Superconducting wire connection structure and superconducting wire connection method

Abstract

A linear material protection member (100) has a plurality of blocks (20) that protect a linear material (10) including a superconducting tape wire material (11). A component (20A2) constituting the bottom (23) of a first block (20A) has a first edge (20s1) disposed along one of a first side-wall (24) and a second side-wall (25) of the first block (20A), a second edge (20s2) disposed on a side opposite to the first edge (20s1), and a central region (CR1) disposed between the first edge (20s1) and the second edge (20s2). The component (20A2) has: a second wire holding part (TR2) and a third wire holding part (TR3) that are formed along the first edge (20s1) so as to be able to sandwich the first wire holding part (TR1) of the first component (20A1); and a screw hole (TH1) that is disposed in the central region (CR1) and is formed so as to penetrate the component (20A2) in the thickness direction.

Description

Linear material protection member and superconducting wire connection method

[0001] The present invention relates to a linear material protection member for holding a linear material and a method for connecting superconducting wires.

[0002] Japanese Patent Laid-Open Publication No. 2019-102298 (Patent Document 1) describes a superconductor in which a plurality of superconducting tape wires bound in a stacked state are inserted into a flexible tube. Patent Document 1 also describes a molding method in which a superconductor is formed into a coil shape, and then the stacked superconducting tape wires are molded with a molding member made of resin or metal.

[0003] JP 2019-102298 A

[0004] For example, linear materials such as electric wires or pipes may be used in applications where they are deformed, such as by being wrapped around a structure. When using linear materials in such applications, it is necessary to prevent the linear material itself from being damaged by external forces during wrapping or forces applied after wrapping. Furthermore, in order to wrap the linear material around a structure, the linear material and the protective member protecting it must be deformable. The inventors of the present application have been studying a protective member for protecting the linear material that has a deformable structure while preventing damage to the linear material.

[0005] As part of our research into protective members, we have investigated protective members with a structure that can connect multiple linear materials. If multiple linear materials that can be separated from each other can be connected via a protective member, a long linear material can be obtained by joining the multiple linear materials.

[0006] One embodiment of the linear material protection element includes a plurality of blocks for surrounding and holding a linear material extending in a first direction, and a first wire extending in the first direction and engaged with the plurality of blocks. The linear material includes a first linear material including a plurality of stacked first superconducting tape wires. The plurality of blocks are arranged in order along the first direction. Each of the plurality of blocks includes a holding space for holding the linear material, a roof portion covering the holding space, a bottom portion located on the opposite side of the roof portion across the holding space, a first sidewall portion connected to each of the roof portion and the bottom portion, and a second sidewall portion connected to each of the roof portion and the bottom portion and located on the opposite side of the first sidewall portion. The plurality of blocks includes a first block and a second block having a shape different from that of the first block. The first block includes a first part that constitutes the roof, the first sidewall, and the second sidewall, and a second part that is connected to the first part via the first wire and that constitutes the bottom. The first part has a first wire holding part that is formed at one of a position where the first sidewall and the bottom are combined and a position where the second sidewall and the bottom are combined and that can engage the first wire, and a first fixing part that is formed at the other of a position where the first sidewall and the bottom are combined and a position where the second sidewall and the bottom are combined and that can fix the second part. The second component has a first side arranged along one of the first side wall portion and the second side wall portion, a second side arranged on the opposite side of the first side, a central region arranged between the first side and the second side in a second direction intersecting the first direction, a second wire holding portion and a third wire holding portion formed along the first side in a state capable of sandwiching the first wire holding portion of the first component, a second fixing portion arranged along the second side and fixable to the first fixing portion of the first component, and a first screw hole arranged in the central region and formed to penetrate the second component in the thickness direction.

[0007] Another embodiment of the linear material protection element is a linear material protection element that protects a first linear material that includes a plurality of stacked first superconducting tape wires and extends in a first direction, a second linear material that includes a plurality of stacked second superconducting tape wires and extends in the first direction, and a plurality of third superconducting tape wires that extend in a second direction intersecting the first direction and electrically connects the plurality of first superconducting tape wires and the plurality of second superconducting tape wires. The linear material protection member includes a first block group consisting of a plurality of blocks for surrounding and holding the first linear material, a second block group consisting of a plurality of blocks for surrounding and holding the second linear material, a third block for surrounding and holding the portion where the plurality of first superconducting tape wires and the plurality of second superconducting tape wires are electrically connected via the plurality of third superconducting tape wires, a first wire extending in the first direction and engaged with the first block group and the third block, and a second wire extending in the first direction and engaged with the second block group and the third block. The third block includes a first holding space for holding the first linear material, a second holding space for holding the second linear material, a roof covering the first holding space and the second holding space, a first bottom located on the opposite side of the roof across the first holding space, a second bottom located on the opposite side of the roof across the second holding space, a first sidewall connected to the roof and the first bottom, and a second sidewall connected to the roof and the second bottom and located on the opposite side of the first sidewall. The housing includes a side wall portion, a middle wall portion located between the first side wall portion and the second side wall portion, a third holding space formed to communicate between the first holding space and the second holding space and holding the plurality of third superconducting tape wires, a first part constituting the roof portion, the first side wall portion, the second side wall portion, and the middle wall portion, a second part connected to the first part via the first wire and constituting the first bottom, and a third part connected to the first part via the second wire and constituting the second bottom.The first part has a first wire holding part formed at a position where the first side wall part and the first bottom part are combined and capable of engaging the first wire, a first fixing part formed at a position where the middle wall part and the first bottom part are combined and capable of fixing the second part, and a second fixing part formed at a position where the second side wall part and the second bottom part are combined and capable of fixing the third part. The second part has a first side arranged along the first side wall part, a second side arranged on the opposite side of the first side, a first central region arranged between the first side and the second side in the second direction, a second wire holding part and a third wire holding part formed along the first side in a state capable of sandwiching the first wire holding part of the first part, a third fixing part arranged along the second side and capable of being fixed to the first fixing part of the first part, a fourth wire holding part formed at a position where the middle wall part and the second bottom part are combined and capable of engaging the second wire, and a first screw hole arranged in the first central region and formed to penetrate the second part in the thickness direction. The third part has a third side arranged along the second side of the second part, a fourth side arranged on the opposite side of the third side, a second central region arranged between the third side and the fourth side in the second direction, a fifth wire holding portion and a sixth wire holding portion formed along the third side in a state capable of sandwiching the second wire holding portion of the second part, a fourth fixing portion arranged along the fourth side and fixable to the second fixing portion of the first part, and a second screw hole arranged in the second central region and formed to penetrate the third part in the thickness direction.

[0008] Another embodiment of a method for connecting linear materials includes the steps of: (a) preparing a first superconducting wire having a first stack consisting of a plurality of stacked first superconducting tape wires; (b) preparing a second superconducting wire having a second stack consisting of a plurality of stacked second superconducting tape wires; (c) after steps (a) and (b), forming a third stack by alternately stacking portions of the plurality of first superconducting tape wires and portions of the plurality of second superconducting tape wires so that they overlap each other; (d) preparing a first block as a protective member capable of holding the third stack so as to surround it; and (e) after steps (c) and (d), inserting screws into screw holes formed in the first block and tightening the screws to fix the third stack in a holding space of the first block. The first block includes a holding space capable of holding the third stack, a roof portion covering the holding space, a bottom portion located on the opposite side of the roof portion across the holding space, and the screw hole that penetrates the bottom portion in the thickness direction and communicates with the holding space.

[0009] According to an exemplary embodiment of the present invention, a deformable linear material protection member is provided that prevents damage to the linear material.

[0010] 1 is an explanatory diagram showing an example of the structure of a linear material held in a protective member according to an embodiment. It is an explanatory diagram showing a state in which the superconducting wire shown in FIG. 1 is held in a protective member according to an embodiment. It is a cross-sectional view taken along line A-A in FIG. 2. It is a plan view of a block, among a plurality of blocks, that is arranged at an end of an arrangement, viewed from the bottom. It is a perspective view showing the block shown in FIG. 4 before assembly. It is a perspective view showing the state in which two components constituting the block shown in FIG. 5 are assembled. It is a cross-sectional view taken along line B-B in FIG. 2. It is a perspective view showing the block shown in FIG. 7 before assembly. It is a perspective view showing the state in which two components constituting the block shown in FIG. 7 are assembled. It is a cross-sectional view taken along line C-C in FIG. 2. It is a perspective view showing an example of a case in which superconducting wire is used as a coil. It is a perspective view showing an example of a block that protects a portion where superconducting wire is connected in parallel, among a plurality of blocks that are used in the coil shown in FIG. 11. It is a cross-sectional view taken along line D-D in FIG. 12. It is a cross-sectional view taken along line E-E in FIG. 12. It is a perspective view showing one of the two blocks shown in FIG. 12. It is a perspective view showing the state in which the block shown in FIG. 13 is assembled. 21 is an explanatory diagram showing an example of a process flow of a method for connecting superconducting wires. FIG. 22 is an explanatory diagram showing an example of a process flow of a method for connecting superconducting wires. FIG. 23 is an explanatory diagram showing an example of a structure of a superconducting tape wire shown in FIG. 22. FIG. 24 is an explanatory diagram showing an example of a structure of a superconducting tape wire shown in FIG. 22. FIG. 25 is an explanatory diagram showing an example of a structure of a superconducting tape wire shown in FIG. 22. FIG. 26 is an explanatory diagram showing an example of a structure of a superconducting tape wire shown in FIG. 22. FIG. 27 is an explanatory diagram showing an example of a structure of a superconducting tape wire shown in FIG. 22.

[0011] The present inventors are conducting research and development of a nuclear fusion reactor, which generates a nuclear fusion reaction by confining high-temperature, high-density plasma within the reactor. As part of this research, they are considering using high-temperature superconducting tape wires as a material for coils that generate a magnetic field to confine the plasma within the reactor. The technology described below can be used as a protective member for various linear materials, such as high-temperature superconductors, electric wires, or pipes. However, the following description focuses on an embodiment in which the technology is applied to a protective member that protects a high-temperature superconductor. In the following description, a distinction is made between a "linear material" and a "linear material protective member" that protects the "linear material." Wires that are engaged with multiple blocks of the protective member are described as components included in the "linear material protective member." In the following description, the transition of a superconductor from a superconducting state to a normal conducting state may be referred to as a "quench."

[0012] <Superconducting Wire> In this application, a superconductor that exhibits superconductivity at 77 K or higher is referred to as a high-temperature superconductor. Hereinafter, the terms "superconductor," "superconductor layer," "superconducting tape wire," or "superconducting wire" will be used simply to refer to a material containing a high-temperature superconductor. A superconducting tape wire (more specifically, a high-temperature superconducting tape wire) is a tape material in which a superconductor layer (more specifically, a high-temperature superconductor layer) is formed on a metal tape approximately 100 micrometers thick. When a superconducting tape wire is used as a coil, for example, a superconducting wire (more specifically, a high-temperature superconducting wire) is formed by stacking and bundling multiple superconducting tape wires, and a superconducting coil (more specifically, a high-temperature superconducting coil) is formed by forming the superconducting wire into a coil shape. Furthermore, when a strong magnetic field needs to be generated, such as in coils used in nuclear fusion reactors or high-energy particle accelerators, a stacked coil may be formed by winding multiple superconducting wires in a stacked manner.

[0013] The superconducting wire includes, for example, a flexible tube that bundles stacked superconducting tape wires. The flexible tube is formed, for example, by wrapping a metal band around the stacked superconducting tape wires. Furthermore, as described in the above-mentioned Patent Document 1, when the superconducting wire is formed and then the stacked superconducting tape wires are molded with a molding member made of resin or a low-melting-point metal, the strength can be improved compared to a single superconducting tape wire.

[0014] However, according to the inventors' investigations, when forming a superconducting wire into a complex shape, the external forces applied to the superconducting wire or the stresses generated in the superconducting wire are large, and therefore further improvement in strength is necessary. For example, in the case of coils used in helical-type nuclear fusion reactors, the superconducting wire is wound into a coil shape by twisting it, so a large force is likely to be applied during the winding process, resulting in large stresses generated in the superconducting wire. In addition, a large external force may be applied to the superconducting wire after it is formed into a coil shape. For example, when a large current flows through a superconducting coil, a magnetic field generated around the coil may cause a large external force, such as a Lorentz force, to be applied to the superconducting wire. Therefore, a protective member capable of preventing damage to the superconducting wire is needed.

