JP7404187B2 - Superconducting coils and superconducting coil devices - Google Patents

Description

Embodiments of the present invention relate to a superconducting coil and a superconducting coil device having a function of preventing thermal runaway or quenching.

A superconducting wire has a range of current, temperature, and magnetic field that can maintain a superconducting state, that is, a so-called critical current, critical temperature, and critical magnetic field. Therefore, even though the electrical resistance is almost zero, it does not mean that the current can flow infinitely; if any critical value is exceeded, a transition phenomenon to a normal conduction state, that is, quenching occurs. Joule heat generation in the normal conduction transition region caused by such quenching can cause instantaneous thermal runaway in the superconducting coil, and in the worst case, there is a risk of burnout, so protection technology against quenching is essential.

As a conventional technique regarding quench protection, for example, there is a method of connecting a protection resistor in parallel with a superconducting coil. This method detects the coil voltage and temperature rise that occur due to transition to a normal conduction state, and uses this as a trigger to cut off the excitation power source. After shutoff, the superconducting coil and protective resistor form a closed circuit, so the Joule heat generated by the protective resistor placed at room temperature consumes the energy stored in the superconducting coil, making it possible to attenuate the current flowing through the coil.

Examples of superconducting wires used in such superconducting coils include high-temperature superconducting wires such as Bi ₂ Sr ₂ Ca ₂ Cu ₃ O ₁₀ wire and RE ₁ B ₂ C ₃ O ₇ wire. A superconducting coil using a high-temperature superconducting wire has a higher critical current density even at a high temperature of 20K to 50K than a conventional low-temperature superconducting wire such as NbTi, so high current density operation at high temperatures is possible.

However, if quenching occurs during high current density operation, the expansion of the normal conduction transition region is slow in the temperature range of 20K to 50K because the specific heat is larger than the operating temperature of magnets using low-temperature superconducting wires, and When high-density operation is performed, the density of heat generation increases, so in the conventional quench protection method described above, there is a possibility that thermal runaway occurs locally and burnout occurs before detection.

Therefore, if the superconducting wires in different turns inside the superconducting coil are short-circuited between turns, the current flowing through the part where the normal conduction transition has occurred can be diverted to the superconducting wire in different turns. By causing the current to bypass the normal conducting portion, it is possible to suppress local heat generation and thermal runaway in the normal conducting transition region.

Specifically, for example, by providing a detour electrically connected to the superconducting wire on the side surface of the winding portion of the superconducting coil along the coil radial direction, superconducting wires of different turns can be short-circuited via the detour. A means for doing so has been disclosed (Patent Document 1).

Furthermore, regarding the electrode part, a superconducting coil is disclosed in which the electrode is arranged between the superconducting wire of the outermost turn and the superconducting wire within one turn of the outermost turn of the winding part (Patent Document 2). .

Furthermore, as a structure of a joint between an electrode and a superconducting wire, a structure is disclosed in which a superconducting tape for a cover is provided so as to cover at least a part of the electrode provided on the superconducting wire, and these are electrically connected to each other. (Patent Document 3). At this time, soldering is used as a specific method for electrically connecting the superconducting wire and the superconducting tape for the cover.

Patent No. 6486817 Patent No. 5858723 Patent No. 5568361

However, if a normal conduction transition occurs in the outermost (outermost) turn or the innermost (innermost) turn, compared to the case in which a normal conduction transition occurs in other turns, Since the area of the detour between the superconducting wires becomes smaller, the resistance value of the detour becomes relatively large, and the current cannot be sufficiently detoured, raising the temperature of the superconducting coil and causing quenching.

In addition, the superconducting wire within one turn from the outermost circumference of the winding section is bonded to the electrode with an adhesive made of insulating material, so it is not electrically connected to the electrode and flows through the superconducting coil. Current flows to the electrodes only through the superconducting wire in the outermost turns of the superconducting coil. Therefore, when a normal conduction transition occurs in the superconducting wire at the outermost turn, there is no path for current to flow to the electrodes avoiding the normal conduction transition portion, and there is a risk of burnout.

Furthermore, although conventional methods for joining electrodes and superconducting wires can be expected to have the effect of reducing the amount of heat generated near the electrodes, there is a problem in that the superconducting coils may burn out when normal conduction transition occurs at the outermost periphery of the superconducting coils. be. If the installation location of the superconducting wire for the cover is limited to the vicinity of the electrodes, when a normal conduction transition occurs at a location on the outermost periphery of the superconducting coil where the superconducting wire for the cover is not installed, the current will not flow normally. There is no path for flow to the electrodes that avoids the conductive transition area, and there is a risk of burnout.

On the other hand, if we consider the case where the superconducting wire for the cover is not limited to the vicinity of the electrodes but covers the entire outermost circumference of the superconducting coil, it will be necessary to solder the entire circumference of the superconducting wire, so solder only the vicinity of the electrodes. There is a problem in that the risk of deterioration of the superconducting wire due to the heat of the soldering iron increases compared to when the superconducting wire is attached. In addition, there is a possibility that local stress is generated at the corners of the superconducting wire for the cover and the electrode due to thermal contraction during cooling, resulting in deterioration of the superconducting wire for the cover.

Embodiments of the present invention have been made to solve the above problems, and an object thereof is to provide a superconducting coil and a superconducting coil device that can suppress the occurrence of thermal runaway or quench.

In order to solve the above problems, a superconducting coil according to the present embodiment includes: a winding portion in which a superconducting wire is wound; a detour electrically connecting the superconducting wires that are adjacent to each other in the radial direction; A superconducting coil comprising an outer electrode and an inner electrode electrically connected to a winding section, wherein the outer electrode is connected to an end in a winding direction and an end in a counter-winding direction of the outermost turn of the winding section. and/or the inner electrode is electrically connected across both the winding direction end and the counter-winding direction end of the innermost turn of the winding part. It is characterized by

Further, the superconducting coil device according to the present embodiment is a superconducting coil device in which a plurality of superconducting coils according to the present embodiment are laminated in the winding axis direction, and in which two adjacent superconducting coils among the plurality of laminated superconducting coils are stacked. It has an outer metal plate and an inner metal plate that are installed and function as electrodes, and the outer metal plate covers both the winding direction end and the counter-winding direction end of the outermost turn of the winding part of one superconducting coil. and/or the inner metal plate is electrically connected across both the winding direction end and the counter-winding direction end of the innermost turn of the winding portion of one superconducting coil. It is characterized by

According to the embodiments of the present invention, it is possible to suppress the occurrence of thermal runaway or quenching of a superconducting coil and a superconducting coil device.

