JP4897608B2 - Superconducting magnet - Google Patents

Description

  The present invention relates to a superconducting electromagnet in which a magnetic field is formed by passing a current through a coil composed of a superconducting wire.

  Conventionally, as a superconducting electromagnet, a wire made of a superconducting conductor on a winding frame, that is, a coil formed by winding a superconducting wire, and a strong magnetic field is formed by passing a current through the coil. It has been known.

  Specifically, as shown in FIG. 4, the superconducting electromagnet 110 includes a winding frame 111 and a coil 120. The winding frame 111 includes a hollow cylindrical winding core portion 112 extending along the central axis C ′ of the coil 120 and flanges 113 provided at both ends thereof and extending radially outward. The coil 120 is formed by winding the superconducting wire S ′ along the outer peripheral surface of the winding core portion 112. As the superconducting wire S 'forming the coil 120, in recent years, a bismuth-based or yttrium-based oxide superconducting conductor having a higher critical temperature can be maintained at a higher temperature. The general shape of these oxide-based superconducting conductors is a tape shape. That is, the superconducting current flows only in the AB plane of the crystal in the oxide superconducting conductor. The oxide-based superconducting conductor is easy to grow in the AB plane direction and becomes a plate-like crystal having anisotropy with the AB plane as the plane. Therefore, as the superconducting wire using the oxide-based superconducting conductor, a tape-shaped superconducting wire formed by orienting crystals so that the ab surface is parallel to the tape surface (hereinafter simply referred to as “tape-shaped superconducting”). Also referred to as “wire”.) S ′ is commonly used. The tape-shaped superconducting wire S ′ is wound around the winding core portion 112 so that the width direction thereof is parallel to the central axis C ′ direction of the winding core portion 112. In crystallographic terms, the thickness direction of the plate crystal is the c-axis direction, and the plate surface is a plane defined by the a-axis and the b-axis.

  The anisotropy of the crystal also appears characteristically. That is, the critical current value in the crystal differs depending on whether the magnetic field is applied perpendicularly or parallel to the ab plane of the crystal. When applied perpendicularly, the critical current value under the magnetic field is higher than when applied in parallel. The decrease in value is remarkable. Thus, the critical current value has an angle dependency of the magnetic field direction with respect to the crystal.

  Therefore, in the tape-shaped superconducting wire S ′ formed using the crystal as described above, the direction of the magnetic field applied to the tape-shaped superconducting wire S ′ and the critical current density (critical current value / magnetic field when the magnetic field is parallel to the tape surface). The qualitative relationship with the critical current value is as shown in FIG. 5. When the magnetic field direction is perpendicular to the tape surface, the critical current density is reduced to about 1/1000 of the parallel time.

  Here, when the coil 120 is energized and a magnetic field is formed by the superconducting electromagnet 110, a large magnetic field is formed in the hollow portion 116 surrounded by the winding core portion 112. This magnetic field is also formed in the winding portion of the tape-shaped superconducting wire S ′ in the coil 120. As shown in FIG. 6, the magnetic field formed in this winding portion forms a large magnetic field in the direction of the central axis C ′ in the direction parallel to or substantially parallel to the central axis C ′ in the vicinity of the central portion of the coil 120. In addition, a magnetic field in a direction perpendicular or substantially perpendicular to the central axis C ′ is formed at the coil ends (upper and lower portions in a range surrounded by a dotted line in FIG. 6), so-called edge portions. That is, in the central axis C ′ direction, a magnetic field is applied to the central portion of the coil 120 in parallel or substantially parallel to the tape surface of the tape-shaped superconducting wire S ′. On the other hand, a magnetic field is applied vertically or substantially perpendicularly. Therefore, the critical current value of the tape-shaped superconducting wire S ′ at the end of the coil 120 is lowered, and is much smaller than the critical current value of the tape-shaped superconducting wire S ′ at the central portion (see FIG. 11).

  The upper limit of the current value that can be passed through the coil 120 is defined by the minimum critical current value in the tape-shaped superconducting wire S ′ forming the coil 120. Therefore, in the central axis C ′ direction, the critical current value of the tape-shaped superconducting wire S ′ at the center of the coil 120 is large, but the critical current value of the tape-shaped superconducting wire S ′ at the end of the coil 120 is defined. Only a very small current can flow through the coil 120.

  Therefore, an object of the present invention is to provide a superconducting electromagnet having a larger current that can be passed through a coil.

