JP7356934B2 - Superconducting magnet device and bending electromagnet device - Google Patents

Description

The present invention relates to a superconducting magnet device and a bending electromagnet device.

As background technology in this technical field, the summary of Patent Document 1 below states, ``A deflection electromagnet device that deflects a passing charged particle beam, comprising a pair of vertically opposed magnets that are vertically opposed to each other with a gap through which the charged particle beam passes. Yokes 5A, 5B are arranged, and the yokes have main poles 1A, 1B, side poles 21A, 21B, 22A, 22B, a pair of coils 41A, 41B that generate a magnetic field on the poles, and a pair of coils 41A, 41B on the outer peripheral side thereof. It includes coils 41A and 41B and a pair of coaxial coils 51A and 51B, and the upper yoke 5A and lower yoke 5B are connected by a non-magnetic support member.'' In addition, claim 1 of Patent Document 2 below states that ``in the single crystal REBa ₂ Cu ₃ O _7-x phase (RE is a rare earth element containing Y or a combination thereof, x is the amount of oxygen vacancies) A coil including an oxide superconductor having a structure in which a conductive phase is finely dispersed, the coil being composed of a single core wire of the oxide superconductor, and the shape of the coil having a straight part and a curved part. ``An oxide superconductor coil characterized by being of a quasi-racetrack type having a deformed structure.'' The descriptions of these documents are included as part of this specification.

JP2017-84595 Publication Patent No. 4799979 Public Relations

Incidentally, it is desired that a superconducting magnet device be constructed in a small size and capable of generating a strong magnetic field.
The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a superconducting magnet device and a bending electromagnet device that can be constructed in a small size and generate a strong magnetic field.

In order to solve the above problems, a superconducting magnet device of the present invention includes a yoke having a magnetic material and formed in an annular shape, a pair of first magnetic poles protruding from the yoke so as to face each other, and a superconducting wire. a pair of first coils each wound around the first magnetic pole of the second coil, a second coil straight section formed by extending the superconducting wire in a straight line, and a pair of coils formed by bending the superconducting wire into a substantially arc shape. a second coil having a second coil curved portion, the first coil having a first coil straight portion in which the superconducting wire extends in a straight line; a pair of first coil curved parts, the radius of curvature of the inner peripheral surface of the first coil curved part is larger than the half width of the inner peripheral surface of the first coil straight part, The radius of curvature of the inner circumferential surface of the second coil curved portion is approximately the same as the half width of the inner circumferential surface of the second coil straight portion.

According to the present invention, it is possible to realize a superconducting magnet device that can be constructed in a small size and can generate a strong magnetic field.

FIG. 3 is a schematic cross-sectional perspective view of a bending electromagnet according to a comparative example. FIG. 3 is a schematic cross-sectional view of a bending electromagnet according to a comparative example. FIG. 3 is a schematic vertical cross-sectional view of a bending electromagnet according to a comparative example. FIG. 4 is an enlarged cross-sectional view of the main part of FIG. 3; FIG. 6 is a schematic diagram showing the magnetic flux distribution in the main part of the main coil of a comparative example. 1 is a sectional view of a main part of a bending electromagnet device according to a first preferred embodiment; FIG. FIG. 7 is a schematic diagram showing a manufacturing process of a bending electromagnet device according to a second preferred embodiment. FIG. 7 is a schematic diagram showing a manufacturing process of a bending electromagnet device according to a third preferred embodiment. It is a schematic diagram which shows the manufacturing process of the bending electromagnet device by a suitable 4th embodiment.

[Premise of embodiment]
A superconducting magnet device is a device that generates a desired magnetic field by passing current through a coil having a superconducting material cooled to an extremely low temperature. Superconducting materials are materials whose electrical resistance becomes zero below a certain temperature, and because they can conduct a larger current than normal conductive metals at room temperature, they can be used in devices that require strong magnetic fields, such as magnetic resonance. It is used in deflection magnets for imaging devices and accelerators. The deflection magnets used in accelerators include normal conducting magnets with copper wire wound around an iron core, and permanent magnets. However, in recent years, bending magnets are required to generate a strong magnetic field in a smaller area, so superconducting magnets are increasingly being used.

A superconducting magnet is an electromagnet in which a magnetic circuit is constructed of a core made of a magnetic material such as iron, a magnetic pole in which a superconducting coil is wound around a yoke, and a yoke. Superconducting coils are made of superconducting materials that have zero electrical resistance when cooled to extremely low temperatures. Although the temperature varies depending on the superconducting material, it is necessary to cool it to an absolute temperature of about 4 Kelvin to 77 Kelvin. For this reason, in superconducting coils using niobium titanium, which is the material for superconducting coils commonly used today, in order to maintain a cooled state at about 4 Kelvin, for example, liquid with a boiling point of 4.2 Kelvin immersed in helium. In addition, in order to maintain the liquid state of helium, the superconducting coil and liquid helium are stored in a metal container called a helium container, a radiation shield that surrounds it and blocks heat transfer due to radiation, and a vacuum state inside to prevent heat transfer from the outside. It is housed in a vacuum container to reduce heat intrusion. Furthermore, the cryogenic temperature is maintained by suppressing the evaporation of liquid helium using a refrigerator.

