A method of manufacturing a superconducting products

 

(57) Abstract:

The invention relates to the field of electrical engineering and can be used in the manufacture of the superconducting magnetic system for generating a stationary magnetic field. According to the invention in the manufacture of products form a helical spiral based on the composition of the superconductor and metal with normal conductivity, insulate the turns of the helix from each other, and then bond, and the superconductor and the metal with normal conductivity are in the form of layers having a width generally equal to the width of the spiral, and have on one another. First form a layer with normal conductivity and put on him a superconducting layer. The superconducting layer provide the relative anisotropy of the pinning force, the maximum of which is directed orthogonal to the surface of the coil, and insulating the turns of the spiral is produced by forming on the surface of the oxide dielectric film. In the composition as the material of the superconducting layer using niobium or connection stunned niobium with the a-15 structure, and the material layer with normal conductivity using stainless steel, and one or more Metalicy the result is to increase the dynamic stability of superconducting products to the jumps of the magnetic flux, what contributes to the stable operation of the product at a higher power level, reducing the time for thermal shock, reduction of hysteresis losses and increase the efficiency of the superconducting material at its minimum flow. In addition, simplifies the manufacturing process of the product. 16 C.p. f-crystals.

The invention relates to the field of cryogenic engineering and can be used in the manufacture of the superconducting magnetic system for generating a stationary magnetic fields, including tokamaks, inductive energy storage devices, particle accelerators, generators with superconducting winding, MHD generators, MRI and other products.

In the superconducting windings of the industrial magnetic systems under the action of ponderomotive forces arise high mechanical stress. Due to the axial components of the magnetic field in the coils of the winding are large tensile forces, but due to the radial components - axial compressive efforts, which can reach hundreds and thousands of pounds on stage, in connection with which a superconducting product must have a high mechanical strength, especially its current-carrying parts and between the appropriate insulation materials have lower mechanical strength compared with superconductors and metals with normal conductivity, a large temperature coefficient of expansion-compression, less resistant to low temperatures. On the other hand, given the high cost of superconducting materials is of great importance to decrease their consumption, which requires a more complete use of the current-carrying capacity of the superconductor in different fields. In addition, for large-scale magnets becomes a significant problem of dynamic stability to the jumps of the magnetic flux and reduce hysteresis losses in transient modes, and output energy of the superconducting winding at its transition into the normal state. This requires lowering the inductance of the winding and to increase the working current, using work items larger cross-section, which limited the available technical means. Superconducting materials with high critical characteristics type of intermetallic compounds with a crystalline structure a-15, chalcogenides and high temperature ceramic oxides are brittle materials, making it difficult to fabricate winding wires. In many cases, these difficulties almost insurmountable.

A known method of manufacture of sverkhprovodyashchuyu and metal with normal conductivity. The spiral form of a set of annular superconducting foils and foils with normal conductivity, having a radial slot and arranged one on the other, the surface of the superconducting foil except for the portion adjacent to the radial slits are provided with an insulating coating. Bare land adjacent to the slits of one foil, placed on a non-insulated area adjacent to the slits of the other neighboring foil, solder these sites to each other. In this article, the current is distributed in exact accordance with the magnetic field optimally filling the winding.

The disadvantage of this method is the large number of radial superconductor junctions between the coils. In this regard, the product does not possess sufficient mechanical rigidity and is not able to withstand a tensile load generated by the axial components of the magnetic field. In addition, a large number of junctions reduces the dynamic resistance to the jumps of the magnetic flux and leads to a large hysteresis losses in transient conditions, as well as premature transition of products from the superconducting to the normal state. Use as a superconductor such HgI magnets large size is a very difficult technical problem. An additional disadvantage of this method is that when you isolate the coils from each other cannot be fixed insulating layer on the superconductor.

There is also known a method of manufacturing a superconducting products (see Ed. mon. USSR N 1325587, IPC4H 01 F 41/06, 1987), including the formation of a continuous helical spiral flat coils based on the composition of the superconductor and metal with normal conductivity by simultaneous feeding of multiple coaxial cables, the inner part of which consists of a superconductor, and the outer part is made of metal with normal conductivity, they are wound in the same plane with continuous longitudinal external connection parts between them, for example by soldering, and isolate the coils. Made in this way, the product has greater compared to foil magnets rigidity, because of the tensile forces of revolution due to the axial components of the magnetic field and mechanical bending moments are perceived all flat round.

The disadvantage of this method is the high inductance due to the multitude of coaxial wires constituting the spiral turn, as well as a large level of the hysteresis losses and rigaut speed limit input current and, accordingly, increase the time of feeding. Furthermore, the method is characterized by low efficiency of the superconducting material and complexity of manufacture of the product by reason of the mounting of individual strands of superconductor and an insulating layer in the plane of the loop.