A configuration diagram of a general high-temperature superconducting wire. An overview diagram of a superconducting coil. (a) and (b) are explanatory views of the winding direction. FIG. 3 is a sectional view taken along line AA in FIG. 2. FIG. 5 is an enlarged sectional view of region R1 in FIG. 4. FIG. 3 is a cross-sectional view of a detour made of conductive resin. (a) is a general view of a conventional superconducting coil with electrodes attached, and (b) is a configuration diagram of a conventional electrode attachment. An overview diagram of a conventional superconducting coil device. FIG. 3 is a configuration diagram of an outer electrode attachment according to the first embodiment. (a) and (b) are diagrams showing the flow of detour current in the conventional electrode mounting configuration, and (c) is a diagram showing the flow of detour current in the electrode mounting configuration according to the first embodiment. FIG. 7 is a configuration diagram of an electrode attachment according to a second embodiment. FIG. 7 is a diagram showing the flow of detour current in the electrode mounting configuration according to the second embodiment. (a) is a partial cross-sectional view of the outermost peripheral part of the winding part according to the third embodiment, and (b) is a cross-sectional view of the innermost peripheral part.

First, the configuration and operation of a general superconducting coil and superconducting coil device will be explained using FIGS. 1 to 8.
Note that high-temperature superconducting wires or low-temperature superconducting wires are used in superconducting coils and superconducting coil devices, and in the following explanation, an example will be described in which a high-temperature superconducting wire that exhibits particularly high effects is used.

(High-temperature superconducting wire)
As shown in FIG. 1, a general high temperature superconducting wire 20 is generally composed of a tape-shaped thin film wire in which thin film layers are laminated. A REBCO wire rod containing the like is used.

The high-temperature superconducting wire (hereinafter also referred to as "thin film wire") 20 includes a substrate 22 made of a high-strength metal material such as a nickel-based alloy, stainless steel, or copper, and an intermediate layer formed on the substrate 22. 24, an alignment layer 23 made of magnesium or the like that orients the intermediate layer 24 on the surface of the substrate 22, a high-temperature superconducting layer 25 made of a rare metal oxide or the like formed on the intermediate layer 24, and a layer 25 of silver, gold, platinum, etc. The stabilizing layer 21 is made of a highly conductive metal such as copper or aluminum.

The intermediate layer 24 prevents thermal distortion caused by thermal contraction of the substrate 22 and the superconducting layer 25. The protective layer 26 protects the superconducting layer 25 by preventing oxygen contained in the superconducting layer 25 from diffusing from the superconducting layer 25. The stabilizing layer 21 serves as a detour path for excessive current flowing to the superconducting layer 25 and prevents thermal runaway. Note that the type and number of each layer constituting the thin film wire 20 are not limited to these, and the type and number may be increased or decreased as necessary.

(superconducting coil)
The superconducting coil 10 formed by winding the high temperature superconducting wire 20 described above will be explained using FIGS. 2 to 8. Here, FIG. 2 is an overview diagram of the superconducting coil 10, FIGS. 3(a) and 3(b) are explanatory diagrams of the winding direction of the winding part 12, FIG. 4 is a sectional view taken along the line AA in FIG. 2, and FIG. is an enlarged sectional view of region R1 in FIG. 4, FIG. 6 is a sectional view of the detour path 19 made of conductive resin, and FIG. FIG. 7B is an explanatory diagram of the electrode mounting structure, and FIG. 8 is an outline diagram of the conventional superconducting coil device 100.

FIG. 2 is a schematic view of a pancake-shaped superconducting coil 10 consisting of a winding portion 12 in which a thin film wire 20 is concentrically wound, and is also called a pancake coil. As shown in FIG. 2, the direction parallel to the winding axis of the superconducting coil 10 is the winding axis direction C, the direction in which the thin film wire 20 is wound is the coil circumferential direction, and the direction in which the thin film wire 20 is stacked by winding is the coil diameter. It's called direction.

Further, the circumferential direction of the coil is determined as shown in FIGS. 3(a) and 3(b). That is, in the coil circumferential direction, the direction in which the thin film wire 20 goes from the inside to the outside in the coil radial direction of the winding part 12 is defined as the winding direction, and the direction in which the thin film wire 20 goes from the outside to the inside in the coil radial direction is defined as the counter-winding direction. As shown in FIG. 2, the winding part 12 has a pair of winding side parts 18 formed by laminating the thin film wire 20 by winding.

FIG. 4 is a cross-sectional view taken along the line AA in FIG. 2, and is a partial cross-sectional view of the superconducting coil 10. Here, by winding the thin film wire 20 around the winding frame 14, a pancake-shaped winding portion 12 having a space passing through the winding axis direction C is formed.

In addition, the gap between adjacent thin film wires 20 of different turns in the superconducting coil 10 is simply referred to as a coil-turn gap. FIG. 5 is an enlarged sectional view of region R1 in FIG. 4, and an insulating member 33 is disposed between the thin film wires 20 to insulate adjacent turns. As the insulating member 33, an insulating tape made of polyimide or the like is preferably used, for example. The tape-shaped insulating member 33 is inserted between the coil turns by being co-wound with the thin film wire 20 .

The superconducting coil 10 may also be impregnated with an adhesive insulating material such as epoxy resin. By being impregnated with the sticky resin, the insulating member 33 is fixed to the adjacent thin film wire 20 in the superconducting coil 10, and the thermal conductivity and mechanical strength of the superconducting coil 10 are improved.

Note that an insulating material with adhesive properties such as epoxy resin also functions as the insulating member 33 by being inserted between the turns, but in order to reliably insulate between the coil turns, an insulating tape made of polyimide or the like is used. It is preferable to use

(Detour)
As shown in FIGS. 4 and 5, the superconducting coil 10 electrically connects thin film wires 20 at different positions within the superconducting coil 10 to at least one surface of a pair of winding side portions 18 (see FIG. 2). A detour path 19 is provided. Note that the detour path 19 may be provided on both sides of the pair of winding side portions 18.

