Superconducting materials, superconducting coils and superconducting equipment

Abstract

To provide a superconducting member, a superconducting coil, and a superconducting device in which occurrence of quenching is suppressed.SOLUTION: A superconducting material according to an embodiment includes a superconducting wire, a first resin layer including a plurality of particles and a first resin surrounding each particle, and a second resin layer containing a second resin and having a lower tensile modulus than the first resin layer, and the second resin layer is inside the first resin layer, the first resin layer is positioned around the superconducting wire, and the first resin layer exists between the superconducting wire and the second resin layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to a superconducting member, a superconducting coil, and a superconducting device. [Background technology]

[0002] For example, in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) devices, superconducting coils are used to generate strong magnetic fields. Superconducting coils are formed by winding superconducting wire around a bobbin. The superconducting wire is surrounded by resin.

[0003] When a superconducting coil cools, strain energy accumulates in the resin due to the difference in thermal contraction between the metal and resin that make up the superconducting wire. Furthermore, when current is applied to the superconducting coil, strain energy accumulates in the resin so as to suppress the movement of the superconducting wire due to electromagnetic force. The accumulated strain energy is released, for example, when cracks occur in the resin or when heat is generated. Furthermore, when cracks occur in the resin, frictional heat is generated secondarily, for example, when resins rub against each other. This heat generation raises the temperature of the superconducting wire above its superconducting transition temperature, causing a quench, in which part of the superconducting coil loses its superconducting state and transitions to a normal conducting state.

[0004] When a quench occurs, for example, the current flowing through the superconducting coil fluctuates, causing the magnetic field generated by the superconducting coil to become unstable. Furthermore, for example, Joule heat generated in the quenched portion may lead to thermal runaway, in which a large amount of heat is generated instantaneously. Thermal runaway may result in the superconducting coil burning out. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4607540 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of embodiments of the present invention is to provide a superconducting member, a superconducting coil, and a superconducting device that can suppress the occurrence of quenching. [Means for solving the problem]

[0007] According to an embodiment, a superconducting wire is provided, a first resin layer including a superconducting wire, a plurality of particles, and a first resin surrounding each particle, a second resin layer including a second resin and having a lower tensile modulus than the first resin layer, and a third region that is present around the second resin layer and has a tensile modulus lower than that of the second resin layer; Equipped with the distribution of particles in the first resin layer varies in density in the first direction, and the density of particles in the vicinity of the superconducting wire is lower than the density of particles in the vicinity of the second resin layer; A superconducting member is provided in which the second resin layer is located inside the first resin layer, the first resin layer is located around the superconducting wire, and the first resin layer is present between the superconducting wire and the second resin layer. Also, by using the above-mentioned superconducting member, a superconducting coil and a superconducting device in which the occurrence of quenching is suppressed are provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is an enlarged schematic cross-sectional view of a portion of the superconducting member and the first resin layer of the first embodiment. [Figure 2] FIG. 10 is an enlarged schematic cross-sectional view of a portion of a superconducting member and a first resin layer of a second embodiment. [Figure 3] FIG. 10 is an enlarged schematic cross-sectional view of another example of the superconducting member of the second embodiment and a part of the first resin layer. [Figure 4] FIG. 10 is an enlarged schematic cross-sectional view of a portion between a superconducting wire and a second resin layer in a superconducting member according to a second embodiment. [Figure 5] FIG. 10 is an enlarged schematic cross-sectional view of still another part of the superconducting member and part of the first resin layer of the second embodiment. [Figure 6] FIG. 10 is a schematic cross-sectional view of a superconducting coil and a superconducting wire according to a third embodiment. [Figure 7] FIG. 10 is a schematic perspective view of a superconducting coil according to a third embodiment. [Figure 8] FIG. 10 is a block diagram of a superconducting device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the following description, components that perform the same or similar functions are designated by the same reference numerals throughout the drawings, and duplicate descriptions will be omitted. Each drawing is a schematic diagram for explaining and facilitating understanding of the embodiments, and the shapes, dimensions, ratios, etc. may differ from those of an actual device. However, these may be appropriately modified in design, taking into consideration the following description and known techniques.

