Connection structure for high-temperature superconducting wires

Abstract

To provide a connection structure of a high-temperature superconducting wire capable of improving the degree of freedom of wiring of a high-temperature superconducting wire.SOLUTION: A connection structure of a high-temperature superconducting wire includes a first high-temperature superconducting wire, and a second high-temperature superconducting wire superconductingly connected to the first high-temperature superconducting wire. The second high-temperature superconducting wire is arranged with respect to the first high-temperature superconducting wire such that the first longitudinal direction of the first high-temperature superconducting wire and the second longitudinal direction of the second high-temperature superconducting wire intersect each other at a connecting portion between the first high-temperature superconducting wire and the second high-temperature superconducting wire.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a connection structure for high-temperature superconducting wires. [Background technology]

[0002] JP 2013-235699 A (Patent Document 1) discloses a connection structure for high-temperature superconducting wires in which a first high-temperature superconducting wire and a second high-temperature superconducting wire are superconductively connected to each other. In this connection structure for high-temperature superconducting wires, the first high-temperature superconducting wire and the second high-temperature superconducting wire are connected to each other in a straight line at the connection between the first high-temperature superconducting wire and the second high-temperature superconducting wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-235699 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a connection structure for high-temperature superconducting wires that can improve the degree of freedom in wiring the high-temperature superconducting wires. [Means for solving the problem]

[0005] The disclosed connection structure for high-temperature superconducting wires includes a first high-temperature superconducting wire and a second high-temperature superconducting wire superconductively connected to the first high-temperature superconducting wire. The second high-temperature superconducting wire is disposed relative to the first high-temperature superconducting wire such that a first longitudinal direction of the first high-temperature superconducting wire and a second longitudinal direction of the second high-temperature superconducting wire intersect with each other at a connection between the first high-temperature superconducting wire and the second high-temperature superconducting wire. Effect of the Invention

[0006] According to the present disclosure, it is possible to provide a connection structure for high-temperature superconducting wires that can improve the degree of freedom in wiring the high-temperature superconducting wires. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic plan view of a connection structure of high temperature superconducting wires according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the high temperature superconducting wire connection structure according to the embodiment taken along the cross-sectional line II-II shown in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view of the high temperature superconducting wire connection structure according to the embodiment taken along the cross-sectional line III-III shown in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view of the high temperature superconducting wire connection structure according to the embodiment taken along the cross-sectional line IV-IV shown in FIG. [Diagram 5] FIG. 5 is a diagram showing the crystal structures of the first and second high temperature superconducting layers. [Figure 6] FIG. 6 is a flowchart showing a method for manufacturing a connection structure of high temperature superconducting wires according to an embodiment. [Figure 7] FIG. 7 is a flowchart showing steps for preparing a first high temperature superconducting wire and a second high temperature superconducting wire. [Figure 8] FIG. 8 is a flowchart showing steps for superconductively connecting a first high temperature superconducting wire and a second high temperature superconducting wire to each other. [Figure 9] FIG. 9 is a schematic plan view of a connection structure of high temperature superconducting wires according to a first modified example of the embodiment. [Figure 10] FIG. 10 is a schematic plan view of a connection structure of high temperature superconducting wires according to a second modified example of the embodiment. [Figure 11] FIG. 11 is a schematic plan view of a connection structure of high temperature superconducting wires according to a third modified example of the embodiment. [Figure 12] FIG. 12 is a schematic diagram of a first example of a wiring structure of a high temperature superconducting wire according to an embodiment to which a connection structure of a high temperature superconducting wire according to an embodiment is applied. [Figure 13]FIG. 13 is a schematic diagram of a second example of a wiring structure of a high temperature superconducting wire according to an embodiment to which a connection structure of a high temperature superconducting wire according to an embodiment is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described.

[0009] (1) A connection structure for high-temperature superconducting wires according to the present disclosure includes a first high-temperature superconducting wire and a second high-temperature superconducting wire superconductively connected to the first high-temperature superconducting wire. The second high-temperature superconducting wire is disposed relative to the first high-temperature superconducting wire such that a first longitudinal direction of the first high-temperature superconducting wire and a second longitudinal direction of the second high-temperature superconducting wire intersect with each other at a connection between the first high-temperature superconducting wire and the second high-temperature superconducting wire.

[0010] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0011] (2) In the connection structure for high temperature superconducting wires relating to (1) above, the angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is greater than 5° and less than 175°.

[0012] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0013] (3) In the connection structure for high temperature superconducting wires relating to (1) above, the angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is equal to or greater than 15° and equal to or less than 165°.

[0014] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0015] (4) In the connection structure for high temperature superconducting wires relating to (1) above, the angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is equal to or greater than 30° and equal to or less than 150°.

[0016] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0017] (5) In the connection structure of high temperature superconducting wires according to any one of (1) to (4) above, the first high temperature superconducting wire includes a first substrate including a first main surface, a first intermediate layer formed on the first main surface, and a first high temperature superconducting layer formed on the first intermediate layer. The second high temperature superconducting wire includes a second substrate including a second main surface, a second intermediate layer formed on the second main surface, and a second high temperature superconducting layer formed on the second intermediate layer. The second high temperature superconducting layer is superconductively joined to the first high temperature superconducting layer.