The material for the detour path 19 is selected to have a resistance greater than the resistance of the superconducting coil 10 during normal operation and smaller than the resistance of the superconducting coil 10 when the superconducting coil 10 transitions to normal conductivity. For example, normal conductive metals such as copper, stainless steel, aluminum, and indium, semiconductors, conductive plastics, ceramic materials, conductive resins, superconducting materials, and the like are used.

Further, carbon materials such as graphite, carbon fiber, or carbon fiber composite material can also be suitably used as the detour 19. These materials are formed into a sheet-like plate material, a foil, or the like, and are formed into the winding side surface portion 18 by crimping, soldering, or the like.

Note that the detour path 19 may be formed by plating or coating one surface of the winding side surface portion 18. In particular, when the detour path 19 is formed by plating, the detour path 19 can be made thin, and free deformation of the superconducting coil 10 is not inhibited. Furthermore, by forming the detour path 19 by plating or coating, the thickness of the detour path 19 in the winding axis direction can be adjusted, and the resistance value of the detour path 19 can be adjusted.

FIG. 6 shows an example in which a detour 19 is formed by applying conductive resin 36 to one surface of the winding side surface portion 18. As the conductive resin 36, for example, a resin having no conductivity mixed with conductive powder 35 can be used. At this time, by changing the proportion and type of conductive powder 35 mixed into the conductive resin 36, it becomes possible to easily adjust the volume resistivity of the conductive resin 36.

As the conductive powder 35, carbon-based powder such as carbon black, carbon fiber, graphite, etc. is used, for example. Further, as the conductive powder 35, metal-based powder such as metal fine particles, metal oxide, metal fibers, whiskers, etc. may be used. Further, the conductive powder 35 may be formed by coating fine particles or synthetic fibers with a metal, or the detour path 19 may be formed by applying conductive resin 36 of a different composition to each position of the winding side surface portion 18. .

Further, the conductive resin 36 may be formed by impregnating a part or all of the winding portion 12 including the spaces between the thin film wires 20 adjacent to each other in the coil radial direction. Thereby, the contact area between the conductive resin 36 and the thin film wire 20 can be increased, and the contact resistance between the conductive resin 36 and the thin film wire 20 can be reduced.

Note that the insulating member 33 may not be provided between the thin film wires 20 adjacent to each other in the coil radial direction, and the adjacent thin film wires 20 may be brought into direct contact with each other. In this case, the stabilizing layers 21 covering the outer surfaces of the adjacent thin film wires 20 contact each other in the radial direction of the coils to be electrically connected and function as a detour 19 .

(Effects of detour)
Here, the effect of suppressing the occurrence of thermal runaway etc. by providing the detour 19 will be explained.

As the thin film wire 20 approaches a critical current, which is the limit of current flow, an external magnetic field gradually penetrates the thin film wire 20, and the portion where the superconducting state is locally destroyed transitions to normal conductivity. The flux flow resistance associated with this local normal conduction transition generates heat due to Joule loss, so if it increases due to a rise in coil temperature, etc., it induces thermal runaway or quench (hereinafter collectively referred to as "thermal runaway, etc."). .

Therefore, by providing the detour path 19, when local flux flow resistance occurs due to normal conduction transition in a part of the thin film wire 20, the current Ia ( (hereinafter referred to as a "detour current") can detour to the thin film wire 20 of another adjacent turn via the detour path 19.

Here, the current flowing in the circumferential direction of the coil decreases from I to I-Ia. At this time, when the resistance of the detour path 19 is Ra and the flux flow resistance is R, the detour current Ia detouring in the coil radial direction is proportional to R/(R+Ra).

Therefore, as the flux flow resistance R increases, more of the detour current Ia will detour in the coil radial direction. As a result, it is possible to prevent a large amount of current I from flowing into a normally conductive portion that has locally transitioned to a normally conductive state, thereby suppressing the occurrence of thermal runaway or the like.

Note that if the coil turns are electrically connected via the detour 19, induction will occur not only when the flux flow resistance R occurs, but also when the superconducting coil 10 is energized from a non-energized state to the rated current value. A part of the detour current Ia of the energizing current I supplied from the power source due to the voltage detours through the detour path 19 to the thin film wire 20 of another turn in the coil radial direction. Moreover, since no induced voltage is generated after excitation is completed, the detour current Ia flowing through the detour path 19 gradually flows in the circumferential direction of the coil, and it takes time to reach the designed magnetic field value. Therefore, the lower the resistance between the coil turns, the more current will be diverted during excitation, which may unnecessarily lengthen the excitation time.

Therefore, the resistance Ra of the detour path 19 is small enough to allow a sufficient amount of current to be commutated to the detour path 19 when the flux flow resistance R occurs, and the superconducting coil 10 is excited from the de-energized state to the rated current value. It is preferable to set the resistance so large that the excitation time does not become unnecessarily long.

(insulating board)
As shown in FIG. 4, an insulating plate 16 is provided on the side surface of the superconducting coil 10 to insulate the detour 19 and the winding portion 12 from other adjacent superconducting coils 10 and the like. As the insulating plate 16, epoxy resin or fiber-reinforced plastic is suitably used.

(electrode)
Generally, in order to energize the superconducting coil 10 described above, as shown in FIG. 20 is provided with an inner electrode 40b. The outer electrode 40a and the inner electrode 40b are electrically connected to the thin film wire 20 by soldering or the like, and allow the current I flowing through the superconducting coil 10 to flow in or out. The outer electrode 40a and the inner electrode 40b are made of, for example, copper, silver, gold, indium, or an alloy thereof.

FIG. 7(a) is an overview diagram of a conventional superconducting coil 10 to which an outer electrode 40a and an inner electrode 40b are attached, and FIG. 7(b) is a schematic diagram of the superconducting coil 10 when viewed from the winding axis direction C. FIG. 3 is a configuration diagram of a conventional electrode attachment.

Here, to explain the positional relationship between the winding part 12, the outer electrode 40a, and the inner electrode 40b, when attaching the outer electrode 40a to the thin film wire 20 at the outermost turn of the winding part 12, The non-current carrying area 52A up to the outer peripheral end portion 51A of the winding portion 12 is determined to be as small as possible in the winding direction.

Similarly, when attaching the inner electrode 40b to the thin film wire 20 at the innermost turn of the winding portion 12, as shown in FIG. 7(b), the thin film wire 20 is It is determined so that the non-current-carrying region 52B up to the end portion 51B on the inner peripheral side is as small as possible.