[0015] On the other hand, if the superconducting wire is housed in, for example, a metal pipe to prevent damage to the superconducting wire, it is possible to protect the superconducting wire, but this makes it difficult to process the wire, such as bending it.

[0016] The technology described below can be applied to various applications as described above, but is particularly effective when applied to a protective member for protecting superconducting wires used in molded articles such as superconducting coils. In addition, the following also describes a technology that is particularly effective when multiple superconducting wires are stacked.

[0017] FIG. 1 is an explanatory diagram showing an example of the structure of a linear material held in a protective member according to one embodiment. As shown in FIG. 1 , the linear material according to this embodiment is a superconducting wire 10 including a plurality of superconducting tape wires 11 stacked together and a metal band 12 wound around a stack 11A of the plurality of superconducting tape wires 11. While FIG. 1 illustrates a state in which 152 superconducting tape wires 11 are stacked, the number of superconducting tape wires is not limited to the example shown in FIG. 1 and can be determined depending on the coil size or the specifications of the current value to be passed through the coil. For example, as a modification of this embodiment, the number of superconducting tape wires 11 stacked in the stack 11A may be 151 or less or 153 or more.

[0018] The superconducting tape wire 11 is a tape wire in which a superconductor layer (more specifically, a high-temperature superconductor layer) is formed on a metal tape having a thickness of approximately several tens of micrometers. In the example shown in FIG. 1 , the thickness of the superconducting tape wire 11 is approximately 0.1 mm, and the width of the superconducting tape wire 11 is approximately 12 mm. The thickness and width of the superconducting tape wire 11 are merely examples, and various modifications are possible. The multiple superconducting tape wires 11 are stacked without being bonded to each other, allowing them to be displaced relative to each other. This allows the superconducting wire 10, which is a stack 11A of multiple superconducting tape wires 11, to be formed into, for example, a coil shape. Although not shown, as a modification of FIG. 1 , the stack 11A of multiple superconducting tape wires 11 may be bound together using a wire or the like (not shown). In this case, the handleability of the stack 11A is improved. On the other hand, from the viewpoint of improving the degree of freedom of movement of the plurality of superconducting tape wires 11 within the tube made of the metal band 12, it is preferable that the stack 11A of the plurality of superconducting tape wires 11 is not bound together as in this embodiment.

[0019] A stack 11A of multiple superconducting tape wires 11 is inserted into a metal band 12 formed into a tube shape. In the example shown in FIG. 1 , the thickness of the metal band 12 is, for example, approximately 100 μm to several hundred μm, and the width is approximately 3 to 5 mm. Furthermore, in the cross-sectional view shown in FIG. 3 (described later), the metal band 12 is formed into a cylindrical shape. Hereinafter, a structure formed by the metal band 12 may be referred to as a tube. The outer diameter of the tube is, for example, 23 mm, and the inner diameter is, for example, 22 mm. Although the tube is a metal cylinder, it can be formed into a coil shape if it has this thickness. The metal band 12 functions as a bundling member that bundles the stack 11A of multiple superconducting tape wires 11 to prevent them from scattering. However, each of the multiple superconducting tape wires 11 can move freely to some extent within the tube formed by the metal band 12.

[0020] In the example shown in Fig. 1 , the metal bands 12 surrounding the periphery of the laminate 11A are spring-shaped, with a gap provided between adjacent metal bands 12. As will be described later, when molding the laminate 11A of a plurality of superconducting tape wires 11 with a molding member after forming the superconducting wire 10 into a coil shape, an opening is required for introducing the molding member into the tube of the metal band 12. When a gap is provided between adjacent metal bands 12 as shown in Fig. 1 , the molding member can be introduced through this gap to mold the laminate 11A of a plurality of superconducting tape wires 11.

[0021] 1, the metal bands 12 may be wound so as to overlap each other in part. In this case, when molding a stack 11A of a plurality of superconducting tape wires 11, it is preferable to provide an opening at one or more locations in the tube made of the metal bands 12 for introducing a molding material.

[0022] 1, the superconducting wire 10 has a cooling pipe 13 and a spacer 14 disposed next to the stack 11A of superconducting tape wires 11. In the example shown in FIG. 1, a plurality of (two in FIG. 1) cooling pipes 13 and a plurality of (two in FIG. 1) spacers 14 are disposed next to the stack 11A of a plurality of superconducting tape wires 11.

[0023] The cooling pipe 13 is a pipe that serves as a flow path for a coolant and is arranged along the stack 11A of a plurality of superconducting tape wires 11. Liquid hydrogen or gaseous helium at a temperature of, for example, about 20 K (Kelvin) flows through the cooling pipe 13. The cooling pipe 13 has an outer diameter of, for example, 8 mm and an inner diameter of, for example, 7 mm. The cooling pipe 13 has a wall thickness of 1 mm. With this thickness, even if the cooling pipe 13 is made of metal, it can be deformed to fit the shape of the superconducting wire 10. Note that, in order to improve the flexibility of the cooling pipe 13, a bellows-shaped pipe may be used. By arranging the cooling pipe 13 next to the stack 11A of the superconducting tape wires 11 as in this embodiment, the cooling efficiency of the superconducting tape wire 11 can be improved.

[0024] The spacers 14 are, for example, wires, and are provided to prevent misalignment of the stack 11A of superconducting tape wires 11 and the plurality of cooling pipes 13 within the tube made of the metal band 12.

[0025] The spacer 14 is made of, for example, copper. The spacer 14 may come into contact with the superconducting tape wire 11. Therefore, it is preferable to use a wire made of copper as the spacer 14 so as not to impair the electrical characteristics of the superconducting tape wire 11.

[0026] The wire diameter of the spacer 14 is, for example, about 2 mm to 3 mm. In the example shown in Fig. 1, one spacer 14 is disposed in the space surrounded by the two cooling pipes 13 and the stack 11A of superconducting tape wires 11, and one spacer 14 is disposed in the space surrounded by the two cooling pipes 13 and the metal band 12.

[0027] However, various modifications can be made to the number and shape of the spacers 14 depending on the position or cross-sectional area of ​​the space generated inside the tube. For example, if a gap is generated between the metal band 12 and the stack 11A of superconducting tape wires 11, a spacer 14 can be inserted into the gap.

[0028] Similarly, there are various variations in the presence or absence and number of cooling pipes 13. For example, in the case of a small superconducting wire having about 30 superconducting tape wires 11 stacked one upon the other, there is a case where no cooling pipe 13 is provided. There is also a case where there is one cooling pipe 13, or three or more cooling pipes 13.

[0029] The stack 11A of superconducting tape wires 11, the cooling pipes 13, and the spacers 14 are each inserted into a metal band 12 formed into a tubular shape. Since two cooling pipes 13 and two spacers 14 are arranged inside the tube, the stack 11A of superconducting tape wires 11 has a cross-sectional shape such that one side of the stack 11A conforms to the inner wall of the tube. The multiple superconducting tape wires 11 are not bonded to each other and are stacked in a state where they can be displaced from one another, so that the stack can be deformed into the shape shown in FIG. 1 without any prior shaping.

[0030] There is also a method of forming a coil shape by directly winding the superconducting wire 10 shown in Fig. 1 around the core material of a coil. However, according to the study of the present inventors, it has been found that when the superconducting wire 10 is directly wound around the core material of a coil, the superconducting wire 10 may be damaged during the winding process. It has also been found that when the superconducting wire 10 is wound in multiple layers around the core material of a coil, the position of the stacked superconducting wire 10 may be shifted.

[0031] Therefore, the inventors of the present application have studied a protective member for protecting the superconducting wire 10. The functions required of the protective member are as follows. First, the protective member itself must be deformable when the superconducting wire 10 is formed (e.g., into a coil shape). Second, the protective member must have a structure that can prevent damage to the superconducting wire 10 when the superconducting wire 10 is formed (e.g., into a coil shape). Furthermore, when the superconducting wire 10 is wound in multiple layers, it is preferable that the superconducting wire 10 can be prevented from shifting in position. Furthermore, when the superconducting wire 10 is attached to the protective member, it is preferable that the superconducting wire 10 can be easily attached. Furthermore, a large current flows through the superconducting wire 10. At this time, it is preferable that the protective member has a structure that makes it difficult for components to be damaged by the influence of electromagnetic forces generated around the superconducting wire 10.

[0032] <Protective Member> FIG. 2 is an explanatory diagram showing the superconducting wire shown in FIG. 1 held by a protective member according to this embodiment. Although FIG. 2 is a perspective view, component 20A2 and component 20B2 are hatched to clearly indicate the boundaries between the components constituting the protective member. FIG. 3 is a cross-sectional view taken along line A-A in FIG. 2. FIG. 4 is a plan view of a block located at an end of an array of multiple blocks, viewed from the bottom. FIG. 5 is a perspective view showing the block shown in FIG. 4 before assembly. FIG. 6 is a perspective view showing the two components constituting the block shown in FIG. 5 assembled together. Of the multiple wires 30 shown in FIG. 3, only wire 31, which contributes to connecting component 20A1 and component 20A2, is shown in FIGS. 5 and 6. In this embodiment, wires 32, 33, and 34 shown in FIG. 3 are engaged with block 20A in addition to wire 31 shown in FIGS. 5 and 6.

[0033] In the following description, the extension direction of the superconducting wire 10 shown in FIG. 2 is referred to as the X direction, the direction intersecting the X direction in a plan view (the direction perpendicular to the X direction in the example shown in FIG. 2) is referred to as the Y direction, and the normal direction (sometimes referred to as the thickness direction) of the X-Y plane including the X and Y directions is referred to as the Z direction.

[0034] As shown in FIG. 2 , the protective member 100 of this embodiment has a plurality of blocks 20 for surrounding and holding the periphery of the superconducting wire 10, which is a linear material, and wires 30 engaged with the plurality of blocks 20. In this embodiment, the protective member 100 has four wires 30, as shown in FIG. 3 . The four wires 30 are made of wires 31, 32, 33, and 34, as shown in FIG. 3 . Each of the plurality of wires 30 is made of metal. Examples of metal materials that make up the wires 30 include so-called stainless steel (e.g., SUS304), titanium (Ti), and titanium alloys. The wire diameter of the wires 30 is, for example, about 2 mm.

[0035] The protective member 100 of this embodiment can be divided into a plurality of blocks 20, and has a structure in which the plurality of blocks 20 are connected via wires 30. Therefore, when the protective member 100 (in other words, a linear material with a protective member) holding the superconducting wire 10 is wound around a core material of a coil, for example, gaps can be generated at the boundaries between the plurality of blocks 20 as needed. This makes it possible to deform the protective member 100 and wind it around a structure such as a core material. In other words, the plurality of blocks 20 have a deformable structure like a spine.

[0036] The wire 30 functions as a reinforcing member for preventing damage to the superconducting wire 10 due to a pulling force when the superconducting wire 10 housed in the protective member 100 is wound around, for example, a core material of a coil. For this reason, the wire 30 is arranged so as to extend in the same direction as the extension direction of the superconducting wire (the X direction in the case of FIG. 2 ). At least one wire 30 is sufficient, but providing a plurality of wires 30 as shown in FIG. 2 is preferable in that the reinforcing strength of the superconducting wire 10 is increased.

[0037] As shown in Fig. 3, each of the plurality of blocks 20 includes a holding space 21 (see Fig. 6) for holding superconducting wire 10, a roof portion 22 covering holding space 21, a bottom portion 23 located on the opposite side of roof portion 22 across holding space 21, and side wall portions 24 and 25 connected to roof portion 22 and bottom portion 23, respectively. Side wall portion 25 is located on the opposite side of side wall portion 24 across holding space 21 (see Fig. 6).

