergistic strengthening structure is obtained, and 3-10% of metastable beta phase is reserved. The central conductor made of the material has longitudinal and transverse absorption energy of not less than 180 J / cm and not less than 178 J / cm at-273 DEG C, longitudinal and transverse performance difference of not more than 8%, yield strength of not less than 780 MPa, salt spray corrosion resistance of not less than 1000 hours, and no obvious corrosion, and is suitable for manufacturing the central conductor of the low-temperature superconducting wire.

The invention discloses a preparation method of Bi-2212 precursor powder capable of remarkably improving the phase density of Bi-2201 nanometer stripes in a Bi-2212 wire rod, and the Bi-2212 precursor powder capable of remarkably improving the phase density of the Bi-2201 nanometer stripes in the Bi-2212 wire rod is obtained by controlling the components of a precursor solution, adjusting in cooperation with a fine heat treatment method and controlling the molar ratio of Sr to Ca. According to the method disclosed by the invention, the components of the precursor solution are controlled, the large-size Bi-2201 phase is eliminated in combination with heat treatment, and the molar ratio of powder Sr to Ca is controlled to be within a proper range, so that the density of the nano stripe Bi-2201 phase in the Bi-2212 wire rod is improved, and the pinning performance of the Bi-2212 wire rod is favorably improved; the method is easy to operate, low in cost and high in controllability and operability, the cost performance of the Bi-2212 superconducting wire is improved, and rapid application of the Bi-2212 superconducting wire in the field of high-temperature superconducting magnets is further promoted.

A superconducting coil comprises a superconducting wire, an insulating sheet, and an adhesive resin. The insulating sheet includes a plurality of resin sheets and two semi-cured resin fiber sheets. The plurality of resin sheets have electrical insulation and are disposed in at least two layers. The two semi-cured resin fiber sheets are disposed in layers with the plurality of resin sheets disposed therebetween. The plurality of resin sheets and the two semi-cured resin fiber sheets have mutually adjacent resin and semi-cured resin fiber sheets bonded together.

The invention belongs to the technical field of superconducting material processing, and discloses a near-infrared optical response Nb3Sn superconducting wire and a preparation method thereof. The Nb3Sn superconducting wire with near-infrared optical response comprises an optical functional coating, the optical functional coating is formed by embedding periodically-arranged plasmon metal micro-nano structures into a high-transparency dielectric substrate, the plasmon metal micro-nano structures are gold nanorod arrays or silver nanoring, the dielectric substrate is made of a SiO2-polyimide composite material, and the thickness of the dielectric substrate is 10-20 micrometers. The Nb3Sn superconducting wire with the near-infrared optical response has high absorptivity and photoelectric response in the near-infrared band, in-situ optical sensing of temperature, stress and magnetic field intensity can be synchronously achieved, the interface compatibility of the optical functional coating and the Nb3Sn superconducting basic wire is good, meanwhile, the influence of the added optical functional coating on the performance of the superconducting wire is small, and the service life of the superconducting wire is prolonged. And the method has a wide application prospect in the aspect of constructing an integrated optical-electric-magnetic multifunctional device.

The present invention relates to a high-temperature superconducting magnet and, more specifically, to: a high-temperature superconducting magnet achieving uniform critical current density using dissimilar metal wire materials; and a design parameter determination method thereof. To this end, in a high-temperature superconducting (HTS) magnet (100) formed by stacking an HTS coil (50) having a tape-type HTS conductor wire material wound thereon, the HTS coil (50) comprises: a first metal wire material (110) wound on the HTS coil (50); and a second metal wire material (130) that is made of a different metal from the first metal wire material (110) and wound while at least partially overlapping the first metal wire material (110) in the longitudinal direction of the first metal wire material (110), thereby forming a composite winding portion (140). Accordingly, the HTS magnet achieving uniform critical current density using dissimilar metal wire materials is provided, wherein the uniformity of the critical current density increases on the longitudinal cross-section of the HTS magnet (100).

A superconducting coil has a superconducting wire (3), an insulating sheet (4), and an adhesive resin (5). The insulating sheet (4) includes a plurality of resin sheets and two sheets of semi-cured resin fiber sheet (7). The plurality of resin sheets have electrical insulation and are laminated with at least two or more layers. The two sheets of semi-cured resin fiber sheet (7) are laminated in a manner that the plurality of resin sheets are sandwiched between each other. In the plurality of resin sheets and the two sheets of semi-cured resin fiber sheet (7), the resin sheets and the semi-cured resin fiber sheet (7) that are adjacent to each other are engaged with each other.