[0018] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0019] (6) In the connection structure of high-temperature superconducting wires according to (5) above, a first angle between a first rolling direction of the first substrate and a first direction of the first crystal axis of the first high-temperature superconducting layer in a plan view of the first main surface is different from a second angle between a second rolling direction of the second substrate and a second direction of the second crystal axis of the second high-temperature superconducting layer corresponding to the first crystal axis in a plan view of the second main surface. In the connection between the first high-temperature superconducting wire and the second high-temperature superconducting wire, the first direction of the first crystal axis of the first high-temperature superconducting layer is aligned with the second direction of the second crystal axis of the second high-temperature superconducting layer.

[0020] Therefore, the degree of freedom in wiring the high-temperature superconducting wires can be improved. In addition, the critical current density J c A significant decrease in the

[0021] (7) In the connection structure for high temperature superconducting wires according to (6) above, the difference between the second angle and the first angle is greater than 5° and less than 175°.

[0022] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0023] (8) In the connection structure for high temperature superconducting wires according to (6) above, the difference between the second angle and the first angle is equal to or greater than 15° and equal to or less than 165°.

[0024] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0025] (9) In the connection structure for high temperature superconducting wires according to (6) above, the difference between the second angle and the first angle is equal to or greater than 30° and equal to or less than 150°.

[0026] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0027] (10) In the connection structure for high temperature superconducting wires according to any one of (5) to (9) above, the first substrate is a textured metal substrate, and the second substrate and the second intermediate layer are IAD substrates.

[0028] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0029] (11) In the connection structure of high temperature superconducting wire according to any one of (5) to (9) above, the first substrate and the first intermediate layer are a first IAD substrate, and the second substrate and the second intermediate layer are a second IAD substrate.

[0030] This improves the degree of freedom in wiring the high temperature superconducting wire.

[0031] [Details of the embodiment of the present disclosure] Next, the details of the embodiments of the present disclosure will be described with reference to the drawings. Note that the same or corresponding parts in the following drawings are given the same reference numerals, and the description thereof will not be repeated. At least some of the configurations of the embodiments described below may be arbitrarily combined.

[0032] A connection structure 1 for high temperature superconducting wires according to an embodiment will be described with reference to Figures 1 to 5. The connection structure 1 for high temperature superconducting wires according to the present embodiment includes a first high temperature superconducting wire 10 and a second high temperature superconducting wire 20.

[0033] 1 to 3, first high temperature superconducting wire 10 includes a first substrate 11, a first intermediate layer 12, a first high temperature superconducting layer 13, and a first stabilization layer 14.

[0034] The first substrate 11 includes a first main surface 11a. The first substrate 11 is rolled along a first rolling direction 11r. The first rolling direction 11r is, for example, a first longitudinal direction of the first high temperature superconducting wire 10.

[0035] The first intermediate layer 12 is formed on the first main surface 11a. The first intermediate layer 12 may be composed of a single layer or multiple layers. The first intermediate layer 12 is provided between the first substrate 11 and the first high-temperature superconducting layer 13. The first intermediate layer 12 is formed of a material that has extremely low reactivity with the elements that constitute the first high-temperature superconducting layer 13. The first intermediate layer 12 prevents the elements that constitute the first high-temperature superconducting layer 13 from reacting with the first substrate 11. Therefore, the superconducting properties of the first high-temperature superconducting layer 13 formed on the first intermediate layer 12 can be prevented from deteriorating. The first intermediate layer 12 is composed of at least one of, for example, YSZ (yttria-stabilized zirconia), CeO2 (cerium oxide), MgO (magnesium oxide), Y2O3 (yttrium oxide), Al2O3 (aluminum oxide), LaMnO3 (lanthanum manganese oxide), Gd2Zr2O7 (gadolinium zirconate), or SrTiO3 (strontium titanate).

[0036] In one example, the first substrate 11 may be a textured metal substrate. The textured metal substrate means a metal substrate in which the crystal orientation is aligned on the surface of the metal substrate. The textured metal substrate may be, for example, a clad-type metal substrate in which a copper layer, a nickel layer, etc. are laminated on a base metal substrate such as SUS or Hastelloy (registered trademark). In another example, the first substrate 11 and the first intermediate layer 12 may be an IAD substrate. The IAD substrate includes a metal substrate such as a nickel-based alloy substrate and an oriented intermediate layer formed on the metal substrate by an ion beam assisted deposition (IAD) method. In the IAD substrate, the metal substrate may be a non-oriented metal substrate. The textured metal substrate and the IAD substrate have the function of aligning the crystal orientation of the crystal grains that form the high temperature superconducting layer formed thereon. Therefore, the critical current density J of the high temperature superconducting layer is increased by 100%. c increases.

[0037] The first high temperature superconducting layer 13 is formed on the first intermediate layer 12. The first high temperature superconducting layer 13 is made of, for example, RE11Ba2Cu3O y1 (6.0≦y1≦8.0, RE1 represents a rare earth element). RE1 is, for example, yttrium (Y), gadolinium (Gd), dysprosium (Dy), europium (Eu), samarium (Sm), lanthanum (La), neodymium (Nd), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) or holmium (Ho). y1 is, for example, 6.8 or more and 7.0 or less.