[0038] The roof portion 22, the bottom portion 23, the side wall portion 24, and the side wall portion 25 are each made of a metal material. Examples of metal materials that can be used to make the roof portion 22, the bottom portion 23, and the side wall portion 24 include titanium (Ti) and titanium alloys. In particular, in the case of protective members for linear materials through which a large current flows, such as the superconducting wire 10, non-magnetic materials are preferred. Considering the hardness, processability, non-magnetic properties of the material, the roof portion 22, the bottom portion 23, the side wall portion 24, and the side wall portion 25 can also be made of stainless steel (e.g., SUS304) in addition to the titanium alloy described above.

[0039] The protective member 100 has a plurality of types of blocks 20 with different shapes. In the example shown in Fig. 2, the protective member 100 includes a block 20A and a block 20B with a different shape from the block 20A. As will be described in detail later, the block 20A has a structure that makes it easy to connect the stack 11A of the superconducting tape wires 11 to the lead portion 40. On the other hand, the block 20B has a simple structure that makes it easy to wind the block 20B around the superconducting wire 10.

[0040] Therefore, of the multiple blocks 20 arranged along the X direction, blocks 20A are arranged at the ends of the array. In the example shown in Fig. 2, only the blocks 20 arranged at the ends of the array are blocks 20A, and the others are blocks 20B. However, the locations where blocks 20A are arranged are not limited to the ends of the array, and there are cases where multiple blocks 20A are arranged consecutively along the X direction, including the ends of the array.

[0041] <Block 20A> First, the structure of block 20A shown in Fig. 2 will be described. As shown in Fig. 3, block 20A includes a component 20A1 that forms roof portion 22, side wall portions 24, and side wall portions 25, and a component 20A2 that is connected to component 20A1 via wire 31 and that forms bottom portion 23.

[0042] Component 20A1 has a wire holding portion TR1 capable of engaging wire 31 and a fixing portion BP1 (see FIG. 5 ) capable of fixing component 20A2. Wire holding portion TR1 is formed at either the position where sidewall portion 24 and bottom portion 23 are combined or the position where sidewall portion 25 and bottom portion 23 are combined. In the example shown in FIG. 3 , wire holding portion TR1 is formed at the end of sidewall portion 24 (the position where sidewall portion 24 and bottom portion 23 are combined). Fixing portion BP1 is formed at the other of the position where sidewall portion 24 and bottom portion 23 are combined or the position where sidewall portion 25 and bottom portion 23 are combined. In the example shown in FIG. 3 , fixing portion BP1 is formed at the end of sidewall portion 25 (the position where sidewall portion 25 and bottom portion 23 are combined).

[0043] As shown in FIG. 4, the component 20A2 has a side 20s1, a side 20s2, a central region CR1, a wire holding portion TR2, a wire holding portion TR3, a fixing portion BP2 (see FIG. 5), and a screw hole TH1.

[0044] Each of the sides 20s1 and 20s2 extends along the X direction. The side 20s1 is disposed along one of the side wall portion 24 (see FIG. 3) and the side wall portion 25 (see FIG. 3). In the example shown in FIG. 4, the side 20s1 is disposed along the side wall portion 24 (see FIG. 3). The side 20s2 is disposed on the opposite side of the side 20s1. In a plan view, the central region CR1 is disposed between the sides 20s1 and 20s2. Specifically, in the Y direction that intersects with the X direction (orthogonal to the X direction in FIG. 4), the central region CR1 is disposed between the sides 20s1 and 20s2.

[0045] Each of the wire holding portions TR2 and TR3 extends along the X direction. Each of the wire holding portions TR2 and TR3 is formed along the side 20s1 in a state in which they can sandwich the wire holding portion TR1 of the component 20A1. In other words, in the X direction, the wire holding portion TR1 of the component 20A1 is sandwiched between the wire holding portions TR2 and TR3.

[0046] The fixed portion BP2 shown in Fig. 5 is arranged along the side 20s2. In the present embodiment, as shown in Figs. 5 and 6, the fixed portion BP2 (see Fig. 5), which is a convex portion, is combined with the fixed portion BP1 (see Fig. 6), which is a concave portion, so that the fixed portions BP1 and BP2 are tightly attached to each other and fixed. Hereinafter, this fixing method will be referred to as "crimping," and the portion fixed by crimping may be referred to as the crimped portion.

[0047] The method of fixing the fixing parts BP1 and BP2 is not limited to the crimping method, and various modifications are possible, such as welding.

[0048] The screw hole TH1 is disposed in the central region CR1 and is formed to penetrate the component 20A2 in the thickness direction. As shown in Fig. 3, a screw SS1 is inserted into the screw hole TH1. In the example shown in Fig. 3, one end of the screw SS1 is in contact with the stack 11A of the superconducting tape wires 11. In the present embodiment, the block 20A provided at the end of the array of multiple blocks 20 can fix the stack 11A with the screw SS1.

[0049] In the case of a structure in which the stack 11A of superconducting tape wires 11 can be fixed with the screw SS1, it is particularly suitable as a protective member to be placed at the joint of the superconducting wire 10 or at the portion connected to the lead portion 40 shown in Fig. 2. When attempting to connect a plurality of superconducting wires 10 to obtain a long superconducting wire 10, fixing the stack 11A at the portion where the superconducting wires 10 are connected makes it easier to maintain the electrical properties of the superconducting wire 10. The method of connecting the superconducting wires 10 will be described in detail later.

[0050] The screw SS1 is a set screw (also called a "set screw") that does not have a thread. Therefore, the entire screw SS1 can be embedded in the screw hole TH1. The screw SS1 does not protrude from the lower end of the screw hole TH1. In other words, the screw SS1 does not protrude from the lower surface 23b of the bottom portion 23.

[0051] 2, the superconducting wire 10 may be stacked while being protected by the protective member 100. In this case, it is preferable to reduce the protruding portion from the protective member 100 from the viewpoint of preventing interference between the protective member 100 arranged in the upper layer and the protective member 100 arranged in the lower layer.

[0052] In the present embodiment, set screws are used as the screws SS1, thereby making it possible to easily stack superconducting wires 10.

[0053] Furthermore, to facilitate fastening the stack 11A with the screws SS1, the block 20A preferably has the following structure. That is, the inner surfaces 24a of the side wall portions 24 and the inner surfaces 25a of the side wall portions 25 of the component 20A1 of the block 20A shown in FIG. 3 each have an arc shape when viewed from the side in the X direction (see FIG. 2). The upper surface 23a of the bottom portion 23 of the block 20A is flat. The lower surface 22b of the roof portion 22 of the block 20A is also flat.

[0054] In other words, the surface (upper surface 23a) of the bottom 23 of the block 20A that comes into contact with the stack 11A of the superconducting tape wires 11 and the surface (lower surface 22b) of the roof 22 of the block 20A that comes into contact with the stack 11A of the superconducting tape wires 11 are both flat. In this case, it is possible to improve the adhesion between the stack 11A and the lower surface 22b and between the stack 11A and the upper surface 23a.

[0055] 20 , which will be described later, a metal plate 19 may be disposed on the upper surface 23 a of the bottom portion 23. In this case, the screw SS1 inserted into the screw hole TH1 is in contact with the metal plate 19. This modification can prevent the screw SS1 from coming into direct contact with the superconducting tape wire 11. This is preferable in that damage to the superconducting tape wire 11 can be suppressed even when the screw is tightened by S1.

[0056] 3, each of the side wall portions 24 and 25 of the component 20A1 of the block 20A has an opening that penetrates the side wall portion 24 or the side wall portion 25 in the Y direction. Specifically, the side wall portion 24 has an opening portion 26 that penetrates the side wall portion 24 in the Y direction. Furthermore, the side wall portion 25 has an opening portion 27 that penetrates the side wall portion 25 in the Y direction.

[0057] The provision of opening 26 or opening 27 has the following advantages. That is, by forming opening 26, side wall 24 has an arched shape. Similarly, by forming opening 27, side wall 25 has an arched shape. In this case, the strength of side wall 24 and side wall 25 against external forces applied in the Z direction shown in FIG. 3 can be improved.

[0058] 3 , when the superconducting wire 10 includes a cooling pipe 13 in addition to the stack 11A of superconducting tape wires 11, the cooling pipe 13 may be drawn out in a direction different from the extending direction of the stack 11A. In this case, the openings 26 and 27 can be used as paths for drawing out the cooling pipe 13. In other words, the provision of the openings 26 and 27 improves the degree of freedom in the layout of the cooling pipe 13.

[0059] Alternatively, when superconducting wire 10 is used as a coil, superconducting wire 10 may be formed into a coil shape with protective member 100 attached, and then sealed with a sealing material to prevent displacement of superconducting wire 10. In this case, if openings 26 and 27 are provided, these openings can be used as a supply path for the sealing material. In other words, the provision of openings 26 and 27 makes it easy to supply the sealing material for sealing superconducting wire 10. The sealing material may be made of a metal as well as a resin.

[0060] A groove for inserting the wires 30 is formed in at least one of the roof portion 22, the bottom portion 23, the side wall portion 24, and the side wall portion 25 shown in Fig. 3. In the example shown in Fig. 3, four wires 30 are engaged, so a groove for inserting each of the four wires 30 is formed.

[0061] Specifically, grooves 31T1 and 31T2, into which wire 31 can be inserted, are formed in the region where bottom 23 and sidewall 24 intersect. Groove 31T1 is a groove provided in component 20A1 and has an opening facing component 20A1. Groove 31T1 communicates with wire holding portion TR1 at its bottom. Groove 31T2 is a groove provided in component 20A2 and has an opening on the lower surface of bottom 23. Groove 31T2 communicates with wire holding portion TR2 (see FIG. 4) or wire holding portion TR3 (see FIG. 4) at its bottom. As shown in FIG. 3 , by inserting wire 31 through grooves 31T1 and 31T2, which have openings facing in different directions, components 20A1 and 20A2 can be connected via wire 31 held in wire holding portions TR1, TR2, and TR3.

[0062] A groove 32T into which a wire 32 can be inserted is formed in the region where the roof 22 and the side wall 24 intersect. A groove 33T into which a wire 33 can be inserted is formed in the region where the roof 22 and the side wall 25 intersect. A groove 34T into which a wire 34 can be inserted is formed in the region where the bottom 23 and the side wall 25 intersect.

[0063] Superconducting wire 10 is wound around the core material of the coil while being held by protective member 100. During this operation, superconducting wire 10 is reinforced by a plurality of wires 30, and therefore, damage to superconducting wire 10 caused by external force during the operation can be prevented or suppressed.

[0064] <Block 20B> Next, the structure of block 20B shown in Figure 2 will be described. Figure 7 is a cross-sectional view taken along line B-B in Figure 2. Figure 8 is a perspective view showing the block shown in Figure 7 in a state before assembly. Figure 9 is a perspective view showing the state in which two components constituting the block shown in Figure 7 are assembled. Of the multiple wires 30 shown in Figure 7, Figures 8 and 9 only show wire 32, which contributes to connecting component 20B1 and component 20B2. In this embodiment, in addition to wire 32 shown in Figures 8 and 9, wires 31, 33, and 34 shown in Figure 7 are engaged.

[0065] 3 to 6 is advantageous in that the stack 11A of the superconducting tape wires 11 can be fixed with the screws SS1. On the other hand, from the viewpoint of ease of assembly of the block 20A, a simple structure that does not require fixation with the screws SS1 is preferable.

[0066] As shown in FIG. 2 , the protective member 100 further includes a wire 32 that extends along the X direction and is engaged with the plurality of blocks 20 .

[0067] 7, the block 20B includes a part 20B1 that forms the roof portion 22 and the side wall portion 24, and a part 20B2 that forms the bottom portion 23 and the side wall portion 25. In the present embodiment, the block 20B is made up of the part 20B1 and the part 20B2.

[0068] As shown in Figures 8 and 9, part 20B1 has wire holding parts TR5 and TR6 (see Figure 9) formed along the X direction in a state capable of sandwiching wire holding part TR4 of part 20B1, and fixing part BP3 capable of fixing part 20B2.