[0010] [First embodiment] According to a first embodiment, a superconducting component is provided, comprising a superconducting wire, a first resin layer containing a plurality of particles and a first resin surrounding each particle, and a second resin layer containing a second resin and having a lower tensile modulus than the first resin layer, wherein the second resin layer is located inside the first resin layer, the first resin layer is located around the superconducting wire, and the first resin layer is present between the superconducting wire and the second resin layer.

[0011] Fig. 1 is an enlarged schematic cross-sectional view of a portion of a superconducting member and a first resin layer according to the first embodiment. Fig. 1 is also a schematic cross-sectional view of a superconducting coil. In Fig. 1, a superconducting member 200 includes a superconducting wire 20, a first resin layer 21 in contact with the superconducting wire 20, and a second resin layer 22 provided inside the first resin layer 21 at a position away from the superconducting wire 20.

[0012] When superconducting wire 20 is wound and used in a superconducting coil, it has first region 20a and second region 20b spaced a predetermined distance apart in a first direction, which is a direction from the axis of the superconducting coil toward the outside, and second region 20b faces first region 20a. For superconducting wire 20, for example, a low-temperature superconducting material with a low critical temperature Tc is used.

[0013] First resin layer 21 includes a plurality of particles 21a and first resin 21b surrounding particles 21a, and is in contact with superconducting wire 20.

[0014] The second resin layer 22 contains a second resin. When wound and used in a superconducting coil, the second resin layer 22 is present between the first region 20a and the second region 20b.

[0015] In FIG. 1, the bisector p of the thickness of the second resin layer 22 in the first direction is within the range from the line dividing the distance d1 between the surface of the first region 20a, which is closer to the second resin layer 22 in the first direction, and the surface of the second region 20b, which is considered similarly, at a ratio of 2:8 to a line dividing the distance d1 at a ratio of 8:2. The aforementioned line p is preferably on a line dividing the distance d1 at a ratio of 5:5. Furthermore, if the second resin layer 22 is not parallel to the first region 20a or the second region 20b, or if the second resin layer 22 is not substantially rectangular as shown in FIG. 1 in cross section, consider the point on the second resin layer 22 that is closest to the first region 20a or the second region 20b when viewed in the first direction. It is preferable that this point be within the range from the line dividing the distance d1 at a ratio of 2:8 to a line dividing the distance d1 at a ratio of 8:2.

[0016] The second resin layer 22 has a lower tensile modulus of elasticity than the first resin layer 21. Preferably, the ratio of the tensile modulus of elasticity of the first resin layer 21 to that of the second resin layer 22 at 23° C. is 2 or more.

[0017] The tensile modulus of elasticity of the first resin layer 21 and the second resin layer 22 can be compared by the following method.

[0018] The cross section of the superconducting coil is cut to cut out a small specimen of approximately 1 to 3 cm. This specimen is subjected to chemical analysis of the regions corresponding to the first resin layer 21 and the second resin layer 22 using, for example, a micro-Raman spectrometer, to identify the respective resin components. Since micro-Raman spectroscopy allows laser irradiation to be focused on an area of ​​several tens of micrometers, the first resin layer 21 and the second resin layer 22 can be separated for chemical analysis. The region to be the first resin layer 21 is the region closest to the superconducting wire 20, among the four equal parts of the distance from the superconducting wire 20 to the second resin layer 22. Similarly, when the first resin layer 21 and the second resin layer 22 each have a third region, the region closest to the superconducting wire 20 is selected among the four equal parts of the distance from the superconducting wire 20 to the second resin layer 22. In this case, regions with dense filler should not be selected as specimens.

[0019] For the identified resins, the numerical values ​​of the tensile modulus of elasticity at 23°C measured in accordance with JIS K 7161-2 established in 2014 are cited. In addition, the ratio of the tensile modulus of elasticity of the first resin layer 21 to that of the second resin layer 22 can be defined as the value obtained by dividing the tensile modulus of elasticity of the first resin layer 21 described above by the tensile modulus of elasticity of the second resin layer 22.

[0020] The tensile modulus of elasticity corresponds to the slope of the linear portion of the stress-strain curve in the small tensile strain region when the curve is plotted with tensile strain on the horizontal axis and tensile stress on the vertical axis.