Liquid helium is expensive because it is difficult to collect, and in response to the need for simpler and more compact devices, efforts are being made to develop superconducting magnets that use less or no liquid helium. One method that does not use liquid helium is to use a conduction-cooled superconducting coil that is cooled from a refrigerator via a solid heat-conducting material. If the cooling capacity of the refrigerator is sufficiently large, the superconducting coil can be maintained at a temperature sufficiently lower than the temperature at which it becomes superconducting, for example, 4 Kelvin or less.

The superconducting material that makes up the superconducting wire of a superconducting coil becomes a superconducting state when it is cooled to a temperature determined for each material, and this temperature is called the normal conduction transition temperature. A superconducting coil held below the normal conduction transition temperature has zero electrical resistance, but if a current with a large current density is passed through it or if it is placed in a strong magnetic field environment, it will no longer be able to maintain its superconducting state. Current density and magnetic field, like temperature, are factors that determine the superconducting state, and superconducting coils are often operated within a range in which the superconducting state determined by these three factors can be stably maintained. The superconducting wire that makes up a superconducting coil has the same wire wrapped around the entire coil, but if the temperature and magnetic field strength differ depending on the location, the performance of the wire in the part where the temperature and magnetic field environment is the harshest will be higher than that of the wire. It is not possible to conduct current. That is, this portion imposes a limit on the magnetic field generation strength of the superconducting magnet.

Some superconducting coils used in bending electromagnets of accelerators have a racetrack shape consisting of a straight part and an arc part. This is because the deflection magnet generates a uniform magnetic field in the long axis direction of the race track, and a magnetic field that changes sharply in the short axis direction. Generally, the reason why superconducting coils are used as deflection magnets is to generate a stronger magnetic field in a narrow area compared to normal conducting coils or permanent magnets. Therefore, in many cases, a strong magnetic field is generated by passing a larger current through the superconducting coil, and a magnetic field is generated in a narrower region by shortening the short axis direction of the race track.

If the entire racetrack-shaped superconducting coil is wound with the same superconducting wire, the magnetic field on the inner circumferential side of the arc of the racetrack will become stronger, and even if the coil is cooled to a uniform temperature, the magnetic field on the inner circumferential side of the arc will become stronger. The magnetic field performance of a superconducting magnet is determined by the tolerance of the superconducting wire in the environment. In particular, when the short axis direction of the race track is shortened and the curvature of the arc portion is reduced, the magnetic field on the inner circumferential side of the coil arc portion becomes stronger than in the straight portion.

It is conceivable to apply the technique disclosed in Patent Document 1 mentioned above to configure a magnet device that uses a pair of main magnetic poles and two pairs of side magnetic poles. Compared to a configuration in which three independent magnets (one pair of main magnets and two pairs of side magnets) are arranged, this magnet device has a higher number of turns of the side coil (the side magnet or the coil wound around the side magnetic pole). The overall configuration can be made smaller. However, in this magnet device, the number of turns of the main coil (the coil wound around the main magnet or main magnetic pole) increases, and the magnetic field generated in the arc portion of the main coil increases, which reduces the tolerance of the superconducting wire. This makes it difficult to improve the magnetic field strength generated by the magnet device.

It is also conceivable to apply the technology shown in Patent Document 2 to configure a magnet device that increases the cross-sectional area of the superconductor, that is, the superconducting wire, in the curved portion where magnetic flux is concentrated in a racetrack-type superconducting coil. . However, in this magnet device, it is necessary to change the cross-sectional area of the superconducting wire during winding. Therefore, in superconducting wires manufactured by drawing niobium titanium wires, etc., it is necessary to connect wires with different cross sections in the middle of the winding when manufacturing the coil. The superconducting performance of the connecting portion of the superconducting wire tends to deteriorate, and the cross-sectional area of the coil increases, making it difficult to simultaneously improve the magnetic field strength and reduce the size. Therefore, the preferred embodiments described below are intended to realize a magnet device that can be constructed in a small size and can generate a strong magnetic field.