[0038] The first high-temperature superconducting layer 13 has a crystal structure which is a layered perovskite structure as shown in FIG. 5. The crystal structure of the first high-temperature superconducting layer 13 has an a-axis, a b-axis, and a c-axis as crystal axes. The a-axis direction 13a and the b-axis direction of the first high-temperature superconducting layer 13 are perpendicular to the thickness direction of the first high-temperature superconducting wire 10. The thickness direction of the first high-temperature superconducting wire 10 is the stacking direction of the first substrate 11, the first intermediate layer 12, and the first high-temperature superconducting layer 13, or is the normal direction of the first main surface 11a. The a-axis direction 13a and the b-axis direction of the first high-temperature superconducting layer 13 are aligned along the in-plane direction of the first high-temperature superconducting wire 10. The a-axis direction 13a and the b-axis direction of the first high-temperature superconducting layer 13 are aligned along the in-plane direction of the first main surface 11a. The c-axis direction of first high temperature superconducting layer 13 is aligned along the thickness direction of first high temperature superconducting wire 10 .

[0039] The a-axis direction 13a of the first high-temperature superconducting layer 13 is given by the average direction of the a-axis direction of a plurality of crystal grains forming the first high-temperature superconducting layer 13. The in-plane orientation degree Δφ of the first high-temperature superconducting layer 13 is, for example, 6.0° or less. The in-plane orientation degree Δφ of the high-temperature superconducting layer is the full width at half maximum (FWHM) value of the dispersion in the a-axis direction of the high-temperature superconducting layer, obtained by performing X-ray diffraction (XRD) measurement on the high-temperature superconducting layer. The in-plane orientation degree Δφ of the high-temperature superconducting layer defines the degree to which the crystal orientation of the crystal grains of the high-temperature superconducting material is aligned in the in-plane direction of the high-temperature superconducting layer. The smaller the in-plane orientation degree Δφ, the more aligned the crystal orientation of the crystal grains is, and the better the crystal orientation of the high-temperature superconducting layer is.

[0040] Referring to FIG. 1 , when the first high temperature superconducting wire 10 includes a textured metal substrate, i.e., when the first substrate 11 is a textured metal substrate, the a-axis direction 13a of the first high temperature superconducting layer 13 is the first rolling direction 11r of the first substrate 11 and also the first longitudinal direction of the first high temperature superconducting wire 10.

[0041] When the first high-temperature superconducting wire 10 includes an IAD substrate, that is, when the first substrate 11 and the first intermediate layer 12 are IAD substrates, the a-axis direction 13a of the first high-temperature superconducting layer 13 can be set to any direction in the in-plane direction of the first high-temperature superconducting layer 13 by changing the irradiation direction of the ion beam in the IAD method. With reference to FIG. 1 , in this embodiment, the a-axis direction 13a of the first high-temperature superconducting layer 13 is the first rolling direction 11r of the first substrate 11 and the first longitudinal direction of the first high-temperature superconducting wire 10. However, when the first high-temperature superconducting wire 10 includes an IAD substrate, the a-axis direction 13a of the first high-temperature superconducting layer 13 is not limited to the first rolling direction 11r of the first substrate 11 and the first longitudinal direction of the first high-temperature superconducting wire 10.

[0042] 2 and 3, the first stabilization layer 14 is formed of a metal such as copper or silver. The first stabilization layer 14 is formed on the first high-temperature superconducting layer 13. When a quench occurs in the first high-temperature superconducting layer 13, the first stabilization layer 14 bypasses the current flowing through the first high-temperature superconducting layer 13 to prevent the first high-temperature superconducting wire 10 from burning. A quench is a phenomenon in which a superconducting state transitions to a normal conducting state. The first stabilization layer 14 may also be formed on the first substrate 11. In the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the first stabilization layer 14 is not formed on the first high-temperature superconducting layer 13. In the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the first high-temperature superconducting layer 13 is exposed from the first stabilization layer 14.

[0043] 1, 2 and 4, second high temperature superconducting wire 20 includes second substrate 21, second intermediate layer 22, second high temperature superconducting layer 23, and second stabilization layer 24.

[0044] The second substrate 21 includes a second main surface 21a. The second substrate 21 is rolled along a second rolling direction 21r. The second rolling direction 21r is, for example, a second longitudinal direction of the second high temperature superconducting wire 20.

[0045] The second intermediate layer 22 is formed on the second main surface 21a. The second intermediate layer 22 may be composed of a single layer or multiple layers. The second intermediate layer 22 is provided between the second substrate 21 and the second high-temperature superconducting layer 23. The second intermediate layer 22 is formed of a material that has extremely low reactivity with the elements that constitute the second high-temperature superconducting layer 23. The second intermediate layer 22 prevents the elements that constitute the second high-temperature superconducting layer 23 from reacting with the second substrate 21. Therefore, the superconducting properties of the second high-temperature superconducting layer 23 formed on the second intermediate layer 22 can be prevented from deteriorating. The second intermediate layer 22 is composed of, for example, at least one of YSZ (yttria stabilized zirconia), CeO2 (cerium oxide), MgO (magnesium oxide), Y2O3 (yttrium oxide), Al2O3 (aluminum oxide), LaMnO3 (lanthanum manganese oxide), Gd2Zr2O7 (gadolinium zirconate), or SrTiO3 (strontium titanate).

[0046] The second substrate 21 and the second intermediate layer 22 may be, for example, an IAD substrate. That is, the second high temperature superconducting wire 20 may include, for example, an IAD substrate.