When a current is passed from the inner circumferential side to the outer circumferential side of the winding portion 12, the current-carrying region 53 in which the current I can flow is from the inner electrode attachment position of the innermost circumference turn to the outer electrode attachment position of the outermost circumference turn. It is an interval. That is, the non-energized area 52B, which is the area from the innermost end 51B to the inner electrode attachment position, and the non-energized area 52A, which is the area from the outermost end 51A to the outer electrode attachment position, are energized. Current I does not flow and does not contribute to the formation of the magnetic field of superconducting coil 10.

In the following description, the innermost circumference of the winding portion 12 refers to a section corresponding to one turn in the winding direction based on the innermost end portion 51B of the winding portion 12, that is, the opposite end portion 57B in the winding direction. It refers to the section from the winding direction end portion 58B. On the other hand, the innermost circumference of the current-carrying region 53 refers to a section corresponding to one turn in the winding direction based on the electrode attachment position on the innermost circumference side. When simply written as the innermost circumference, it refers to the innermost circumference of the winding portion 12.

Similarly, the outermost periphery of the winding portion 12 refers to a section corresponding to one turn in the counter-winding direction based on the outermost end portion 51A of the winding portion 12, that is, from the end portion 58A in the winding direction to the counter-winding direction. It refers to the section up to the direction end 57A. On the other hand, the outermost periphery of the current-carrying region 53 refers to a section corresponding to one turn in the counter-winding direction based on the electrode attachment position on the outermost periphery side. When simply written as the outermost periphery, it refers to the outermost periphery of the winding portion 12.

(Superconducting coil device)
As shown in FIG. 8, the superconducting coil device 100 is constructed by laminating a plurality of superconducting coils 10 concentrically in the direction of the winding axis. The superconducting coil device 100 includes metal plates 41 (outer metal plate 41a, inner metal plate 41b) that are installed between two adjacent superconducting coils 10 and function as electrodes among the plurality of superconducting coils 10 stacked in this way. have

The outer metal plate 41a is electrically connected to the thin film wire 20 by soldering or the like, and allows the current I flowing out from one of the two superconducting coils 10 to flow into the other superconducting coil 10. let The metal plate 41 is preferably made of copper, silver, gold, indium, or an alloy thereof, for example.

Note that the outer metal plate 41a can be directly joined to the thin film wire 20 with solder 71 or the like, but as shown in FIG. The outer metal plate 41a may be joined to the outer metal plate 41a. As the conductive tape 27, a low resistance metal such as indium, gold, silver, or copper, or a superconducting wire can be used. The same applies to the inner metal plate 41b.

The attachment position when attaching the outer metal plate 41a to the thin film wire 20 at the outermost turn of the winding part 12 is shown in FIG. The non-current carrying area 52A from the metal plate attachment position to the outer peripheral end portion 51A of the winding portion 12 in the winding direction is determined to be as small as possible.

Similarly, when attaching the inner metal plate 41b to the thin film wire 20 at the innermost turn of the winding section 12, the metal plate attachment position is from the metal plate attachment position to the counter-winding direction as shown in FIG. 7(b). On the other hand, the non-current-carrying region 52B up to the end portion 51B on the inner peripheral side of the thin film wire 20 is determined to be as small as possible. Thereby, the non-current-carrying regions 52A and 52B that do not contribute to magnetic field formation are shortened, and the current-carrying region 53 that contributes to magnetic field formation is lengthened.

(Main surface of thin film wire)
Here, the orientation of the two main surfaces 60 of the thin film wire 20 when joining the thin film wire 20 to the outer electrode 40a, inner electrode 40b, outer metal plate 41a, or inner metal plate 41b will be described.
As shown in FIG. 1, the thin film wire 20 has two main surfaces 60, the main surface 60 closer to the superconducting layer 25 is called a proximal surface 60a, and the main surface 60 farther away is called a distal surface 60b.

When joining the thin film wire 20 and the outer electrode 40a, the inner electrode 40b, or the outer metal plate 41a, or the inner metal plate 41b, the proximal surface 60a is connected to the outer electrode 40a, the inner electrode 40b, or the outer metal plate 41a, or the inner metal plate 41b. It is preferable to arrange them so as to face each other. That is, by shortening the distance between the superconducting layer 25 and the outer electrode 40a, inner electrode 40b, outer metal plate 41a, or inner metal plate 41b, the electrical resistance at the joint can be reduced.

In particular, as shown in FIG. 1, when the substrate 22 made of a high resistance metal such as a nickel-based alloy or stainless steel is provided between the distal surface 60B and the superconducting layer 25, the distal surface 60b and the outer electrode 40a, If the inner electrode 40b or the outer metal plate 41a and the inner metal plate 41b are joined so as to face each other, there is a possibility that the resistance of the joint portion becomes large.

Therefore, the winding portion 12 is formed such that the proximal surface 60a of the thin film wire 20 faces outward in the coil radial direction at the outermost periphery of the energizing region 53, and the proximal surface 60a of the thin film wire 20 at the innermost periphery of the energizing region 53. It is preferable that the superconducting coil 10 is configured such that the coil faces inward in the coil radial direction.

[First embodiment]
The superconducting coil according to the first embodiment will be described below with reference to FIG. 9 and FIGS. 10(a) to (c).

(composition)
FIG. 9 is an outer electrode attachment configuration diagram of the superconducting coil 10 according to the first embodiment viewed from the winding axis direction C, showing the positional relationship between the winding portion 12 and the outer electrode 40a.

The outer electrode 40a is electrically connected across both the winding direction end 58A of the outermost turn of the winding portion 12 and the opposite winding direction end 57A of the outermost turn, and It is arranged radially outward of the winding direction end 58A and the anti-winding direction end 57A.

As a result, in the first embodiment, compared to the conventional superconducting coil 10 shown in FIG. 7A, the outer electrode 40a is electrically connected to the thin film wire 20 on the inner peripheral side by about one turn. It turns out.
By electrically connecting the outer electrode 40a to the counter-winding direction end 57A of the outermost turn of the winding portion 12 in this manner, one or more turns of the non-current carrying region 52A are secured.

The outer electrode 40a can be directly joined to the thin film wire 20 with solder 71 or the like, but as shown in FIG. may be joined. As the conductive tape 27, a low resistance metal such as indium, gold, silver, or copper, or a superconducting wire can be used.