[Comparative example]
Before describing a preferred embodiment, a bending electromagnet according to a comparative example will first be described. FIG. 1 is a schematic cross-sectional perspective view of a bending electromagnet 1 according to a comparative example. In FIG. 1, the front-rear direction is the x-axis, the left-right direction is the y-axis, and the up-down direction is the z-axis.
The bending electromagnet 1 generates synchrotron radiation by applying periodic motion in a direction perpendicular to the beam traveling direction to a charged particle beam such as an electron beam or a proton beam emitted from an accelerator or the like (not shown). It is a device. The bending electromagnet 1 includes a beam duct 2, an iron core 30, and a coil group 40. The beam duct 2 is a duct having a substantially rectangular cross section. Inside the beam duct 2, for example, a charged particle beam or the like passes along a straight trajectory RS shown by a broken line.

The iron core 30 includes a pair of upper and lower yokes 31 (yokes), a pair of side yokes 32 (yokes), a pair of main magnetic poles 34, a pair of side magnetic poles 33, and a pair of side magnetic poles 35. The pair of upper and lower yokes 31 are formed into rectangular plate shapes and are arranged above and below the beam duct 2. The pair of side yokes 32 are formed into rectangular plate shapes, and connect the left ends and right ends of the upper and lower yokes 31. The pair of main magnetic poles 34 protrude toward the beam duct 2 from each opposing surface of the pair of upper and lower yokes 31. The pair of side magnetic poles 33 protrude toward the beam duct 2 from the opposing surfaces of the pair of upper and lower yokes 31 behind the main magnetic pole 34 . Further, the pair of side magnetic poles 35 protrude toward the beam duct 2 from the opposing surfaces of the pair of upper and lower yokes 31 in front of the main magnetic pole 34 .

Further, the coil group 40 includes a pair of main coils 44, a pair of side coils 43, and a pair of side coils 45. The pair of main coils 44 are each wound around the pair of main magnetic poles 34. The pair of side coils 43 are wound around the pair of side magnetic poles 33, respectively. Further, the pair of side coils 45 are each wound around the pair of side magnetic poles 35. Thereby, the bending electromagnet 1 becomes a three-pole superconducting magnet.

In addition, in order to maintain the superconducting state of the side coils 43, 45 and the main coil 44, the bending electromagnet 1 is housed in a cryostat that includes a vacuum container, a radiation shield, etc., and is also provided with a refrigerator that cools the inside of the cryostat. . The bending electromagnet 1 is also provided with a support structure and connection lines. However, in FIG. 1, illustration of these members is omitted.

FIG. 2 is a schematic cross-sectional view of a bending electromagnet 1 according to a comparative example.
As shown in the figure, the side magnetic poles 33, 35 and the main magnetic pole 34 each have a racetrack outer periphery, that is, a shape in which two circles with the same radius are connected by a common external tangent. Further, the side coils 43, 45 and the main coil 44 are wound in a racetrack shape along the outer circumferences of the side magnetic poles 33, 35 and the main magnetic pole 34, respectively.

By forming a magnetic field inside the beam duct 2, the iron core 30 and the coil group 40 curve the trajectory of the charged particle beam passing through the inside of the beam duct 2, and generate synchrotron radiation. In the illustrated example, the magnetic fields formed by the side coils 43 and 45 are H43 and H45, and the magnetic field formed by the main coil 44 is H44. Assuming that no current flows through the coil group 40, the strength of the magnetic fields H43, H44, and H45 will be "0", so the charged particle beam emitted from the accelerator etc. (not shown) will follow the straight trajectory RS. Proceed.

On the other hand, when synchrotron radiation is generated by a charged particle beam, the iron core 30 and the coil group 40 generate magnetic fields H43, H44, and H45 so that the trajectory of the charged particle beam becomes, for example, a deflection trajectory RC as shown in the figure. . When the charged particle beam travels along the deflection trajectory RC, synchrotron radiation is generated at a point where the deflection trajectory RC bends. In the illustrated example of the deflection trajectory RC, immediately after the charged particle beam enters from the rear of the beam duct 2, the deflection trajectory RC coincides with the straight trajectory RS.

However, the charged particle beam is then deflected to the left by the magnetic field generated by the side magnetic poles 33. The charged particle beam is then deflected to the right by the magnetic field generated by the main magnetic pole 34. Further, the charged particle beam is deflected by the magnetic field generated by the side magnetic poles 35 so as to match the original straight trajectory RS. In order to realize such a deflection trajectory, the polarity of the magnetic field H44 and the polarity of the magnetic fields H43 and H45 are reversed, and the integral value of the magnetic field H44 that the charged particle beam receives along the beam trajectory (for example, deflection trajectory RC) and It is preferable to determine the magnetic fields H43, H44, H45 so that the integral values of the magnetic fields H43, H45 are equal.