[0021] In a superconducting coil or superconducting device having a superconducting member, a quench may occur in which a part of the superconducting wire of the superconducting member loses its superconducting state and transitions to a normal conducting state. In particular, in the case of the superconducting member 200 in which a low-temperature superconducting material with a low critical temperature Tc is used for the superconducting wire 20 as in the first embodiment, a phenomenon called a training quench may occur.

[0022] The training quench is an unstable phenomenon in which a quench occurs when the current flow value is lower than the allowable current value of the superconducting wire 20. It is necessary to suppress this unstable phenomenon and ensure that the rated current can be stably passed through the superconducting member 200. By ensuring that the rated current can be stably passed through the superconducting member 200, the operation of the superconducting member 200 becomes stable.

[0023] Possible causes of training quenching include stress caused by differences in thermal expansion coefficients between superconducting members 200 during cooling, or stress caused by deformation of the members due to electromagnetic force. When a superconducting coil including superconducting member 200 is excited, a hoop force acts on superconducting wire 20 in a direction that causes it to expand toward the coil periphery, causing first resin layer 21 to distort and impede the action of that force. This stress causes cracks in the resin and generates heat in order to release accumulated strain energy. When this occurs, friction occurs between superconducting wire 20 and first resin layer 21, or between first resin layers 21, generating secondary frictional heat at the interface, releasing strain energy. Training quenching is believed to occur when the superconducting wire 20 exceeds its critical temperature Tc due to heat, including this frictional heat.

[0024] When superconducting member 200 of the first embodiment is wound and used in a superconducting coil, second resin layer 22 having a lower tensile modulus of elasticity than first resin layer 21 is provided between opposing superconducting wires 20. First resin layer 21 is located around superconducting wire 20, and second resin layer 22 is provided inside first resin layer 21 and away from superconducting wire 20. As a result, even if a crack occurs, second resin layer 22 has a lower tensile modulus of elasticity than first resin layer 21, so that the crack can be controlled to occur in second resin layer 22 away from superconducting wire 20. Therefore, energy release near superconducting wire 20 can be reduced, and the occurrence of quenching can be suppressed.

[0025] A first resin layer 21 is provided between the opposing superconducting wires 20, and the first resin layer 21 includes particles 21a and a first resin 21b. The particles 21a included in the first resin layer 21 are fillers. The particles 21a may be inorganic. The particles 21a include an insulating material. The particles 21a also include at least one inorganic substance selected from the group consisting of silica, alumina, talc, and mica. The crystals included in the particles 21a may be single crystals of one inorganic substance selected from the group described above, or may be crystals of two or more compounds selected from the group described above. In this case, the particles 21a may include an inorganic substance other than silica, alumina, talc, and mica. The aforementioned crystals included in the particles 21a can be identified, for example, by powder X-ray diffraction. The particles 21a may also include an amorphous substance. The amorphous material contained in the particles 21a can be identified by, for example, an energy dispersive x-ray spectroscopy (EDS).

[0026] The particle size of the particles 21a is, for example, 1 μm or more and 100 μm or less. Furthermore, the particle size of the particles 21a is preferably 1 μm or more and 10 μm or less. Within this range, the area where the particles 21a and the first resin 21b peel off is small, so that the cracks that occur can be reduced. Reducing the cracks makes it possible to suppress the relatively large energy release resulting from peeling at the interface between the particles 21a and the first resin. The particle sizes of the particles 21a may be the same or may be different as long as they are within the above-mentioned particle size range. The particle size of the particles 21a can be determined, for example, from an image (SEM image) acquired with a scanning electron microscope (SEM).

[0027] The shape of the particles 21a is not particularly limited, and may be, for example, plate-like, spherical, bale-like, spheroidal, cylindrical, fibrous, or irregular. Fig. 1 illustrates an example in which the shape of the particles 21a is spherical.

[0028] First resin 21b is a thermosetting resin. First resin layer 21b surrounds particles 21a. First resin 21b is a binder. First resin 21b bonds particles 21a to one another and firmly fixes superconducting wire 20 so that it does not move.

[0029] The first resin 21b is, for example, at least one resin selected from the group consisting of epoxy resin, phenol resin, urea resin, and melamine resin.

[0030] The resin contained in the first resin 21b can be determined, for example, by a Fourier transform infrared spectrophotometer (FT-IR).