(effect)
The operation of the superconducting coil 10 configured as described above will be explained using FIGS. 10(a) to 10(c).
Here, FIGS. 10(a) and 10(b) are diagrams showing the flow of detour current Ia when a normal conduction point 15 occurs in the conventional electrode mounting configuration shown in FIGS. 7(a) and 7(b). FIG. 7B is an enlarged view of region R2 in FIG. 7(b).

Also. FIG. 10(c) is a diagram showing the flow of detour current Ia when a normal conduction point 15 occurs in the superconducting coil 10 according to the first embodiment, and is an enlarged view of region R3 shown in FIG.

(Effect of conventional electrode mounting configuration)
First, as shown in FIG. 10(a), consider a case where a normally conductive point 15 occurs in the thin film wire 20 in turns other than the outermost and innermost peripheries of the current-carrying region 53.

Here, it is assumed that the energizing current I flows from the inner circumferential side to the outer circumferential side of the superconducting coil 10, but the same effect can be obtained even if the direction of the current is reversed. In the normal superconducting coil 10, the outermost and innermost peripheries of the current-carrying region 53 and the outermost and innermost peripheries of the winding portion 12 generally match.

In FIG. 10A, since the adjacent thin film wires 20 are electrically connected by the detour 19, a part of the detour current Ia of the energizing current I flows into the detour 19 so as to avoid the normally conducting portion 15. . The resistance when the detour current Ia flows in the coil radial direction through the detour path 19 and the contact resistance when the detour current Ia is commutated to the detour path 19 are proportional to the cross-sectional area in the direction perpendicular to the direction in which the detour current Ia flows.

Assuming that the thickness of the detour path 19 is constant, its cross-sectional area is proportional to the circumferential length of the turn in which the normal conduction transition occurs. Although the circumferential length varies somewhat depending on the coil radial position of the turn where the normal conduction transition occurs, the detour current Ia can flow through a cross-sectional area at least equal to the circumferential length.

Next, a case will be considered in which a normally conductive portion 15 occurs in the thin film wire 20 at the outermost periphery of the current-carrying region 53 as shown in FIG. 10(b).
The energizing current I and the bypass current Ia flow to the outer electrode 40a attached near the end portion 51A of the thin film wire 20, but since the thin film wire 20 does not exist further outside the outermost periphery of the energizing region 53, The cross-sectional area through which the detour current Ia can flow becomes smaller than in the case of FIG. 10(a), which increases the resistance when the detour current Ia flows through the detour path 19.
Therefore, since the detour current Ia is not sufficient, a large amount of current may flow into the normally conducting portion 15, causing quenching.

(Function of the electrode mounting structure of the first embodiment)
On the other hand, when the outer electrode 40a is electrically connected across both the winding direction end 58A and the anti-winding direction end 57A as shown in FIG. The outermost turn of the thin film wire 20 of the winding portion 12 is wound on the outside as a non-current-carrying region 52A.
This allows the detour current Ia to detour through the cross-sectional area 56 corresponding to the circumferential length.

In this way, the electrical resistance when the detour current Ia flows through the detour path 19 in FIG. Since the electrical resistance can be reduced to the same level as the electrical resistance when (See a) and (b)) The resistance value will not be large.

Furthermore, in the electrode mounting configuration of FIG. 10(c), since the end portion 58A of the thin film wire 20 in the winding direction is electrically connected to the outer electrode 40a, the winding direction end portion 58A of the thin film wire 20 is electrically connected to the outermost thin film wire 20 of the winding portion 12. In addition to the path in which the detour current Ia flows into the outer electrode 40a via the thin film wire 20 within one turn of the outermost circumference, it flows directly into the outer electrode 40a without returning to the thin film wire 20 within one turn of the outermost circumference. Therefore, the number of paths through which the detour current Ia flows to the outer electrode 40a increases, and the amount of heat generated by the detour current Ia is reduced.

As described above, in the first embodiment, in the superconducting coil 10 in which the thin film wires 20 adjacent to each other in the coil radial direction are electrically connected by the detour 19, the outer electrode 40a is counter-wound with the winding direction end 58A. By electrically connecting both of the turning direction ends 57A, even if a normally conductive spot 15 occurs at the outermost turn of the energized area 53, a non-energized area that covers the outermost part of the energized area 53 A part of the detour current Ia of the current I can be detoured to the region 52A.

Note that in the case of a conventional electrode mounting configuration in which a cover superconducting tape is provided to cover at least a portion of the electrode provided on the superconducting wire 20 and these are electrically connected to each other, in other words, the outer electrode 40a is In the case of an electrode mounting configuration provided between the winding direction end 58A and the anti-winding direction end 57A (see Patent Document 3), the superconducting coil 10 Concentrated stress occurs due to thermal contraction during cooling, and there is a risk that the thin film wire 20 may deteriorate at the portion where the edge of the outer electrode 40a and the thin film wire 20 are in contact.

However, in the electrode mounting configuration of the first embodiment, since the outer electrode 40a is provided radially outward of the winding direction end 58A and the counter-winding direction end 57A, there is a risk of deterioration due to thermal contraction during cooling. There is no.

Note that instead of providing the outermost turn of the winding section 12, a structure in which the superconducting tape for the cover is attached over the entire circumference of the winding section 12 can be considered; Therefore, the risk of deteriorating the thin film wire 20 due to the heat of the soldering iron increases.

Furthermore, when the outer electrode 40a is provided between the winding direction end 58A and the counter-winding direction end 57A, the thin film wire 20 near the winding direction end 58A is connected to the outer electrode 40a in the radial direction through solder or the like. A further need arises for electrical connections from the outside.

However, in the electrode attachment configuration of the first embodiment, the thin film wire 20 at the outermost turn of the winding portion 12 is electrically connected in the radial direction to the thin film wire 20 at the outermost turn one turn earlier via the detour 19. Therefore, there is no need to solder the thin film wires 20 together. That is, it is sufficient to attach the outer electrode 40a across both the winding direction end 58A and the anti-winding direction end 57A, and the number and area of soldering work is similar to that of the conventional superconducting coil 10 when the outer electrode 40a is attached to the superconducting coil 10. The same applies when installing.

(effect)
As explained above, according to the first embodiment, a sufficient amount of detour current Ia can be commutated to other thin film wires 20 in which the normal conductive portion 15 is not generated, so that the superconducting coil 10 It is possible to suppress the occurrence of thermal runaway or quenching.
Note that the above-mentioned effects are the same for the mounting configuration of the inner electrode 40b.