Accordingly, in order to achieve the above object, a superconducting electromagnet according to the present invention is a superconducting magnet in which a magnetic field is formed by passing a current through a coil composed of a tape-shaped superconducting wire, and is along the central axis of the coil. extending Te, comprising a winding core, wherein the superconducting wire constituting the coil is wound around the outer peripheral surface, and a magnetic circuit member connecting the two ends of the winding core to form a magnetic circuit, the winding core Is a hollow cylindrical shape, the magnetic circuit member is formed of a ferromagnetic material, and is connected to both ends of the winding core, and has a pair of outer diameters that is at least the size of the winding core and the coil. And a connecting portion that connects between the pair of winding core connecting portions through the outside of the coil, the winding core connecting portion when the current is passed through the coil, In the direction of the central axis That together with the orientation of the magnetic field formed at an end portion of the coil is closed the length of the central axis such that the parallel or substantially parallel to the tape surface of the superconducting wire constituting the end of the coil The hollow portion surrounded by the winding core communicates with the outside and has a through hole extending along the central axis direction. The inner diameter of the through hole of the winding core connecting portion is the inner diameter of the hollow portion of the winding core. It is characterized by being smaller than .

  According to such a configuration, the direction of the magnetic field applied to the coil end (hereinafter also simply referred to as “coil end”) in the central axis direction is parallel to the tape surface of the tape-shaped superconducting wire constituting the coil end, or Since they are substantially parallel, the critical current value of the tape-shaped superconducting wire (hereinafter also simply referred to as “tape-shaped superconducting wire”) at the coil end is maintained at a high value. Therefore, a larger current flows through the coil, and a magnetic field having a large magnetic field strength is formed.

  That is, when the coil is energized, a magnetic field in a direction perpendicular or substantially perpendicular to the central axis of the coil is formed at the coil end portion (edge portion) in a conventional superconducting electromagnet without a magnetic circuit member. . However, by providing a magnetic circuit member as in the above configuration, the magnetic field in the direction perpendicular or substantially perpendicular to the central axis direction formed at the coil end is pulled by the winding core connecting portion, and the coil end It becomes the magnetic field of the direction along the tape surface of the tape-shaped superconducting wire which constitutes. Therefore, the critical current value of the tape-shaped superconducting wire constituting the coil end is high, in other words, the same as the critical current value of the coil central part (hereinafter also simply referred to as “coil central part”) in the central axis direction. Alternatively, it is maintained at almost the same value.

Moreover, according to the said structure, a strong magnetic field is formed in the hollow part enclosed by the hollow cylindrical winding core. Therefore, a sample or the like can be carried through the through hole of the magnetic induction unit into the space where the strong magnetic field is formed, and the sample can be analyzed in the magnetic field.
Further, according to the above configuration, the magnetic field applied to the coil end at the peripheral portion of the through hole forming the through hole in the winding connection portion and radially inward from the inner diameter of the winding core is on the radial center side. Pull towards. Therefore, the magnetic field applied to the end of the coil further approaches the direction along the tape surface. As a result, a decrease in the critical current value of the tape-shaped superconducting wire at the coil end is suppressed, and a large current flows through the coil.

  In addition, flanges for restricting both end positions in the central axis direction of the superconducting wire wound around the core having an outer diameter larger than the outer diameter of the core are respectively provided at both ends of the core. The flange is formed of a ferromagnetic material to constitute at least a part of the winding core connecting portion, and a yoke that connects the flanges so as to form a magnetic circuit constitutes the magnetic circuit member together with the flange. It is preferable.

  According to this configuration, since the flange is provided at both ends of the core, the coil can be formed by accurately winding the tape-shaped superconducting wire around the core. In addition, the magnetic circuit member that connects both ends of the winding core so as to form a magnetic circuit by connecting the flange formed of a ferromagnetic material and a yoke formed of a ferromagnetic material to the flange. Composed. That is, by forming the flange in contact with both ends of the coil in the central axis direction from a ferromagnetic material, a magnetic circuit is formed in a state where there is little leakage of a magnetic field from both ends of the coil to other than the magnetic circuit member. The winding core connecting portion of the magnetic circuit member has a length in the central axis direction. Therefore, the magnetic field applied to the coil end is pulled in the direction along the central axis direction by the winding core connecting portion, and becomes a magnetic field in the direction along the tape surface of the tape-shaped superconducting wire. As a result, a large current flows through the coil, and a magnetic field having a larger magnetic field strength is formed.

  The winding core is preferably formed of a weak magnetic material. Since such a winding core is not magnetized or difficult to magnetize, the magnetic field formed in the hollow portion is hardly absorbed by the winding core, and a magnetic field having a larger magnetic field strength can be formed in the hollow portion.