FIG. 3 is a schematic vertical cross-sectional view of a bending electromagnet 1 according to a comparative example.
That is, FIG. 3 is a cross-sectional view at a location along the linear trajectory RS (see FIG. 2), and the magnetic flux Φ flowing inside the bending electromagnet 1 is shown by a broken line. Further, the current flowing through the main coil 44 is called I44, and the current flowing through the side coils 43 and 45 is called I43 and I45. As shown in FIG. 3, the bending electromagnet 1 forms a closed magnetic circuit between a pair of main magnetic poles 34 and two pairs of side magnetic poles 33 and 35. As a result, the magnetic flux passing between the pair of main magnetic poles 34 is approximately twice the magnetic flux passing between the pair of side magnetic poles 33 or the pair of side magnetic poles 35.

FIG. 4 is an enlarged sectional view of the main part of FIG. 3 in a comparative example. In particular, FIG. 4 shows a detailed example of the distribution of the magnetic flux Φ in the upper front part of FIG.
In order to increase the magnetic flux density of the magnetic flux Φ between the pair of main magnetic poles 34, the current I44 in the main coil 44 and the current I45 in the adjacent side coil 45 are set in the same direction. As described above, in this comparative example, the magnetic flux between the pair of main magnetic poles 34 is approximately twice the magnetic flux between the pair of side magnetic poles 33 (or between the side magnetic poles 35).

The magnetic field strength at the position where the superconducting wire forming the main coil 44 or the side coils 43 and 45 is placed is greatest near the height center of the main coil 44 on the main magnetic pole 34 side, that is, near the illustrated region 44a.
According to Ampere's law (2πrH=I, where H is the strength of the magnetic field, I is the current included in the integral path, and r is the radius of the integral path), the magnetic field is strongest near the surface of the main coil 44 than at the center. . Similarly, the smaller the cross-sectional area of the main coil 44, the stronger the magnetic field received by the superconducting wire on the surface of the coil.

FIG. 5 is a schematic diagram showing the magnetic flux distribution in a main part of the main coil 44 according to a comparative example, that is, about a quarter circumference of the front right corner in plan view (see FIG. 2).
That is, in FIG. 5, the density of the broken line corresponds to the magnetic flux density of the magnetic flux Φ. The inner circumferential portion of the main coil 44 where it is curved in an arc shape is referred to as an arcuate inner circumferential region 44b. Further, the inner peripheral portion where the main coil 44 is linear is referred to as a linear inner peripheral region 44c. In the arc inner peripheral region 44b, the magnetic flux Φ is concentrated and the magnetic flux density is higher than in the straight inner peripheral region 44c. Thereby, the magnetic field strength that the superconducting wire receives in the arcuate inner peripheral region 44b becomes higher than the magnetic field strength in the linear inner peripheral region 44c.

Furthermore, the smaller the inner radius of the arc portion of the main coil 44, the higher the magnetic field strength of the arc inner peripheral region 44b. The current value that can be passed through the superconducting wire is determined by the temperature and the strength of the magnetic field. Therefore, if the temperature of the entire main coil 44 is uniform, the current value determined by the magnetic flux density of the arcuate inner peripheral region 44b becomes the maximum current value that can be passed through the main coil 44. That is, the smaller the diameter of the main coil 44 in the minor axis direction, the smaller the current value that can be passed through the main coil 44. Therefore, by increasing the radius of curvature of the arcuate inner peripheral region 44b, it is possible to increase the current value that can be passed through the main coil 44, and it is possible to generate a stronger magnetic field between the opposing magnetic poles.

[First embodiment]
<Configuration of first embodiment>
FIG. 6 is a sectional view of a main part of the bending electromagnet device 100 (superconducting magnet device) according to the first preferred embodiment. In the following description, the same reference numerals are given to parts corresponding to those in the above-described comparative example, and the description thereof may be omitted.
In place of the side magnetic poles 33, 35, main magnetic pole 34, side coils 43, 45, and main coil 44 in the bending electromagnet 1 of the comparative example shown in FIG. 1, the bending electromagnet device 100 of this embodiment is shown in FIG. As shown in FIG. We are prepared.

The configuration of the side magnetic poles 53, 55 is the same as that of the side magnetic poles 33, 35 of the comparative example (see FIGS. 1 to 5), and the configuration of the side coils 63, 65 is the same as that of the side coils 43, 45 of the comparative example. It is similar to the configuration. That is, the side coil 63 is formed in a racetrack shape and includes a coil straight section 63a (second coil straight section) in which a superconducting wire extends in a straight line, and a pair of coils in which the superconducting wire is curved into a substantially arc shape. It has a curved portion 63b (second coil curved portion). The side coil 65 is also configured similarly to the side coil 63, and includes a coil straight section 65a (third coil straight section) and a coil curved section 65b (third coil curved section). On the other hand, the main magnetic pole 54 as a whole has a substantially dumbbell shape in plan view, and includes a magnetic pole straight portion 54a (first magnetic pole straight portion) having a straight peripheral edge and a roughly arcuate peripheral edge. A pair of magnetic pole curved parts 54b (first magnetic pole curved parts) are provided.