[0047] The second high temperature superconducting layer 23 is formed on the second intermediate layer 22. The second high temperature superconducting layer 23 is made of, for example, RE21Ba2Cu3O y2 (6.0≦y2≦8.0, RE2 represents a rare earth element). RE2 is, for example, yttrium (Y), gadolinium (Gd), dysprosium (Dy), europium (Eu), samarium (Sm), lanthanum (La), neodymium (Nd), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) or holmium (Ho). RE2 may be the same as RE1 or may be different from RE1. y2 is, for example, 6.8 or more and 7.0 or less.

[0048] The second high-temperature superconducting layer 23 has a crystal structure which is a layered perovskite structure as shown in FIG. 5. The crystal structure of the second high-temperature superconducting layer 23 has an a-axis, a b-axis, and a c-axis as crystal axes. The a-axis direction 23a and the b-axis direction of the second high-temperature superconducting layer 23 are perpendicular to the thickness direction of the second high-temperature superconducting wire 20. The thickness direction of the second high-temperature superconducting wire 20 is the stacking direction of the second substrate 21, the second intermediate layer 22, and the second high-temperature superconducting layer 23, or is the normal direction of the second main surface 21a. The a-axis direction 23a and the b-axis direction of the second high-temperature superconducting layer 23 are aligned along the in-plane direction of the second high-temperature superconducting wire 20. The a-axis direction 23a and the b-axis direction of the second high-temperature superconducting layer 23 are aligned along the in-plane direction of the second main surface 21a. The c-axis direction of second high temperature superconducting layer 23 is aligned along the thickness direction of second high temperature superconducting wire 20 .

[0049] The a-axis direction 23a of the second high temperature superconducting layer 23 is given by the average direction of the a-axis directions of a plurality of crystal grains forming the second high temperature superconducting layer 23. The in-plane orientation degree Δφ of the second high temperature superconducting layer 23 is, for example, 6.0° or less.

[0050] By changing the irradiation direction of the ion beam in the IAD method, the a-axis direction 23a of the second high-temperature superconducting layer 23 can be set to any direction in the in-plane direction of the second high-temperature superconducting layer 23. With reference to FIG. 1, in this embodiment, the a-axis direction 23a of the second high-temperature superconducting layer 23 is inclined at 45° with respect to the second rolling direction 21r of the second substrate 21 and is also inclined at 45° with respect to the second longitudinal direction of the second high-temperature superconducting wire 20. However, as shown in FIGS. 9 to 13, when the second high-temperature superconducting wire 20 includes an IAD substrate, the a-axis direction 23a of the second high-temperature superconducting layer 23 is not limited to the direction inclined at 45° with respect to the second rolling direction 21r of the second substrate 21 and the second longitudinal direction of the second high-temperature superconducting wire 20.

[0051] 2 and 4, the second stabilization layer 24 is formed of a metal such as copper or silver. The second stabilization layer 24 is formed on the second high-temperature superconducting layer 23. When a quench occurs in the second high-temperature superconducting layer 23, the second stabilization layer 24 bypasses the current flowing through the second high-temperature superconducting layer 23 to prevent the second high-temperature superconducting wire 20 from burning. The second stabilization layer 24 may also be formed on the second substrate 21. In the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the second stabilization layer 24 is not formed on the second high-temperature superconducting layer 23. In the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the second high-temperature superconducting layer 23 is exposed from the second stabilization layer 24.

[0052] 1 and 2, the second high temperature superconducting layer 23 is superconductively joined to the first high temperature superconducting layer 13 by a superconducting joining layer 40 made of a high temperature superconducting material. y3 (6.0≦y3≦8.0, RE3 represents a rare earth element). RE3 is, for example, yttrium (Y), gadolinium (Gd), dysprosium (Dy), europium (Eu), samarium (Sm), lanthanum (La), neodymium (Nd), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) or holmium (Ho). RE3 may be the same as at least one of RE1 or RE2, or may be different from at least one of RE1 or RE2. y3 is, for example, 6.8 or more and 7.0 or less.

[0053] The second high temperature superconducting wire 20 is disposed relative to the first high temperature superconducting wire 10 such that the first longitudinal direction of the first high temperature superconducting wire 10 and the second longitudinal direction of the second high temperature superconducting wire 20 intersect with each other at the joint 2 between the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20. The angle θ (see FIG. 1 and FIG. 9 to FIG. 11) between the first longitudinal direction of the first high temperature superconducting wire 10 and the second longitudinal direction of the second high temperature superconducting wire 20 is greater than 0° and smaller than 180°. The angle θ is defined as the angle smaller than 180° of the two angles between the first longitudinal direction of the first high temperature superconducting wire 10 and the second longitudinal direction of the second high temperature superconducting wire 20.

[0054] For example, at the connection 2 between the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20, the second high temperature superconducting wire 20 is bent edgewise with respect to the first high temperature superconducting wire 10. The edgewise direction is the width direction of the first high temperature superconducting wire 10. The width direction of the first high temperature superconducting wire 10 is along the first main surface 11a and perpendicular to the first longitudinal direction of the first high temperature superconducting wire 10. The width direction of the first high temperature superconducting wire 10 is perpendicular to the normal direction of the first main surface 11a and the first longitudinal direction of the first high temperature superconducting wire 10.