The application relates to a magnetic resonance device, a superconducting shimming coil and a manufacturing method thereof. The superconducting shimming coil comprises a winding drum, the winding drum is provided with a saddle-shaped winding groove group, the winding groove group comprises a plurality of layer-by-layer sleeved winding grooves, and each winding groove is in a closed shape; and a superconducting wire is arranged in the winding groove. By fixing the superconducting wire in the winding groove of the winding drum, the winding process of the superconducting wire is simplified, the manufacturing of the superconducting shimming coil can be directly realized by fixing the superconducting wire in the winding groove, the superconducting wire does not need to be bent during winding and can be directly placed in the winding groove, the operation is convenient, the manufacturing of the superconducting shimming coil is facilitated, meanwhile, the superconducting wire can generate a uniform main magnetic field during work, the service performance of the magnetic resonance device is guaranteed, and the accuracy of an imaging result is further guaranteed.

This Nb3Sn superconducting wire precursor comprises a cylindrical stabilized copper layer, a cylindrical first Sn diffusion barrier layer provided inside the copper layer, and a superconducting element group precursor housed inside the barrier layer. The superconducting element group precursor includes a plurality of Sn-based reinforced element wires and a plurality of Nb-based superconducting element wire precursors. The reinforced element wires include a Cu or Cu-based alloy first stabilization matrix, a plurality of Sn-based filaments that are Sn or Sn-based alloys and that are embedded in the first stabilization matrix, and a plurality of reinforcement-material multi-core wires that are configured from a plurality of metal or alloy-made reinforcement filaments. The wire precursors comprise a second stabilization matrix of Cu or a Cu-based alloy, and an Nb-based superconducting filament precursor that is Nb or an Nb-based alloy and that is embedded in the second stabilization matrix.

The application provides a current lead joint structure and a welding method thereof, and the structure comprises a current lead, a fixing component, a superconducting wire and solder; the first end of the current lead is provided with a groove along the axial direction of the current lead; the fixing component is a U-shaped plate structure matched with the groove, and the fixing component is inverted in the groove to form a tubular structure with open ends; the first section of the superconducting wire is a superconducting bare wire with a wrapping layer removed, and the second section is a superconducting bus with a wrapping layer not removed; the superconducting bare wire is arranged in the tubular structure, and the superconducting bus is arranged outside the tubular structure; the solder is laid in the tubular structure and completely immerses the superconducting bare wire; the superconducting bare wire, the first end of the current lead and the solder are fused into one by heating and cooling the solder, so as to realize the welding of the superconducting wire and the current lead. The application can solve the technical problems of the current lead joint structure in the prior art, such as large welding point contact resistance, local hot spot hidden danger and difficult disassembly.

The invention belongs to the field of superconducting materials, and particularly relates to a method for preparing an iron-based superconducting wire strip, which comprises the following steps of: a) filling precursor powder of an iron-based superconductor into a first metal sheath to prepare a superconducting wire, and cutting to obtain a superconducting section material; b) preparing a metal raw material consistent with the material of the first metal sheath, preparing a metal wire, and cutting to obtain a metal section material; c) loading the superconducting section materials and the metal section materials into a second metal sheath, wherein the superconducting section materials and the metal section materials are alternately arranged in the second metal sheath; d) performing length extension on the material prepared in the step c) to obtain a wire strip; e) the wire strip is cut, the cutting position is the area, filled with the metal section material, of the wire strip, and wire strip sections are obtained; and f) welding and sealing the end surfaces of the wire strip sections, and then carrying out heat treatment to obtain the iron-based superconducting wire strip. According to the method, a segmented tubing mode is adopted, so that the error-tolerant rate of product preparation can be greatly improved, and meanwhile, various wire strip products can be efficiently prepared.

The invention discloses a preparation method of a high-stability bronze-process niobium-tin wire, and relates to the technical field of superconducting wire preparation, and the preparation method comprises the following steps: assembling a composite ingot according to a composite structure which sequentially comprises an outer copper matrix, an outer barrier layer, a bronze-based CuNb layer, an inner barrier layer and an inner copper matrix from outside to inside; the composite ingot is sequentially subjected to heat preservation extrusion and multi-pass cold drawing, and a composite wire is obtained; carrying out heat treatment on the composite wire to obtain a Ni3Sn wire; the outer blocking layer and the inner blocking layer are made of Nb or Ta or Nb alloy or Ta alloy or Ta / Nb alternating composite layers. The Ni3Sn wire is prepared by designing a composite structure with double barrier layers and combining heat preservation extrusion, multi-pass cold drawing and heat treatment, the critical current density and the residual resistance ratio of the wire are increased, and then the stability of the wire is improved.