[0031] The second resin layer 22 has a lower tensile modulus than the first resin layer 21. The second resin is a thermosetting resin or a thermoplastic resin. Examples of the second resin that can be used include unsaturated polyester resin, silicone resin, urethane resin, polyethylene, polyamide, and phenoxy.

[0032] When second resin layer 22 is observed in a direction perpendicular to the first direction, second resin layer 22 has a line width L2 that is 50% to 100% of the line width L1 of superconducting wire 20. This range allows cracks to be generated near second resin layer 22, thereby reducing energy release near superconducting wire 20 and suppressing quenching. If L2 of second resin layer 22 is less than 50% of L1, cracks cannot be generated in second resin layer 22 away from superconducting wire 20, resulting in cracks in superconducting wire 20 and quenching. If L2 is greater than 100% of L1, overlapping with other second resin layers 22 provided on adjacent superconducting wires 20 may occur when observed in the first direction. This overlapping may cause misalignment of adjacent superconducting wires 20 when viewed in the first direction, making it impossible to generate a magnetic field as designed. Furthermore, when second resin layer 22 is observed in a direction perpendicular to the first direction, line width L2 of second resin layer 22 is preferably 80% to 100% of line width L1 of superconducting wire 20.

[0033] The superconducting member according to this embodiment includes a superconducting wire, a first resin layer containing a plurality of particles and a first resin surrounding each particle, and a second resin layer containing a second resin and having a lower tensile modulus than the first resin layer, wherein the second resin layer is located inside the first resin layer, the first resin layer is located around the superconducting wire, and the first resin layer is present between the superconducting wire and the second resin layer. As a result, when the superconducting member according to this embodiment is wound and used as a superconducting coil, cracks occur in the second resin layer that is distant from the superconducting wire, and the occurrence of quenching is suppressed.

[0034] [Second embodiment] The superconducting member of the second embodiment has a third region around the second resin layer. The third region is created when the second resin is compatible with the first resin. The second embodiment differs from the first embodiment in that the second resin is compatible with the first resin. Below, some of the explanations that overlap with the first embodiment will be omitted.

[0035] FIG. 2 is an enlarged schematic cross-sectional view of a part of a superconducting member and a first resin layer of the second embodiment.

[0036] The first resin 21b has epoxy groups and amino groups. The first resin 21b is, for example, an epoxy resin. The first resin 21b is formed by mixing an epoxy resin base with an amine curing agent and reacting the epoxy groups with the amino groups to form a three-dimensional network structure, resulting in a high-strength cured resin body. In the case of a superconducting coil including the superconducting member 200 as in the third embodiment, for example, the superconducting coil is relatively large in size, making it difficult to uniformly heat it to a high temperature. Therefore, it is suitable to use a room-temperature curing amine, which can be cured without heating, as the curing agent.

[0037] On the other hand, the second resin may be any resin compatible with the first resin 21b. The second resin is, for example, a phenoxy resin. The second resin is a thermoplastic resin that is flexible and contains epoxy groups therein. The inclusion of epoxy groups therein allows the second resin to be compatible with the first resin 21b. The second resin is more flexible than described above. Furthermore, since the second resin layer 22 is provided inside the first resin layer 21, the epoxy groups of the first resin 21b and the second resin come into contact at the interface, causing the second resin layer 22 to swell. After the second resin layer 22 swells, the amino groups in the amine contained in the first resin 21b react with the epoxy groups, forming a third region 23 at the interface between the first resin layer 21 and the second resin layer 22.

[0038] As the third region 23 is formed, the particles 21a that were originally present at the position of the third region 23 move. However, as this reaction progresses, the curing reaction of the first resin 21b also progresses, so the elastic modulus gradually increases and the particles 21a cannot diffuse beyond a certain distance. Therefore, when viewed in the first direction, the distribution of the particles 21a present in the third region 23 and in the first resin layer 21 that is in contact with the third region 23 varies in density.

[0039] Due to the aforementioned movement of particles 21a, there are fewer particles 21a or no particles 21a in third region 23 compared to other regions. If a resin layer does not contain a filler such as particles 21a, its tensile modulus will be low. Therefore, the tensile modulus of third region 23, which contains relatively fewer particles 21a, will be lower than that of first resin layer 21, which contains particles 21a. This makes it possible to control cracks to occur in third region 23, reducing the release of energy near superconducting wire 20 and suppressing the occurrence of quenching. The presence or absence of third region 23 can be confirmed from a cross-sectional SEM image, and the presence or absence of third region 23 can be determined, for example, by comparing the spectra of each layer using Raman spectroscopy to determine whether they are compatible with each other.

