223 results about "Critical current" patented technology

The invention discloses a state evaluation and fault early warning method and system based on superconducting current limiter modeling, an electromagnetic heat multi-physical field coupling model of a superconducting current limiter is constructed based on finite element software, and the method comprises the following steps: constructing a three-dimensional geometric structure of a solenoid-shaped superconducting current limiter, and setting a peripheral electromagnetic environment boundary; establishing an electromagnetic field control equation based on a Maxwell equation set and the nonlinear resistivity characteristic of the superconducting material, and coupling a solid heat transfer control equation to form a multi-physical field interaction model; optimizing grid division to balance calculation precision and solving efficiency; body parameters of the superconducting current limiter including the initial critical current Ic0 and the critical temperature Tc and working condition parameters including the environment temperature and the transmission current It are input, the parameters are dynamically adjusted according to the actual operation scene, and the voltage U at the two ends during normal operation is calculated through a model; by collecting voltage measured values Up at the two ends of the superconducting current limiter during actual operation in real time, whether the voltage measured values Up exceed a threshold value set according to the voltage U or not is judged, and an early warning mechanism is triggered.

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.

A Floquet mode traveling wave parametric amplifier (TWPA) is disclosed. The Floquet mode TWPA comprises a plurality of stages, where each stage is made up of a nonlinear element and a shunt capacitor. The nonlinear elements may be Josephson junctions, or a combination of series and / or parallel Josephson junctions. The Floquet mode TWPA is designed such that the critical current of the nonlinear elements in each stage is not constant. In some embodiments, the ratio of the largest critical current to the smallest critical current in the Floquet mode TWPA is at least 2:1. In some embodiments, the nonlinear elements with the largest critical current are disposed at or near the input or output of the amplifier. In this way, reflections and backward amplification may be minimized. Further, the TWPA is formed using planar capacitors on a high resistivity substrate, or using low loss parallel plate capacitors.

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.

The invention relates to a superconducting electrical switch. The switch comprises two parallel branches of superconducting material in a loop, and a magnetic field generator which generates a time-varying magnetic field through the loop in a direction generally parallel to the axis of the loop. The magnetic field generator is selectively activated and de-activated to switch the electrical switch between a low-resistance state and a higher-resistance state. In the low-resistance state, there is no magnetic field through the loop and transport current flows through the loop. In the higher-resistance state, a magnetic field through the loop induces a screening current such that the sum of the transport current and the screening current is substantially equal to the critical current or is greater than the critical current of the superconducting material. The switch may be used in, for example, a rectifier or fault current limiter.

To provide a precursor for MgB2 superconducting wire having a homogeneous MgB2 sintered body and capable of obtaining a MgB2 superconducting wire capable of achieving a high critical current density, a MgB2 superconducting wire, a producing method thereof, a superconducting magnet, and a superconducting device.SOLUTION: According to one aspect of the present invention, a precursor for MgB2 superconducting wire 10 is provided, comprising a metal sheath 11, a magnesium rod 12 located within the metal sheath 11, and a mixed powder 13 located within the metal sheath 11 and filled in contact with a magnesium rod 12, which includes at least boron powder and MgB2 powder, where a molar fraction of MgB2 powder with respect to a total of boron powder and MgB2 powder is greater than 0% and less than 30%.SELECTED DRAWING: Figure 1

The invention belongs to the field of superconducting material measurement, and discloses a sample rod for testing the anisotropy of a critical current of a superconducting strip. The sample rod comprises a mechanical transmission device, a sample mounting platform, a Hall sensor and an electric signal transmission device, the mechanical transmission device comprises a worm and worm wheel transmission set, a straight gear set and a transmission shaft, and the transmission shaft is vertically connected between a worm wheel and the straight gear set. The sample mounting platform comprises a sample table and a copper current terminal, the sample table is arranged in the middle of the copper current terminal, and the copper current terminal is fixedly connected with the straight gear set; the Hall sensor is arranged on the back of the sample table and electrically connected with the electric signal transmission device. According to the invention, the sample mounting platform is driven to complete continuous rotation based on a dual transmission mechanism of the worm and worm gear transmission group and the straight gear group, and meanwhile, the Hall sensor is combined to realize critical current measurement of the superconducting tape under low-temperature, large-current, different-size and angle magnetic fields.

