917results about "Superconductor devices" patented technology

The invention discloses a method for improving deformation uniformity of a core wire of an NbTi superconducting wire, and belongs to the technical field of superconducting wire processing. The method comprises the following steps: performing deep hole drilling on an oxygen-free copper ingot rod, then assembling, welding and extruding the oxygen-free copper ingot rod and a single-core rod to obtain a composite rod, and performing multi-pass drawing on the composite rod to obtain the NbTi superconducting wire with high performance, low loss and high N value. The Jc of the prepared NbTi superconducting wire is 2880-3120 A / mm < 2 >, the loss is 450-550 mJ / cm < 3 >, the N value is 70-95, compared with a superconducting wire prepared through a conventional process, the N value is remarkably increased, the loss is remarkably reduced, the critical current density is increased, and the NbTi superconducting wire has wide application prospects in MRI magnets.

The invention discloses a self-adaptive anti-sticking cable and a preparation method and application thereof. The self-adaptive anti-sticking cable comprises a superconducting core wire, a self-adaptive anti-sticking layer, a self-repairing insulating layer and a multifunctional outer sheath which are sequentially arranged from inside to outside. According to the scheme, the problems of debonding, breakdown, energy consumption and failure of a traditional cable in an extreme environment are comprehensively solved through gradient piezoelectric-phase change synergistic dynamic stress compensation, vertical boron nitride insulation network directional blocking, thermoelectric-super-hydrophobic multifunctional outer sheath integration and an extreme environment adaptive self-repairing system.

The invention relates to a high-temperature superconducting cable and a manufacturing process thereof, and belongs to the technical field of electric wires and cables.The cable comprises a supporting framework, a buffer layer, a three-phase superconducting composite layer, a shielding layer, a heat insulation layer and a sheath layer which are sequentially arranged from inside to outside; the heat insulation layer comprises at least two layers of corrugated pipes formed by continuous rolling and welding, and the corrugated pipes are of periodic concave-convex structures obtained by conducting continuous rolling and side seam welding on metal strips to form closed pipe bodies and then conducting embossing treatment on the closed pipe bodies. A woven reinforcing layer wrapping the peripheries of the corrugated pipes is further arranged in the heat insulation layer, and the adjacent corrugated pipes are connected through supporting pieces to form a vacuum interlayer. According to the application, the corrugated pipe formed by continuous coiling and welding is combined with the combined structure of the braided reinforcing layer and the supporting piece, so that the continuous production of the large-length high-temperature superconducting cable can be conveniently realized, and the problems of axial stress concentration and seam accumulation defects existing in a heat insulating layer of a traditional prefabricated sleeve pipe can be eliminated; and the air tightness stability of the vacuum interlayer of the large-length high-temperature superconducting cable is ensured.

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 invention belongs to the technical field of cable processing, and relates to a preparation method and application of a flexible superconducting coaxial cable outer conductor. The preparation method comprises the following steps: mixing Nb powder and Ti powder by adopting a vibrating ball mill to prepare NbTi composite powder; a substrate of laser powder bed melting equipment is preheated, the NbTi composite powder is spread on the substrate of the laser powder bed melting equipment, a melting powder layer is scanned through the laser powder bed melting technology, a three-dimensional communicated grid structure is formed through interlayer staggered scanning, finally, the NbTi net-shaped alloy pipe is placed in a strong acid solution to be soaked for a short time, redundant metal powder is removed, and the NbTi net-shaped alloy pipe is obtained. And finally, the preparation of the flexible superconducting coaxial cable outer conductor for the quantum computer is realized.