[0055] The angle θ may be greater than 5° and less than 175°. The angle θ may be greater than or equal to 15° and less than or equal to 165°. The angle θ may be greater than or equal to 30° and less than or equal to 150°.

[0056] The angle θ may be greater than 5° and less than 80°, or greater than 100° and less than 175°. The angle θ may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The angle θ may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0057] For example, in the present embodiment shown in Figure 1, the angle θ is 45°. In a first modification of the present embodiment shown in Figure 9, the angle θ is 135°. In a second modification of the present embodiment shown in Figure 10, the angle θ is 60°. In a third modification of the present embodiment shown in Figure 11, the angle θ is 120°.

[0058] 1 and 9 to 11, by setting at least the second angle β of the first angle α and the second angle β to an arbitrary angle, the angle θ can be set to an arbitrary angle. This can improve the degree of freedom in wiring the second high temperature superconducting wire 20 with respect to the first high temperature superconducting wire 10.

[0059] The first angle α is an angle between the first rolling direction 11r of the first substrate 11 and a first direction of the first crystal axis of the first high-temperature superconducting layer 13 in a plan view of the first main surface 11a. The first direction of the first crystal axis of the first high-temperature superconducting layer 13 is, for example, the a-axis direction 13a of the first high-temperature superconducting layer 13. The second angle β is an angle between the second rolling direction 21r of the second substrate 21 and a second direction of the second crystal axis of the second high-temperature superconducting layer 23 corresponding to the first crystal axis in a plan view of the second main surface 21a. The second direction of the second crystal axis of the second high-temperature superconducting layer 23 corresponding to the first crystal axis is, for example, the a-axis direction 23a of the second high-temperature superconducting layer 23. The fact that the second crystal axis of the second HTS layer 23 corresponds to the first crystal axis of the first HTS layer 13 means that, in terms of the crystal axes of the crystal structure of the HTS layer, the second crystal axis of the second HTS layer 23 is the same as the first crystal axis of the first HTS layer 13. For example, when the first crystal axis of the first HTS layer 13 is the a-axis of the first HTS layer 13, the second crystal axis of the second HTS layer 23 is the a-axis of the second HTS layer 23.

[0060] The first angle α is different from the second angle β. The difference between the second angle β and the first angle α may be greater than 5° and less than 175°. The difference between the second angle β and the first angle α may be greater than or equal to 15° and less than or equal to 165°. The difference between the second angle β and the first angle α may be greater than or equal to 30° and less than or equal to 150°.

[0061] The difference between the second angle β and the first angle α may be greater than 5° and less than 80°, or greater than 100° and less than 175°. The difference between the second angle β and the first angle α may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The difference between the second angle β and the first angle α may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0062] For example, in the present embodiment shown in FIG. 1, the first angle α is 0°, the second angle β is 45°, and the difference between the second angle β and the first angle α is 45°. In a first variant of the present embodiment shown in FIG. 9, the first angle α is 0°, the second angle β is 135°, and the difference between the second angle β and the first angle α is 135°. In a second variant of the present embodiment shown in FIG. 10, the first angle α is 0°, the second angle β is 60°, and the difference between the second angle β and the first angle α is 60°. In a third variant of the present embodiment shown in FIG. 11, the first angle α is 0°, the second angle β is 120°, and the difference between the second angle β and the first angle α is 120°.

[0063] In a plan view of the second main surface 21a, the second direction of the second crystal axis of the second high temperature superconducting layer 23 may be inclined with respect to the second rolling direction 21r of the second substrate 21. The second direction of the second crystal axis of the second high temperature superconducting layer 23 is, for example, the a-axis direction 23a of the second high temperature superconducting layer 23. Therefore, even if the first angle α is 0° or 90°, the second angle β can be made different from the first angle α.

[0064] The second angle β may be greater than 5° and less than 175°. The second angle β may be greater than or equal to 15° and less than or equal to 165°. The second angle β may be greater than or equal to 30° and less than or equal to 150°.

[0065] The second angle β may be greater than 5° and less than 80°, or greater than 100° and less than 175°. The second angle β may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The second angle β may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0066] For example, in the present embodiment shown in Figure 1, the second angle β is 45°. In a first variation of the present embodiment shown in Figure 9, the second angle β is 135°. In a second variation of the present embodiment shown in Figure 10, the second angle β is 60°. In a third variation of the present embodiment shown in Figure 11, the second angle β is 120°.

[0067] In the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the first direction of the first crystal axis of the first high-temperature superconducting layer 13 is aligned with the second direction of the second crystal axis of the second high-temperature superconducting layer 23. The first direction of the first crystal axis of the first high-temperature superconducting layer 13 is, for example, the a-axis direction 13a of the first high-temperature superconducting layer 13. The second direction of the second crystal axis of the second high-temperature superconducting layer 23 is, for example, the a-axis direction 23a of the second high-temperature superconducting layer 23. In this specification, the fact that the first direction of the first crystal axis of the first high-temperature superconducting layer 13 is aligned with the second direction of the second crystal axis of the second high-temperature superconducting layer 23 means that the absolute value of the angle between the first direction of the first crystal axis of the first high-temperature superconducting layer 13 and the second direction of the second crystal axis of the second high-temperature superconducting layer 23 is 5° or less. The absolute value of the angle between the first direction of the first crystal axis of the first high-temperature superconducting layer 13 and the second direction of the second crystal axis of the second high-temperature superconducting layer 23 may be 3° or less, or may be 1° or less. Therefore, the critical current density J c A significant decrease in the

[0068] A method for manufacturing a connection structure 1 for high temperature superconducting wires according to the present embodiment will be described with reference to Fig. 6. The method for manufacturing a connection structure 1 for high temperature superconducting wires according to the present embodiment includes preparing a first high temperature superconducting wire 10 and a second high temperature superconducting wire 20 (S10) and superconductively connecting the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20 to each other (S20).