The present invention is the goal of improving the dynamic stability of superconducting products to the jumps of the magnetic flux, reducing hysteresis losses and the efficiency of the superconducting material at its minimum flow. In addition, the invention solves the problem of simplifying the manufacturing process of the product, while forming a helical spiral, and when the insulating coils, and also improves the quality and effectiveness of insulating the layer.

The problem is solved in that in the method of manufacturing a superconducting products, including the formation of helical spirals based on the composition of the superconductor and metal with normal conductivity, insulating the turns of the helix from each other and bond turns, according to the invention the superconductor and the metal with normal conductivity are in the form of layers having a width generally equal to the width of the spiral, and have Oh, this superconducting layer provide the relative anisotropy of the pinning force, the maximum of which is directed orthogonal to the surface of the coil, and insulating the turns of the spiral is produced by forming an oxide dielectric film on the surface of the coils. Under pinning force see force Fpthat causes engagement (pinning) vortex magnetic field in the superconductor, preventing their movement, and thereby eliminates the ohmic resistance and the release of Joule heat in the superconducting material during the passage through it of an electric current. Power of pinning Fpoperates on a vortex filament in the opposite direction with respect to the Lorentz force and is associated with a critical current density of Icin the superconductor by the equation IcB = Fp, where B is the magnetic induction. Based on this equation, the relative anisotropy of the pinning force is characterized by the coefficient of anisotropy k, is equal to the ratio of critical current density in a parallel and perpendicular orientation to the plane of the superconducting layer relative to the vector of magnetic induction B, and the maximum pinning force is determined by the maximum critical current density.

Fasting is Obi.

The task contributes to the fact that in the composition as the material of the superconducting layer is used as a compound of stunned niobium with the structure a-15, representing intermetallide with the chemical formula Nb3Sn.

The problem is solved and the fact that the composition of the material layer with normal conductivity using stainless steel.

The task is helped by the fact that in the composition as a material layer with normal conductivity using one or more metals selected from the group consisting of copper, molybdenum, tungsten, tantalum, chromium and rhenium.

The problem is solved also by the fact that in the composition as a material layer with normal use conductivity niobium.

The task contributes to the fact that niobium is applied by electrolysis of the molten salt in the atmosphere of inert gas, and the anisotropy of the relative strength of the pinning reach by providing total content of impurities in the superconducting layer, 0.05-0.50 wt.%.

The problem is solved in that the connection of stunned niobium with the structure a-15 is applied by electrolysis of the molten salt in the atmosphere is entrusted power of pinning reach by alloying caused connection tantalum, moreover, the content of tantalum in the superconducting layer is 0.3-1.5 wt.%.

The task also helps that the anisotropy of the relative strength of the pinning reach by alloying caused connection zirconium, the zirconium content in the superconducting layer is 0.1-0.5 wt.%.

The problem is solved also by the fact that the anisotropy of the relative strength of the pinning reach by alloying caused connection copper, and the copper content in the superconducting layer is 3-10 wt.%.

The task is helped by the fact that the anisotropy of the relative strength of the pinning reach by alloying of the applied compounds of carbon, and the carbon content in the superconducting layer is 0.06-0.24 wt.%.

The problem is solved also by the fact that the anisotropy of the relative strength of the pinning reach by alloying of the applied compounds with nitrogen, and the nitrogen content in the superconducting layer is between 0.07 to 0.21 wt.%.

The task contributes to the fact that the connection of stunned niobium with the structure a-15 contains phase Nb6Sn5and/or NbSn2when this compound is applied during the through phase Nb6Sn5and/or NbSn2.

The task is helped by the fact that as the inert gas used argon, helium and their mixtures.

The problem is solved and the fact that the composition is formed from multiple superconducting layers and multiple layers of normal conductivity.

The task also helps that as an insulating oxide dielectric film on the surface of the coils form an amorphous film of Nb2O5thickness of 0.05 to 5.0 μm.

The implementation of the superconductor and metal with normal conductivity in the form of layers having a width generally equal to the width of the spiral, increases the rigidity of the coil necessary to withstand great tension generated in the coil axial magnetic field component, and reduces the inductance of a coil and thus contributes to reducing hysteresis losses. In this line, forming the surface of the helical spiral, can be direct with the formation of superconducting products in the form of a helix or a curve with constant or variable radii of curvature and signs of curvature, and spatial axis helical spiral mo the t of several sublayers. It should be noted that when using the device as inductive energy accumulator stored energy more than a few megajoules, it is the strength of metal with the normal conductivity limits the current density, since it is proportional to the voltage acceptable to the metal with normal conductivity. However, solid materials have a large electric resistance. In this regard, of practical importance is the composition of the superconductor and metal with normal conductivity, in which the latter would combine high strength and high conductivity. Such a layer can be created on the basis of two or more metals with normal conductivity with high strength and electrical conductivity, such as copper and steel, copper and tungsten, copper and molybdenum, tungsten and rhenium, chromium and tungsten, etc. And the best layer with normal conductivity is a layer consisting of copper and steel, because along with the high conductivity of copper is characterized by high plasticity and viscosity up to temperatures close to absolute zero, in the field of cryogenic temperatures, the copper does not show any signs of fragile bit is sposobstvuet increase dynamic stability of the product to the occurrence of jumps of the magnetic flux.