The invention relates to the technical field of electric wires and cables, and discloses an ultrahigh-conductivity electric wire and cable and a preparation method thereof. A graphene enhancement layer; a nano composite insulating material layer; an inner semi-conductive layer; a conductive copper strip shielding layer; a silver-plated copper wire woven mesh shielding layer; an intelligent monitoring and protection sheath; the method comprises the following steps: step S01, preparing a superconducting core wire strand; step S02, preparing a nano composite insulating material layer; s03, preparing a shielding layer; step S04, intelligent monitoring and protection sheath preparation; the superconducting core wire strand formed by twisting a plurality of YBCO superconducting material filaments forms a stable structure with excellent conductivity under the precise control of twisting process parameters, so that the resistance is effectively reduced, the loss in the electric energy transmission process is reduced, the electric energy transmission efficiency is improved, high-density current can be borne for stable transmission, and the service life of the cable is prolonged. And the requirement of the modern electrical engineering field on high conductivity of wires and cables is met.

The invention provides a method for preparing an iron-based superconducting material single crystal in a microgravity environment, and belongs to the field of superconducting materials. The method specifically comprises the following steps: carrying out a microgravity crystal growth experiment in a high-temperature experiment cabinet of a space station, putting a solid-phase sintered or pre-melted rod-like raw material into a furnace body, heating and melting, then slowly solidifying, and finally growing the iron-based superconducting material single crystal with large size and extremely low defect density.

To suppress reduction of an electrification performance (current value) in an end structure for a superconducting cable.SOLUTION: An end structure for a superconducting cable comprises at least a multilayer conductor 10 and an electrode part 30, and the multilayer conductor 10 is configured by laminating a plurality of superconducting wires 20, each presenting a tape shape, in a thickness direction of the superconducting wire 20. The electrode part 30 includes at least a plurality of slits 40. The multilayer conductor 10 is divided into a plurality of wire units 11, and stored in the slit 40 for each wire unit 11. When storing two superconducting wires 20 in the slit 40, it is preferable that directions of faces of the superconducting wires 20 are adjusted in such a manner that faces at the sides of a superconducting layer 23 and a stabilizing layer 24 constituting the superconducting wire 20 is brought into contact with or made close to an inner wall surface of the slit 40.SELECTED DRAWING: Figure 1

The embodiment of the invention provides a temperature monitoring optical cable and a cable assembly, and belongs to the field of optical cables. The temperature monitoring optical cable comprises a heating cable body, a heat transfer layer, at least one pressure sensing unit, a heat preservation buffer layer and a temperature sensing layer. The heat transfer layer covers the heating cable body so as to transfer heat of the heating cable body; the pressure sensing unit is arranged on the outer side of the heat transfer layer and extends in the length direction of the heating cable body; the temperature sensing layer wraps the pressure sensing unit, the temperature sensing layer is configured to apply pressure to one side of the pressure sensing unit according to temperature change, the pressure sensing unit generates a strain signal when being subjected to pressure so as to feed back the temperature of the temperature sensing layer, and the heat preservation buffer layer is used for preventing heat of the heating cable body from being transmitted to the temperature sensing layer. According to the temperature monitoring optical cable provided by the embodiment of the invention, the temperature of the environment where the superconducting cable of the cable assembly is located can be continuously monitored, and the working temperature monitoring precision of the superconducting cable is improved.

Provided herein are methods and systems used with a repairable stellarator, including maintaining magnetic coils, such as HTS tape coils, and allowing for deconstruction and reconstruction of one or more components of the repairable stellarator. Further provided herein are methods and systems for a stellarator system which integrates a modular sacrificial coil set.