[Second embodiment]
A superconducting coil according to a second embodiment will be explained using FIGS. 11 and 12. Note that the same components as in the first embodiment are given the same reference numerals, and overlapping explanations will be omitted.

(composition)
In the superconducting coil 10 according to the second embodiment, the inner electrode 40b has an opposite winding direction end 57B of the innermost turn of the winding portion 12 and a winding direction end 58B of the outermost turn. It is electrically connected across both, and is arranged radially inside of the winding direction end portion 58B and the counter-winding direction end portion 57B.

The superconducting coil 10 according to the second embodiment shown in FIG. 11 has an inner electrode 40b on the thin film wire 20 on the outer peripheral side by about one turn, compared to the conventional superconducting coil 10 shown in FIG. 7(b). It will be installed. In this way, by electrically connecting the inner electrode 40b to the innermost winding direction end 58B of the winding portion 12, one turn or more of the non-current-carrying region 52B is secured.

(effect)
The operation of the second embodiment will be explained using FIG. 12.
FIG. 12 is an enlarged sectional view of region R4 of superconducting coil 10 shown in FIG. 11, and is a diagram showing the flow of detour current.

In the second embodiment, as in the first embodiment, the thin film wire 20 of the innermost turn of the winding part 12 is wound further inside the innermost circumference of the energized area 53 as a non-energized area 52B. As shown in FIG. Resistance can be reduced.

Furthermore, since the end portion 51B of the thin film wire 20 is electrically connected to the inner electrode 40b, the detour current Ia detoured to the thin film wire 20 on the innermost circumference of the winding portion 12 is transferred to the one turn outside the innermost circumference. In addition to the path flowing into the inner electrode 40b via the thin film wire 20, a path is formed that flows directly into the inner electrode 40b without returning to the thin film wire 20 one turn before the innermost circumference, so that the detour current Ia Similarly to the first embodiment, the number of paths through which the current flows to the inner electrode 40b increases, and the amount of heat generated by the detour current Ia is reduced.

(effect)
As explained above, according to the second embodiment, a sufficient amount of detour current Ia can be commutated to the detour path 19, so that thermal runaway or quenching of the superconducting coil 10 can be suppressed. It is possible.

[Third embodiment]
A superconducting coil according to the third embodiment will be described using FIGS. 13(a) and 13(b). Here, FIG. 13(a) is a partial sectional view of the outermost peripheral portion of the winding portion 12, and is an enlarged sectional view of region R3 in FIG. 9, and FIG. 13(b) is a partial sectional view of the outermost peripheral portion of the winding portion 12. FIG. 12 is a partial sectional view of FIG. 12 and an enlarged sectional view of region R4 in FIG.
Note that the same components as those in the above embodiment are denoted by the same reference numerals, and overlapping explanations will be omitted.

(composition)
In the superconducting coil 10 according to the third embodiment, at least a part of the outermost turns of the winding part 12 has a connecting part 70 that connects the thin film wires 20 to each other.

As described above, since the proximal surface 60a of the thin film wire 20 faces inward in the coil radial direction at the outermost turn of the current-carrying region 53 of the thin film wire 20, as shown in FIG. The proximal surfaces 60a of the thin film wire 20 are connected to each other at the outermost turn of the thin film wire 20 so as to face each other (see FIG. 1).

As a result, in the non-energized region 52A located further outside the energized region 53, the proximal surface 60a of the thin film wire 20 is arranged to face inward in the coil radial direction. Here, as the wire connected to the thin film wire 20, a bismuth-based superconducting wire may be used.

Note that the connecting portion 70 between the proximal surfaces 60a of the thin film wire 20 described above only needs to have a part of the connecting portion 70 in the winding circumferential direction included in the outermost turn of the winding portion 12. In particular, as shown in FIG. ) may include a common area with respect to the electrode mounting position 50A and the winding circumferential direction. In this case, by filling the gap between the connecting portion 70 and the outer electrode 40a with solder 71 or the like, it is possible to mechanically fix them and to electrically connect them.

Similarly, the superconducting coil 10 according to the third embodiment has a connecting portion 70 between the thin film wires 20 at least in a portion of the innermost circumference of the winding portion 12.

As described above, the proximal surface 60a of the thin film wire 20 faces outward in the coil radial direction at the innermost periphery of the current-carrying region 53 of the thin film wire 20, and as shown in FIG. The proximal surfaces 60a of the thin film wires 20 are connected to each other while facing each other at the inner periphery. As a result, in the non-energized region 52B located further inside the energized region 53, the proximal surface 60a of the thin film wire 20 is arranged facing outward in the coil radial direction.

Note that the connection portion 70 between the proximal surfaces 60a of the thin film wire 20 described above only needs to be at least partially included in the innermost turn of the winding portion 12, and in particular, as shown in FIG. It may include a common area with respect to the electrode mounting position 50B and the winding circumferential direction.

(effect)
In the third embodiment, in addition to the effects of the first and second embodiments, the proximal surfaces 60a of adjacent thin film wires 20 face each other at the innermost turn or the outermost turn of the winding portion 12. Therefore, the electrical resistance between these thin film wires 20 is reduced.

Therefore, as shown in FIGS. 13(a) and 13(b), even if the normally conductive portion 15 occurs in the thin film wire 20 located at the innermost or outermost periphery of the current-carrying area 53, the detour current Ia It is possible to further reduce the electrical resistance when flowing through 19.

(effect)
As explained above, according to the third embodiment, a sufficient amount of detour current Ia can be commutated to the detour path 19, so that thermal runaway or quenching of the superconducting coil 10 can be suppressed. It is possible.

[Fourth embodiment]
A superconducting coil device according to a fourth embodiment will be described. Note that the same components as those in the above embodiment are denoted by the same reference numerals, and overlapping explanations will be omitted.

(composition)
As shown in FIG. 8, the superconducting coil device 100 is constructed by laminating a plurality of superconducting coils 10 concentrically in the direction of the winding axis. The superconducting coil device 100 includes metal plates 41 (outer metal plate 41a, inner metal plate 41b) that are installed between two adjacent superconducting coils 10 and function as electrodes among the plurality of superconducting coils 10 stacked in this way. have

The outer metal plate 41a is electrically connected to the thin film wire 20 by soldering or the like, and allows the current I flowing out from one of the two superconducting coils 10 to flow into the other superconducting coil 10. let The metal plate 41 is preferably made of copper, silver, gold, indium, or an alloy thereof, for example.