The formation of the first layer with normal conductivity and causing him superconducting layer simplifies the process of manufacturing a product, because when forming composition layer with normal conductivity may be subjected to various mechanical influences (rolling, drawing, bending, and so on) and there is no danger of destruction or damage is usually brittle layer of superconductor, which creates a magnetic field in the coils of the product.

Providing a superconducting layer anisotropy relative to the pinning force maximum force in the direction orthogonal to the surface of the turn, promotes more effective use of superconducting material, since the direction of the magnetic field created by the product, is always an angle close to 90ofor any arbitrary surface of revolution.

Insulating the turns of the spiral formation of the oxide dielectric film on the surface of the coils makes it easier to run an insulating layer between the coils.

The use of niobium as the material of the superconducting layer in the composition contributes to the dynamic stability of the product to the jumps of the magnetic flux and reduce tamago layer compositions of the compounds stunned niobium with the a-15 structure contributes to the dynamic stability of the product to the jumps of the magnetic flux in the stationary high intensity fields.

The use of stainless steel as a material layer with normal conductivity in the composition of thermally and electrically stabilizes the superconducting layer that helps to counter the ponderomotive forces that occur when exposed to a magnetic field, and thereby increases the dynamic stability of the product to the jumps of the magnetic flux. Used steel HT, HN, 12H18N10T, 08KH18N10T, HN or 12H18N9, as they have low sensitivity to brittle fracture at low temperatures, high strength and technological processing.

Use as a material layer with normal conductivity of the composition of one or more metals selected from the group consisting of copper, molybdenum, tungsten, tantalum, chromium and rhenium, are also thermally and electrically stabilizes the superconducting layer and contributes to its anti ponderomotive forces arising from the effect on the superconducting layer of a magnetic field and thereby contribute to the dynamic stability of the product to the jumps of the magnetic flux.

The execution of the composition layer with normal conductivity of niobium promotes better damping a superconducting layer, because of niobid niobium with the a-15 structure. The result of the above-mentioned damping is to increase the stability of the product to the jumps of the magnetic flux.

The application of superconducting niobium layer by electrolysis of the molten salt in the atmosphere of inert gas with a total impurity content of 0.05-0.50 wt.% ensure growth of the columnar structure grains emitting impurities at the boundaries, which contributes to the anisotropy of the relative strength of the pinning its maximum in the direction orthogonal to the surface of the coil and thereby enhances the efficiency of the use of superconducting material by minimizing consumption. When the impurity content of less than 0.05 wt.%, niobium is similar in its properties to the superconductor of the first kind and does not provide for the passage of the product high critical currents. When the impurity content of more than 0.50 wt. % decreases sharply critical temperature of the superconducting layer, resulting in reduced dynamic stability of the product to the jumps of the magnetic flux.

Drawing connections stunned niobium with the structure a-15 by electrolysis of the molten salt in the atmosphere containing an inert gas, contributes to the efficiency of the superconducting material.

Content is dogonline surface of revolution, and thereby enhances the efficiency of the use of superconducting material by minimizing consumption. When the concentration of tantalum less than 0.3 wt.% the number of precipitates at grain boundaries is not sufficient to create effective pinning centers in the superconductor. The increase in the content of tantalum is more than 1.5 wt.% leads to a significant departure from stoichiometry on the tin phase a-15, which, in turn, leads to the degradation of the critical temperature and the critical current of the superconducting layer.

The zirconium content in the superconducting layer in an amount of 0.1-0.5 wt.% provides maximum pinning force in the direction orthogonal to the surface of the coil, and thereby enhances the efficiency of the use of superconducting material by minimizing consumption. When the concentration of zirconium is less than 0.1 wt. % the impact on the superconducting characteristics is negligible. The increase in the content of zirconium in the superconducting layer is more than 0.5. % changes the relative anisotropy of the pinning force and its maximum occurs in the direction parallel to the surface of revolution.

The copper content in the superconducting layer in an amount of 3-10 wt.% contributes to its more obstet increase dynamic stability of the product to the jumps of the magnetic flux, and also provides the maximum pinning force in the direction orthogonal to the surface of the coil, and thereby enhances the efficiency of the use of superconducting material by minimizing consumption. When the copper content less than 3 wt.% its influence on the stabilization layer is negligible. When the copper content of more than 10 wt.% degradation of the superconducting phase a-15, a member of the superconducting layer.