[0069] With reference to FIG. 7, the preparation of first high temperature superconducting wire 10 and second high temperature superconducting wire 20 (S10) will be described.

[0070] The first substrate 11 and the second substrate 21 are rolled (S11). For example, a rolling roll is used to roll the substrates. The first substrate 11 is rolled, for example, along a first longitudinal direction of the first substrate 11. The first rolling direction 11r of the first substrate 11 is, for example, the first longitudinal direction of the first substrate 11. The second substrate 21 is rolled, for example, along a second longitudinal direction of the second substrate 21. The second rolling direction 21r of the second substrate 21 is, for example, the second longitudinal direction of the second substrate 21.

[0071] A first intermediate layer 12 and a second intermediate layer 22 are formed (S12). The first intermediate layer 12 is formed on the first substrate 11. The second intermediate layer 22 is formed on the second substrate 21. The intermediate layers are formed by, for example, an IAD method or the like.

[0072] When first substrate 11 is a textured metal substrate, the crystal orientation of the surface of first substrate 11 is set by first rolling direction 11r of first substrate 11. In order to improve the crystal orientation of the surface of first substrate 11, first substrate 11 may be rolled while applying heat to first substrate 11.

[0073] When the first substrate 11 and the first intermediate layer 12 are IAD substrates, the first substrate 11 may be a non-oriented metal substrate such as Hastelloy (registered trademark). The second substrate 21 and the second intermediate layer 22 are, for example, IAD substrates. The second substrate 21 may be a non-oriented metal substrate such as Hastelloy (registered trademark). The IAD substrate includes an oriented intermediate layer as an intermediate layer (first intermediate layer 12, second intermediate layer 22). The orientation direction of the intermediate layer (first intermediate layer 12, second intermediate layer 22) can be set to any direction by changing the irradiation direction of the ion beam in the IAD method.

[0074] A first high temperature superconducting layer 13 and a second high temperature superconducting layer 23 are formed (S13). The first high temperature superconducting layer 13 is formed on the first intermediate layer 12. The second high temperature superconducting layer 23 is formed on the second intermediate layer 22. The high temperature superconducting layers (first high temperature superconducting layer 13, second high temperature superconducting layer 23) are formed on the intermediate layers (first intermediate layer 12, second intermediate layer 22) by using, for example, a pulsed laser deposition (PLD) method, a metal organic chemical vapor deposition (MOCVD) method, a coating pyrolysis method (Metal Organic Deposition (MOD) method), or the like.

[0075] When the first substrate 11 is a textured metal substrate, the first direction of the first crystal axis of the first high temperature superconducting layer 13 is determined by the crystal orientation of the surface of the first substrate 11. The first direction of the first crystal axis of the first high temperature superconducting layer 13 is, for example, the a-axis direction 13a of the first high temperature superconducting layer 13. With reference to FIG. 1 , the first direction of the first crystal axis of the first high temperature superconducting layer 13 is the first rolling direction 11r of the first substrate 11 and also the first longitudinal direction of the first high temperature superconducting wire 10.

[0076] When the first substrate 11 is an IAD substrate, a first direction of the first crystal axis of the first HTS layer 13 is determined by the orientation direction of the first intermediate layer 12. The first direction of the first crystal axis of the first HTS layer 13 is, for example, the a-axis direction 13a of the first HTS layer 13. When the second substrate 21 is an IAD substrate, a second direction of the second crystal axis of the second HTS layer 23 is determined by the orientation direction of the second intermediate layer 22. The second direction of the second crystal axis of the second HTS layer 23 is, for example, the a-axis direction 23a of the second HTS layer 23.

[0077] By changing the irradiation direction of the ion beam in the IAD method, the crystal orientation of the high-temperature superconducting layer can be set to any direction in the in-plane direction of the high-temperature superconducting layer. Therefore, by including at least the second high-temperature superconducting wire 20 in the IAD substrate, the second angle β between the second rolling direction 21r of the second substrate 21 in the plan view of the second main surface 21a and the second direction of the second crystal axis of the second high-temperature superconducting layer 23 corresponding to the first crystal axis can be made different from the first angle α between the first rolling direction 11r of the first substrate 11 in the plan view of the first main surface 11a and the first direction of the first crystal axis of the first high-temperature superconducting layer 13. The first direction of the first crystal axis of the first high-temperature superconducting layer 13 is, for example, the a-axis direction 13a of the first high-temperature superconducting layer 13. The second direction of the second crystal axis of the second high-temperature superconducting layer 23 corresponding to the first crystal axis is, for example, the a-axis direction 23a of the second high-temperature superconducting layer 23.

[0078] The difference between the second angle β and the first angle α may be greater than 5° and less than 175°. The difference between the second angle β and the first angle α may be greater than or equal to 15° and less than or equal to 165°. The difference between the second angle β and the first angle α may be greater than or equal to 30° and less than or equal to 150°.