The invention discloses a preparation method of a multi-core Nb3Sn composite wire and the composite wire. The method comprises the following steps: loading an Nb rod into an oxygen-free copper pipe to obtain a CuNb single-core rod; the CuNb single-core rods and the hexagonal copper core rods are sequentially arranged in a CuMn alloy pipe at intervals to obtain a multi-core CuNb composite sheath, and then the multi-core CuNb composite sheath is machined into a CuNb composite rod; the CuNb composite rod is machined into a CuNb composite pipe; the SnTi alloy bar is loaded into the CuNb composite tube to obtain a sub-component; a hexagonal CuMn subcomponent is obtained through machining; the hexagonal CuMn subcomponent and the SnCu alloy bar are assembled into a Ta tube and then integrally assembled into an oxygen-free copper tube to obtain a composite wire, and the composite wire is processed to obtain the Nb3Sn superconducting wire. CuNb single core rods on the outermost layer are adjusted to be in discontinuous close arrangement, the problem that machining cracking is prone to occurring in the subcomponent preparation stage due to the fact that Cu on the outer portions of the single core rods is little is solved, the deformation consistency of the wire in the composite wire machining stage is further enhanced by using the CuMn alloy on the outer portions of the subcomponents, it is also guaranteed that the wire cannot crack when stretched, and the service life of the wire is prolonged. The fan-shaped SnCu alloy bars are additionally arranged, so that sufficient Sn is ensured when the wire Nb generates Nb3Sn.

The invention discloses a dynamic load adjustment-liquid nitrogen cold storage integrated high-temperature superconducting power grid capacity expansion system and method. The system comprises a data preprocessing system, a dynamic load adjustment device, a liquid nitrogen cold storage device, a state monitoring device, a high-temperature superconducting cable capacity expansion device and a communication coordination system. The method comprises the steps of generating a standardized feature matrix through normalization processing; multi-time-scale load prediction is realized through an LSTM (Long Short-Term Memory) network, a collaborative instruction set is generated by adopting an optimal scheduling engine of mixed integer linear programming, and adaptive closed-loop control based on a fuzzy PID (Proportion Integration Differentiation) algorithm is realized; a multi-physics field coupling optimization model of a real-time cold energy distribution diagram is adopted to realize power grid capacity improvement; and the time sequence consistency of the whole system is coordinated and circulation is formed. Zero-resistance power transmission is realized in a liquid nitrogen temperature region by adopting the high-temperature superconducting cable, the loss is reduced to 0.5% or below, and the transmission capacity is improved by 3-5 times; the load demand is predicted in combination with the AI algorithm, and the renewable energy consumption rate is increased to 95%.

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 relates to the field of superconducting wire forming methods, in particular to a Nb3Sn superconducting wire preparation method based on multi-core wire liquid nitrogen cold drawing, and the Nb3Sn superconducting wire preparation method based on multi-core wire liquid nitrogen cold drawing comprises the following steps: preparing ultrahigh-tin-content copper-tin alloy powder by adopting a gas atomization method; the oxygen-free copper pipe, the oxygen-free copper rod and the pure niobium rod are machined, and the oxygen-free copper pipe and an oxygen-free copper bolt plug are obtained; acid pickling, cleaning and drying are carried out; uniformly fixing the pure niobium rods in the oxygen-free copper pipe to form a combined blank; performing rotary swaging to a required size, and then continuously drawing to obtain a finished wire; carrying out pulse treatment, and then carrying out air cooling to room temperature; and finally obtaining the Nb3Sn superconducting wire. According to the method, the strength and plasticity of the oxygen-free copper pipe sheath are improved through a liquid nitrogen cold drawing method, the combined blank is subjected to subzero treatment in the rotary swaging and drawing process, the plasticity of the combined blank is improved, and the high-strength and high-plasticity Ni3Sn superconducting wire can be obtained.

The invention belongs to the technical field of superconducting cables, and discloses a superconducting cable, a preparation method and a preparation device.The preparation method of the superconducting cable comprises the steps that a core wire, X superconducting wires and Y carbon fibers are prepared, the X superconducting wires and the Y carbon fibers are used for being woven on the surface of the core wire, and Y is smaller than or equal to X; spirally winding a hot melt adhesive film on the surfaces of the Y carbon fibers; the core wire, the superconducting wires and the carbon fibers are woven in a heating environment, and the X superconducting wires and the Y carbon fibers wound with the hot melt adhesive films are woven on the surface of the core wire under the heating condition; cooling the heated and braided superconducting cable through conveying; and after cooling, wrapping an insulating layer outside the superconducting braid layer formed by the superconducting wires and the carbon fibers. In conclusion, the superconducting braid layer of the superconducting cable is formed by mixing and weaving the superconducting wires and the carbon fibers, and the hot melt adhesive film is spirally wound on the surfaces of the carbon fibers, so that the core wires, the superconducting wires and the carbon fibers are bonded with one another after weaving, and the structural strength of the whole cable is improved.