[0069] Component 20B2 has a wire holding portion TR4 capable of engaging wire 32 and a fixing portion BP4 capable of being fixed to fixing portion BP3 of component 20B1. Wire holding portion TR4 is formed at either the position where side wall portion 24 (see FIG. 7 ) and roof portion 22 (see FIG. 7 ) are combined or the position where side wall portion 25 (see FIG. 7 ) and bottom portion 23 (see FIG. 7 ) are combined. Fixing portion BP3 is formed at the other of the position where side wall portion 24 and roof portion 22 are combined or the position where side wall portion 25 and bottom portion 23 are combined. In the present embodiment, wire holding portion TR4 is formed at the position where side wall portion 24 and roof portion 22 are combined, and fixing portion BP3 is formed at the position where side wall portion 25 and bottom portion 23 are combined.

[0070] Block 20B does not have the screw hole TH1 that block 20A shown in Fig. 3 has. In other words, block 20B does not have the function of fixing stack 11A of superconducting tape wires 11, but is simply attached so as to cover the periphery of superconducting wire 10 (see Fig. 1). Block 20B can be assembled in fewer steps than block 20A shown in Fig. 3. Therefore, by providing block 20B as a block 20 that is provided midway in an arrangement of multiple blocks 20, assembly efficiency can be improved.

[0071] 9, the holding space 21 of the block 20B has a cylindrical shape when viewed from the side in the X direction. As shown in FIG. 1, a cylindrical tube-shaped metal strip can be easily accommodated inside the holding space 21 of the block 20B.

[0072] As shown in Fig. 7, the stack 11A does not contact the components 20B1 and 20B2 of the block 20B. There is a gap between the stack 11A and the metal band 12. Therefore, in the example shown in Fig. 7, the metal band 12 and the spacer 14 are arranged between the roof portion 22 and the stack 11A in the Z direction. Similarly, the metal band 12 and the spacer 14 are arranged between the bottom portion 23 and the stack 11A in the Z direction. Specifically, the spacer 14 is arranged between the metal band 12 and the stack 11A in the Z direction.

[0073] The block 20B is engaged with each of the wires 31, 32, 33, and 34. For this reason, similar to the block 20A, the block 20B is formed with grooves into which each of the four wires 30 is inserted.

[0074] Specifically, grooves 32T1 and 32T2, into which wire 32 can be inserted, are formed in the region where roof portion 22 and sidewall portion 24 intersect. Groove 32T1 is a groove provided in component 20B1 and has an opening on top surface 22a of roof portion 22. Groove 32T1 communicates at its bottom with wire holding portion TR5 (see FIG. 9 ) or wire holding portion TR6 (see FIG. 9 ). Groove 32T2 is a groove provided in component 20B2 and has an opening facing component 20B1. Groove 31T2 communicates at its bottom with wire holding portion TR4. As shown in FIG. 7 , by inserting wire 32 through grooves 32T1 and 32T2, which have openings facing in different directions, components 20B1 and 20B2 can be connected via wire 32 held in wire holding portions TR4, TR5, and TR6.

[0075] Furthermore, a groove 31T into which a wire 31 can be inserted is formed in the region where the bottom 23 and the side wall 24 intersect. A groove 33T into which a wire 33 can be inserted is formed in the region where the roof 22 and the side wall 25 intersect. Groove 33T has an opening in the upper surface 22a of the roof 22. A groove 34T into which a wire 34 can be inserted is formed in the region where the bottom 23 and the side wall 25 intersect. Groove 34T has an opening in the side surface of the bottom 23.

[0076] <Method of connecting to lead portion> Next, a method of electrically connecting the lead portion 40 shown in Fig. 2 to the superconducting wire 10 will be described. Fig. 10 is a cross-sectional view taken along line CC in Fig. 2. As described above, the stack 11A of superconducting tape wires 11 shown in Fig. 3 is formed by stacking 152 superconducting tape wires 11. However, Fig. 10 shows a smaller number of stacked layers in order to make it easier to see the structure in which the stack 11A of superconducting tape wires 11 and the stack 16A of superconducting tape wires 16 are superimposed.

[0077] When the superconducting wire 10 shown in FIG. 2 is used as a coil for generating a magnetic field in a magnetic confinement fusion device, the lead 40 functions as a terminal for connecting the coil to a power supply source (not shown). By attaching the lead 40 functioning as a terminal to the superconducting wire 10 containing a superconductor, the superconducting wire 10 can be easily electrically connected to an external device. The lead 40 shown in FIG. 10 includes a support 41 that supports a stack 16A of multiple superconducting tape wires 16 and a lid 42 that covers the stack 16A of multiple superconducting tape wires 16. The support 41 and the lid 42 are each made of a metal such as copper. The stack 16A of multiple superconducting tape wires 16 is sandwiched between the support 41 and the lid 42. The stack 16A of multiple superconducting tape wires 16 is also fixed between the support 41 and the lid 42.

[0078] Each of the plurality of superconducting tape wires 16 is a tape wire including a superconductor layer, similar to the superconducting tape wire 11 described with reference to Fig. 1. A method of sandwiching a stack 11A of superconducting tape wires 11 between a support part 41 and a lid part 42 of a lead part 40 may also be applied. However, from the viewpoint of facilitating a good connection between a superconductor and a metal that is not a superconductor in the lead part 40, it is preferable to use a stack 16A of superconducting tape wires 16 for connection to the lead part 40, as in this embodiment.

[0079] 10 , the upper surface 41a of the support 41 and the lower surface 42b of the lid 42 are each formed in a stepped shape. Each of the plurality of superconducting tape wires 16 is in contact with one of the steps of the stepped upper surface 41a or lower surface 42b. The stack 16A is in close contact with the support 41 and the lid 42. Because the upper surface 41a of the support 41 and the lower surface 42b of the lid 42 are each formed in a stepped shape, each of the superconducting tape wires 16 constituting the stack 16A can be in contact with the support 41 or the lid 42.

[0080] As shown in FIG. 2 , the support portion 41 and the lid portion 42 each have a plurality of through holes 41H and a plurality of through holes 42H. Bolts 43 are inserted into some of the through holes 41H and 42H, passing through both the through holes 42H and 41H. Nuts 44 are attached to the bolts 43. When the bolts 43 and nuts 44 are tightened, an external force is applied so as to reduce the distance between the support portion 41 and the lid portion 42. The laminate 16A shown in FIG. 10 is clamped between the support portion 41 and the lid portion 42 by the external force generated by tightening the bolts 43 and nuts 44. The surface pressure that the laminate 16A receives from the support portion 41 and the lid portion 42 of the lead portion 40 is, for example, approximately 100 MPa (megapascals).

[0081] In this embodiment, the tightness of the contact interface between the superconducting tape wire 16 and the support part 41 or the lid part 42 can be improved by adjusting the tightening force of the bolt 43 and the nut 44. As a result, the reliability of the electrical connection between the lead part 40 and the superconducting tape wire 16 can be improved.

[0082] Furthermore, the stack 16A of superconducting tape wires 16 extends from the lead portion 40 toward the block 20A adjacent to the lead portion. The location where the stack 16A of superconducting tape wires 16 and the stack 11A of superconducting tape wires 11 are electrically connected is surrounded by the block 20A as shown in Fig. 10. In other words, the stack 16A of superconducting tape wires 16 and the stack 11A of superconducting tape wires 11 are arranged in the holding space 21 (see Fig. 6) of the block 20A.

[0083] In this embodiment, a plurality of superconducting tape wires 11 and a plurality of superconducting tape wires 16 are alternately stacked in the holding space 21 (see FIG. 6 ) of the block 20A. In the structure in which the superconducting tape wires 11 and the superconducting tape wires 16 are alternately stacked, the contact area between the superconducting tape wires 11 and the superconducting tape wires 16 can be increased compared to the case in which a stack 16A of superconducting tape wires 16 is simply placed on a stack 11A of superconducting tape wires 11. In other words, the number of paths electrically connecting the superconducting tape wires 11 and the superconducting tape wires 16 increases. This improves the reliability of the electrical connection between the superconducting tape wires 11 and the superconducting tape wires 16.

[0084] In this embodiment, a plurality of (e.g., two or three) superconducting tape wires 11 and a plurality of (e.g., two or three) superconducting tape wires 16 may be alternately stacked. However, from the viewpoint of increasing the contact area between the superconducting tape wires 11 and the superconducting tape wires 16, it is preferable that the superconducting tape wires 11 and the superconducting tape wires 16 are alternately stacked one by one, as in this embodiment.

[0085] Increasing the number of paths electrically connecting the superconducting tape wire 11 and the superconducting tape wire 16 is advantageous in the following respects. That is, for example, if a portion of the multiple superconducting tape wires 11 or multiple superconducting tape wires 16 quenches, the resistance increases in the portion that has become normal-conducting. However, if there are multiple current paths, the current flows preferentially through the path in the superconducting state. As a result, heat generation in the quenched portion can be suppressed, and therefore the propagation of the quench can be suppressed. In other words, the degradation of electrical characteristics due to a locally occurring quench can be suppressed.

[0086] The stack 11B of the superconducting tape wire 11 and the superconducting tape wire 16 is pressed by the screws SS1 against the underside 22b of the roof portion 22. As described above, the underside 22b of the roof portion 22 is flat, so that by tightening the screws SS1, the stack 11B of the superconducting tape wire 11 and the superconducting tape wire 16 is fixed in the holding space 21 (see FIG. 6 ) of the block 20A.

[0087] 10 , a plurality of screws SS1 (three in FIG. 10 ) are arranged along the X direction. In this case, a force for fixing the stack of superconducting tape wires 11 and superconducting tape wires 16 to the block 20A acts at a plurality of locations. This improves the adhesion between the superconducting tape wires 16 and superconducting tape wires 11, which are alternately stacked. More specifically, the area of ​​the region where a good adhesion state is achieved increases at the adhesion interface between the superconducting tape wires 16 and superconducting tape wires 11. As a result, the reliability of the electrical connection between the superconducting tape wires 16 and superconducting tape wires 11 can be improved.

[0088] As shown in Figure 10, in the case of block 20B, stack 11A does not contact roof portion 22 and bottom portion 23. Therefore, block 20B is not suitable from the viewpoint of fixing stack 11A like block 20B. Conversely, block 20A requires a more complicated assembly method than block 20B in that screws SS1 must be attached, but is superior to block 20B from the viewpoint of fixing stack 11B. In other words, the structure of block 20A is suitable as a block 20 to be placed at the end of an arrangement of multiple blocks 20 in order to connect superconducting wire 10 (see Figure 2) to other components (e.g., lead portion 40).

[0089] <Application to Joint Portions of Superconducting Wires> Next, a connection method for connecting a plurality of superconducting wires will be described. When the superconducting wires 10 shown in Fig. 2 are connected in series along the X direction, they can be connected in the same manner as the connection method for the superconducting tape wire 11 and the superconducting tape wire 16 described with reference to Fig. 10. In this case, the lead portion 40 shown in Fig. 10 can be replaced with a block 20B, and the stack 16A of the superconducting tape wires 16 has the same structure as the stack 11A of the superconducting tape wires 11.

[0090] Incidentally, when a superconducting wire is used as a coil, the superconducting wire may be connected in parallel to form a multi-layer coil, as in the coil 200 shown as an example in Fig. 11. Fig. 11 is a perspective view showing an example of the use of a superconducting wire as a coil.

[0091] 11 has a structure in which a first layer coil 201 and a second layer coil 202 are connected to each other. In this case, in order to electrically connect the first layer coil 201 and the second layer coil 202, a connection method in which the coils are bent at 90 degrees with respect to the extending direction of the superconducting wire is required.

[0092] The following describes the structure of a protective member that is particularly effective when used in a connection method in a direction bent 90 degrees relative to the extension direction of superconducting wires. FIG. 12 is a perspective view showing an example of a block that protects a portion where superconducting wires are connected in parallel, among multiple blocks used in the coil shown in FIG. 11. FIG. 13 is a cross-sectional view taken along line D-D in FIG. 12. FIG. 14 is a cross-sectional view taken along line E-E in FIG. 12. FIG. 5 is a perspective view showing one of the two blocks shown in FIG. 12. FIG. 15 is a perspective view showing the block shown in FIG. 13 in a state before assembly. FIG. 16 is a perspective view showing the three components that make up the block shown in FIG. 13 assembled. Note that FIGS. 15 and 16 show the blocks shown in FIGS. 12, 13, and 14 in an inverted state. FIG. 17 is a plan view of the block shown in FIG. 16 as seen from the bottom. FIG. 18 is a perspective view showing the superconducting wire shown in FIG. 12 in an inverted state with multiple wires and the bottom removed.