The invention discloses a method for reducing critical current density in SOT driving magnetization overturning, and relates to the technical field of spintronics, and the method comprises the following steps: building a structure model of a magnetic film which is of a double-layer structure, symmetrically arranging two defect areas on the magnetic layer along the x-axis direction, the physical parameter value of the defect area is smaller than that of the magnetic layer; the junction of the magnetic layer and the defect region is a domain wall; the structure model is subjected to micro-magnetic simulation, a magnetic domain and domain wall evolution process is obtained, the critical current density in SOT driving magnetization overturning is determined based on the evolution process, the critical current density is the minimum current density for driving domain wall movement, and the maximum current density is the minimum current density for driving domain wall movement. And the SOT effective field generated by the critical current density is the minimum SOT effective field required for unpinning the domain wall from the defect area. The method can be compatible with the existing micro-nano electronic process and material system.

The invention discloses a critical current nondestructive testing device for a joint-free high-temperature superconducting tape. The critical current nondestructive testing device comprises a testing tape reel, a fixing plate, a testing tape reel motor rotating shaft, an air heater, a tension sensor, a wire guide wheel, a magnetizing device, a double-hole Hall sensor, a liquid nitrogen Dewar and the joint-free high-temperature superconducting tape. The test tape reel is used for placing the joint-free high-temperature superconducting tape; the testing tape reel motor rotating shaft is used for connecting the motor and the testing tape reel, and the air heater is used for blow-drying the tape to prevent the surface of the superconducting tape from freezing. The tension sensor is used for carrying out real-time and on-line monitoring on the tension applied to the superconducting tape. The wire guide wheel is of a bearing supporting structure and comprises a built-in deep groove ball bearing or sliding bearing. And the magnetizing device is used for magnetizing the high-temperature superconducting tape. The double-hole Hall sensor can detect magnetic field distribution on the surface of the magnetized strip. The double-hole Hall sensor is provided with a double-hole structure, and the slit strip is detected through the wire passing double holes.

The invention relates to the technical field of electric variable data compensation, in particular to a metering error dynamic compensation method and system of an intelligent measuring switch. The method comprises the following steps: calculating to obtain phase delay compensation time of each sampling point based on original instantaneous current of each sampling point, equivalent excitation inductance of a current transformer, internal resistance of a secondary side winding, resistance value of a sampling resistor and a magnetic circuit saturation critical current value; performing high-order correction on the original instantaneous current to obtain a real current value of the sampling point; based on the original instantaneous voltage, the real current value and the phase delay compensation time of the sampling point in the metering period, the active power of the metering period is calculated so as to realize metering error dynamic compensation, and the accuracy of active power calculation of the intelligent measurement switch in the dynamic load switching process can be effectively improved.

The invention discloses a magnetic electronic device for generating track torque by using a metal vanadium or titanium track Hall effect and a manufacturing method thereof. The device comprises a substrate, a track Hall structure containing a vanadium or titanium layer, and a heavy metal layer and a ferromagnetic layer which are adjacent to the track Hall structure, when a charge current passes through the vanadium or titanium layer, a transverse track current is generated based on the track Hall effect, and the track current is injected into the ferromagnetic layer and then converted into an effective track torque for controlling the magnetization state of the ferromagnetic layer. Preferably, the ferromagnetic layer has a perpendicular magnetic anisotropy. According to the invention, the light transition metal vanadium or titanium is used as the track Hall material, the experiment proves that a huge track Hall angle greater than 0.45 can be obtained, and meanwhile, the resistivity of the material is lower, so that the shunting phenomenon can be reduced in an actual device, and the critical current density for realizing write-in flipping can be obviously reduced. The device is simple in structure and compatible with an existing semiconductor process, and a brand new material platform is provided for developing a low-power-consumption and high-density magnetic random access memory (MRAM).