[0040] Moreover, the tensile modulus of elasticity of third region 23 is preferably lower than that of second resin layer 22. This makes it even more likely for cracks to occur in third region 23, thereby reducing the release of energy near superconducting wire 20 and suppressing the occurrence of quenching.

[0041] The thickness of third region 23 along the first direction from the surface of second resin layer 22 and along a third direction perpendicular to the first direction is, for example, 5 to 40 μm. By setting the thickness of third region 23 within this range, cracks can be controlled to occur in third region 23 away from superconducting wire 20. Therefore, energy release near superconducting wire 20 can be reduced, thereby suppressing the occurrence of quenching. The thickness of third region 23 is preferably 10 to 30 μm.

[0042] Fig. 3 is an enlarged schematic cross-sectional view of another example of the superconducting member of the second embodiment and a part of the first resin layer. Fig. 4 is an enlarged schematic cross-sectional view of the portion between the superconducting wire and the second resin layer in the superconducting member of the second embodiment.

[0043] As described above, second resin layer 22 swells and forms third region 23, causing particles 21a to move. However, the curing reaction of first resin 21b also progresses, forming fourth region 24 in which particles 21a become dense near third region 23 inside first resin layer 21. In contrast, with respect to particles 21a on the superconducting wire 20 side, the sufficient distance between superconducting wire 20 and second resin layer 22 and the aforementioned curing reaction of first resin 21b make it difficult for the movement of particles 21a near second resin layer 22 accompanying the formation of third region 23 to propagate, and particles 21a do not disperse as compared with fourth region 24. Particles 21a present on the second resin layer 22 side become dense. Therefore, a density variation is formed in the distribution of particles 21a present in third region 23 and in first resin layer 21 in contact with third region 23 in the first direction. When a crack occurs in fourth region 24 where particles 21a are densely packed, the crack is likely to propagate along the particle 21a interface unless the interfacial adhesion between particles 21a and first resin 21b is particularly strong. Furthermore, when a crack occurs at the particle 21a interface, a large amount of strain energy is released, increasing the amount of heat generated, which can lead to quenching. Therefore, strain energy release can be controlled to occur near second resin layer 22, which is far from superconducting wire 20, and energy release near superconducting wire 20 can be reduced, thereby suppressing the occurrence of quenching.

[0044] FIG. 5 is an enlarged schematic cross-sectional view of still another part of the superconducting member and part of the first resin layer of the second embodiment.

[0045] In the first direction, the distribution of particles 21a present in first resin layer 21 varies in density, and the density of particles 21a present near superconducting wire 20 is lower than the density of particles 21a present near second resin layer 22.

[0046] The aforementioned density distribution of particles 21a means, for example, that when the thickness in the first direction of first resin layer 21 existing between the surface of superconducting wire 20 and the surface of second resin layer 22 is d2, density A of particles 21a in a region up to a distance of (1 / 4)×d2 from the surface of second resin layer 22 is greater than density B of particles 21a in a region up to a distance of (1 / 4)×d2 from the surface of superconducting wire 20. Preferably, density A is 1.1 times or more density B (density A≧1.1×density B).

[0047] The superconducting member according to the present embodiment includes a superconducting wire, a first resin layer including a plurality of particles and a first resin surrounding each particle, a second resin layer including a second resin and having a lower tensile modulus of elasticity than the first resin layer, and a third region surrounding the second resin and having a lower tensile modulus of elasticity than the second resin layer. As a result, when the superconducting member according to the present embodiment is wound and used as a superconducting coil, cracks occur in the second resin layer at a distance from the superconducting wire, and the occurrence of quenching is suppressed.

[0048] [Third embodiment] According to a third embodiment, there is provided a superconducting coil, which includes the superconducting member according to the first or second embodiment.

[0049] 6 is a schematic cross-sectional view of a superconducting coil and a superconducting wire according to the third embodiment, in which an enlarged schematic cross-sectional view of adjacent superconducting wire 20 is the same as FIG.