The invention discloses an on-line testing method for the twisting pitch of a superconducting wire rod. The method comprises the following steps of: before the superconducting wire rod is twisted, performing straight line marking at the end of the superconducting wire rod in a color marking form; twisting, stretching and shaping the marked superconducting wire rod to obtain a marked finished superconducting wire rod; cutting the marked part in the finished superconducting wire to obtain a synchronously stretched and shaped marked superconducting wire; performing fixed-point division on a plurality of positions at two ends and in the middle of the marked superconducting wire and measuring the length of the marked superconducting wire corresponding to one twisting period; and averaging the lengths of the marked superconducting wire rod corresponding to all the twisting periods measured on the marked superconducting wire rod to obtain the twisting pitch of the end of the superconducting wire rod. According to the invention, the twisting pitch is directly measured by marking on the surface of the wire rod before twisting, so that the sample corrosion process is avoided, the testing efficiency is improved, and the environmental protection and the protection of the personal safety of operators are realized.

Provided are a method and an apparatus for plating a superconducting wire rod, the method and apparatus making it possible to form a plating layer while suppressing the dog bone effect on the surface of a superconducting wire rod by electroplating, through a method different from a conventional method. Provided is a method for plating a superconducting wire rod, the method including forming a copper plating layer 11 by performing electroplating on the surface of a tape-shaped superconducting wire rod 10 that includes a superconductor layer, wherein the electroplating is performed in a state in which a plurality of superconducting wire rods 10 are arranged in parallel at intervals from each other on the same plane 50.

The invention provides a composite insulating layer of a light superconducting cable and a preparation method and application of the composite insulating layer. The composite insulating layer is prepared from the following raw materials in parts by weight: 40-60 parts of fusible polytetrafluoroethylene, 30-50 parts of fluorinated ethylene propylene, 0.5-5 parts of an auxiliary agent, 1-5 parts of filler and 0.1-0.6 part of a nucleating agent. The composite insulating layer of the light superconducting cable has relatively high tensile strength, relatively low dielectric constant and dielectric loss factor, good mechanical property and high insulating strength; compared with the prior art, the composite insulation layer has the advantages of low average cell diameter and high cell density, which indicates that a uniform and fine cell structure is formed in the composite insulation layer, the overall density of the material can be effectively reduced, the insulation layer is light, and the composite insulation layer can be applied to preparation of light superconducting cables for medical equipment and realizes integrity and low loss of high-frequency signal transmission.

The invention discloses a method for introducing a magnetic flux pinning center into a Bi2212 superconducting wire. The method comprises the following steps: 1, mixing strontium carbonate, calcium carbonate, copper and an M compound, and then mixing with nitric acid to react; 2, performing spray pyrolysis to obtain doped second-phase raw powder, and mixing the doped second-phase raw powder with Bi2212 powder; 3, carrying out one-step heat treatment to obtain Bi2212 phase forming powder containing a doped second phase; 4, tubing and drawing to obtain a multi-core Bi2212 wire rod; and 5, heat treatment. Nano-scale doping elements are dispersed on the surface of a micro-nano-scale hollow microspherical alkaline earth cuprate carrier and then introduced into a Bi2212 wire, so that AEC participates in a reaction in the recrystallization process to generate Bi2212 crystal grains, a nano-scale second phase is carried to enter the Bi2212 crystal grains, the second phase is prevented from appearing at a crystal boundary and abnormally growing, a magnetic flux pinning center is effectively introduced, and the magnetic flux pinning efficiency is improved. The current-carrying performance of the Bi2212 superconducting wire in a magnetic field is improved, and the Bi2212 superconducting wire is suitable for the field of superconducting wires.

The invention belongs to the technical field of superconducting material processing, and discloses a magic angle graphene modified niobium-tin superconducting wire and a preparation method thereof. The magic angle graphene is modified on the surface of the core wire of the Nb3Sn superconducting wire prepared by the bronze method, the material can eliminate work hardening of a bronze matrix, and one-time and uninterrupted continuous stretching forming from a composite billet to the final wire is realized. In addition, the Nb3Sn superconducting wire has excellent mechanical performance, superconducting performance and strain tolerance, the magic angle graphene layer can effectively inhibit crack initiation and expansion of the Nb3Sn reaction layer under strain, and the mechanical performance of the wire is improved; the material not only can be used as an additional magnetic flux pinning center, but also can induce formation of finer Nb3Sn grains with tough grain boundaries, so that the critical current density of the wire is remarkably improved; the critical current irreversible strain limit of the Ni3Sn superconducting wire modified by the magic angle graphene is 0.8% and is obviously higher than that of a Ni3Sn superconducting wire prepared by a traditional bronze method.