The invention relates to the technical field of superconducting tape performance evaluation, and discloses a method for evaluating the influence of epoxy resin impregnation on the performance of a superconducting tape, which comprises the following steps: carrying out critical current test on a superconducting tape body; completely immersing the superconducting tape body into epoxy resin, and curing the epoxy resin on the surface of the superconducting tape body; cooling the superconducting tape with the epoxy resin to a temperature below a critical temperature, carrying out a critical current test on the superconducting tape with the epoxy resin, and rewarming the superconducting tape with the epoxy resin to a room temperature after the critical current test is completed; and corroding the stable layer on the surface of the superconducting tape to expose the superconducting layer of the superconducting tape, and carrying out electron microscope observation on the superconducting layer. Critical currents of a superconducting tape body before and after epoxy resin impregnation and curing are compared and analyzed to represent the performance degradation amplitude, and the surface morphology of a superconducting layer is observed through an electron microscope, so that the surface morphology of the superconducting layer corresponds to the degradation amplitude of the superconducting tape body in a quantified manner.

The invention discloses a grid-control superconducting nanowire low-temperature thermometer and a preparation method thereof, and relates to the technical field of superconducting electronics and low-temperature detection. Comprising a substrate and a superconducting layer, and the superconducting layer comprises a grid electrode, a superconducting nanowire and an inductor; the grid electrode is vertical to the superconductive nanowire, has a distance from the superconductive nanowire and is used for electric field regulation and control; the superconducting nanowire is connected with the inductor and is used for responding to particles injected into the grid electrode and outputting a pulse signal; the inductor is connected with the superconducting nanowire and is used for inhibiting a latch-up effect under high bias current; the superconducting layer material is a superconducting thin film material with a superconducting transition temperature Tc exceeding a measurement temperature zone; according to the invention, (quasi) particle injection in the critical current process of the superconducting nanowire is regulated and controlled through the grid electric field, high-precision measurement of the low temperature is realized in combination with nonlinear response of the pulse counting rate and the temperature, and the device and the method have the advantages of wide temperature zone measurement, low noise, high sensitivity, low power consumption, small self-heating, simple measurement system and low cost.

The invention provides a magnetic superconducting memory and a preparation method and a read-write method thereof. According to the magnetic superconducting memory, the superconducting layer maps the magnetization state by using the resistance difference between the superconducting state and the normal state; the ferromagnetic layer serves as a free layer capable of adjusting magnetization, and the magnitude of superconductive critical current of the superconductive layer is influenced through the magnetization direction. The heavy metal layer generates spin orbit torque through a spin Hall effect to drive the ferromagnetic layer to be magnetized and overturned; an infinite switching ratio between a superconducting state and a normal state is realized through a superconducting diode magnetoresistance effect, a high-efficiency and high-reliability nonvolatile storage scheme is realized in combination with a current-driven spin-orbit torque magnetization overturning technology, inherent defects of a traditional TMR are thoroughly overcome, and the signal contrast of a storage unit is remarkably improved; the heterostructure designed by the invention replaces a traditional magnetic tunnel junction, reduces material stacking and process complexity, and adopts a material compatible with a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) process to promote large-scale integration of the low-temperature memory.

The invention discloses a high-temperature superconducting strip with non-uniform distribution of critical current density and a preparation method thereof, and belongs to the technical field of high-temperature superconducting materials. The critical current density of the high-temperature superconducting strip is non-uniformly distributed in the width direction, the current distribution of the high-temperature superconducting strip can be regulated and controlled according to requirements, the high-temperature superconducting strip comprises a high-temperature superconducting layer, the chemical formula of the high-temperature superconducting layer is Re < 1 + a > Ba < 2 + b > Cu < 3 + c > O < 7-d + x% (mol) BaMO3, and Re is selected from Y, Gd, Eu and Sm; m is selected from Hf, Zr and Sn; the preparation method comprises the following steps: depositing the high-temperature superconducting layer on the strip substrate; depositing a metal silver layer on the deposited strip; and carrying out heat treatment on the deposited strip in an oxygen environment, and carrying out laser heat treatment after slitting and / or copper plating. The critical current density of the high-temperature superconducting strip in the width direction is non-uniformly distributed and controllable, the failure risk of the strip is effectively reduced, and the service performance of the strip is improved.