The carbon content in the superconducting layer in the amount of 0.06 to 0.24 wt.% provides maximum pinning force in the direction orthogonal to the surface of the coil, and thereby enhances the efficiency of the use of superconducting material by minimizing consumption. When the concentration of carbon, less than 0.06 wt.% its influence on critical current of the windings is negligible. The increase of carbon content in the superconducting layer up to 0.24 wt.% changes the relative anisotropy of the pinning force and its maximum occurs in the direction parallel to the surface of revolution.

The nitrogen content in the superconducting layer in the amount of 0.07 to 0.21 wt.% provides maximum pinning force in the direction orthogonal to the surface of the coil, and thereby contributes to the efficiency of the S.% it has little effect on the magnitude of the critical current in the circuit. The increase of carbon content in the superconducting layer more of 0.21 wt. % changes the value of the relative anisotropy of the pinning force and its maximum occurs in the direction parallel to the surface of revolution.

The content in connection stunned niobium with the structure a-15 phase Nb6Sn5and/or NbSn2when the deposition of the superconducting layer during the transfer from the molten salt in the atmosphere of inert gas provides the relative anisotropy of the pinning force in the direction orthogonal to the surface of the coil, and thereby enhances the efficiency of the use of superconducting material by minimizing consumption.

The relative anisotropy of the pinning force in the direction orthogonal to the surface of the coil, may be provided not only by the doping, but also other methods. For the undoped compounds stunned niobium with the structure a-15 it can be achieved by using galvanostatically of the electrolysis process.

Use as the inert gas argon, helium or mixtures thereof contributes to obtaining a superconducting layer with a high critical characteristics and thereby increases the efficiency of corprew the yaschih layers and multiple layers of normal conductivity leads to an increase in the operating current of the winding, greater resistance to thermal disturbance, increase dynamic stability of superconducting products to the jumps of the magnetic flux, reduction of hysteresis losses.

Forming on the surface of coils as an insulating oxide dielectric film is an amorphous film of Nb2O5thickness of 0.05 to 5.0 μm simplifies the isolation of spiral turns, and also improves the quality and efficiency of the insulation layer. This is due to the fact that this film has a higher dielectric constant, have greater mechanical strength, is more resistant to low temperatures and cyclic temperature changes compared to insulating materials currently used to isolate the superconducting coils. In addition, the amorphous film is stable during heating of the winding in the event of an emergency transition of the superconductor to the normal state, and increasing the voltage in the coils during emergency transition turn-to-turn electrical capacity, due to the oxide film is reduced by about 10 times, contributing to the protection of products from damage. When the film thickness of Nb2O5less than 0.05 μm, the oxide layer may be SUB>5more than 5 μm worsening conditions of the cooling coil, which reduces the dynamic stability of superconducting products to the jumps of the magnetic flux.

The essence of the invention can be illustrated by the following examples of embodiment of the invention.

In General, the method of manufacturing a superconducting products implemented as follows. Sheet metal with normal conductivity in the thickness d form the basis of a helical spiral with an inner diameter D having n coils with the coil width w, with the following application on the basis of the superconducting layer. Then produce insulating the turns of the spiral through the formation of amorphous oxide dielectric film in a 0.01% solution of phosphoric acid. Then fasten the coils, mounted current leads, submerge the product in a metallic helium cryostat KG-150 and at a temperature of 4.2 To examine the stability of the superconducting state. Dynamic stability is estimated by the rate of rise field dB/dt (where In the induction magnetic field a t the time) using a low-temperature probe, which is made in the form of a non-magnetic rod mounted in the lower part of the magnetic field sensor, with. the. After testing the products in General from him cut some coils, produce from them samples of the appropriate size and conduct research. The impurity composition of the superconducting layers is determined spark mass spectrometry, phase composition was determined by x-ray diffractometer, and the structure of the cross-sections are examined by the method of metallographic analysis. Measurements of the critical current is produced by four-probe method in a superconducting solenoid, with analyzed samples have so that the current is perpendicular to the magnetic field and the surface of the superconducting layer is either parallel or perpendicular to the field. The critical current is fixed by the appearance of the sample voltage, equal to 10-6C. the relative Anisotropy of the pinning force is characterized by the coefficient of anisotropy k, is equal to the ratio of the critical currents in the parallel and perpendicular orientation to the plane of the superconducting layer relative to the magnetic field, i.e., the Critical temperature Twithmeasure the resistive method. For measurements of the upper critical field INC2connection stunned niobium with the a-15 structure at several values of the field generated by a superconducting solenoid, the ptx2">