  As described above, according to the present invention, it is possible to provide a superconducting electromagnet having a larger current that can be passed through the coil.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  The superconducting electromagnet according to the present embodiment has a large magnetic field strength, that is, a strong magnetic field, when a current is passed through a coil composed of a superconducting wire formed in a tape shape (hereinafter also simply referred to as “tape wire”). It forms a magnetic field. Specifically, as shown in FIGS. 1 and 2, the superconducting electromagnet 10 includes a winding frame 11, a coil 20 formed by winding a tape wire S around the winding frame 11, and the winding frame 11. And a yoke 30 for connecting both axial ends through the outside of the coil 20.

  The winding frame 11 includes a winding core 12 extending along the central axis C of the coil 20 and a pair of flanges 13 and 13 provided at both ends of the winding core 12 in the direction of the central axis C of the coil 20. In the present embodiment, the central axis C of the coil 20 is simply referred to as “C axis”, and the direction along the central axis C of the coil 20 is also simply referred to as “C axis direction”.

  The winding core 12 is formed in a hollow cylindrical shape in which the central axis of the winding core 12 coincides with the central axis C of the coil. Specifically, the winding core 12 is formed in a hollow cylindrical shape having an outer diameter r1 of 100 mm, an inner diameter r2 of 96 mm, and a length L1 of 150 mm. Both ends in the C-axis direction of the winding core 12 are bent toward the radially inner side (center axis side) to form a flange portion 14 having a constant width along the circumferential direction. The flange 14 is used when attaching the flange 13, and a plurality of through holes 15, 15,... Are formed at predetermined intervals along the circumferential direction of the winding core 12. In this embodiment, the winding core 12 is formed of a weak magnetic aluminum alloy. However, it is not necessary to be limited to this, and it may be made of other materials as long as it is made of a weak magnetic material such as SUS. That is, the winding core 12 should just be formed with the material which is hard to magnetize. By forming the winding core 12 with such a material, a magnetic field described later formed in the hollow portion 16 surrounded by the winding core 12 is not absorbed or hardly absorbed by the winding core 12, and the magnetic field strength is increased. A larger magnetic field is formed in the hollow portion 16.

  The flanges 13 are provided at both ends of the winding core 12 in the C-axis direction, thereby restricting the positions of both ends of the tape wire S wound around the winding core 12 in the C-axis direction. The flange 13 is formed in a disc shape. Specifically, the flange 13 has an outer diameter r3 larger than the outer diameter r1 of the winding core 12, and this outer diameter r3 is the same as the outer diameter r3 ′ of the coil 20 disposed along the outer periphery of the winding core 12. Alternatively, they are formed to be substantially the same. A flange through hole 17 that is a circular through hole is formed in the center of the flange 13. The inner diameter r4 of the flange through hole 17 is smaller than the inner diameter r2 of the winding core 12. Therefore, when the flange 13 is attached to the winding core 12, the peripheral edge portion of the flange through-hole 17 protrudes (projects) toward the central axis side of the winding core 12. Specifically, the flange 13 is formed in a disk shape having an outer diameter r3 of 150 mm, an inner diameter (inner diameter of the flange through hole 17) r4 of 60 mm, and a thickness (length in the C-axis direction) L2 of 15 mm.

  The flange 13 having such a shape is made of electromagnetic soft iron in this embodiment. However, the material constituting the flange 13 need not be limited to electromagnetic soft iron, and may be any ferromagnetic material such as a silicon steel plate, pure iron, iron alloy, nickel, or nickel alloy. That is, as will be described later, if the flange 13 is formed of a ferromagnetic material, a magnetic circuit with less magnetic field leakage can be obtained by connecting both ends of the coil 20 in the C-axis direction together with the yoke 30 formed of the ferromagnetic material. It is formed.

  The pair of flanges 13 and 13 formed in this manner are respectively provided on the flange portions 14 at both ends of the winding core 12 so that the plate surface is orthogonal to the C axis and the center of the flange through hole 17 is positioned on the C axis. It is attached. At this time, the flange 13 is fixed to the winding core 12 by screwing a screw 18 from the hollow portion 16 side through the through hole 15 of the flange portion 14.

  The coil 20 is formed by winding the tape wire S in a solenoid shape along the outer peripheral surface of the winding core 12. The outer diameter r3 'of the coil (solenoid coil) 20 is the same as or substantially the same as the outer diameter r3 of the flange 13, and the length L3 in the C-axis direction is 150 mm.