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.

The invention relates to the technical field of superconducting material processing, in particular to a preparation method of an Nb3Sn superconducting wire. The method mainly comprises the steps that Nb-Zr alloy is loaded into the exterior and / or the center of a Sn-Cu single-core rod, oxide powder is filled between the Nb-Zr alloy and the Sn-Cu single-core rod, then the Sn-Cu single-core rod and the Nb-Zr alloy are loaded into a copper substrate, and Nb3Sn subcomponents are obtained after multi-pass stretching, forming and fixed-length cutting; and uniformly arranging the Nb3Sn sub-components in the copper pipe along the circumferential direction to form a bundle, and after multi-pass stretching, carrying out heat treatment and cutting to obtain the Nb3Sn superconducting wire. By introducing the artificial point pinning array in density gradient distribution, the critical current density of the Nb3Sn superconducting wire in a high magnetic field of 8T-16T is enhanced, the problems that an existing uniform artificial point pinning center scheme generates a matching effect and limits the actual application of the superconducting wire are solved, and the decline degree of the critical current density of the Nb3Sn superconducting wire in the high field is relieved.

A multi-objective optimization method for structural parameters of a superconducting cable, comprising steps of: S1, obtaining structural parameters and performance parameters of the superconducting cable, setting a constraint range of the structural parameters of the superconducting cable, based on the structural parameters and performance parameters of the superconducting cable, constructing an objective function, to establish a multi-objective optimization model of the structural parameters of the superconducting cable; and S2, through an improved multi-objective grey wolf optimization algorithm, iteratively solving the multi-objective optimization model of the structural parameters of the superconducting cable, to obtain an optimal solution for each of the structural parameters of the superconducting cable; where, to an iteration coefficient in a multi-objective grey wolf optimization algorithm, a weight coefficient negatively correlated with an overall sensitivity index of each of the structural parameters of the superconducting cable is given, to obtain the improved multi-objective grey wolf optimization algorithm.

The utility model provides a high-temperature superconducting cable and a high-temperature superconducting magnet. The high-temperature superconducting cable comprises a metal coating layer and a plurality of superconducting sub-cables arranged in an array. The superconducting sub-cable comprises a superconducting conductor extending in the cable extending direction and a heat conduction layer wrapping the periphery of the superconducting conductor, and the periphery of the superconducting conductor is tightly attached to the inner wall of the heat conduction layer. A first attaching part and a first gap part are arranged between the outer walls of the heat conduction layers of the adjacent parts of any two adjacent superconducting sub-cables, and a second attaching part and a second gap part are arranged between the inner wall of the metal coating layer and the outer wall of the heat conduction layer of the closest superconducting sub-cable. The first gap portion and the second gap portion each form at least one cooling channel. The current of the quenched superconducting sub-cable can be shunted to the heat conduction layer of the adjacent superconducting sub-cable through the heat conduction layer, and the heat conduction layer can exchange heat with the cooling liquid of the cooling channel, so that the temperature of the superconducting sub-cable can be quickly reduced to a superconducting interval, and the cable can be prevented from being burnt down due to quenching.