The half width of the peripheral edge of the magnetic pole straight portion 54a is called r ₁ . Further, the radius of curvature of the peripheral edge of the magnetic pole curved portion 54b is referred to as _ra , and the radius of curvature of the peripheral edge of the connection portion between the magnetic pole straight portion 54a and the magnetic pole curved portion 54b is referred to as _rb . The radii of curvature r _a and r _b are both larger than the half width r ₁ . In other words, the radius of curvature of the peripheral edge of the magnetic pole curved portion 54b is larger than the half width r ₁ of the magnetic pole straight portion 54a at any location.

The main coil 64 is formed in a shape along the peripheral edge of the main magnetic pole 54, and includes a coil straight part 64a in which a superconducting wire extends in a straight line, and a pair of coil curved parts in which the superconducting wire is curved into a substantially arc shape. It has a portion 64b. The half width of the inner peripheral surface of the coil straight portion 64a is approximately the same as the half width _r1 of the magnetic pole straight portion 54a described above. Further, the radius of curvature of the inner peripheral surface of the coil curved portion 64b is approximately the same as the radius of curvature r _a of the magnetic pole curved portion 54b. Further, the radius of curvature of the inner circumferential surface at the connection portion between the coil straight portion 64a and the coil curved portion 64b is approximately the same as the radius of curvature r _b described above. In other words, the radius of curvature of the inner peripheral surface of the coil curved portion 64b is larger than the half width of the coil straight portion 64a at any location.

Here, among the x-axis components of the outer peripheral position of the coil curved portion 64b of the main coil 64, those farthest from the center position O of the main coil 64 are referred to as positions x1 and x11 (first position). Further, among the x-axis components of the outer peripheral positions of the coil straight portions 63a and 65a, those closest to the center position O are referred to as positions x2 and x12 (second positions). Further, among the outer peripheral positions of the coil straight portion 64a of the main coil 64, those where the x-axis component is farthest from the center position O are referred to as positions x3 and x13 (third position). In this embodiment, the position x2 is between the positions x1 and x3, and the position x12 is between the positions x11 and x13. Thereby, the coils 63, 64, and 65 can be arranged in a nested manner, and the bending electromagnet device 100 can be miniaturized.

The configuration of the bending electromagnet device 100 other than that described above is the same as that of the comparative example (see FIGS. 1 to 5). That is, the iron core 30 of the bending electromagnet device 100 includes a pair of upper and lower yokes 31 (yokes) and a pair of side yokes 32 (yokes), similar to the one shown in FIG. The pair of upper and lower yokes 31 have magnetic poles 53, 54, and 55, respectively shown in FIG. 6, protruding so as to face each other. Coils 63, 64, 65 are wound around each pair of magnetic poles 53, 54, 55, respectively.

According to the above configuration, it is possible to reduce the magnetic field strength particularly at the inner peripheral portion of the coil curved portion 64b. As a result, a large current can be passed through the main coil 64, thereby forming a strong magnetic field between the pair of main magnetic poles 54. On the other hand, if it is sufficient to generate a magnetic field strength comparable to or the same as that of the above-mentioned comparative example, this can be achieved using a smaller bending electromagnet device 100.

Further, the magnetic pole curved portion 54b of the main magnetic pole 54 has a shape that follows the inner circumference of the coil curved portion 64b of the main coil 64. As a result, the area through which the magnetic flux passes can be increased, so that more magnetic flux can be generated between the opposing main magnetic poles 54. Further, in this embodiment, the axial length of the side coils 63 and 65 disposed in the front-rear direction of the main coil 64 in the long axis direction (y-axis direction) is made shorter than that of the main coil 64, and these coils are arranged in a nested manner. It is placed. Thereby, a strong magnetic field can be generated over a short distance along the traveling direction (x-axis direction) of the charged particle beam.

When the main coil 64 generates a magnetic field that deflects the charged particle beam, the range in the x-axis direction in which the magnetic field is generated is sufficiently shorter than the length of the main coil 64 in the y-axis direction. Therefore, the influence of the coil curved portion 64b of the main coil 64 on the magnetic field can be ignored. Thereby, the superconducting wire forming the main coil 64 can be made uniform over the entire circumference of the main coil 64. That is, the main coil 64 can be configured by winding a single type of wire. However, the main coil 64 may be configured using a plurality of types of wire rods depending on the load factor in the cross section of the main coil 64 and the wire length.

As the material constituting each magnetic pole 53, 54, 55, it is preferable to mainly use a magnetic material, and it is more preferable to use a ferromagnetic material such as iron, silicon steel plate, or permendur. Thereby, it is possible to increase the magnetic flux passing through the magnetic poles and generate a strong magnetic field between the opposing magnetic poles. Furthermore, between the magnetic poles 53, 54, 55 and the coils 63, 64, 65, it is preferable to insert ceramic or reinforced fiber resin for insulation. Metal materials such as aluminum and copper may be inserted for the purpose.