  As the tape wire S constituting the coil 20, a bismuth-based or yttrium-based oxide superconducting conductor is used. The tape wire S is a long tape-shaped superconducting wire having a certain width, and the ab surface of the crystal of the oxide-based superconducting conductor is oriented parallel to the tape surface, and its periphery is covered with a silver sheath or the like. It is formed so that. The tape wire S is wound along the outer peripheral surface of the winding core 12 so that the width direction thereof is parallel to the C-axis direction, and constitutes the coil 20.

  The yoke 30 is formed of a ferromagnetic material such as electromagnetic soft iron like the flange 13, and the coil 20 includes a pair of flanges 13 and 13 formed of the ferromagnetic material at both ends in the C-axis direction of the winding frame 11. The magnetic circuit is formed by connecting so as to pass outside. The yoke 30 includes a pair of flange coupling portions 31 and 31 that are coupled to the pair of flanges 13 and 13, respectively, and a connection portion 32 that connects the pair of flange coupling portions 31 and 31. The yoke 30 is made of electromagnetic soft iron in the present embodiment, but is not limited to this. The yoke 30 may be made of a ferromagnetic material like the flange 13, and may be a silicon steel plate or the like. Also good.

  The flange connecting portion 31 extends from the surface of the outer side of the flange 13 (on the side opposite to the hollow portion 16 side of the winding core 12 in the C-axis direction) to the outer side along the C-axis direction and is formed along the C-axis. The connecting part through-hole 33 is provided. Specifically, the flange connecting portion 31 has the same shape as the flange 13 when viewed from the C-axis direction. That is, when viewed in the C-axis direction, the outer diameter r3 ″ and the inner diameter (the inner diameter of the coupling portion through hole 33) r4 ″ of the flange coupling portion 31 are the same as the outer diameter r3 and the inner diameter (the inner diameter of the flange through hole 17) r4. is there. The flange connecting portion 31 constitutes a winding core connecting portion 41 described later together with the flange 13. In the present embodiment, although not shown, a plurality of counterbore holes are formed from the front end side (the outer side) of the flange connecting portion 31 toward the flange 13 and are screwed through the counterbored holes to thereby form the flange 13. And the flange connecting portion 31 are connected.

  The winding core connecting portion 41 has a cylindrical shape whose outer diameter is the same or substantially the same as the outer diameter r3 ′ of the coil 20, and is formed by connecting the flange through hole 17 and the connecting portion through hole 33 to each other. Have The yoke through hole 42 is a straight through hole having an inner diameter along the same C axis as the inner diameter r4 of the flange 13, and communicates the hollow portion 16 of the winding core 12 with the outside.

  The connecting portion 32 is a hollow cylindrical shape extending along the C-axis direction, and both end portions thereof are formed to bend toward the radially inner side (center axis side). The connecting portion 32 is formed such that its inner diameter r5 is larger than the outer diameter r3 'of the coil 20. That is, the connecting portion 32 is sized so that a gap 34 is generated between the outer peripheral surface of the coil 20 and the inner peripheral surface of the connecting portion 32 when the coils 20 are accommodated so that their center axes coincide with each other. Is formed. Specifically, the connection portion 32 has an outer diameter r6 of 240 mm, an inner diameter r5 of 190 mm, a length L4 in the C-axis direction of 290 mm, a length (width) L5 in the direction orthogonal to the C-axis of the gap 34 of 25 mm, C The length L6 in the axial direction is formed to be 220 mm.

  The connection portion 32 connects the tip ends (the end portions on the side away from the flange 13) of the pair of flange connection portions 31 (or the winding core connection portions 41). Specifically, the coil 20 formed by winding the tape wire S around the winding core 12 in the cylindrical connection portion 32 so that the center axes thereof coincide with each other, and both ends of the coil 20 in this state in the C-axis direction. The pair of connected core connection parts 41 (the flange 13 and the flange connection part 31) are accommodated. In this state, the front end portion of the flange connection portion 31 and the bent portion front end of the connection portion 32 are connected. At this time, the front end side surface of the flange connection portion 31 and the end surface in the C-axis direction of the connection portion 32 are flush with each other, and the peripheral surface of the front end portion of the flange connection portion 31 and the bent portion of the connection portion 32 The shaft end is connected. The connecting portion 32 constitutes a magnetic circuit member 40 formed of a ferromagnetic material, which will be described later, together with a winding core connecting portion 41 including the flange connecting portion 31 and the flange 13. The yoke 30 composed of the flange connecting portion 31 and the connecting portion 32 is not shown in the figure, but is once separated into two or more portions at a predetermined position, and the reel 11 provided with the coil 20 and the predetermined portion. After each is connected, each part is connected.