The invention discloses a high-temperature superconducting current lead structure and a preparation method thereof, and relates to the field of high-temperature superconducting material preparation, and the high-temperature superconducting current lead structure comprises a magnetic material tube and a high-temperature superconducting section wrapped in the magnetic material tube; the high-temperature superconducting section comprises a first high-temperature superconducting stack and a second high-temperature superconducting stack, and the first high-temperature superconducting stack and the second high-temperature superconducting stack are arranged in the length direction of the magnetic material tube and are formed by stacking a plurality of high-temperature superconducting strips; the partition plate is used for separating the first high-temperature superconducting stack and the second high-temperature superconducting stack; and one end of the copper plate is simultaneously connected with the same-direction end parts of the first high-temperature superconducting stack and the second high-temperature superconducting stack. By adopting the scheme, an external magnetic field is shielded through the magnetic material tube, and the two high-temperature superconducting strip stacks are separated from the middle through the partition plate, so that the magnetic coupling effect between the two high-temperature superconducting strip stacks is reduced, the critical current of the high-temperature superconducting strip stacks in the self-field is increased, and the test stability and reliability are improved.

The invention belongs to the field of superconducting material measurement, and discloses an external field critical current test sample rod under axial strain of a superconducting tape, which comprises a mechanical transmission device, a worm vertical to a left-right rotation trapezoidal screw rod, and a worm gear connected with the middle part of the left-right rotation trapezoidal screw rod through an optical axis key; the axial strain loading platform and the nut seat are respectively screwed into a left thread part and a right thread part of the left-handed and right-handed trapezoidal screw rod, the sample holder is supported and fixed through convex parts at two sides of the nut seat, the copper current terminals are respectively fixed at two ends of a platform part of the sample holder, and the strain gauge is used for being fixed on a middle shaft in the middle of a superconducting tape to be tested; and the electric signal transmission device is electrically connected with the strain gauge. According to the invention, the left-handed and right-handed trapezoidal screw rods are driven to rotate, so that the pair of nut seats with opposite threads are linearly opened and closed, the superconducting tape to be measured on the sample holder tape welding platform is driven to generate axial strain, and the critical current of the superconducting tape under the axial strain in a background magnetic field is measured.

The invention belongs to the field of superconducting magnets, and particularly discloses a superconducting magnet quenching protection method and device, and the method comprises the steps: applying an alternating magnetic field with a preset amplitude and a preset frequency to a superconducting magnet when the superconducting magnet is quenched, enabling the energy loss of the superconducting magnet to be increased, enabling the critical current to be reduced, and / or enabling the temperature to be increased, the overall quench propagation of the superconducting magnet is accelerated, and quench protection of the superconducting magnet is achieved; and the component of the alternating magnetic field acting in the radial direction of the superconducting magnet is relatively large. According to the invention, the method can achieve the propagation of a normal conduction region after quenching with high efficiency in the quenching protection of the superconducting magnet, and is higher in reliability of quenching protection.

The invention discloses a superconductive contact and a preparation method thereof, and belongs to the technical field of superconductive contact processing. Raw materials of the superconducting electrical contact are composed of Nb powder, Ti powder and TiB2 powder, the mass ratio of the Nb powder to the Ti powder to the TiB2 powder in the raw materials is 50-55: 40-45: 4-5, the TiB2 powder is added into the raw materials, the fusion welding resistance of NbTi alloy can be enhanced, and it is tested that fusion welding does not happen to the superconducting electrical contact prepared through the method in 20000 electric contact tests. The invention provides an electrical contact material for the superconducting field. The electrical contact material has a high critical current value and excellent fusion welding resistance.