[0093] 12 shows two blocks 20C shown in FIG. 11 lined up along the extending direction of superconducting wire 10. Also, in FIG. 12, cooling pipe 13 (see FIG. 3) and spacer 14 (see FIG. 3) of superconducting wire 10 and cooling pipe 13 (see FIG. 13) and spacer 14 (see FIG. 13) of superconducting wire 10A are not shown. In FIGS. 13 and 14, similar to FIG. 10, the number of layers is shown to be small in order to make it easier to see the structure in which superconducting tape wire 18 is superimposed on either superconducting tape wire 11 or 17.

[0094] In the example described below, the linear material protection member protects a superconducting wire (linear material) 10 shown in Fig. 12 , a superconducting wire (linear material) 10A, and a stack 18A of a plurality of superconducting tape wires 18 shown in Fig. 13 . The superconducting wire includes a plurality of stacked superconducting tape wires 11. The superconducting wire 10A includes a plurality of stacked superconducting tape wires 17 (a stack 17A in which a plurality of superconducting tape wires 17 are stacked). The superconducting tape wire 17 and the superconducting tape wire 18 are the same as the superconducting tape wire 11 already described, and therefore a duplicated description will be omitted.

[0095] As shown in Fig. 12 , each of the superconducting wire 10 and the superconducting wire 10A extends in the X direction. Furthermore, at a position where a plurality of superconducting tape wires 11 and a plurality of superconducting tape wires 17 are electrically connected, the superconducting wire 10 and the superconducting wire 10A are adjacent to each other. In other words, a portion of the superconducting wire 10 and a portion of the superconducting wire 10A are adjacent to each other. At the portion where the superconducting wire 10 and the superconducting wire 10A are adjacent to each other, the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 17 are electrically connected via a plurality of superconducting tape wires 18 shown in Fig. 13 .

[0096] 11 , superconducting wire 10 and block group 20GA consisting of a plurality of blocks 20 holding superconducting wire 10 constitute first layer coil 201. In coil 200, superconducting wire 10A and block group 20GB consisting of a plurality of blocks 20 holding superconducting wire 10A constitute second layer coil 202.

[0097] 7 to 9 can be used as the plurality of blocks 20 that surround and hold the superconducting wire 10. However, in the example shown in Fig. 11, among the plurality of blocks 20, the block 20A described with reference to Figs. 3 to 6 is used at the end of the arrangement that is connected to the lead portion.

[0098] 11, the coil 200 has a block 20C having a structure different from the blocks 20A and 20B. As shown in Fig. 12, the block 20C is a block 20 for surrounding and holding the portion where the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 17 are electrically connected via the plurality of superconducting tape wires 18 (see Fig. 13).

[0099] A wire 31 extending in the X direction is engaged with the plurality of blocks 20 and blocks 20C that make up block group 20GA (see FIG. 11). A wire 31A extending in the X direction is engaged with the plurality of blocks 20 and blocks 20C that make up block group 20GB (see FIG. 11).

[0100] 16, block 20C has holding space 21A for holding superconducting wire 10 (see FIG. 12), holding space 21B for holding superconducting wire 10A (see FIG. 12), and holding space 21C formed to communicate with holding space 21A and holding space 21B and for holding a plurality of superconducting tape wires 18. Block 20C also has roof 22 covering holding space 21A and holding space 21B, bottom 23A located on the opposite side of roof 22 across holding space 21A, and bottom 23B located on the opposite side of roof 22 across holding space 21B.

[0101] As shown in Figure 14, block 20C has side wall portions 24 that are continuous with each of roof portion 22 and bottom portion 23A, side wall portions 25 that are continuous with each of roof portion 22 and bottom portion 23B and are located on the opposite side of side wall portion 24, and a middle wall portion 28 that is located between side wall portions 24 and 25.

[0102] The configuration of block 20C can be classified by separable parts as follows: That is, as shown in Fig. 14, block 20C has part 20C1 that forms roof portion 22, side wall portions 24, 25, and middle wall portion 28. Block 20C has part 20C2 that is connected to part 20C1 via wire 31 and that forms bottom portion 23A. Block 20C has part 20C3 that is connected to part 20C1 via wire 31A and that forms bottom portion 23B.

[0103] 15, part 20C1 has a wire holding portion TR1 formed at a position where side wall portion 24 and bottom portion 23A are combined, and capable of engaging wire 31. Part 20C1 has a fixing portion BP5 formed at a position where middle wall portion 28 and bottom portion 23A are combined, and capable of fixing part 20C2. Part 20C1 has a fixing portion BP6 formed at a position where side wall portion 25 and bottom portion 23B (see FIG. 6) are combined, and capable of fixing part 20C3.

[0104] As shown in FIG. 17, component 20C2 has a side 20s1 arranged along side wall portion 24, a side 20s2 arranged on the opposite side of side 20s1, and a central region CR1 arranged between sides 20s1 and 20s2 in the Y direction perpendicular to the X direction.

[0105] Component 20C2 has wire holding portions TR2 and TR3 formed along 20s1 in a state capable of sandwiching wire holding portion TR1 of component 20C1. Wire holding portions TR2 and TR3 each extend along the X direction. In the X direction, wire holding portion TR1 of component 20C1 is sandwiched between wire holding portions TR2 and TR3.

[0106] Component 20C2 has a wire holding portion TR4 formed at a position where middle wall portion 28 and bottom portion 23B are assembled, and capable of engaging wire 31A. Component 20C2 is located in central region CR1 and has a screw hole TH1 formed to penetrate component 20C2 in the thickness direction. Component 20C2 has a fixing portion BP7 (see FIG. 15 ) located along side 20s2 and capable of being fixed to fixing portion BP5 of component 20C1.

[0107] The component 20C3 has a side 20s3 that is arranged along the side 20s2 of the component 20C2, a side 20s4 that is arranged on the opposite side of the side 20s3, and a central region CR2 that is arranged between the sides 20s3 and 20s4 in the Y direction. The sides 20s1, 20s2, 20s3, and 20s4 each extend in the X direction.

[0108] Component 20C3 has wire holding portions TR5 and TR6 formed along side 20s3 in a state capable of sandwiching wire holding portion TR4 of component 20C2. Wire holding portions TR5 and TR6 each extend in the X direction. In the X direction, wire holding portion TR4 of component 20C2 is sandwiched between wire holding portions TR5 and TR6.

[0109] The component 20C3 is disposed in the central region CR2 and has a screw hole TH2 formed to penetrate the component 20C3 in the thickness direction. The component 20C3 further has a fixing part BP8 (see FIG. 16) disposed along the side 20s4 and fixable to the fixing part BP6 (see FIG. 15) of the component 20C1.

[0110] In the example shown in Figures 12 to 17, as shown in Figures 15 and 16, the fixing portion BP7 (see Figure 15), which is a convex portion, is combined with the fixing portion BP5 (see Figure 15), which is a concave portion, to form a structure in which the fixing portion BP5 and the fixing portion BP7 are in close contact with each other and fixed. That is, in the example shown in Figures 12 to 17, the fixing portion BP5 and the fixing portion BP7 are fixed by crimping. Similarly, the fixing portion BP6 shown in Figure 15 is fixed to the fixing portion BP8 of the part 20C3 shown in Figure 16 by crimping. The fixing portion BP8 of the part 20C3 is a convex portion having a structure similar to that of the fixing portion BP7 shown in Figure 15.

[0111] 5 and 6, the method of fixing the fixing parts BP5 and BP7 shown in Fig. 15 and the method of fixing the fixing parts BP6 and BP8 shown in Fig. 16 are not limited to the crimping method and may be modified in various ways, such as by welding.

[0112] 13 and 17, the screw hole TH1 is located in the central region CR1 (see FIG. 17) and penetrates the component 20C2 in the thickness direction. Similarly, the screw hole TH2 is located in the central region CR2 (see FIG. 17) and penetrates the component 20C3 in the thickness direction.

[0113] A screw SS1 is inserted into the screw hole TH1. In the example shown in Fig. 13, one end of the screw SS1 is in contact with a stack 11C in which superconducting tape wires 11 and superconducting tape wires 18 are alternately stacked. In the present embodiment, a block 20C provided at a connection portion of the superconducting wires can fix the stack 11C in the holding space 21A (see Fig. 16) with the screw SS1.

[0114] Similarly, a screw SS2 is inserted into the screw hole TH2. In the example shown in Fig. 13, one end of the screw SS2 is in contact with a stack 17C in which superconducting tape wires 17 and superconducting tape wires 18 are alternately stacked. In the case of this embodiment, a block 20C provided at a connection portion of the superconducting wires can fix the stack 17C in the holding space 21B (see Fig. 16) with the screw SS2.

[0115] By fixing the laminate 11C and the laminate 17C, the laminate 18A of the superconducting tape wire 18 arranged between the laminate 11C and the laminate 17C in the Y direction is fixed within the holding space 21C (see Figure 16).

[0116] In the case of block 20C, the laminate 11C is fixed by the screw SS1, which improves the reliability of the electrical connection between the superconducting tape wire 11 and the superconducting tape wire 18. Similarly, in the case of block 20C, the laminate 17C is fixed by the screw SS2, which improves the reliability of the electrical connection between the superconducting tape wire 17 and the superconducting tape wire 18.

[0117] 17 , a plurality of screws SS1 (three in FIG. 17 ) are arranged along the X direction. As already explained with reference to FIG. 10 , a force for fixing the stack of superconducting tape wires 11 and superconducting tape wires 18 shown in FIG. 13 to the block 20C acts at a plurality of locations. This improves the adhesion between the superconducting tape wires 11 and 18, which are alternately stacked. More specifically, the area of ​​the region where a good adhesion state is achieved at the adhesion interface between the superconducting tape wires 11 and 18 increases. As a result, the reliability of the electrical connection between the superconducting tape wires 11 and 18 can be improved. Similarly, in the example shown in FIG. 17 , a plurality of screws SS2 (three in FIG. 17 ) are arranged along the X direction. This improves the reliability of the electrical connection between the superconducting tape wires 17 and 18 shown in FIG. 13 .

[0118] The screws SS1 and SS2 are set screws (also called "set screws") that do not have threads. The entire screw SS1 is embedded in the screw hole TH1. Similarly, the entire screw SS2 is embedded in the screw hole TH2. By using set screws as the screws SS1 and SS2, linear materials covered with protective materials can be easily stacked.

[0119] Furthermore, to facilitate fastening the stack 11A with the screws SS1, the block 20C preferably has the following structure. Specifically, the inner surfaces 24a of the side wall portions 24 and the inner surfaces 25a of the side wall portions 25 of the component 20C1 of the block 20C shown in FIG. 14 each have an arc shape when viewed from the side in the X direction (see FIG. 2). The upper surfaces 23a1 and 23a2 of the bottom portions 23A and 23B of the block 20C are each flat. The lower surface 22b of the roof portion 22 of the block 20C is also flat.

[0120] In other words, the surface of bottom 23A of block 20C that comes into contact with stack 11C (upper surface 23a1) and the surface of roof 22 of block 20C that comes into contact with stack 11C (lower surface 22b) are both flat. The surface of bottom 23B of block 20C that comes into contact with stack 17C (upper surface 23a2) and the surface of roof 22 of block 20C that comes into contact with stack 17C (lower surface 22b) are both flat.

[0121] In this case, the adhesion between the laminate 11C and the lower surface 22b and the adhesion between the laminate 11C and the upper surface 23a1 can be improved. Similarly, the adhesion between the laminate 17C and the lower surface 22b and the adhesion between the laminate 17C and the upper surface 23a2 can be improved.

[0122] 13, each of the side wall portions 24 and 25 of the component 20A1 of the block 20C has an opening that penetrates the side wall portion 24 or the side wall portion 25 in the Y direction. Specifically, the side wall portion 24 has an opening portion 26 that penetrates the side wall portion 24 in the Y direction. Furthermore, the side wall portion 25 has an opening portion 27 that penetrates the side wall portion 25 in the Y direction.