  The superconducting electromagnet 10 according to the present embodiment has the above configuration, and the operation thereof will be described next.

  The superconducting electromagnet 10 is cooled in liquid helium. If it does so, the tape wire S which comprises the coil 20 will be in a superconducting state, and an electrical resistance will be zero. In this state, when a current is passed through the coil 20, a magnetic field having a high magnetic field strength in the direction along the C axis is formed in the hollow portion 16 of the winding core 12.

  At this time, a magnetic field is also formed in the inside of the coil 20, specifically, in the winding portion of the tape wire S of the coil 20. The magnetic field formed in the coil 20 is such that both ends of the coil 20 in the C-axis direction are connected by a ferromagnetic magnetic circuit member 40 to form a magnetic circuit. The direction is parallel or substantially parallel to the surface. The term “substantially parallel” refers to the extent that the magnetic flux lines of the magnetic field formed in the coil 20 appear almost parallel to the tape surface of the tape wire S.

  Specifically, in a conventional superconducting electromagnet that does not include the magnetic circuit member 40, when the coil is energized, the coil end in the central axis direction (hereinafter simply referred to as "coil end") is used. A magnetic field is formed in a direction perpendicular or substantially perpendicular to the central axis of the coil. On the other hand, by providing the magnetic circuit member 40 like the superconducting electromagnet 10 according to the present embodiment, a conventional superconducting magnet is perpendicular to or approximately the center axis of the coil formed at the coil end. A magnetic field in a perpendicular direction becomes a magnetic field in a direction along the tape surface of the tape wire S constituting the end of the coil 20 by being pulled toward the winding core connecting portion 41 side.

  More specifically, the coil 20 formed by winding (winding) the tape wire S around the winding frame 11 is formed on a pair of flanges 13 and 13 provided at both ends of the winding core 12 in the C-axis direction. Both ends in the C-axis direction are in contact. The flange 13 is formed of a ferromagnetic material, and a yoke 30 formed of a ferromagnetic material is connected to the flange 13 so that both ends of the coil 20 in the C-axis direction are connected to form a magnetic circuit. A member 40 is configured. At this time, the pair of flanges 13 and 13 that are in contact with both ends of the coil 20 in the C-axis direction are formed of a ferromagnetic material, so that there is little leakage of the magnetic field from both ends of the coil 20 to other than the magnetic circuit member 40. A magnetic circuit is formed. And the winding core connection part 41 which includes the flange 13 of the magnetic circuit member 40 in a part has a predetermined length (70 mm in this embodiment) in the C-axis direction. Therefore, the magnetic field applied to the coil end is pulled in the C-axis direction by the winding core connecting portion 41.

  Moreover, the inner diameter r 4 ″ of the yoke through hole 42 of the winding core connecting portion 41 is smaller than the inner diameter r 2 of the hollow portion 16 of the winding core 12, that is, the yoke through hole peripheral portion forming the yoke through hole 42 is the winding core 12. Therefore, the portion of the winding connecting portion 41 that is the yoke through-hole peripheral portion that forms the yoke through-hole 42 and that is radially inward from the inner diameter r2 of the winding core 12 (see above). The projecting portion) pulls the magnetic field applied to the end of the coil 20 toward the radial center (C-axis side), so that the magnetic field applied to the end of the coil 20 is further increased in the C-axis direction compared to the case where there is no projecting portion. It becomes straight so as to follow, and becomes closer to the direction along the tape surface of the tape wire S.

  Accordingly, the tape surface of the tape wire S constituting the coil 20 and the direction of the magnetic field applied to the winding portion of the coil 20 are parallel or substantially parallel over the entire C-axis direction of the coil 20. Therefore, it is possible to suppress a decrease in the critical current value in the tape wire S at the end of the coil 20 with respect to the critical current value in the tape wire S in the central portion of the coil 20 in the C-axis direction. That is, the critical current value of the tape wire S constituting the end portion of the coil 20 of the superconducting electromagnet 10 is maintained at a high value, in other words, the same value as or substantially the same as the critical current value at the central portion of the coil 20 in the C axis direction. Thus, a larger current flows through the coil 20. As a result, a magnetic field having a large magnetic field strength is formed by the coil 20 (superconducting electromagnet 10).