[Second embodiment]
FIG. 7 is a schematic diagram showing the manufacturing process of the bending electromagnet device 102 according to the second preferred embodiment. In the following description, parts corresponding to those in the first embodiment described above may be denoted by the same reference numerals, and the description thereof may be omitted.
The bending electromagnet device 102 of this embodiment differs from that of the first embodiment (see FIG. 6) in that an insulating member 18 is inserted between the coils 63, 64, and 65. When the main coil 64 is wound around the substantially dumbbell-shaped main magnetic pole 54 along its periphery, the main coil 64 tends to separate from the main magnetic pole 54 due to the tension of the superconducting wire. For example, in the illustrated example, the front coil straight portion 64a is spaced apart from the magnetic pole straight portion 54a.

Therefore, in this embodiment, after the main coil 64 is wound around the main magnetic pole 54, the coil is connected to the side coils 63 and 65 from the outside of the coil straight portion 64a through the flexible plate-shaped insulating member 18. Press the straight portion 64a inward. This makes it easier to set the main coil 64 in a desired shape. Further, after the main coil 64 is pressed by the insulating member 18, if the main coil 64 and the like are impregnated with resin, it becomes easier to maintain the shape thereafter. Further, if a pressing force is continued to be applied to the main coil 64 in the direction shown by the white arrow 19 even during cooling and energization, tension is applied to the superconducting wire, thereby improving the resistance to maintain the superconducting state.

[Third embodiment]
FIG. 8 is a schematic diagram showing the manufacturing process of the bending electromagnet device 104 according to the third preferred embodiment. In the following description, parts corresponding to those in the other embodiments described above may be denoted by the same reference numerals, and the description thereof may be omitted.
The bending electromagnet device 104 of this embodiment is configured similarly to the bending electromagnet device 100 of the first embodiment (see FIG. 6).
As described above, when the main coil 64 is wound around the substantially dumbbell-shaped main magnetic pole 54 along its periphery, the main coil 64 tends to separate from the main magnetic pole 54 due to the tension of the superconducting wire. .

Therefore, in this embodiment, after the main coil 64 is wound around the main magnetic pole 54, the compression jig 20 is pressed against the coil straight portion 64a in the direction shown by the white arrow 19, and in the pressed state, the main coil 64 is wound around the main magnetic pole 54. The coil 64 and the like are impregnated with resin. Thereby, the shape of the main coil 64 can be maintained independently, and the main coil 64 and the side coils 63 and 65 (see FIG. 6) can be formed independently. In the present embodiment, the main coil 64 can be configured by winding a superconducting wire around a jig (not shown) having the same shape as the main magnetic pole 54. Thereby, the main coil 64 and the main magnetic pole 54 can be configured independently, and the bending electromagnet device 104 can be easily assembled.

[Fourth embodiment]
FIG. 9 is a schematic diagram showing the manufacturing process of the bending electromagnet device 106 according to the fourth preferred embodiment. In the following description, parts corresponding to those in the other embodiments described above may be denoted by the same reference numerals, and the description thereof may be omitted.
The bending electromagnet device 106 of this embodiment differs from the bending electromagnet device 100 of the first embodiment (see FIG. 6) in that a main magnetic pole 74 shown in FIG. 9 is applied instead of the main magnetic pole 54. . The main magnetic pole 74 includes a magnetic pole straight portion 74a having a straight peripheral edge, and a plurality of magnetic pole curved portion pieces 74b (first magnetic pole curved portion) divided into small pieces.

The overall shape of the main magnetic pole 74 including the magnetic pole straight portion 74a and the magnetic pole curved portion small piece 74b is similar to the shape of the main magnetic pole 54 (see FIG. 6) in the first embodiment. When creating the main coil 64, first, the magnetic pole straight portion 74a and the magnetic pole curved portion small piece 74b are arranged, for example, in the illustrated positions, and the superconducting wire is wound along their peripheral edges. Next, as shown in the figure, side magnetic poles 53, 55 and side coils 63, 65 are arranged before and after the main coil 64, and while pressing the coil straight part 64a from the front and back, the shape of the coil curved part 64b is adjusted. I'm going to go.

That is, the magnetic pole curved portion small piece 74b is pushed to spread the coil curved portion 64b in the x-axis direction, that is, in the direction indicated by the arrow 22. Thereby, the shape of the main coil 64 becomes similar to that of the first embodiment (see FIG. 6). In other words, it is possible to realize a radius of curvature larger than the half width of the straight portion in the short axis direction of the coil straight portion 64a in the coil curved portion 64b, and when the coils 63, 64, and 65 are impregnated with resin, the coil 63 , 64, 65 can be maintained thereafter.