Note that the outer metal plate 41 a can be directly joined to the thin film wire 20 with solder 71 or the like, but it is also possible to attach a reinforcing conductive tape 27 to the thin film wire 20 and then join the outer metal plate 41 a to the conductive tape 27 . You may. As the conductive tape 27, a low resistance metal such as indium, gold, silver, or copper, or a superconducting wire can be used. The same applies to the inner metal plate 41b.

As in the electrode attachment configuration of the first embodiment (see FIG. 10(c)), the outer metal plate 41a is located at the end 58A in the winding direction of the outermost turn of the winding portion 12 of one superconducting coil 10. It is arranged on the outside in the radial direction and is electrically connected across both the winding direction end 58A and the counter-winding direction end 57A.

Thereby, about one turn of the non-current area 52A can be secured further outside the outermost periphery of the current-carrying area 53. The outer metal plate 41a can be directly joined to the thin film wire 20 with solder 71 or the like.

(effect)
In the fourth embodiment, as in the first embodiment, the thin film wire 20 of the outermost turn of the winding portion 12 is wound further outside the outermost circumference of the energized region 53 as a non-energized region 52A. Therefore, even if the normally conductive portion 15 occurs in the thin film wire 20 at the outermost periphery of the current-carrying region 53, the electrical resistance when the detour current Ia flows through the detour path 19 can be reduced.

Furthermore, as shown in FIG. 10(c), since the end portion 58A of the thin film wire 20 in the winding direction is electrically connected to the outer metal plate 41a, a detour is made to the thin film wire 20 on the outermost periphery of the winding portion 12. In addition to the path in which the detour current Ia flows into the outer metal plate 41a via the thin film wire 20 within one turn of the outermost circumference, it also flows into the outer metal plate 41a without returning to the thin film wire 20 within one turn of the outermost circumference. Since a direct outflow path is formed, the number of paths through which the detour current Ia flows to the outer metal plate 41a increases, and the amount of heat generated by the detour current Ia is reduced.

In this way, in the superconducting coil device 100 in which the thin film wires 20 adjacent to each other in the coil radial direction are electrically connected by the detour 19, the outer metal plate 41a is connected to the thin film wire 20 within one turn from the outermost turn of the winding portion 12. By disposing it on the surface 54A of the wire 20, even if a normally conductive spot 15 occurs at the outermost turn of the energized region 53, a part of the energized current I is transferred to the non-energized region 52A covering the outermost periphery of the energized region 53. The detour current Ia of the section can be detoured.

(effect)
As explained above, according to the fourth embodiment, a sufficient amount of detour current Ia can be commutated to the detour path 19, so that thermal runaway or quenching of the superconducting coil device 100 can be suppressed. is possible.

[Fifth embodiment]
A superconducting coil device according to a fifth embodiment will be described. Note that the same components as those in the above embodiment are denoted by the same reference numerals, and overlapping explanations will be omitted.

(composition)
In the superconducting coil device 100 according to the fifth embodiment, as in the case where the inner electrode 40b shown in FIG. 12 is connected to the thin film wire 20, the inner metal plate 41b functioning as an electrode It is arranged radially inside the counter-winding direction end 57B and is electrically connected across both the winding direction end 58B and the counter-winding direction end 57B. Thereby, about one turn of non-current area 52B can be secured further inside the innermost circumference of energized area 53.
Note that an outer electrode 40a and an inner electrode 40b can be attached to the superconducting coil device 100 to allow the current I to flow in or out from the outside.

As a preferred example, the superconducting coil 10 to which the electrodes 40a and 40b are attached based on the first to third embodiments is incorporated as the superconducting coil 10 at the end in the winding axis direction C of the superconducting coil device 100, and The superconducting coils 10 are electrically connected to each other by constructing the outer metal plate 41a and the inner metal plate 41b based on the fourth or fifth embodiment, so that the energizing current I can be applied to the plurality of superconducting coil devices 100 that constitute the superconducting coil device 100. A series circuit can be formed in which the current flows through the superconducting coils 10 in sequence.

(effect)
In the fifth embodiment as well, similarly to the second embodiment, in each superconducting coil 10, the innermost turn of the winding portion 12 is further inside the innermost circumference of the energized region 53 as a non-energized region 52B. Since the thin film wire 20 is wound around the thin film wire 20, even if the normal conduction point 15 occurs in the thin film wire 20 on the innermost periphery of the current carrying area 53, the electrical resistance when the detour current Ia flows through the detour path 19 is small. can be reduced.
Note that since the thin film wire 20 on the innermost circumference and the metal plate 41 are electrically connected, the detour current Ia can directly flow from the metal plate 41 into the thin film wire 20 on the innermost circumference of the winding portion 12. .

(effect)
As described above, according to the fifth embodiment, a sufficient amount of detour current Ia can be commutated to the detour path 19, so that thermal runaway or quenching of the superconducting coil device 100 can be suppressed. is possible.

[Sixth embodiment]
A superconducting coil device according to a sixth embodiment will be described. Note that the same components as those in the above embodiment are denoted by the same reference numerals, and overlapping explanations will be omitted.

(composition)
Similar to the superconducting coil 10 according to the third embodiment, the superconducting coil device 100 according to the sixth embodiment has a connection section 70 between the thin film wires 20 in at least a part of the outermost periphery of the winding section 12. . Specifically, as shown in FIG. 13(a) according to the third embodiment, by connecting the proximal surfaces 60a of the thin film wire 20 to face each other at the outermost periphery of the winding portion 12. In a non-current-carrying region 52A located further outside the current-carrying region 53, the proximal surface 60a of the thin film wire 20 is arranged facing inward in the coil radial direction.

As the wire connected to the thin film wire 20, a bismuth-based superconducting wire may be used. As shown in FIG. 13(b), it may include a common area with respect to the electrode attachment position 50A and the winding circumferential direction.

Similarly, in the superconducting coil device 100 according to the sixth embodiment, like the superconducting coil 10 according to the third embodiment, in at least a part of the innermost periphery of the winding part 12, the connection portion between the thin film wires 20 is It has 70.

The point where the proximal surfaces 60a of the thin film wire 20 are connected to each other while facing each other, and the point where the electrode mounting position 50B may include a common area in the winding circumferential direction as shown in FIG. This is similar to the embodiment.