Example 1. Formed from stainless steel AND the basis of a helical spiral, having a thickness d of 0.2 mm, inner diameter D = 20 mm, number of turns n - 120 and the width of a coil of w - 27 mm, Then at a temperature of 800oC in an atmosphere of argon in molten halides of alkali metals containing salt of niobium, cause electrolysis of the superconducting layer of a niobium thickness of 15 μm. As a soluble anode is used niobium car brand NBR-1. After deposition of the superconducting layer to form amorphous oxide layer Nb2O5thickness of 0.05 μm. Testing has shown that dynamic stability is preserved when dB/dt 1,4 10-2T/C. the Obtained niobium coating according to spark mass spectrometry had the following impurities, wt.%:Ta-310-4, Zr-110-4Fe-910-4TO-110-4, Na-110-4Li-210-4, Al-510-4, Mg-410-4,

Ni-810-4S-510-4F-510-4O-210-2N-210-4C-310-4. Other impurities total $ 2,510-2wt. %. The total content of impurities in the superconducting layer is equal to 0.05 wt.%. Studies conducted using optical and scanning electron microscopy indicate the continuity and uniformity of niobium and oxide layers. Crit is Kai density of the current Icin the field of 0.5 T, calculated on the superconducting layer 2107A/m2the coefficient of anisotropy k = 2,1. The maximum pinning force in the direction orthogonal to the surface of the coil, is provided by the total content of impurities in the superconducting layer, 0.05 wt.%.

Example 2. Form the basis of a helical spiral with parameters d - 0,5 mm, ø 75 mm, n - 70 and w - 20 mm of technical copper M1 having the chemical composition according to GOST 859-78. Then at a temperature of 700oC in an atmosphere of helium from a melt of alkali metal halides containing a salt of niobium, cause electrolysis of the superconducting layer of a niobium thickness of 25 microns. As a soluble anode is used technical niobium content of the base metal 97 wt.%. After deposition of the superconducting layer to form amorphous oxide layer Nb2O5thickness of 5.0 μm. Testing has shown that dynamic stability is preserved when dB/dt 2,4x10-2T/C. the Obtained niobium coating had a composition of impurities, similar to Example 1, except for tantalum, the content of which was 310-1wt.%. The total content of impurities in the superconducting layer is equal to 0.35 wt.%. The critical temperature Twithsostavit, designed for superconducting layer is 5 to 107A/m2the coefficient of anisotropy k = 1,9. The maximum pinning force in the direction orthogonal to the surface of the coil, is provided by the total content of impurities in the superconducting layer, equal to 0.35 wt. %.

Example 3. Form the basis of a helical spiral with parameters d - 0,3 mm D 10 mm, n - 80 and w - 15 mm as metal with normal conductivity using molybdenum. Then at a temperature of 750oC in an atmosphere of argon and helium, taken in a volumetric ratio of 1:1, from a melt of alkali metal halides containing a salt of niobium, cause electrolysis of the superconducting layer of a niobium thickness of 15 μm. As a soluble anode is used technical niobium content of the base metal 95 wt.%. After deposition of the superconducting layer to form amorphous oxide layer Nb2O5thickness of 1.0 μm. Testing has shown that dynamic stability is preserved when dB/dt 1,8 10-2T/C. the Total content of impurities in the superconducting layer is 0.5 wt.%. The critical temperature Tcwas 9.3, the value of the upper critical field Hc2(4.2 K) = 1.5 T. The critical current density of Icin the field of 0.5 T, calculated on the t, orthogonal to the surface of the coil, is provided by the total content of impurities in the superconducting layer of 0.5 wt.%.

Example 4. Form the product as in example 3. The difference lies in the fact that, as the metal with normal conductivity using tungsten. The test results of the product are the same as in Example 3.

Example 5. Form the product as in Example 3. The difference lies in the fact that, as the metal with normal conductivity using tantalum. The test results of the product are the same as in example 3.

Example 6. Form the product as in example 3. The difference lies in the fact that, as the metal with normal conductivity using chrome. The test results of the product are the same as in example 3.

Example 7. Form the product as in example 3. The difference lies in the fact that, as the metal with normal conductivity using rhenium. The test results of the product are the same as in example 3.

Example 8. Form the product as in example 3. The difference lies in the fact that, as the metal with normal use conductivity niobium. The test results of the product are the same as in example 3.

Example 9. The integration is from the electrolyte, containing salt of niobium and tin, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 12 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film of 1.5 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,5 10-2T/C. the Content of impurities in stannide niobium according to spark mass spectrometry was as follows, wt. %: Ta - 3 10-3, Zr - 1 10-3Fe - 9 10-3K - 1 10-4, Na - 1 10-4Li - 2 10-4, Al - 5 10-3, Mg - 4 10-3, Ni - 8 10-3S - 5 10-2F - 1 10-3O - 5 10-2N - 5 10-4C - 7 10-4. X-ray analysis showed in the superconducting layer, the ratio [Nb]/[Sn] = 2,50. X-ray phase analysis identified only the phase with the a-15 structure with the interplanar distance a = 5,289 0,001 A. study of a microprobe analyzer "Cameca" in characteristic and reflected electrons, indicate the continuity and homogeneity of the layer of stunned niobium. The critical temperature Twith17.7 K. the Calculated values of the upper critical field Bc2(0) = 22,5 T, Bc2(4.2 K) = 21,0 TL. The the coefficient of anisotropy k = 1,9. The maximum pinning force in the direction orthogonal to the surface of the coil, is provided by the columnar structure of the layer, resulting in galvanostatically the electrolysis mode.