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).

The invention provides a multi-longitudinal-mode fiber laser weak current detection method based on a magnetic rotation sensitive material, and the method comprises the following steps: building a multi-longitudinal-mode fiber laser weak current detection system; a relationship between the magnetic field intensity and the current in the DC coil; determining the relationship between the intra-cavity loss and the Faraday rotation angle of the multi-longitudinal-mode fiber laser resonant cavity within the magnetic field range which does not reach the magnetic saturation intensity of the magneto-optical material; calculating a current value when the magnetic field reaches the magnetic saturation intensity value of the magneto-optical material; when the to-be-measured current value on the coil is between 0 and the critical current, calculating the to-be-measured current value; the magneto-optical sensor is arranged in the multi-longitudinal-mode fiber laser resonant cavity, and the corresponding relation between light intensity change and weak current is constructed through the matching relation between the magneto-optical sensor and the multi-longitudinal-mode fiber laser resonant cavity, so that small current change which is difficult to measure by a traditional sensor can be detected, and high-sensitivity measurement is realized.

The application discloses a method for improving critical current of REBCO superconducting layer and relates to the technical field of superconducting materials.The method for improving critical current of REBCO superconducting layer comprises the following steps: REBCO superconducting tapes are annealed in a pure oxygen atmosphere, quenched to 20-25 DEG C, and then the surface silver layer is removed by a chemical method, after which the REBCO superconducting tapes are annealed in a mixed atmosphere of ozone and oxygen, and a protective layer is deposited, so that the critical current of the REBCO superconducting layer is finally improved.The carrier concentration of the REBCO superconducting tapes can be effectively controlled through the specific multi-step oxidation process, so that the REBCO superconducting tapes break through the under-doped state commonly existing in the prior art, reach the over-doped level, and then the critical current performance of the tapes is significantly improved.The method has simple process, high stability and high industrial feasibility, and can meet the demand of higher current-carrying capacity of REBCO tapes in key fields such as power transmission and high-field magnets.

The invention provides a double-refrigeration device applied to high-temperature superconducting magnetic fluid propulsion, and relates to the technical field of high-temperature superconducting magnet cooling, the device comprises a magnet Dewar, a magnet liquid nitrogen cylinder, a fixing assembly and a conduction refrigeration system; the magnet liquid nitrogen cylinder is located in the magnet Dewar, one end of the fixing assembly is fixed to the side portion of the magnet liquid nitrogen cylinder, and the other end of the fixing assembly is fixed to the magnet Dewar; dewar protrusions are arranged on the circumferential side wall of the magnet Dewar, and the conduction refrigeration system is installed on the Dewar protrusions and exchanges heat with the superconducting magnet coil in the magnet liquid nitrogen cylinder. The superconducting magnet coil is also provided with a wiring port. The dual-refrigeration device provided by the invention breaks through the dilemma that the critical current cannot be tested after packaging, the liquid nitrogen cooling unit can independently, quickly and uniformly cool the packaged magnet, and the detachable sealing wiring port is arranged, so that the performance verification after packaging is realized, and the quality blind area is eliminated.

The invention discloses a superconducting tape axial strain critical current testing device and a manufacturing method thereof. The manufacturing method comprises the following steps: uniformly smearing soldering tin on a sample area and two outer side surfaces of a skeleton, the surface of a test sample and the surfaces of two current leads; placing a test sample in a sample area of the skeleton, placing two current leads on two outer side surfaces of the skeleton respectively, and enabling the two current leads to be in contact with two ends of the test sample respectively; providing a clamp I to fix the test sample on the framework, and providing a clamp II to fix the two current leads on the framework to obtain a semi-finished product; and heating and cooling the semi-finished product to obtain the axial strain critical current testing device for the superconducting tape. According to the manufacturing method of the axial strain critical current testing device for the superconducting tape, the problem that when a traditional welding method is used, the transmission performance of the superconducting tape is reduced due to the fact that the heating time is too long or the heating temperature is too high can be solved.