[0123] As already explained, the provision of opening 26 or opening 27 can improve the strength of side wall portion 24 and side wall portion 25 against external forces applied in the Z direction shown in Fig. 13. Other effects obtained by providing opening 26 or opening 27 have already been explained, so redundant explanations will be omitted.

[0124] As shown in FIG. 13 , grooves 31T1 and 31T2, into which wire 31 can be inserted, are formed in the region where bottom 23A and sidewall 24 intersect. Groove 31T1 is a groove provided in component 20C1 and has an opening facing component 20C1. Groove 31T1 communicates with wire holding portion TR1 at its bottom. Groove 31T2 is a groove provided in component 20C2 and has an opening on the lower surface of bottom 23A. Groove 31T2 communicates with wire holding portion TR2 (see FIG. 17 ) or wire holding portion TR3 (see FIG. 17 ) at its bottom. As shown in FIG. 13 , by inserting wire 31 through grooves 31T1 and 31T2, which have openings facing in different directions, components 20C1 and 20C2 can be connected via wire 31 held in wire holding portions TR1, TR2, and TR3.

[0125] Grooves 31AT1 and 31AT2, into which wire 31A can be inserted, are formed in the region where bottom 23A intersects with middle wall 28 (see FIG. 14). Groove 31AT1 is a groove provided in component 20C2 and has an opening facing component 20C3. Groove 31AT1 communicates with wire holding portion TR4 (see FIG. 17) at its bottom. Groove 31AT2 is a groove provided in component 20C3 and has an opening on the lower surface of bottom 23B. Groove 31AT2 communicates with wire holding portion TR5 (see FIG. 17) or wire holding portion TR6 (see FIG. 17) at its bottom. As shown in FIG. 33, by inserting wire 31A through grooves 31AT1 and 31AT2 having openings facing in different directions, parts 20C2 and 20C3 can be connected via wire 31A held in wire holding parts TR4, TR5, and TR6.

[0126] In the example shown in Figure 13, in addition to the above, a groove 32T into which wire 32 can be inserted is formed in the region where roof 22 and side wall 24 intersect. A groove 33T into which wire 33 can be inserted and a groove 32AT into which wire 32A can be inserted are formed in the region where roof 22 and middle wall 28 (see Figure 14) intersect. A groove 33AT into which wire 33A can be inserted is formed in the region where roof 22 and side wall 25 intersect. A groove 34T into which wire 34 can be inserted is formed in the region where bottom 23A and middle wall 28 intersect. A groove 34AT into which wire 34A can be inserted is formed in the region where bottom 23B and side wall 25 intersect.

[0127] Fig. 18 is a perspective view showing the superconducting wire shown in Fig. 12 turned upside down with the plurality of wires and the bottom portion removed. In the example shown in Fig. 12, a plurality of blocks 20C (two in Fig. 12) are arranged adjacent to each other. In other words, in the example shown in Fig. 18, the superconducting wire 10 including a plurality of superconducting tape wires 11 and the superconducting wire 10A including a plurality of superconducting tape wires 17 are connected by a plurality of blocks 20C arranged adjacent to each other. In this case, the cross-sectional area of ​​the path through which current flows in the superconducting state can be made larger than when the superconducting wire 10 and the superconducting wire 10A are connected by only one block 20C.

[0128] 13, in the region where only superconducting tape wires 18 are stacked, the superconducting tape wires 18 are stacked with a space between them. Therefore, the number of superconducting tape wires 18 stacked in the stack 18A is, for example, half that of the superconducting tape wires 11 in the stack 11A. Therefore, when the superconducting wire 10 (see FIG. 18) and the superconducting wire 10A (see FIG. 18) are connected by only one block 20C, the cross-sectional area of ​​the path of the current in the superconducting state is halved in the portion of the stack 18A.

[0129] 18, when superconducting wire 10 and superconducting wire 10A are connected by two blocks 20C arranged adjacent to each other, two portions of laminate 18A are connected in parallel, which makes it possible to compensate for the reduction in the cross-sectional area of ​​the path through which current flows in the superconducting state at the connection portion.

[0130] The connection method using the block 20C shown in Figures 11 to 18 can also be realized using the block 20A shown in Figures 3 to 6. For example, by combining two blocks 20A, a connection method using one block 20C can be realized. Furthermore, by combining four blocks 20A, a connection method using two blocks 20C can be realized, as shown in Figures 12 and 18. However, as explained using Figures 11 to 18, when connecting superconducting wires in parallel, it is more preferable to connect them in parallel using the block 20C, from the viewpoint of improving the positional accuracy of, for example, the first layer coil 201 and the second layer coil 202 shown in Figure 11.

[0131] As shown in Figures 13 and 18, the method of electrically connecting a plurality of superconducting tape wires 18 extending in a direction (Y direction) intersecting (more specifically, perpendicular to) the extension direction (X direction) of the superconducting wire 10 to a plurality of superconducting tape wires 11 constituting the superconducting wire 10 can be applied to the connection with the lead portion described using Figure 10.

[0132] For example, in the case of the coil 200 shown in FIG. 11 , the lead portion 40 is connected to a block 20A arranged at an end of the arrangement of the blocks 20. In the case of the coil 200, the lead portion 40 extends in a direction perpendicular to the arrangement direction of the plurality of blocks 20 constituting the coil 200. In this case, each of the plurality of superconducting tape wires 16 sandwiched between the lead portions 40 described with reference to FIG. 10 extends into the holding space 21 (see FIG. 6 ) of the block 20A through the opening 26 or opening 27 of the block 20A shown in FIG. 3 . Furthermore, in the holding space 21 of the block 20A, the plurality of superconducting tape wires 11 (or the plurality of superconducting tape wires 17) and the superconducting tape wires 16 are alternately stacked. As a result, in the coil 200 shown in FIG. 11 , the lead portion 40 extending in a direction perpendicular to the arrangement direction of the plurality of blocks 20 can be electrically connected to the superconducting wire.

[0133] <Modification of the Method of Connecting to the Lead Portion> Next, a modification of the method of connecting to the lead portion described with reference to Fig. 10 will be described. As described with reference to Fig. 10, when superconducting tape wires 11 and superconducting tape wires 16 are alternately stacked, a gap BL is generated between the end of the superconducting tape wire 11 and the end of the superconducting tape wire 16. In the region overlapping with the gap BL in the Z direction, the number of superconducting tape wires 11 (or superconducting tape wires 16) is small. For example, in the example shown in Fig. 10, 152 superconducting tape wires are stacked in the region not overlapping with the gap BL. On the other hand, in the region overlapping with the gap BL, the number of stacked superconducting wires is half of 152 (76).

[0134] In this case, the maximum value of the current that can flow in the path through which the current flows in the superconducting state (hereinafter referred to as the maximum current value) is restricted at the location with the fewest number of stacked layers (for example, 76 layers). In other words, from the viewpoint of flowing a large current, the location where the gap BL exists becomes a bottleneck.

[0135] However, it is difficult to arrange the end of the superconducting tape wire 11 and the end of the superconducting tape wire 16 shown in Figure 10 so that they are in contact with each other and face each other, and the occurrence of a gap BL must be tolerated.

[0136] The following describes an embodiment for reducing the restriction on the maximum current value caused by the gap BL by devising a lamination state of the superconducting tape wire 11 and the superconducting tape wire 16. Fig. 19 is a cross-sectional view showing a modification of Fig. 10 .

[0137] The linear material protection member shown in Fig. 19 differs from the linear material protection member shown in Fig. 10 in the following respects: In the modified example shown in Fig. 19, each of the plurality of superconducting tape wires 11 is electrically connected to the lead portions 40 via the plurality of superconducting tape wires 16 sandwiched between the lead portions 40 arranged adjacent to the block 20A. This is the same as the example described using Fig. 10.

[0138] Between the lead portion 40 and the block 20B, a first block 20A (block 20AA), a second block 20A (block 20AB), and a third block 20A (block 20AC) are arranged along the X direction, in order from the side closest to the lead portion 40.

[0139] The lead portion 40 includes a support portion 41 that supports the stack 16A of the multiple superconducting tape wires 16, and a lid portion 42 that covers the stack 16A. The stack 16A is sandwiched between the support portion 41 and the lid portion 42, and extends toward the first block 20AA.

[0140] A plurality of superconducting tape wires 11 and a plurality of superconducting tape wires 16 are arranged in the holding spaces 21 (see FIG. 6) of the first, second, and third blocks 20A. In the holding spaces 21 of the first, second, and third blocks 20A, a plurality of superconducting tape wires 11 and a plurality of superconducting tape wires 16 are stacked.

[0141] The structures of blocks 20AA, 20AB, and 20AC are the same as block 20A described with reference to FIGS.

[0142] In the example shown in Figure 19, multiple blocks 20A are arranged adjacent to each other along the X direction, which reduces the number of gaps BL that overlap each other in the thickness direction (Z direction).

[0143] 19 , in the first layer (e.g., the layer closest to the bottom 23), the superconducting tape wire 11 extends from the stack 11A protected by the block 20B to the second block 20AB via the third block 20AC. The superconducting tape wire 11 terminates before reaching the first block 20AA. In the first layer, the superconducting tape wire 16 extends from the stack 16A sandwiched between the lead portions 40 to the first block 20AA and terminates at the boundary between the block 20AA and the block 20AB.

[0144] In the second layer (e.g., the layer immediately above the first layer), the superconducting tape wire 11 extends from the laminate 11A protected by the block 20B to the third block 20AC. The superconducting tape wire 11 terminates before reaching the second block 20AB. In the second layer, the superconducting tape wire 16 extends from the laminate 16A sandwiched between the lead portions 40 to the second block 20AB via the first block 20AA. The superconducting tape wire 16 terminates at the boundary between the block 20AB and the block 20AC.

[0145] In the third layer (e.g., the layer immediately above the second layer), the superconducting tape wire 11 extends from the stack 11A protected by the block 20B to the first block 20AA via the third block 20AC and the second block 20AB. The superconducting tape wire 11 terminates before reaching the lead portion 40. In the third layer, the superconducting tape wire 16 terminates at the boundary between the lead portion 40 and the first block 20AA.

[0146] In the fourth layer (e.g., the layer immediately above the third layer), the superconducting tape wire 11 terminates between the laminate 11A protected by the block 20B and the third block 20AC. In the third layer, the superconducting tape wire 16 extends from the laminate 16A sandwiched between the lead portions 40 to the third block 20AC via the first block 20AA and the second block 20AB. The superconducting tape wire 16 terminates before reaching the block 20B.

[0147] In the fifth layer (for example, the layer immediately above the fourth layer), the same pattern as in the first to fourth layers is repeated.

[0148] In such a stacking method, the number of gaps BL that overlap each other in the thickness direction (Z direction) of the linear material is smaller than that in the example shown in Fig. 10. For example, in the example shown in Fig. 19, 152 superconducting tape wires are stacked in the region that does not overlap with the gaps BL.

[0149] On the other hand, in the region overlapping with the gap BL, the number of superconducting wire layers (114 layers) is more than half of 152 layers (76 layers). In other words, in this modification, in the region where the superconducting tape wire 11 and the superconducting tape wire 16 are stacked, the smallest number of superconducting wire layers (114 layers) is more than half of the largest number of superconducting wire layers (152 layers). In the example shown in Fig. 19, in the region where the superconducting tape wire 11 and the superconducting tape wire 16 are stacked, the smallest number of superconducting wire layers (114 layers) is 75% of the largest number of superconducting wire layers (152 layers).

[0150] According to this modification, the number of laminations at the location with the smallest number of laminations in the path through which current flows in the superconducting state can be made more than half of the maximum number of laminations, thereby increasing the maximum current value.

[0151] 19 can be expressed as follows: A stack of a plurality of superconducting tape wires 11 and a plurality of superconducting tape wires 16 is fixed by screws SS1 inserted into screw holes TH1 provided in the first, second, and third blocks 20A, respectively.

[0152] In the X direction, gaps BL are present between the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 16. In the stacking direction of the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 16, the total thickness of the gaps BL is greater than half the thickness of the laminate 11A.