Example 10. Form the basis of a helical spiral analogously to Example 9. Then, the electrolyte containing salts of niobium, tin and tantalum, in the helium atmosphere is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 15 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 2.5 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,6 10-2T/C. the Content of impurities in stannide niobium except tantalum similarly, the content of impurities in Example 9. The concentration of tantalum in the superconducting layer was 0.3 wt.%. X-ray analysis showed in the superconducting layer, the ratio [Nb]/[Sn] = 2,45. The critical temperature Tc17.7 K. the Calculated values of the upper critical field Bc2(0) = 26,0 T, Bc2(4.2 K) = 24.5 Cm TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, ravnomernost round, is provided by doping the superconducting compound tantalum in the amount of 0.3 wt.%.

Example 11. Form the basis of a helical spiral analogously to Example 9. Then, the electrolyte containing salts of niobium, tin and zirconium, in an atmosphere of argon and helium, taken in a volumetric ratio of 1:1, is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 14 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 1.5 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,2 10-2T/C. the Content of impurities in stannide niobium except zirconium similarly, the content of impurities in Example 9. The concentration of zirconium in the superconducting layer was 0.1 wt%. X-ray analysis showed in the superconducting layer, the ratio [Nb]/[Sn] = 2,35. The critical temperature Tcwas 18.1 K. the Calculated values of the upper critical field Bc2(0) = 22,5 T, Bc2(4.2 K) = 21,0 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer is 1.6 1010A/m2the coefficient of anisotropy k = 1,8. Macprovideo compounds of zirconium in a quantity equal to 0.1 wt.%.

Example 12. Form the basis of a helical spiral analogously to Example 9. Then, the electrolyte containing salts of niobium, tin and copper, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 16 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 3 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,9 10-2T/C. the Content of impurities in stannide niobium except copper similar to the content of impurities in Example 9. Copper concentration in the superconducting layer was 3 wt%. X-ray analysis showed in the superconducting layer, the ratio [Nb] /[Sn] = 2,40. The critical temperature Tcwas 18.1 K. the Calculated values of the upper critical field Bc2(0) = 24,0 T, Bc2(4.2 K) = 22,5 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, equal to 1.3 1010A/m2the coefficient of anisotropy k = 1,8. The maximum pinning force in the direction orthogonal to the surface of the coil is achieved by doping the superconducting compound copper in the electrolyte, containing salt of niobium, tin, and carbon tetrachloride, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 12 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 2.5 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,3 10-2T/C. the Content of impurities in stannide niobium except carbon similar to the content of impurities in Example 9. The concentration of carbon in the superconducting layer was 0.06 wt.%. X-ray analysis showed in the superconducting layer, the ratio [Nb]/[Sn] = 2,50. The critical temperature Tcwas 18.1 K. the Calculated values of the upper critical field Bc2(0) = 22,5 T, Bc2(4.2 K) = 21,0 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, equal to 1.1 1010A/m2the coefficient of anisotropy k = 1,8. The maximum pinning force in the direction orthogonal to the surface of the coil is achieved by doping the superconducting compounds with carbon number equal to 0.06 wt.%.

Example 14. Form the basis of a helical spiral analogelectronics layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 10 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 2.5 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,1 10-2T/C. the Content of impurities in stannide niobium except for nitrogen similarly, the content of impurities in Example 9. The nitrogen concentration in the superconducting layer was 0.07 wt. %. X-ray analysis showed in the superconducting layer, the ratio [Nb]/[Sn] = 2,50. The critical temperature Tcwas 17.9 K. the Calculated values of the upper critical field Bc2(0) = 23,5 T, Bc2(4.2 K) = 22,0 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, equal to 2.7 1010A/m2the coefficient of anisotropy k = 1,9. The maximum pinning force in the direction orthogonal to the surface of the coil is achieved by doping the superconducting compounds with nitrogen in a quantity equal to 0.07 wt.%.