The invention discloses a CORC-CICC high-temperature superconducting conductor stability evaluation method and a related device. The method comprises the following steps: acquiring structural information of a CORC-CICC high-temperature superconducting conductor; according to the structural information of the CORC-CICC high-temperature superconducting conductor, determining the shunting temperature, the critical current, the minimum quenching energy and the quenching propagation speed of the CORC-CICC high-temperature superconducting conductor; and evaluating the stability of the CORC-CICC high-temperature superconducting conductor according to the shunting temperature, the critical current, the minimum quenching energy and the quenching propagation velocity of the CORC-CICC high-temperature superconducting conductor, and the method and the related device can evaluate the stability of the CORC-CICC high-temperature superconducting conductor.

The invention discloses a wire structure for improving the mechanical property and critical current density of a Bi-2212 wire, the wire structure is characterized in that a silver core is introduced into the Bi-2212 wire to obtain the Bi-2212 wire with the silver core, in addition, the invention also discloses a preparation method of the wire structure, and the preparation method comprises the following steps: 1, putting the silver core and Bi-2212 powder into a silver tube to obtain an initial wire; and 2, drawing the initial wire rod to obtain the Bi-2212 wire rod with the silver core. By introducing the silver core, based on the change of the wire structure, the original cylindrical core wire is changed into the annular core wire structure in which the silver core is inserted, the core wire is directly refined from the inherent structure of the core wire, the mechanical property of the wire is improved, the core wire is refined, the texture is improved, then the critical current density is improved, operation is easy, cost is low, and the method is suitable for industrial production. And controllability and operability are high, and rapid application in Bi-2212 wire rods is facilitated.

The present disclosure provides a method of charge sensing in a quantum system. The method includes supplying a bias current through a Josephson junction. The bias current is less than a first value of a critical current of the Josephson junction. The method further includes measuring an output voltage of the Josephson junction. Responsive to a change in charge of one or more charge islands coupled to the Josephson junction, the critical current is reduced to a second value less than the bias current, causing a voltage drop across the Josephson junction.

The invention discloses a non-contact continuous nondestructive testing device and method for critical current uniformity of a high-temperature superconducting tape, which is applied to the field of superconducting material detection, and comprises an excitation magnet for generating a background magnetic field and exciting the high-temperature superconducting tape to generate magnetization current; the measuring probe consists of a magnetic circuit iron core, a fluxgate sensor and a copper strip compensation loop; the fluxgate sensor and the copper strip compensation loop are respectively connected with the control and measurement circuit through a fluxgate power supply acquisition circuit and a copper strip compensation loop power supply circuit; and the control and measurement circuit is used for implementing PID (Proportion Integration Differentiation) control through closed-loop negative feedback when the fluxgate sensor detects that the net residual magnetic flux in the magnetic circuit iron core is not zero, generating magnetic flux which is equal to and opposite to the high-temperature superconducting strip in size in the copper strip compensation loop, and calculating critical current according to current in the copper strip compensation loop when the net residual magnetic flux is zero. According to the method, rapid and accurate measurement of the critical current uniformity of the high-temperature superconducting strip without depending on a Hall sensor and calibration back calculation is realized.

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 a superconducting material critical electrical characteristic prediction method and device and a medium, and relates to the field of material analysis, and the method comprises the steps: obtaining the actual working condition parameters and actual category labels of a to-be-predicted superconducting material; the actual working condition parameters comprise actual temperature, actual magnetic field intensity and actual magnetic field angle; performing prediction by utilizing a trained neural network according to the actual working condition parameters and the actual category labels to obtain critical electrical characteristics of the superconducting material; the critical electrical characteristics comprise critical current density and an n value; the trained neural network comprises an input layer, an embedded layer, a feature splicing layer, a hidden layer and an output layer which are connected in sequence; and the input layer is also connected with the feature splicing layer. According to the method, the electrical characteristics of the superconducting material can be efficiently and accurately predicted.