The invention relates to the field of superconducting Tokamak devices, and discloses a support structure of a correction field superconducting coil and a superconducting Tokamak device with the same, the support structure comprises a first support assembly, the first support assembly is arranged on a longitudinal field coil and is used for supporting an upper arc section of the correction field superconducting coil; the second supporting assembly is fixed to the ground supporting structure of the longitudinal field coil and used for supporting the lower arc-shaped section of the correction field superconducting coil; the vertical supporting assembly is located between the first supporting assembly and the second supporting assembly in the vertical direction and used for fixing the two vertical extending sections in the two sets of adjacent correction field superconducting coils; the cooling assembly comprises a first cooling part used for exchanging heat with the first supporting assembly and a second cooling part used for exchanging heat with the second supporting assembly. Therefore, the overall heat balance of the superconducting Tokamak device can be realized, and the position precision and the working efficiency of the superconducting coil in the correction field can be effectively improved.

The invention relates to the technical field of cable preparation, in particular to a superconducting semi-rigid cable made of high-purity aluminum and a preparation method thereof.The method comprises the steps that the high-purity aluminum is adopted as an inner conductor, and the inner conductor is preprocessed; coating the surface of the pretreated inner conductor with a PTFE mixture by using a pushing machine at normal temperature to obtain a normal-temperature pushing core wire; the qualified normal-temperature pushing core wire is wound on a cable reel and then placed in a vacuum high-temperature furnace to be subjected to vacuum sintering so as to obtain an inner conductor wrapped with an insulating layer; and the inner conductor wrapped with the insulating layer penetrates into the processed pure aluminum outer conductor tube, and the outer conductor is wrapped with PTFE to form an outer protective sleeve. According to the invention, the performance stability of the superconducting semi-rigid cable preparation can be improved.

The invention discloses a preparation method of a superconducting composite long wire. The preparation method comprises the following steps: smelting Cu, Mn and a copper alloy to obtain a Cu-Mn-(Cr / Fe / Zr / Ag / Ti) alloy pipe; an Nb cylinder and an NbTi rod are placed in the alloy pipe to be manufactured into a single core rod; combining the single-core rod and an oxygen-free copper rod in an oxygen-free copper pipe to obtain a secondary composite rod; combining the secondary composite rod and an oxygen-free copper rod in an oxygen-free copper pipe to obtain a third composite rod; and carrying out drawing treatment on the tertiary composite rod to obtain a tertiary superconducting composite wire. The alloy resistive matrix is obtained in an alloying mode, the long-line machining capacity of the copper-manganese-based niobium-titanium superconducting wire is improved under the condition that critical current density and alternating-current loss are not reduced, the oxidation resistance of a single-core rod is obviously improved, the thickness of an oxide layer after hot extrusion is obviously reduced, the scaling frequency is effectively reduced in the machining process, and the service life of the single-core rod is prolonged. The deformation uniformity of the superconducting core wire can be effectively improved, so that the critical current density is improved, and the efficiency and cost can be improved.

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.

A method for manufacturing a semiconductor structure and a semiconductor structure are provided. The manufacturing method includes the following operations. A substrate is provided, and a first groove and a second groove are formed in the substrate, each of the first groove and the second groove having a depth in a first direction. The first groove includes multiple first sub-grooves arranged in the first direction, the second groove includes multiple second sub-grooves arranged in the first direction, and sidewalls of the first sub-grooves and sidewalls of the second sub-grooves are convex outwards. Word lines protruding away from the first groove each are formed at an interface of adjacent first sub-grooves. First source-drain layers formed on the sidewalls of the first sub-grooves, and second source-drain layers protruding away from the second groove each are formed at an interface of adjacent second sub-grooves.