Example 15. Form the basis of a helical spiral as in Example 1. Then at a temperature of 800oC in an atmosphere of argon in molten halides of alkali metals containing a salt of copper, by contact displacement is applied to the copper layer of the Chida alkali metals, containing a salt of niobium, is applied by electrolysis layer of niobium thickness of 15 μm. As a soluble anode is used niobium car brand NBR-1. The obtained niobium layer of molten halides of alkali metals containing salt of tin, in an atmosphere of argon method, during transfer receive connection stunned niobium with the structure a-15 of a thickness of 8 μm. After deposition of the superconducting layer to produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 1.8 μm. Testing has shown that dynamic stability is preserved when dB/dt 2,9 10-2T/C. the Content of impurities in stannide niobium according to the mass spectrometric analysis is the same as in Example 9. X-ray phase analysis identifies the phase with the a-15 structure with besplatnotam distance a = 5,291 0.001 a and phase Nb6Sn5and NbSn2. The critical temperature Tcwas 17.9 K. the Calculated values of the upper critical field Bc2(0) = 22,5 T, Bc2(4.2 K) = 21,0 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, 6.7 109A/m2the coefficient of anisotropy k = 1,8. The maximum pinning force in the direction orthogonal is EP 16. Formed from stainless steel AND the basis of a helical spiral, having a thickness d of 0.2 mm, inner diameter D = 20 mm, number of turns n - 120 and the width of a coil of w - 27 mm, Then at a temperature of 650oC in an atmosphere of helium from a melt of alkali metal halides containing a salt of copper, by contact displacement is applied to the copper layer with a thickness of 5 μm. After deposition of the copper layer from the electrolyte containing salts of niobium, tin and tantalum, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 with a thickness of 5 μm, doped with tantalum in the amount of 1.5 wt.%. Then, on this layer by contact displacement again put a layer of copper with a thickness of 5 μm. After deposition of the copper layer from the electrolyte containing salts of niobium, tin and zirconium, in an atmosphere of helium is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 with a thickness of 5 μm, doped zirconium in the amount of 0.5 wt. %. On this layer by contact displacement again put a layer of copper with a thickness of 5 μm. After deposition of the copper layer from the electrolyte containing salts of niobium, tin and copper, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned nochnogo eviction again put a layer of copper with a thickness of 5 μm. After deposition of the copper layer from the electrolyte containing salts of niobium, tin, and carbon tetrachloride, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 with a thickness of 5 μm, doped with carbon in the amount of 0.24 wt.%. On this layer by contact displacement again put a layer of copper with a thickness of 5 μm. After deposition of the copper layer from the electrolyte containing salts of niobium and tin, in an atmosphere of mixture of argon and nitrogen is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 with a thickness of 5 μm, doped with nitrogen in an amount of 0.21 wt.%. Then produce insulating the turns of the spiral through the amorphous oxide dielectric film thickness of 1.9 μm. Testing has shown that dynamic stability is preserved when dB/dt 3,2 10-2T/C. the Content of impurities in stannide niobium except alloying elements similar to the content of impurities in Example 9. The maximum critical temperature Tcamounted to 18.0 K. the Calculated values of the upper critical field Bc2(0) = 25,0 T, Bc2(4.2 K) = 23,5 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, equal to 3.8 1010A/mespecially by doping the superconducting compound tantalum, zirconium, copper, carbon and nitrogen are respectively 1,5; 0,5; 10; of 0.24 and 0.21 wt.%.

Example 17. Form the basis of a helical spiral with parameters d - 0,3 mm, ø 15 mm, n - 80 and w - 12 mm of technical copper mark M3. Then, the electrolyte containing salts of niobium, tin and copper, in an atmosphere of argon is applied by electrolysis layer superconducting compounds stunned niobium with the structure a-15 of a thickness of 6 μm with the content of copper in the amount of 10 wt.%. On the resulting layer of molten halides of alkali metals containing a salt of molybdenum, coated molybdenum with a thickness of 5 μm. This layer is again applied superconducting layer with the structure a-15 of a thickness of 6 μm with a content of copper 8 wt.%. The obtained superconducting layer of molten halides containing a salt of tungsten, put a layer of tungsten with a thickness of 5 μm. This layer is again applied superconducting layer with the structure a-15 with the content of copper 6 wt.%. The molten salt halides containing salt tantalum, put a layer of tantalum with a thickness of 5 μm. This layer is again applied superconducting layer with the structure a-15 of a thickness of 6 μm with a content of copper 8 wt. %. To him by the electrolysis of an aqueous solution containing a salt of chromium, is applied to the copper 7 wt.%. The obtained superconducting layer of molten salt containing a salt of rhenium, put a layer of rhenium thickness of 5 μm. This layer is again applied superconducting layer with the structure a-15 of a thickness of 7 microns with a content of copper 3 wt. %. Then produce insulating the turns of the spiral through the amorphous oxide dielectric film with a thickness of 2.8 μm. Testing has shown that dynamic stability is preserved when dB/dt 2,7 10-2T/C. the Content of impurities in stannide niobium except copper similar to the content of impurities in Example 9. The maximum critical temperature Tcamounted to 18.0 K. the Calculated values of the upper critical field Bc2(0) = 23,5 T, Bc2(4.2 K) = 22,0 TL. The critical current density of Icin a field of 5 T, calculated on the superconducting layer, equal to 1.7 1010A/cm2the coefficient of anisotropy k = 2,2. The maximum pinning force in the direction orthogonal to the surface of the coil is achieved by doping the superconducting compound copper in an amount up to 10 wt.%.