A superconducting electromagnet 10 according to the present invention and a conventional superconducting electromagnet having the same dimensions as the superconducting electromagnet 10 but not including a magnetic circuit member and the entire winding frame (flange and winding core) made of a nonmagnetic aluminum alloy are used. The operation was performed in liquid helium under the following conditions.
Superconducting wire: width 5.0 mm, thickness 0.5 mm.
Coil: winding inner diameter is 100 mm, winding outer diameter is 150.0 mm, winding width (width in the central axis C direction) is 150.0 mm, and number of windings is 1500.

  A current of 207.05 A was passed through this coil so that the central magnetic field (the strength of the magnetic field at the magnetic field center in FIGS. 3 and 6) was 2.0T. As a result, in the conventional superconducting electromagnet, the magnetic field strength applied in the direction perpendicular to the tape surface of the tape wire at the coil end was 1.08T. In the superconducting electromagnet according to the present invention, the magnetic field strength applied in the direction perpendicular to the tape surface of the tape wire at the end of the coil was 0.16T. Moreover, the magnetic field distribution of the coiled portion of the superconducting electromagnet according to the present invention at this time is as shown in FIG.

  From the above results, the superconducting electromagnet according to the present invention can reduce the magnetic field strength applied in the direction perpendicular to the tape surface of the tape-shaped superconducting wire at the coil end to about 1/7 that of the conventional superconducting magnet. It was. Also from FIG. 3, it can be seen that the direction of the magnetic field applied to the coil winding portion is the direction along the tape surface of the tape-shaped superconducting wire (the direction along the vertical direction in FIG. 3).

  Accordingly, the yoke is connected to a pair of flanges in which the superconducting electromagnet is made of a ferromagnetic material, and the magnetic circuit member having the yoke through-hole having an inner diameter smaller than the inner diameter of the winding core is provided to flow through the coil. It was confirmed that the current that can be increased.

  The superconducting electromagnet of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

The perspective central longitudinal cross-sectional view which shows the structure of the superconducting electromagnet which concerns on this embodiment is shown. The perspective center longitudinal cross-sectional view which shows the dimension of the superconducting electromagnet which concerns on the embodiment is shown. The magnetic field distribution figure of the winding part of the superconducting electromagnet concerning the embodiment is shown. The perspective center longitudinal cross-sectional view which shows the structure of the conventional superconducting electromagnet is shown. It is a figure which shows the magnetic field direction dependence of the critical current of an oxide type tape-shaped superconducting wire. The magnetic field distribution figure of the winding part of the conventional superconducting electromagnet is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Superconducting electromagnet 12 Winding core 20 Coil 40 Magnetic circuit member 41 Winding core connection part C Central axis S Superconducting wire (tape-shaped superconducting wire, tape wire)

Claims (3)

In a superconducting electromagnet in which a magnetic field is formed by passing a current through a coil composed of a tape-shaped superconducting wire,
A winding core that extends along the central axis of the coil and that is wound around an outer peripheral surface of the superconducting wire constituting the coil;
A magnetic circuit member for connecting both ends of the winding core so as to form a magnetic circuit,
The winding core has a hollow cylindrical shape,
The magnetic circuit member is formed of a ferromagnetic material, and is connected to both ends of the winding core, and has a pair of winding core coupling portions having an outer diameter of at least the size of the winding core and the coil. Having a connecting portion for connecting between a pair of winding core connecting portions through the outside of the coil;
The winding core connecting portion is a tape surface of the superconducting wire in which the direction of the magnetic field formed at the end portion of the coil in the central axis direction constitutes the end portion of the coil when a current is passed through the coil. while have a length of said central axis such that the parallel or substantially parallel to, the through hole that conforms to and the central axis direction communicates the hollow portion and the outside surrounded by the winding core Have
A superconducting electromagnet, wherein the inner diameter of the through hole of the winding core connecting portion is smaller than the inner diameter of the hollow portion of the winding core . The superconducting electromagnet according to claim 1 ,
Flange that regulates both end positions in the central axis direction of the superconducting wire wound around the winding core having an outer diameter larger than the outer diameter of the winding core is provided at both ends of the winding core, respectively.
The flange is made of a ferromagnetic material and constitutes at least a part of the winding core connecting portion.
A superconducting electromagnet, wherein a yoke that connects the flanges to form a magnetic circuit constitutes the magnetic circuit member together with the flange. The superconducting electromagnet according to claim 1 or 2 ,
The superconducting electromagnet according to claim 1, wherein the winding core is formed of a weak magnetic material.

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