The utility model provides a superconducting cable assembly, a superconductor transmission line and a star simulator. The superconducting cable assembly comprises a superconducting cable and a connector, the superconducting cable comprises a cable body part and a cable connecting part, and the cable connecting part is arranged in the connector in a penetrating mode in the axial direction of the connector; the connector comprises a clamping assembly, the clamping assembly comprises a sleeve and a pressing block, the sleeve comprises a first clamping block and a second clamping block which are oppositely arranged in the circumferential direction of the sleeve and fixed to each other, a cavity is defined by the first clamping block and the second clamping block, the pressing block is arranged in the cavity in the axial direction of the sleeve, and a through hole for a cable connecting part to penetrate through is formed between the pressing block and the second clamping block; the axial direction of the sleeve is parallel to that of the joint; the first clamping block locks and fixes the pressing block through the locking structure so that the pressing block can be connected to the periphery of the cable connecting part in a pressed mode in the radial direction of the sleeve, the position, relative to the locking and fixing position of the first clamping block, of the pressing block in the radial direction of the sleeve can be adjusted, and the hole diameter of the through hole can be adjusted. The superconducting cable assembly has better adaptability and maintainability.

A system includes a cable passing from a first plate to a second plate via an intermediate plate, an attachment coupling the cable to the intermediate plate, and a conductive cladding connected to an outer surface of the cable and extended a first length from the attachment toward the second plate. The total length of the thermally conductive cladding is larger than the total length of the attachment, and the cable is thermally connected to the first plate, the second plate, and the intermediate plate.

To provide a superconducting wire capable of realizing a high residual resistance ratio (RRR) and a high strength, and also a superconducting coil using the superconducting wire.SOLUTION: A superconducting wire 10 includes a superconductor 11 and a superconductivity stabilization material 20. The superconductivity stabilization material 20 includes an inner copper material 21 and an outer copper material 22 including a copper material with a Cu content of 99.9 mass% or more. One or more kinds of elements selected from Ca, Sr, Ba, and a rare-earth element are added to the inner copper material 21, and Mg is added to the outer copper material 22. A KAM value A of the inner copper material 21 is 1.0 or less. A ratio B / A is 1.5 or more with regard to the KAM value A of the inner copper material 21 and a KAM value B of the outer copper material 22.SELECTED DRAWING: Figure 1

To provide a superconducting wire having improved anti-fatigue characteristic.SOLUTION: A superconducting wire includes a substrate, a superconducting layer, and a stabilization layer, where the stabilization layer includes a rolled copper foil, and the rolled copper foil includes recrystallized grains.SELECTED DRAWING: None

Disclosed in the present application are a preparation method for a bronze-process Nb3Sn superconducting wire, and a superconducting wire. The preparation method comprises: placing a bronze rod into an Nb tube, placing the Nb tube into a bronze tube, and performing rotary swaging, drawing and annealing to prepare a bronze / Nb single core rod; bundling up hundreds of bronze / Nb single core rods in a hexagonal close-packed manner and then coating same with a barrier layer, and then placing the bronze / Nb single core rods into a copper tube to form a final billet; and heating the final billet and then sequentially performing extruding, drawing and intermediate annealing thereon, so as to obtain a bronze-process Nb3Sn superconducting wire having ring-shaped core filaments. By means of the present application, an Nb core filament changes from a solid columnar shape to a hollow tubular shape, thereby increasing the interaction area between Nb and a bronze matrix, increasing the reaction rate of Nb with Sn in the bronze matrix during a phase-formation heat treatment, and shortening the reaction time.

The invention discloses a preparation method of stable in-situ 14: 24 AEC second-phase Bi-2212 powder, which comprises the following steps: preparing powder with specific components by controlling the components of a Bi-2212 precursor solution, and then adjusting by a fine heat treatment process to obtain the stable in-situ 14: 24 AEC second-phase Bi-2212 powder. According to the method disclosed by the invention, components of a Bi-2212 precursor solution are controlled, the components of Bi-2212 precursor powder after heat treatment and the molar ratio of Sr to Ca are monitored to be within a specific range, and a heat treatment process is matched for adjustment, so that stable generation of a 14: 24 AEC second phase in the Bi-2212 precursor powder is ensured; the self-generated 14: 24 AEC second phase can improve the critical current density of the Bi-2212 superconducting material; the method is easy to operate, low in cost, high in controllability and operability and suitable for being rapidly applied to the field of Bi-2212 superconducting material preparation.