This invention belongs to the field of superconducting materials technology and discloses an internal tin-based Nb3Sn superconducting wire with integrated piezoelectric sensing function and its preparation method. The method involves preparing a piezoelectric functional layer and a dielectric layer on the surface of a SnAl alloy rod, drilling a hole, inserting a CuAg alloy rod to form a composite rod, inserting it into an internal tin-based Nb3Sn / CuNb composite tube, drawing it into sub-components, and then bundling them into a Ta tube and an oxygen-free copper tube. The wire is then obtained through multiple stretching operations. The piezoelectric functional layer can convert minute strains into measurable electrical signals, enabling in-situ real-time monitoring of internal mechanical stresses within the wire. The CuAg alloy rod can stabilize the tensile strength of the wire and promote the formation of the Nb3Sn phase, improving the operational reliability and safety of high-field magnets under extreme conditions without affecting superconducting performance.

This invention discloses a seven-degree-of-freedom intelligent winding system and method for superconducting magnets suitable for complex irregularly shaped coil frames. The system includes a main frame, a six-axis collaborative robotic arm, a seventh-axis servo cylinder, an integrated multi-functional end effector, a superconducting wire feeding and pre-processing unit, a coil frame positioning and installation unit, and a central integrated control system. The working radius of the six-axis collaborative robotic arm covers the entire space of the small-sized magnet winding station. The seventh-axis servo cylinder works in conjunction with the six-axis collaborative robotic arm to achieve follow-up motion, completing the coil winding work for large-sized magnets. The central integrated control system is based on an industrial PC and a real-time Ethernet bus, integrating a robot control system, motion control card, and tension controller. This invention, through its pioneering seven-axis linkage integrated automatic winding process, reduces the manufacturing cost of irregularly shaped magnets, meets the high-efficiency manufacturing requirements of ultra-large-scale coils, and features a high degree of automation, significantly improving the winding quality and yield of superconducting coils.

An apparatus for continuously measuring the thickness of a thin material includes a main frame configured by upper and lower frames provided in a direction crossing with a movement direction of a thin material and a vertical frame which connects the upper and lower frames, upper and lower sliders moved by sliding along guide grooves formed in the upper and lower frames; an upper confocal sensor radiating light toward the thin material, and a lower confocal sensor radiating light toward the thin material, wherein the upper and lower confocal sensors are disposed on the same axis, and height measurement is performed by receiving light only at a moment when a focus coincides at a measurement position, and wherein the upper confocal sensor and the upper slider and the lower confocal sensor and the lower slider are synchronously controlled, and are controlled in conjunction with movement of the thin material.

Provided are: an enamel-coated superconducting wire material having an insulating layer of an enamel layer formed using a polyimide resin, wherein the insulating layer can be easily peeled off by chemical peeling; and a method for using the enamel-coated superconducting wire material.　Provided are: an enamel-coated superconducting wire material comprising a superconducting wire 2 and an insulating layer 3 covering the outer circumference of the superconducting wire 2, wherein the insulating layer 3 is an enamel layer formed using a polyimide resin, and the imidization degree of the insulating layer 3 is 45% to 92%; and a method for using the enamel-coated superconducting wire material.

The present invention relates to the technical field of superconducting electrical power, and specifically provides a high-temperature superconducting coil and a heat sink assembly for the high-temperature superconducting coil. The high-temperature superconducting coil comprises a superconducting wire turn, and the superconducting wire turn comprises one or more groups arranged along a radial direction of the high-temperature superconducting coil. The heat sink assembly comprises at least one heat sink, the heat sink comprising a heat sink base body. A strip-shaped gap on the heat sink base body extends along a first direction, and a first strip-shaped part on the heat sink base body extends along a second direction. In an assembled state, the heat sink base body and at least a portion of the strip-shaped gap are located on the surface of one side, along the radial direction, of a group of superconducting wire turns, and an included angle is formed between at least a portion part of the first strip-shaped part and the surface of one side, along the radial direction, of a group of superconducting wire turns. By means of such a configuration, heat generated inside the superconducting wire turn can be guided out in a timely manner by means of a multi-directional heat conduction assembly.

Embodiments disclosed in the specification and drawings relate to a superconducting magnet device and a magnetic resonance imaging device. One of the issues to be solved by the embodiment is to efficiently cool a plurality of structures to be cooled while reducing the amount of refrigerant. A superconducting magnet device according to an embodiment includes a superconducting coil, a structure, a refrigerant tank, a heat exchanger, a refrigerator, a solid heat conductor, and a vacuum container. The superconducting coil is composed of a superconducting wire forming a magnetic field. The structure is composed of a superconductor and is electrically connected to the superconducting coil. The refrigerant tank stores a refrigerant. The heat exchanger is exposed to the inside of the refrigerant tank. And the refrigerating machine is used for cooling the refrigerant. The solid heat conductor connects the refrigerant tank with the superconducting coil and the structure directly or indirectly in a heat-conducting manner. The superconducting coil or the structure is configured using at least two structures having different operating temperatures or superconducting characteristics as superconductors.