(effect)
Also in the sixth embodiment, in addition to the effects of the fourth and fifth embodiments, similar to the third embodiment, the thin film wires adjacent to each other at the innermost turn or the outermost turn of the winding portion 12 Since the proximal surfaces 60a of the thin film wires 20 face each other, the electrical resistance between the thin film wires 20 is reduced.

(effect)
As explained above, according to the sixth embodiment, a sufficient amount of detour current Ia can be commutated to the detour path 19, so that thermal runaway or quenching of the superconducting coil device 100 can be suppressed. is possible.

Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, changes, and combinations can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

For example, a so-called pancake-shaped superconducting coil is exemplified as the shape of the winding section provided with the detour, the conductive member, and the insulating material. However, the applicable winding portion is not limited to a pancake shape. It can also be applied to non-circular coils such as racetrack type, saddle type, and elliptical type.

DESCRIPTION OF SYMBOLS 10... Superconducting coil, 12... Winding part, 14... Winding frame, 15... Normal conducting part, 16... Insulating plate, 18... Winding side part, 19... Detour, 20... Superconducting wire (thin film wire), 21... Stabilizing layer, 22... Substrate, 23... Orientation layer, 24... Intermediate layer, 25... High temperature superconducting layer, 26... Protective layer, 27... Conductive tape, 33... Insulating member, 35... Conductive powder, 36... Conductive 40... Electrode, 40a... Outer electrode, 40b... Inner electrode, 41... Metal plate, 41a... Outer metal plate, 41b... Inner metal plate, 51A, 51B... End portion, 52A, 52B... Non-current carrying area, 53 ...Electrification area, 57A, 57B... End in counter-winding direction, 58A, 58B... End in winding direction, 60... Main surface, 60a... Proximal surface, 60b... Distal surface, 70... Connection portion, 71... Solder , 100...Superconducting coil device

Claims (12)

A winding portion formed by winding a superconducting wire, a detour electrically connecting the radially adjacent superconducting wires, and an outer electrode and an inner electrode electrically connected to the winding portion, A superconducting coil comprising:
The outer electrode spans both the winding direction end and the counter-winding direction end of the outermost turn of the winding section, and/or the inner electrode spans the winding end of the outermost turn of the winding section. A superconducting coil characterized in that it is electrically connected across both a winding direction end and a counterwinding direction end. The outer electrode is provided radially outward from the winding direction end and the counter-winding direction end of the outermost turn of the winding portion, and/or the inner electrode is provided at the innermost end of the winding portion. 2. The superconducting coil according to claim 1, wherein the superconducting coil is provided radially inward from an end in a winding direction and an end in a counter-winding direction of the circumferential turn. The superconducting wire is composed of a tape-shaped laminate including at least a high-temperature superconducting layer, and the superconducting wire has a proximal surface close to the high-temperature superconducting layer and a distal surface far from the high-temperature superconducting layer,
The superconducting wire at the outermost turn of the winding section has a proximal surface facing inward in the coil radial direction, and has a connection section where the proximal surfaces of the superconducting wire are connected to each other at least in a part of the outermost turn. The superconducting coil according to claim 1 or 2, characterized in that: The superconducting wire is composed of a tape-shaped laminate including at least a high-temperature superconducting layer, and the superconducting wire has a proximal surface close to the high-temperature superconducting layer and a distal surface far from the high-temperature superconducting layer,
A proximal surface of the superconducting wire in the innermost turn of the winding portion faces outward in the coil radial direction, and a connection portion where the proximal surfaces of the superconducting wire are connected to each other in at least a portion of the innermost turn. The superconducting coil according to any one of claims 1 to 3, characterized in that it has: The superconductor according to any one of claims 1 to 4, wherein the detour is a sheet-like, plate-like, or foil- like conductive member formed on at least one side surface of the winding part. coil. 5. The superconducting coil according to claim 1, wherein the detour is a conductive resin formed on a side surface of the winding portion perpendicular to the winding axis direction. 5. The superconducting coil according to claim 1, wherein the detour is formed by impregnating at least a portion of the winding portion with a conductive resin. A superconducting coil device comprising a plurality of superconducting coils according to any one of claims 1 to 7 stacked in the winding axis direction,
It has an outer metal plate and an inner metal plate that are installed between two adjacent superconducting coils among the laminated superconducting coils and function as electrodes,
The outer metal plate spans both the winding direction end and the opposite winding direction end of the outermost turn of the winding portion of one superconducting coil, and/or the inner metal plate spans the winding portion of one superconducting coil. A superconducting coil device characterized in that the wire portion is electrically connected across both the winding direction end and the counter-winding direction end of the innermost turn of the wire portion. The outer metal plate is provided radially outward from the ends in the winding direction and the ends in the counter-winding direction of the outermost turn of the winding portion of the superconducting coil, and/or the inner metal plate is provided in the superconducting coil. 9. The superconducting coil device according to claim 8, wherein the superconducting coil device is provided radially inward from an end in a winding direction and an end in a counter-winding direction of the innermost turn of the winding portion of the coil. The superconducting wire used in the superconducting coil is composed of a tape-shaped laminate including at least a high-temperature superconducting layer, and the superconducting wire has a proximal surface close to the high-temperature superconducting layer and a distal surface far from the high-temperature superconducting layer. have,
The proximal surfaces of the superconducting wires in the outermost turns of the winding section face inward in the radial direction of the coil, and the proximal surfaces of the superconducting wires are connected to each other in at least a part of the outermost turns. The superconducting coil device according to claim 8 or 9, characterized in that it has a superconducting coil device. The superconducting wire used in the superconducting coil is composed of a tape-shaped laminate including at least a high-temperature superconducting layer, and the superconducting wire has a proximal surface close to the high-temperature superconducting layer and a distal surface far from the high-temperature superconducting layer. have,
A connection in which the proximal surfaces of the superconducting wires in the innermost turns of the winding section face outward in the coil radial direction, and the proximal surfaces of the superconducting wires are connected to each other in at least a part of the innermost turns. 10. The superconducting coil device according to claim 8, further comprising: a superconducting coil device. 12. The outer metal plate and the inner metal plate are bonded directly to the thin film wire of the superconducting coil or to a conductive tape attached to the thin film wire. The superconducting coil device according to any one of the above.

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