[0153] <Modification in which a spacer is disposed in the holding space> Next, a description will be given of a modification of the method of connecting to the lead portion described with reference to Fig. 10. Fig. 20 is a cross-sectional view showing a modification of Fig. 3 .

[0154] The block 20A of the protective member shown in Fig. 20 differs from the block 20A of the protective member shown in Fig. 3 in the following respects. That is, in the case of the modified example shown in Fig. 20, a metal plate 19 is disposed on the upper surface 23a of the bottom portion 23. The screw SS1 inserted into the screw hole TH1 contacts the metal plate 19.

[0155] In the above embodiment, an example has been described in which 152 superconducting tape wires 11 are stacked. However, there are various variations in the dimensions (thickness, width, etc.) and number of layers of the superconducting tape wire 11. On the other hand, in consideration of the manufacturing efficiency of the parts that make up the block of the protective member, it is preferable to manufacture versatile parts that can accommodate a certain range of numbers of layers, rather than creating dedicated parts corresponding to the number of layers of the superconducting tape wire 11.

[0156] Therefore, in this modified example, a metal plate 19 that functions as a spacer is inserted between the stack 11A of multiple superconducting tape wires 11 and the upper surface 23a of the bottom portion 23. In the example shown in Fig. 20, multiple metal plates 19 are stacked. By using multiple metal plates 19 in this way, it is possible to easily accommodate variations in the number of stacked layers.

[0157] Furthermore, in this modified example, the screw SS1 does not come into contact with the superconducting tape wire 11. Therefore, even if the screw SS1 is tightened, it is possible to prevent the force from the screw SS1 from being concentrated on a specific location of the superconducting tape wire 11. As a result, it is possible to prevent damage to the superconducting tape wire 11.

[0158] <Method for connecting superconducting wires> Next, a method for connecting superconducting wires will be described using the example already described with reference to Fig. 10. Fig. 21 is an explanatory diagram showing an example of a process flow of the method for connecting superconducting wires. Fig. 22 is an enlarged cross-sectional view showing a linear material after being connected by the method for connecting superconducting wires shown in Fig. 21. The method for connecting superconducting wires shown in Fig. 21 generalizes the method for electrically connecting lead portion 40 and superconducting wire 10 described with reference to Fig. 10 as a method for connecting a plurality of superconducting wires 10. The method for electrically connecting lead portion 40 and superconducting wire 10 described with reference to Fig. 10 is one aspect of the method for connecting superconducting wires shown in Fig. 21.

[0159] The superconducting wire connection method shown in Figure 21 includes a first superconducting wire preparation step, a second superconducting wire preparation step, a stacking step, a block preparation step, and a screw tightening step. The steps shown in Figure 21 may be performed in various orders. For example, the first superconducting wire preparation step and the second superconducting wire preparation step must each be completed before the stacking step, but the order in which the first superconducting wire preparation step and the second superconducting wire preparation step are performed is not particularly limited. The block preparation step must also be completed before the screw tightening step, but may be completed before the stacking step or may be performed after the stacking step. On the other hand, the screw tightening step must be performed after the stacking step and the block preparation step.

[0160] In the first superconducting wire preparation step shown in FIG. 21, a superconducting wire 10 shown in FIG. 22 is prepared. The superconducting wire 10 has a laminate 11A made up of a plurality of superconducting tape wires 11 stacked one on the other.

[0161] In the second superconducting wire preparation step shown in FIG. 21, a superconducting wire 10B shown in FIG. 22 is prepared. The superconducting wire 10B has a laminate 9A made up of a plurality of superconducting tape wires 9 stacked one on the other.

[0162] 21 , a laminate 9B is formed by alternately stacking a portion of a plurality of superconducting tape wires 11 and a portion of a plurality of superconducting tape wires 9 shown in FIG. 22 so that they overlap each other. Details of each step included in the stacking step shown in FIG. 21 will be described later. As with the laminate 9B described using FIG. 10 , the laminate 9B may also include a plurality of (e.g., two or three) superconducting tape wires 11 and a plurality of (e.g., two or three) superconducting tape wires 9 alternately stacked. However, from the viewpoint of increasing the contact area between the superconducting tape wire 11 and the superconducting tape wire 16, it is preferable that the superconducting tape wires 11 and the superconducting tape wires 9 be alternately stacked one by one so that they overlap each other, as shown in FIG. 22 .

[0163] In the block preparation step shown in Fig. 21, a block 20A is prepared, which is a protective member capable of holding the stack 9B shown in Fig. 22 so as to surround it. As already described with reference to Figs. 3 to 6, the block 20A includes a holding space 21 (see Fig. 6) capable of holding the stack 9B, a roof portion 22 covering the holding space 21, a bottom portion 23 located on the opposite side of the holding space 21 from the roof portion 22, and a screw hole TH1 that penetrates the bottom portion 23 in the thickness direction and communicates with the holding space 21.

[0164] In the method of connecting superconducting wires shown in Fig. 21, for example, after forming the laminate 9B shown in Fig. 22, the block 20A is prepared and placed so as to surround the periphery of the laminate 9B. At this time, the block 20A is engaged with the wire 31 as shown in Fig. 5.

[0165] Thereafter, by combining and fixing the fixing portion BP1 of the part 20A1 and the fixing portion BP2 of the part 20A2 as shown in FIG. 5, the stack 9B shown in FIG. 22 is placed within the holding space 21 (see FIG. 6) of the block 20A.

[0166] Next, in the screw tightening process shown in FIG. 21, a screw SS1 is inserted into a screw hole TH1 formed in the block 20A and tightened to fix the stack 9B to the holding space 21 (see FIG. 6) of the block 20A.

[0167] When a plurality of superconducting wires are connected to form a long superconducting wire, it is necessary to suppress heat generation at the connection portion between the superconducting wires. According to this embodiment, portions of a plurality of superconducting tape wires 11 and portions of a plurality of superconducting tape wires 9 are alternately stacked so that they overlap each other, and this stack 9B is fixed with screws, thereby ensuring surface contact between the stacked superconducting tape wires 11 and the superconducting tape wires 9. This reduces the resistance at the portion electrically connecting the superconducting wire 10 and the superconducting wire 10B. If the resistance at the portion electrically connecting the superconducting wire 10 and the superconducting wire 10B can be reduced, the amount of heat generated when a large current is passed through this portion can be reduced. In other words, the superconducting wire connection method according to this embodiment is suitable from the viewpoint of suppressing heat generation at the connection portion.

[0168] There is a particularly preferable method for suppressing heat generation in the laminate 9B. Details of this method will be explained below. Fig. 23 is an explanatory diagram showing an example of the structure of the superconducting tape wire shown in Fig. 22. Fig. 24 is an enlarged cross-sectional view showing a portion of the laminate shown in Fig. 22. Each of the plurality of superconducting tape wires 11 shown in Fig. 22 has the same structure as the superconducting tape wire 11 shown in Fig. 23. Similarly, each of the plurality of superconducting tape wires 9 shown in Fig. 22 has the same structure as the superconducting tape wire 9 shown in Fig. 23.

[0169] As shown in Figure 23, the superconducting tape wire 11 includes a superconducting layer SCL1 made of a superconducting material, a metal substrate MS1 supporting the superconducting layer SCL1, an intermediate layer MDL1 located between the superconducting layer SCL1 and the metal substrate MS1, a protective metal layer PML1 located on the opposite side of the intermediate layer MDL1 with the superconducting layer SCL1 interposed therebetween, and a coating metal film CMF1 covering the laminate of the superconducting layer SCL1, the metal substrate MS1, the intermediate layer MDL1, and the protective metal layer PML1. Similarly, the superconducting tape wire 9 includes a superconducting layer SCL2 made of a superconducting material, a metal substrate MS2 supporting the superconducting layer SCL2, an intermediate layer MDL2 located between the superconducting layer SCL2 and the metal substrate MS2, a protective metal layer PML2 located on the opposite side of the intermediate layer MDL2 with the superconducting layer SCL2 interposed therebetween, and a coating metal film CMF2 covering the laminate of the superconducting layer SCL2, the metal substrate MS2, the intermediate layer MDL2, and the protective metal layer PML2.

[0170] The superconducting tape wire 11 and the superconducting tape wire 9 have the same structure. Therefore, although a typical structural example of the superconducting tape wire 11 will be described below, the same applies to the components constituting the superconducting tape wire 9. Therefore, in the following description, the metal substrate MS1 can be read as the metal substrate MS2, the intermediate layer MDL1 can be read as the intermediate layer MDL2, the protective metal layer PML1 can be read as the protective metal layer PML2, and the coating metal film CMF1 can be read as the coating metal film CMF2.

[0171] The metal substrate MS1 is a substrate for forming the superconducting layer SCL1. Therefore, the metal substrate MS1 is required to have a sufficient mechanical strength to enable handling of the superconducting tape wire 11. Furthermore, the metal substrate MS1 is preferably made of a material with excellent oxidation resistance to suppress oxidation during the formation of the superconducting layer SCL1. The metal substrate MS1 is, for example, a nickel alloy containing nickel as its main component. Examples of additive elements contained in the metal constituting the metal substrate MS1 include chromium and molybdenum.

[0172] Furthermore, as described above, the metal substrate MS1 is required to have high support strength, and therefore the thickness of the metal substrate MS1 is thicker than the multiple other components (superconducting layer SCL1, intermediate layer MDL1, protective metal layer PML1, and coating metal film CMF1) that constitute the superconducting tape wire 11. For example, the thickness of the metal substrate MS1 is approximately 50 μm to 100 μm or more. On the other hand, the thickness of each of the superconducting layer SCL1, intermediate layer MDL1, and protective metal layer PML1 is approximately 2 μm to 3 μm. Note that, because the coating metal film CMF1 is a cylindrical member, its thickness including the hollow space is thicker than the thickness of the metal substrate MS1. However, the plate thickness of the coating metal film CMF1 excluding the hollow space is, for example, approximately 20 μm, which is thinner than the thickness of the metal substrate MS1.

[0173] The intermediate layer MDL1 is a base layer for forming the superconducting layer SC1. In order to prevent direct contact between the superconducting layer SC1 and the metal substrate MS1 or to improve the characteristics of the superconducting layer SC1, films of various materials are used for the intermediate layer MDL1. Examples of materials constituting the intermediate layer MDL1 include laminated films such as an aluminum oxide film, an yttrium oxide film, a magnesium oxide film, and a selenium oxide film.

[0174] The superconducting layer SC1 is made of a high-temperature superconductor. There are various examples of high-temperature superconducting materials, but for example, the superconducting layer SC1 can be made of a superconductor that contains rare earth elements such as yttrium (Y) and gadolinium (Gd), and also contains barium (Ba), copper (Cu), and oxygen (O) in addition to the rare earth elements. The superconducting material exemplified here is called REBCO.

[0175] The protective metal layer PML1 is provided to protect the upper surface side of the superconducting layer SC1. To prevent deterioration of the electrical characteristics of the superconducting tape wire 11, the protective metal layer PML1 is made of a material having higher electrical conductivity than the metal substrate MS1. An example of the material constituting the protective metal layer PML1 is silver (Ag).

[0176] The coating metal film CMF1 is an outer shell film that encases the entire laminate of the superconducting layer SCL2, the metal substrate MS2, the intermediate layer MDL2, and the protective metal layer PML2. As described above, the superconducting tape wire 11 is used in a laminated state. Therefore, in order to reduce the resistance at the electrical connection between the laminated superconducting tape wires 11, the coating metal film CMF1 is required to have high electrical conductivity. A material having higher electrical conductivity than the metal film CMF1 is used for the coating metal film CMF1. An example of a material that constitutes the coating metal film CMF1 is copper (Cu). Note that when the coating metal film CMF1 is made of copper, it is preferable to take measures to prevent oxidation of the surface of the coating metal film CMF1. For this reason, a thin anti-oxidation film (lamination film) may be formed on the surface of the coating metal film CMF1.

[0177] As described above, the superconducting tape wire 11 includes the metal substrate MS1 with a relatively low electrical conductivity, and therefore the resistance component of the conductive path from the superconducting layer SC1 to the metal substrate MS1 is larger than the resistance component of the conductive path from the superconducting layer SC1 to the protective metal layer PML1. Therefore, from the viewpoint of reducing the resistance component of the conductive path electrically connecting the superconducting tape wire 11 and the superconducting tape wire 9 that are stacked so as to overlap each other as shown in Fig. 22, the connection method shown in Fig. 24 is preferable.