In this embodiment, when winding the main coil 64, the shape of the main coil 64 can be made close to a normal racetrack shape, which facilitates the winding work. Further, in this embodiment, the main coil 64 can be constructed by winding a superconducting wire around a jig (not shown) having the same shape as the magnetic pole straight portion 74a and the magnetic pole curved portion small piece 74b. After forming the main coil 64 in this way, the bending electromagnet device 106 may be configured by combining these with the side magnetic poles 53, 55, side coils 63, 65, etc.

[Effects of embodiment]
As described above, according to the preferred embodiment, the yokes (31, 32) are formed in an annular shape and have a magnetic material, and the pair of first magnetic poles ( 54) and a pair of first coils (64) each containing a superconducting wire and wound around a pair of first magnetic poles (54), the first coil (64) containing a superconducting wire. It has a first coil straight portion (64a) extending in a straight line and a pair of first coil curved portions (64b) formed by curved superconducting wire, and the first coil curved portion (64b) The radius of curvature (r _a , r _b ) of the inner circumferential surface is larger than the half width (r ₁ ) of the inner circumferential surface of the first coil straight portion (64a). By increasing the radius of curvature (r _a , r _b ) of the inner circumferential surface of the first coil curved portion (64b), the magnetic field strength near the inner circumferential surface can be suppressed, and a large current flows through the first coil (64). can flow. Thereby, the superconducting magnet device (100) can be configured in a small size and can generate a strong magnetic field.

The superconducting magnet device (100) also includes a second coil straight section (63a) in which a superconducting wire extends in a straight line, and a pair of second coil curved sections (63b) in which the superconducting wire is curved into a substantially arc shape. ), the radius of curvature of the inner circumferential surface of the second coil curved portion (63b) is approximately half the width of the inner circumferential surface of the second coil straight portion (63a). Preferably, they are the same. In this way, by providing the second coil (63), it is possible to form a magnetic field in a direction different from that of the first coil (64).

In addition, the superconducting magnet device (100) has an axis in the arrangement direction of the first coil (64) and the second coil (63) as the x-axis, and the x-axis at the outer peripheral position of the first coil curved portion (64b). Among the components, the one farthest from the center position (O) of the first coil (64) is defined as the first position (x1), and among the x-axis components of the outer peripheral position of the second coil straight portion (63a), The one closest to the center position (O) is defined as the second position (x2), and the one farthest from the center position (O) among the x-axis components of the outer peripheral position of the first coil straight portion (64a) is defined as the second position (x2). It is more preferable that the second position (x2) is between the first position (x1) and the third position (x3). Thereby, the first coil (64) and the second coil (63) can be arranged in a nested state, and the size of the superconducting magnet device (100) can be further reduced.

The superconducting magnet device (100) also includes a third coil straight section (65a) in which a superconducting wire extends in a straight line, and a pair of third coil curved sections (65b) in which the superconducting wire is curved into a substantially arc shape. ), the radius of curvature of the inner circumferential surface of the third coil curved portion (65b) is approximately half the width of the inner circumferential surface of the third coil straight portion (65a). More preferably, the first coil (64) is provided between the second coil (63) and the third coil (65). In this way, by providing the third coil (65) together with the second coil (63), it is possible to form a magnetic field in a direction different from that of the first coil (64).

Further, the first magnetic pole (54) has a first magnetic pole straight part (54a) whose peripheral part has a shape along the inner circumference of the first coil straight part (64a), and a pair of first magnetic pole straight parts (54a) whose peripheral part has a shape along the inner circumference of the first coil straight part (64a). a pair of first magnetic pole curved parts (54b) having a shape along each inner circumference of the coil curved parts (64b), and a radius of curvature (r) of the peripheral edge of the first magnetic pole curved parts (54b). It is more preferable that _a , r _b ) be larger than the half width (r ₁ ) of the first magnetic pole curved portion (54b). Thereby, the shape of the first magnetic pole (54) can be made to follow the inner circumference of the first coil (64), and an even stronger magnetic field can be formed.

Moreover, it is more preferable that each of the pair of first magnetic pole curved parts (74b) is divided into a plurality of parts. Thereby, when winding the first coil (64), the shape of the first coil (64) can be made close to a normal racetrack shape, and the winding work can be facilitated.

[Modified example]
The present invention is not limited to the embodiments described above, and various modifications are possible. The embodiments described above are exemplified to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to delete a part of the configuration of each embodiment, or add or replace other configurations. Furthermore, the control lines and information lines shown in the figures are those considered necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In reality, almost all components may be considered to be interconnected. Possible modifications to the above embodiment include, for example, the following.