[0050] The superconducting coil 100 includes a bobbin 10, an inner insulating layer (not shown), an upper insulating layer (not shown), a lower insulating layer (not shown), and a winding portion 12. The winding portion 12 includes a superconducting wire 20, a first resin layer 21, and a second resin layer 22.

[0051] The first resin layer 21 and the second resin layer 22 can fix the superconducting wire 20. The first resin layer 21 and the second resin layer 22 can prevent the superconducting wire 20 from being damaged by vibration during use of the superconducting device or by friction between the superconducting wires. The first resin layer 21 and the second resin layer 22 also have the function of insulating the superconducting wires 20 from each other.

[0052] The inner insulating layer, the upper insulating layer, and the lower insulating layer are made of, for example, fiber-reinforced plastic and have the function of insulating the winding portion 12 from the bobbin 10 and the outside.

[0053] Here, a method for producing a superconducting coil using the superconducting member according to the first or second embodiment will be described.

[0054] <Fabrication of superconducting coils> A superconducting coil is manufactured by winding a superconducting wire around a bobbin in a solenoid shape. The superconducting wire is wound one layer, and a first resin containing inorganic particles is applied to the superconducting wire and impregnated therein. A second resin is then wound immediately after the first resin has hardened. The width of the second resin layer is between 80% and 100% of the wire width of the superconducting wire. The same first resin containing inorganic particles as that applied to the superconducting wire is then applied on top of the second resin layer. The superconducting wire is wound one more layer by mixing a curing agent into the first resin or before it hardens due to heat, and the same structure is repeatedly manufactured.

[0055] Specifically, the winding method is as follows: superconducting wire 20 is wound in a solenoid shape around the axis in the third direction. After being wound in a solenoid shape for a predetermined length along the third direction, superconducting wire 20 is wound one more turn at the position of the last winding, around the axis in the third direction as the winding center. Next, superconducting wire 20 is wound in a solenoid shape in a similar manner along a direction antiparallel to the third direction.

[0056] FIG. 6 is a cross-sectional view of superconducting coil 100 cut along a plane defined by a first direction and a third direction in FIG. 7, which will be described later, and therefore appears to show a plurality of different superconducting wires 20.

[0057] For example, a low-temperature superconducting material having a critical temperature Tc of 8 K or more and 40 K or less is used for the superconducting wire 20. The low-temperature superconducting material used for the superconducting wire 20 is, for example, a niobium-titanium alloy-based material, a niobium-tin compound-based material, a niobium-aluminum compound-based material, or a magnesium diboride-based material.

[0058] The superconducting wire 20 has a structure in which a plurality of filaments 20x are arranged in a matrix 20y. The filaments 20x may contain, for example, a niobium-titanium alloy, and the matrix 20y may be made of copper. In the example of Figure 2, the superconducting wire 20 is a rectangular wire, but it may also be a round wire or have any other shape.

[0059] Fig. 7 is a schematic perspective view of the superconducting coil of the first embodiment. Fig. 7 shows a schematic view of the superconducting wire, including the superconducting wire shown in the first and second embodiments and a resin layer, wound around a bobbin. Fig. 6 shows a cross section obtained when the superconducting coil 100 in Fig. 7 is cut along a plane formed by the first direction and the third direction.

[0060] The superconducting wire is, for example, in a wire shape and is wound around the winding center C around the bobbin 10 in a solenoid shape along the second direction.

[0061] The superconducting coil 100 is used as a coil for generating a magnetic field in superconducting equipment such as a nuclear magnetic resonance apparatus (NMR), a magnetic resonance imaging apparatus (MRI), a heavy particle beam therapy apparatus, or a superconducting magnetic levitation train. The superconducting coil according to the third embodiment is equipped with the superconducting member according to the first or second embodiment. Since the occurrence of quenching is suppressed in the superconducting member according to the first or second embodiment, it is possible to provide a superconducting coil in which the occurrence of quenching is similarly suppressed.

[0062] [Fourth embodiment] The superconducting device of the fourth embodiment is a superconducting device including the superconducting coil of the third embodiment. Hereinafter, some of the description overlapping with the first, second and third embodiments will be omitted.