From the above Examples that the proposed method provides improved dynamic stability of superconducting products to the jumps of the magnetic flux that contributes to uslovnosti use of superconducting material by minimizing consumption. The minimum flow of superconducting material not only reduces costs, but also reduces the cost of operation of cryogenic systems, because it requires less amount of the refrigerant for cooling the product to the working temperature. The invention also solves the problem of simplification of the manufacturing process, since it does not require complex and expensive equipment for its implementation. In addition, the invention solves the problem of simplifying the manufacture of the insulating layer, improves efficiency, since the insulating layer is firmly bonded to the metal surface of the coil and at cryogenic temperatures, and by reducing its thickness and increasing thermal conductivity improves the stability of the product to thermal perturbations.

1. A method of manufacturing a superconducting products, including the formation of helical spirals based on the composition of the superconductor and metal with normal conductivity, insulating the turns of the helix from each other and the bond of coils, wherein the superconductor and the metal with normal conductivity are in the form of layers having a width generally equal to the width of the spiral, and have one on another, and initially form a layer with normalniju relative strength of pinning, the maximum of which is directed orthogonal to the surface of the coil, and insulating the turns of the spiral is produced by forming an oxide dielectric film on the surface of the coils.

2. The method according to p. 1, characterized in that the composition as a material sverkhprovodyashchego layer using niobium.

3. The method according to p. 1, characterized in that the composition as a material of the superconducting layer is used as a compound of stunned niobium with the a-15 structure.

4. The method according to one of paragraphs.1-3, characterized in that the composition as a material layer with normal conductivity using stainless steel.

5. The method according to one of paragraphs.1-3, characterized in that the composition as a material layer with normal conductivity using one or more metals selected from the group consisting of copper, molybdenum, tungsten, tantalum, chromium, rhenium.

6. The method according to p. 1 or 3, characterized in that the composition as a material layer with normal use conductivity niobium.

7. The method according to p. 2, wherein the niobium is applied by electrolysis of the molten salt in the atmosphere of inert gas, and the anisotropy of the relative strength of the pinning reach by providing obseg the connection of stunned niobium with the structure a-15 is applied by electrolysis of the molten salt in the atmosphere, containing an inert gas.

9. The method according to p. 8, characterized in that the anisotropy of the relative strength of the pinning reach by alloying caused connection tantalum, and the content of tantalum in the superconducting layer is 0.3-1.5 wt.%.

10. The method according to p. 8, characterized in that the anisotropy of the relative strength of the pinning reach by alloying caused connection zirconium, the zirconium content in the superconducting layer is 0.1-0.5 wt.%.

11. The method according to p. 8, characterized in that the anisotropy of the relative strength of the pinning reach by alloying caused connection copper, and the copper content in the superconducting layer is 3-10 wt.%.

12. The method according to p. 8, characterized in that the anisotropy of the relative strength of the pinning reach by alloying of the applied compounds of carbon, and the carbon content in the superconducting layer is 0.06-0.24 wt.%.

13. The method according to p. 8, characterized in that the anisotropy of the relative strength of the pinning reach by alloying of the applied compounds with nitrogen, and the nitrogen content in the superconducting layer is between 0.07 to 0.21 wt.%.

14. The method according to one of paragraphs. 3-6, characterized in that the connection is worn during transfer from the molten salt in the atmosphere of inert gas, and the anisotropy of the relative strength of the pinning reach through phases Nb6Sn5and/or NbSnn.

15. The method according to one of paragraphs. 7, 8, 14, characterized in that as the inert gas used argon, helium or a mixture thereof.

16. The method according to one of paragraphs. 1-3, 5, 6, characterized in that the composition is formed from multiple superconducting layers and multiple layers of normal conductivity.

17. The method according to p. 1, characterized in that as an insulating oxide dielectric film on the surface of the coils form an amorphous film of Nb2O5thickness of 0.05 to 5.0 μm.

 

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FIELD: electrical engineering including superconductivity; improved technologies for producing semiconductors.

SUBSTANCE: when specimen of desired size is produced from working charge, it is pierced with thin threads, such as silk ones, disposed in parallel with direction of current flow in product so as to raise superconducting junction temperature; during heat treatment these threads burn out to form superconducting passages due to free movement of conducting electrons.

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FIELD: applied superconductivity.

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EFFECT: improved quality of superconductor core due to higher quality of magnesium powder and especially improved condition of magnesium powder surface.

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