[0178] In the example shown in Figure 24, the laminate 9B formed in the lamination process (see Figure 21) includes a connection portion CP1 where the superconducting layer SCL1 and the superconducting layer SCL2 face each other without the metal substrate MS1, intermediate layer MDL1, metal substrate MS2, and intermediate layer MDL2 interposed therebetween, and a connection portion CP2 where the superconducting layer SCL1 and the superconducting layer SCL2 face each other via the metal substrate MS1, intermediate layer MDL1, metal substrate MS2, and intermediate layer MDL2 interposed therebetween.

[0179] According to the connection method shown in FIG. 24 , the resistance value at connection portion CP1 is significantly lower than the resistance value at connection portion CP2. This is because connection portion CP1 does not include metal substrate MS1, which has a relatively high resistance. When a current flows through two branched conductive paths, most of the current flows through the conductive path with a relatively low resistance. Therefore, when a large current flows through superconducting wire 10 and superconducting wire 10B shown in FIG. 22 , most of the current flows through connection portion CP1 shown in FIG. 24. As a result, even if stack 9B shown in FIG. 22 includes connection portion CP2, which has a relatively high resistance, current can flow through a low-resistance conductive path as a whole. In other words, with the connection method shown in FIG. 24 , the resistance value of the main conductive path in stack 9B can be reduced, thereby reducing heat generation in stack 9B.

[0180] Next, a preferred embodiment will be described from the viewpoint of further reducing the resistance value of the laminate 9B shown in Fig. 22. As shown in Fig. 21, the laminating step includes an acid cleaning step, an acid removing step, and a superconducting tape wire laminating step.

[0181] In the acid cleaning step shown in Fig. 21 , each of the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 9 shown in Fig. 22 is acid-cleaned. As explained with reference to Fig. 23 , the superconducting tape wire 11 is covered with a coating metal film CMF1 made of copper. Similarly, the superconducting tape wire 9 is covered with a coating metal film CMF2 made of copper. In addition, to prevent oxidation of the coating metal film CMF1 (or coating metal film CMF2) made of copper, an antioxidant film may be formed on the surface of the coating metal film CMF1 (or coating metal film CMF2). In the acid cleaning step, each of the superconducting tape wires 11 and the superconducting tape wire 9 is cleaned with an acidic cleaning solution to remove the antioxidant film (laminate film).

[0182] 21 , acid is removed from the surfaces of the plurality of superconducting tape wires 11 and the plurality of superconducting tape wires 9 after the acid cleaning step. If the superconducting tape wire lamination step is performed with acidic cleaning solution remaining on the surface of the coating metal film CMF1 (or coating metal film CMF2), there is a concern that the remaining acid may cause oxidation of the superconducting tape wire 11 (or superconducting tape wire 9). An example of a method for removing the acid is wiping it off with dry paper or cloth.

[0183] 21 , after the acid removal step, the superconducting tape wires 11 and the superconducting tape wires 9 are alternately stacked so that portions of the superconducting tape wires 11 and portions of the superconducting tape wires 9 overlap each other. In this way, by acid-cleaning each of the superconducting tape wires 11 and the superconducting tape wires 9 shown in FIG. 22 before carrying out the superconducting tape wire stacking step, the conductivity of the coated metal film CMF1 can be further improved.

[0184] The superconducting wire connection method described with reference to FIGS. 21 to 24 is a description of the features of the superconducting wire connection method extracted from the embodiments described with reference to FIGS. 1 to 20 . Therefore, the technique described in the section <Superconducting Wire Connection Method> can be applied in combination with other techniques already described. For example, by applying the technique described with reference to FIG. 20 to the stack 9B shown in FIG. 22 , the following connection method can be obtained. That is, in the stacking step shown in FIG. 21 , a spacer member 19 (see FIG. 20 ) that can contact the screw SS1 is disposed between the stack 9B shown in FIG. 22 and the bottom 23. When the screw SS1 is tightened, a pressing force from the screw SS1 is applied to the stack 9B via the spacer member 19.

[0185] The present invention is not limited to the above-described embodiments and examples, and various modifications are possible without departing from the spirit and scope of the present invention. For example, as described above, a member for protecting a superconducting wire has been specifically described as an example of a linear material protection member, but the structure of the protection member 100 can be used as a protection member for other linear materials. For example, it can be used as a protection member for protecting piping as a flow path for liquid or gas, or electric wires, etc.

[0186] Furthermore, for example, specific dimensions have been exemplified for each of the components such as the superconducting wire 10 and the protective member 100, but these values ​​can be changed without departing from the gist of the above description. Also, in Fig. 3 and Fig. 7, an example has been described in which four wires 30 are provided as reinforcing members in each of the multiple blocks 20. However, the number of wires 30 is not limited to four, and may be three or less (however, at least one wire is required), or five or more.

[0187] Furthermore, for example, various modified examples have been described above, but a part of an embodiment can be applied in combination with other embodiments.

[0188] The block 20A shown in Figures 3 to 6, 10, 19, 20, and 22 and the block 20C shown in Figures 12 to 16 and 18 can be expressed as follows: That is, a block (block 20A or block 20C) according to one embodiment has a roof portion, a side wall portion, and a side wall portion, and includes a linear material holding portion formed by the roof portion, the side wall portion, and the side wall portion. The block has a screw hole in at least one of the roof portion, the side wall portion, and the side wall portion.

[0189] The present invention can be used for protective members for linear materials used in various devices, such as nuclear fusion reactors, plasma generators, accelerators, superconducting power transmission, power storage, superconducting motors, and liquid transport pipes.

[0190] 2 Cooling pipe 10, 10A, 10B Superconducting wire (linear material) 9, 11, 16, 17, 18 Superconducting tape wire 9A, 9B, 11A, 11B, 11C, 16A, 17A, 17C, 18A Laminate 12 Metal band 13 Cooling pipe 14 Spacer 19 Metal plate 20, 20A, 20B, 20C, 20AA, 20AB, 20AC Block 20A1, 20A2, 20B1, 20B2, 20C1, 20C2, 20C3, Part 20GA, 20GB Block group 20s1, 20s2, 20s3, 20s4 Side 21, 21A, 21B, 21C Holding space 22 Roof portion 22a, 23a, 23a1, 23a2 Upper surface 22b, 23b Lower surface 23, 23A, 23B Bottom 24, 25 Side wall 24a, 25a Inner surface 26, 27 Opening 28 Middle wall 30, 31, 31A, 32, 32A, 33, 33A, 34, 34A Wire 31AT1, 31AT2, 31T, 31T1, 31T2, 32AT, 32T, 32T1, 32T2, 33AT, 33T, 34AT, 34T Groove 40 Lead section 41 Support section 41a Top surface 41H Through hole 42 Cover section 42b Bottom surface 42H Through hole 43 Bolt 44 Nut 100 Protective member 200, 201, 202 Coil BL Gap BP1, BP2, BP3, BP4, BP5, BP6, BP7, BP8 Fixing part CMF1, CMF2 Metal coating film CR1, CR2 Central region MDL1, MDL2 Intermediate layer MS1, MS2 Metal substrate PML1, PML2 Protective metal layer SCL1, SCL2 Superconducting layer SS1, SS2 Screw TH1, TH2 Screw hole TR1, TR2, TR3, TR4, TR5, TR6 Wire holding part

Claims

1. A first superconducting wire having a first laminate consisting of a plurality of stacked first superconducting tape wires; a second superconducting wire having a second stack consisting of a plurality of second superconducting tape wires stacked one on the other; a third stack in which a portion of the first superconducting tape wires and a portion of the second superconducting tape wires are stacked so as to overlap each other; and A superconducting wire connection structure further comprising a pressing portion that presses and fixes the third stack in the stacking direction.

2. In claim 1, a first block having a screw hole and arranged around the third stack; In the pressing portion, the third stack is pressed and fixed in the stacking direction via screws inserted into the screw holes.

3. In claim 2, The superconducting wire connection structure further comprises a spacer member provided between the screw and the third stack.

4. In claim 1, Each of the plurality of first superconducting tape wires comprises: a first superconducting layer made of a superconducting material; a first metal substrate supporting the first superconducting layer; a first intermediate layer located between the first superconducting layer and the first metal substrate; Including, Each of the plurality of second superconducting tape wires comprises: a second superconducting layer made of a superconducting material; a second metal substrate supporting the second superconducting layer; a second intermediate layer located between the second superconducting layer and the second metal substrate; Including, The third stacked body is a first connection portion where the first superconducting layer and the second superconducting layer face each other without the first metal substrate, the first intermediate layer, the second metal substrate, or the second intermediate layer therebetween; a second connection portion where the first superconducting layer and the second superconducting layer face each other via the first metal substrate, the first intermediate layer, the second metal substrate, and the second intermediate layer; A connection structure for superconducting wires, comprising:

5. In claim 1, The third stack is a connection structure for superconducting wires in which a portion of the plurality of first superconducting tape wires and a portion of the plurality of second superconducting tape wires are alternately stacked one by one so as to overlap each other.

6. (a) preparing a first superconducting wire having a first stack made up of a plurality of first superconducting tape wires stacked together; (b) preparing a second superconducting wire having a second stack consisting of a plurality of second superconducting tape wires stacked together; (c) after the steps (a) and (b), forming a third stack by alternately stacking portions of the first superconducting tape wires and portions of the second superconducting tape wires so that they overlap each other; (d) pressing and fixing the third laminate; A method for connecting superconducting wires, comprising:

7. In claim 6, The step (d) (d1) after the step (c), a step of preparing a first block that is a protective member capable of surrounding and holding the third stack; (d2) after the step (d1), inserting a screw into a screw hole formed in the first block and tightening the screw to press and fix the third stack into the holding space of the first block; Including, The first block is the holding space capable of holding the third stack; a roof portion covering the holding space; a bottom portion located on the opposite side of the roof portion across the holding space; the screw hole penetrating the bottom portion in a thickness direction and communicating with the holding space; A method for connecting superconducting wires, comprising:

8. In claim 6, Each of the plurality of first superconducting tape wires comprises: a first superconducting layer made of a superconducting material; a first metal substrate supporting the first superconducting layer; a first intermediate layer located between the first superconducting layer and the first metal substrate; a first protective metal layer having higher electrical conductivity than the first metal substrate and disposed on the opposite side of the first intermediate layer with the first superconducting layer interposed therebetween; Including, Each of the plurality of second superconducting tape wires comprises: a second superconducting layer made of a superconducting material; a second metal substrate supporting the second superconducting layer; a second intermediate layer located between the second superconducting layer and the second metal substrate; a second protective metal layer having higher electrical conductivity than the second metal substrate and disposed on the opposite side of the second intermediate layer with the second superconducting layer interposed therebetween; Including, The third laminate formed in the step (c) is a first connection portion where the first superconducting layer and the second superconducting layer face each other without the first metal substrate, the first intermediate layer, the second metal substrate, or the second intermediate layer therebetween; a second connection portion where the first superconducting layer and the second superconducting layer face each other via the first metal substrate, the first intermediate layer, the second metal substrate, and the second intermediate layer; A method for connecting superconducting wires, comprising:

9. In claim 6, The step (c) (c1) acid-washing each of the plurality of first superconducting tape wires and the plurality of second superconducting tape wires; (c2) after the step (c1), removing the acid from the surfaces of the first superconducting tape wires and the second superconducting tape wires; (c3) after the step (c2), stacking the first superconducting tape wires and the second superconducting tape wires alternately so that portions of the first superconducting tape wires and portions of the second superconducting tape wires overlap each other; A method for connecting superconducting wires, comprising:

10. In claim 7, In the step (d2), a spacer member that can come into contact with the screw is disposed between the third stack and the bottom; When the screw is tightened, a pressing force is applied from the screw to the third laminate via the spacer member.

11. In claim 6, In the step (c), a portion of the first superconducting tape wires and a portion of the second superconducting tape wires are alternately stacked one by one so as to overlap each other.