[0063] 8 is a block diagram of a superconducting device according to a fourth embodiment. The superconducting device according to the fourth embodiment is a heavy ion beam therapy device 300. The heavy ion beam therapy device 300 is an example of a superconducting device.

[0064] The heavy ion beam therapy device 300 includes an injection system 50 , a synchrotron accelerator 52 , a beam transport system 54 , an irradiation system 56 , and a control system 58 .

[0065] The injection system 50 has a function of generating, for example, carbon ions to be used in therapy and pre-accelerating the ions to be injected into the synchrotron accelerator 52. The injection system 50 has, for example, an ion generation source and a linear accelerator.

[0066] The synchrotron accelerator 52 has a function of accelerating the carbon ion beam injected from the injection system 50 to an energy level suitable for treatment. The synchrotron accelerator 52 uses the superconducting coil of the third embodiment.

[0067] The beam transport system 54 has a function of transporting the carbon ion beam injected from the synchrotron accelerator 52 to the irradiation system 56. The beam transport system 54 has, for example, a bending electromagnet.

[0068] The irradiation system 56 has a function of irradiating a patient, who is an irradiation target, with the carbon ion beam injected from the beam transport system 54. The irradiation system 56 has, for example, a rotating gantry that enables the carbon ion beam to be irradiated from any direction. The superconducting coil of the third embodiment is used in the rotating gantry.

[0069] The control system 58 controls the injection system 50, the synchrotron accelerator 52, the beam transport system 54, and the irradiation system 56. The control system 58 is, for example, a computer.

[0070] In the heavy ion beam therapy device 300 of the fourth embodiment, the superconducting coil of the third embodiment is used in the synchrotron accelerator 52 and the rotating gantry, so that the occurrence of quenching is suppressed and high reliability is achieved.

[0071] In the fourth embodiment, a heavy ion beam therapy device 300 has been described as an example of a superconducting device, but the superconducting device may also be a nuclear magnetic resonance device (NMR), a magnetic resonance imaging device (MRI), or a superconducting magnetic levitation railway vehicle.

[0072] The superconducting device according to the fourth embodiment is equipped with the superconducting coil according to the third embodiment. Since the occurrence of quenching is suppressed in the superconducting coil, it is possible to provide a highly reliable superconducting device.

[0073] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0074] 10...winding frame, 20...superconducting wire, 20a...first region, 20b...second region, 21...first resin layer, 21a...particles, 21b...first resin, 22...second resin layer, 23...third region, 24...fourth region, 100...superconducting coil, 200...superconducting member, 300...heavy ion beam therapy device.

Claims

1. A superconducting wire, a first resin layer including a plurality of particles and a first resin surrounding each of the particles; a second resin layer containing a second resin and having a lower tensile modulus than the first resin layer; a third region that is present around the second resin layer and has a tensile modulus lower than that of the second resin layer; the particles in the first resin layer have a density distribution that varies in a first direction, and the density of the particles in the vicinity of the superconducting wire is lower than the density of the particles in the vicinity of the second resin layer; A superconducting member in which the second resin layer is located inside the first resin layer, the first resin layer is located around the superconducting wire, and the first resin layer is present between the superconducting wire and the second resin layer.

2. A superconducting member as described in claim 1, wherein the second resin is compatible with the first resin.

3. 3. The superconducting member according to claim 1, wherein the first resin is a thermosetting resin.

4. 4. The superconducting member according to claim 1, wherein the third resin is a thermoplastic resin.

5. The density variation means that, when the thickness in a first direction of the first resin layer existing between the surface of the superconducting wire and the surface of the second resin layer is d2, the density A of the particles in a region up to a distance of (1 / 4) x d2 from the surface of the second resin layer is higher than the density B of the particles in a region up to a distance of (1 / 4) x d2 from the surface of the superconducting wire.

6. 6. The superconducting member according to claim 5, wherein the density A is 1.1 times or more the density B (density A ≥ 1.1 × density B).

7. The superconducting member according to claim 1 , wherein the particles contain an insulating material.

8. A superconducting coil comprising the superconducting member according to any one of claims 1 to 7.

9. A reel; A superconducting coil comprising: the superconducting member according to any one of claims 1 to 7 wound around the bobbin.

10. A superconducting device comprising the superconducting coil according to claim 8 or 9.

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