(1) The bending electromagnet devices 100 to 106 of each of the above embodiments each include a pair of main magnetic poles, two pairs of side magnetic poles, a pair of main coils, and two pairs of side coils. . However, the two pairs of side magnetic poles and the two pairs of side coils are not essential and can be omitted. For example, by deflecting the charged particles using an electric field before and after the main coil, the charged particles can be caused to travel along the deflection trajectory RC (see FIG. 2).

(2) The superconducting magnet device of the present invention is not limited to the bending electromagnet device of each of the above embodiments, but can be used for various electrical devices such as MRI (Magnetic Resonance Imaging), particle beam medical equipment, superconducting motors, etc. Applicable to magnetic poles.

2 Beam duct 31 Upper and lower yokes (yoke)
32 Side yoke (yoke)
54 Main magnetic pole (first magnetic pole)
54a Magnetic pole straight part (first magnetic pole straight part)
54b Magnetic pole curved part (first magnetic pole curved part)
63 Side coil (second coil)
63a Coil straight part (second coil straight part)
63b Coil curved part (second coil curved part)
64 Main coil (first coil)
64a Coil straight part (first coil straight part)
64b Coil curved part (first coil curved part)
65 Side coil (third coil)
65a Coil straight part (third coil straight part)
65b Coil curved part (third coil curved part)
74b Magnetic pole curved part small piece (first magnetic pole curved part)
100 Bending electromagnet device (superconducting magnet device)
106 Bending electromagnet device O center position x1, x11 position (first position)
x2, x12 position (second position)
x3, x13 position (third position)
r ₁ half width r _a , r _b radius of curvature

Claims (6)

a yoke formed in an annular shape and having a magnetic substance;
a pair of first magnetic poles protruding from the yoke to face each other;
a pair of first coils each containing a superconducting wire and wound around the pair of first magnetic poles;
a second coil having a second coil straight portion in which the superconducting wire extends linearly, and a pair of second coil curved portions in which the superconducting wire is curved into a substantially arc shape;
The first coil has a first coil straight portion in which the superconducting wire extends in a straight line, and a pair of first coil curved portions in which the superconducting wire is curved,
The radius of curvature of the inner circumferential surface of the first coil curved section is larger than the half width of the inner circumferential surface of the first coil straight section,
The radius of curvature of the inner circumferential surface of the second coil curved portion is approximately the same as the half width of the inner circumferential surface of the second coil straight portion.
A superconducting magnet device characterized by: The axis in the arrangement direction of the first coil and the second coil is the x-axis, and among the x-axis components of the outer peripheral position of the first coil curved part, the one farthest from the center position of the first coil is the first position, and among the x-axis components of the outer peripheral position of the second coil straight part, the one closest to the center position is the second position, and the outer peripheral position of the first coil straight part is the second position. Among the x-axis components, when the one farthest from the center position is defined as a third position, the second position is between the first position and the third position. The superconducting magnet device according to claim 1 . Further comprising a third coil having a third coil straight portion in which the superconducting wire extends in a straight line, and a pair of third coil curved portions in which the superconducting wire is curved into a substantially arc shape,
The radius of curvature of the inner circumferential surface of the third coil curved portion is approximately the same as the half width of the inner circumferential surface of the third coil straight portion,
The superconducting magnet device according to claim 2 , wherein the first coil is provided between the second coil and the third coil. The first magnetic pole is
a first magnetic pole straight section whose peripheral edge has a shape along the inner periphery of the first coil straight section;
a pair of first magnetic pole curved parts, the peripheral edge of which is shaped along each inner periphery of the pair of first coil curved parts,
The superconducting magnet device according to any one of claims 1 to 3 , wherein a radius of curvature of a peripheral edge of the first magnetic pole curved portion is larger than a half width of the first magnetic pole curved portion. The superconducting magnet device according to claim 4 , wherein each of the pair of first magnetic pole curved parts is divided into a plurality of parts. a yoke formed in an annular shape and having a magnetic substance;
a pair of first magnetic poles protruding from the yoke to face each other;
a pair of first coils each containing a superconducting wire and wound around the pair of first magnetic poles;
a second coil having a second coil straight portion in which the superconducting wire extends in a straight line; and a pair of second coil curved portions in which the superconducting wire is curved into a substantially arc shape;
a beam duct inserted between the pair of first coils and passing charged particles;
The first coil has a first coil straight portion in which the superconducting wire extends in a straight line, and a pair of first coil curved portions in which the superconducting wire is curved into a substantially arc shape,
The radius of curvature of the inner circumferential surface of the first coil curved section is larger than the half width of the inner circumferential surface of the first coil straight section,
The radius of curvature of the inner circumferential surface of the second coil curved portion is approximately the same as the half width of the inner circumferential surface of the second coil straight portion.
A bending electromagnet device characterized by:

Images