[0079] The difference between the second angle β and the first angle α may be greater than 5° and less than 80°, or greater than 100° and less than 175°. The difference between the second angle β and the first angle α may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The difference between the second angle β and the first angle α may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0080] As shown in Fig. 1, in this embodiment, the a-axis direction 13a of the first high-temperature superconducting layer 13 is the first rolling direction 11r of the first substrate 11 and the first longitudinal direction of the first high-temperature superconducting wire 10. The a-axis direction 23a of the second high-temperature superconducting layer 23 is inclined at 45° with respect to the second rolling direction 21r of the second substrate 21 and is inclined at 45° with respect to the second longitudinal direction of the second high-temperature superconducting wire 20. However, as shown in Figs. 9 to 11, the a-axis direction 23a of the second high-temperature superconducting layer 23 is not limited to the direction inclined at 45° with respect to the second rolling direction 21r of the second substrate 21 and the second longitudinal direction of the second high-temperature superconducting wire 20.

[0081] The second angle β may be greater than 5° and less than 175°. The second angle β may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The second angle β may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0082] The second angle β may be greater than 5° and less than 80°, or greater than 100° and less than 175°. The second angle β may be greater than or equal to 15° and less than or equal to 75°, or greater than or equal to 105° and less than or equal to 165°. The second angle β may be greater than or equal to 30° and less than or equal to 60°, or greater than or equal to 120° and less than or equal to 150°.

[0083] When first high temperature superconducting wire 10 includes an IAD substrate, a-axis direction 13a of first high temperature superconducting layer 13 is not limited to first rolling direction 11r of first substrate 11 or the first longitudinal direction of first high temperature superconducting wire 10.

[0084] The first stabilization layer 14 and the second stabilization layer 24 are formed (S14). With reference to FIG. 3, the first stabilization layer 14 is formed on the first high-temperature superconducting layer 13. With reference to FIG. 2 and FIG. 3, the first stabilization layer 14 may also be formed on the first substrate 11. With reference to FIG. 2, in the connection 2 between the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20, the first stabilization layer 14 is not formed on the first high-temperature superconducting layer 13. With reference to FIG. 4, the second stabilization layer 24 is formed on the second high-temperature superconducting layer 23. With reference to FIG. 2 and FIG. 4, the second stabilization layer 24 may also be formed on the second substrate 21. 2, in the connection 2 between the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20, the second stabilization layer 24 is not formed on the second high temperature superconducting layer 23. In the connection 2 between the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20, the second high temperature superconducting layer 23 is exposed from the second stabilization layer 24.

[0085] In this manner, the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20 are prepared.

[0086] With reference to FIG. 8, the step of superconductively connecting the first high temperature superconducting wire 10 and the second high temperature superconducting wire 20 to each other (S20) will be described.

[0087] Microcrystals of a high temperature superconducting material are formed (S21) in at least one of the first high temperature superconducting layer 13 or the second high temperature superconducting layer 23. Specifically, microcrystals of a high temperature superconducting material are formed in at least one of a first portion of the first high temperature superconducting layer 13 exposed from the first stabilization layer 14 or a second portion of the second high temperature superconducting layer 23 exposed from the second stabilization layer 24. The microcrystals are formed by, for example, the MOD method, the PLD method, the electron beam deposition method, or the like.

[0088] The first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20 are aligned with each other (S22). For example, the first high-temperature superconducting wire 10 and the second high-temperature superconducting wire 20 are aligned with each other so that a first direction of the first crystal axis of the first high-temperature superconducting layer 13 is aligned with a second direction of the second crystal axis of the second high-temperature superconducting layer 23. The first direction of the first crystal axis of the first high-temperature superconducting layer 13 is, for example, the a-axis direction 13a of the first high-temperature superconducting layer 13. The second direction of the second crystal axis of the second high-temperature superconducting layer 23 is, for example, the a-axis direction 23a of the second high-temperature superconducting layer 23.

[0089] The angle θ between the first longitudinal direction of the first high-temperature superconducting wire 10 and the second longitudinal direction of the second high-temperature superconducting wire 20 is determined according to a first angle α between the first rolling direction 11r of the first substrate 11 in a plan view of the first main surface 11a and a first direction of the first crystal axis of the first high-temperature superconducting layer 13, and a second angle β between the second rolling direction 21r of the second substrate 21 in a plan view of the second main surface 21a and a second direction of the second crystal axis of the second high-temperature superconducting layer 23 corresponding to the first crystal axis. By setting at least the second angle β of the first angle α and the second angle β to an arbitrary angle, the angle θ can be set to an arbitrary angle. The degree of freedom of wiring of the second high-temperature superconducting wire 20 to the first high-temperature superconducting wire 10 can be improved.

[0090] Heat is applied to the first high temperature superconducting wire 10, the microcrystals, and the second high temperature superconducting wire 20 while applying pressure (S23). The heating and pressurizing step (S23) is performed, for example, in an atmosphere containing oxygen. In the heating and pressurizing step (S23), the microcrystals grow to become a superconducting joining layer 40 of the high temperature superconducting material. In this way, the first high temperature superconducting layer 13 and the second high temperature superconducting layer 23 are superconductively joined to each other via the superconducting joining layer 40. The first high temperature superconducting wire 10 and the second high temperature superconducting wire 20 are superconductively connected to each other.

[0091] With reference to FIG. 12 and FIG. 13, an example of a wiring structure 5 of high-temperature superconducting wires to which the connection structure 1 of the embodiment of the high-temperature superconducting wire is applied will be described. The wiring structure 5 of high-temperature superconducting wires includes a plurality of high-temperature superconducting wires 30. Among the plurality of high-temperature superconducting wires 30, two adjacent high-temperature superconducting wires 30 are superconductively connected. The connection structure 1 of the high-temperature superconducting wires of the present embodiment is applied to the connection of the plurality of high-temperature superconducting wires 30. Therefore, the wiring structure 5 of the high-temperature superconducting wires can be miniaturized. As shown in FIG. 12, a superconducting coil may be formed by applying the connection structure 1 of the high-temperature superconducting wires of the present embodiment. As shown in FIG. 13, a superconducting motor including a superconducting coil formed by a rectangular superconducting wire may be formed by applying the connection structure 1 of the high-temperature superconducting wires of the present embodiment.

[0092] The embodiments and modifications disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present disclosure is defined by the claims rather than the above-described embodiments, and is intended to include all modifications within the scope of the claims and the meaning equivalent thereto. [Explanation of symbols]

[0093] 1. Connection structure of high-temperature superconducting wire 2 Connection 5. Wiring structure of high-temperature superconducting wire 10. First high-temperature superconducting wire 11 First board 11a 1st main surface 11r First rolling direction 12 First Middle Class 13 First high-temperature superconducting layer 13a a-axis direction 14 1st stabilization layer 20. Second High-Temperature Superconducting Wire 21 Second board 21a 2nd principal surface 21r Second rolling direction 22 The second middle class 23 Second high-temperature superconducting layer 23a a-axis direction 24 Second stabilization layer 30 High-temperature superconducting wire 40 Superconducting junction layer

Claims

1. A first high temperature superconducting wire; a second high temperature superconducting wire superconductively connected to the first high temperature superconducting wire, the second high temperature superconducting wire is disposed relative to the first high temperature superconducting wire such that a first longitudinal direction of the first high temperature superconducting wire and a second longitudinal direction of the second high temperature superconducting wire intersect with each other at a connection portion between the first high temperature superconducting wire and the second high temperature superconducting wire; the first high temperature superconducting wire includes a first substrate including a first main surface, a first intermediate layer formed on the first main surface, and a first high temperature superconducting layer formed on the first intermediate layer; the second high temperature superconducting wire includes a second substrate including a second main surface, a second intermediate layer formed on the second main surface, and a second high temperature superconducting layer formed on the second intermediate layer; the second high temperature superconducting layer is superconductively joined to the first high temperature superconducting layer; the first substrate and the first intermediate layer are a first IAD substrate; The second substrate and the second intermediate layer are a second IAD substrate.

2. A first high temperature superconducting wire; a second high temperature superconducting wire superconductively connected to the first high temperature superconducting wire, the second high temperature superconducting wire is disposed relative to the first high temperature superconducting wire such that a first longitudinal direction of the first high temperature superconducting wire and a second longitudinal direction of the second high temperature superconducting wire intersect with each other at a connection portion between the first high temperature superconducting wire and the second high temperature superconducting wire; the first high temperature superconducting wire includes a first substrate including a first main surface, a first intermediate layer formed on the first main surface, and a first high temperature superconducting layer formed on the first intermediate layer; the second high temperature superconducting wire includes a second substrate including a second main surface, a second intermediate layer formed on the second main surface, and a second high temperature superconducting layer formed on the second intermediate layer; the second high temperature superconducting layer is superconductively joined to the first high temperature superconducting layer; a first angle between a first rolling direction of the first substrate and a first direction of a first crystal axis of the first high temperature superconducting layer in a plan view of the first main surface is different from a second angle between a second rolling direction of the second substrate and a second direction of a second crystal axis of the second high temperature superconducting layer corresponding to the first crystal axis in a plan view of the second main surface; A connection structure of high temperature superconducting wires, wherein, in the connection portion, the first direction of the first crystal axis of the first high temperature superconducting layer is aligned with the second direction of the second crystal axis of the second high temperature superconducting layer.

3. 3. The high temperature superconducting wire connection structure according to claim 2, wherein a difference between the second angle and the first angle is greater than 5 degrees and less than 175 degrees.

4. 3. The high temperature superconducting wire connection structure according to claim 2, wherein a difference between the second angle and the first angle is not less than 15 degrees and not more than 165 degrees.

5. 3. The high temperature superconducting wire connection structure according to claim 2, wherein a difference between the second angle and the first angle is equal to or greater than 30 degrees and equal to or less than 150 degrees.

6. the first substrate and the first intermediate layer are a first IAD substrate; 6. The high temperature superconducting wire connection structure according to claim 2, wherein the second substrate and the second intermediate layer are a second IAD substrate.

7. A connection structure for high temperature superconducting wires as described in claim 1, wherein an angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is greater than 5° and less than 175°.

8. A connection structure for high temperature superconducting wires as described in claim 1, wherein an angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is 15° or more and 165° or less.

9. A connection structure for high temperature superconducting wires as described in claim 1, wherein an angle between the first longitudinal direction of the first high temperature superconducting wire and the second longitudinal direction of the second high temperature superconducting wire is greater than 30° and less than 150°.

Images