JP2014049638A - Superconducting coil, superconducting magnet employing the same coil, and manufacturing method of superconducting coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting coil capable of forming a magnetic field of high spatial uniformity by using a tape-shaped superconducting wire for which a plurality of unit wires are connected, a superconducting magnet employing the coil, and a manufacturing method of the superconducting coil.SOLUTION: In a superconducting coil 20, a tape-shaped superconducting wire 22 is wound over multiple layers in a solenoid shape while turning the thickness direction thereof towards a spiral radial direction. The superconducting wire 22 is configured by connecting a plurality of unit wires 24 in the length direction thereof, and each of the layers of the coil 20 is configured by winding a single unit wire 24 in a solenoid shape. In a connection part 26 where unit wires 24, 24 are connected with each other in the superconducting wire 22, a terminal portion of the unit wire 24 constituting a radially inside layer and a terminal portion of the unit wire 24 constituting a radially outside layer are overlapped with each other in the thickness direction in a terminal portion of the coil 20.

Description

  The present invention relates to a superconducting coil using a tape-shaped superconducting wire, a superconducting magnet using the coil, and a method of manufacturing the superconducting coil.

  Oxide superconductors, which have been developed in recent years, have features such as higher critical temperatures and stronger magnetic fields than metallic superconductors, and are easy to cool. Is spreading.

  A superconducting coil using this oxide superconducting conductor is disclosed in Patent Document 1. This superconducting coil is used for a superconducting magnet 100 as shown in FIG. Specifically, the superconducting magnet 100 includes a winding frame 101 and a superconducting coil 102 provided on the winding frame 101. The superconducting coil 102 is obtained by winding a tape-shaped wire (superconducting wire) 103 formed of an oxide superconducting conductor on a winding frame 101 in a solenoid shape so that the thickness direction thereof faces the spiral radial direction. Is formed.

JP 2003-209021 A

  Oxide superconductors are difficult to form long wires like metal-based superconductors due to manufacturing constraints, so when forming large coils, multiple lengths of each are determined. A coil is formed using a wire in which the oxide superconducting wire (unit wire) 103 is connected in series.

  Since the tape-shaped oxide superconducting wires 103 and 103 are connected by soldering with their end portions stacked in the thickness direction, the thickness of this connecting portion is compared to the thickness of other portions. More than twice. For this reason, in the superconducting coil 102 formed by a wire connecting a plurality of oxide superconducting wires 103, as shown in FIG. 12, the winding is disturbed around the connecting portion 104 (winding outside the connecting portion 104 of the nth layer). The portion 106 of the oxide superconducting wire 103 of the (n + 1) th layer is shifted in the radial position with respect to the portion 108 other than the portion 106 of the oxide superconducting wire 103 constituting the same n + 1 layer as this portion 106, etc. ) Occurs. As described above, when local turbulence of the oxide superconducting wire 103 occurs in the superconducting coil 102, the spatial uniformity of the magnetic field formed by the superconducting coil 102 decreases.

  Therefore, in view of the above problems, the present invention uses a superconducting wire in which a plurality of tape-like unit wires are connected, and can form a magnetic field with high spatial uniformity, a superconducting magnet using this coil, and a superconducting coil It is an object to provide a manufacturing method.

  In order to solve the above problems, the present invention is a superconducting coil in which a tape-shaped superconducting wire is wound in a solenoid shape in a state where its thickness direction is directed to the radial direction of the spiral, and the superconducting wire includes a plurality of superconducting wires. The tape-shaped unit wire is connected in the longitudinal direction, and each layer of the coil is formed by winding the single unit wire in the solenoid shape, and the superconducting wire in the superconducting wire The connecting portion to which the unit wire members are connected has an end portion of the unit wire member constituting the radially inner layer and an end portion of the unit wire member constituting the outer layer at the end portion in the coil axial direction of the coil. They are connected in the state of being overlapped with each other in the thickness direction.

  According to such a configuration, at the end in the coil axial direction of the multi-winding superconducting coil, the end of the single unit wire constituting the radially inner layer and the single unit constituting the outer layer By superimposing and connecting the end portions of the wire, it is possible to suppress turbulence of the superconducting wire due to the thickness of the connection portion. That is, when the connecting portion is provided in the middle portion in the coil axis direction, the superconducting wire constituting the outer layer is disturbed due to the difference in thickness between the connecting portion and the other portion of the superconducting wire (see FIG. 12). ), At the end of the superconducting coil in the coil axial direction, the end of the single unit wire constituting the inner layer and the end of the single unit wire constituting the outer layer are overlapped By configuring the connecting portion (see FIG. 13), the winding of the superconducting wire resulting from the thickness of the connecting portion can be achieved without inserting an insulating material or the like to fill the difference in thickness between the connecting portion and other parts. Disturbance can be suppressed. As a result, according to the superconducting coil, a magnetic field with high spatial uniformity can be formed.

  In the superconducting coil according to the present invention, the superconducting wire has a plurality of the connection portions, and the end portions of the unit wire materials are connected to each other through solder at each connection portion. It is preferable that the coil is provided at different positions in the circumferential direction of the coil so as not to overlap in the radial direction of the coil.

  According to such a configuration, at the end of the superconducting coil in the axial direction of the coil, it is possible to disperse the connection portions that generate heat due to the resistance of the solder when energized in the circumferential direction, thereby preventing disconnection due to the heat generation. .

  Moreover, it is preferable that the plurality of connection portions are provided in a distributed manner at both ends of the coil in the coil axis direction.

  According to such a configuration, since the connecting portion having a thickness larger than that of the other portion is distributed (distributed) to both ends in the coil axis direction, an outer diameter winding thickness is generated only at one end. Can be prevented.

  Moreover, in order to eliminate the said subject, this invention is a superconducting magnet, Comprising: One of said superconducting coils and the winding frame around which the said superconducting wire which comprises the said superconducting coil is wound are provided.

  According to such a configuration, at the end in the coil axial direction of the multi-winding superconducting coil, the end of the single unit wire constituting the radially inner layer and the single unit constituting the outer layer By superimposing and connecting the end portions of the wire, it is possible to suppress turbulence of the superconducting wire due to the thickness of the connection portion. For this reason, according to the superconducting magnet, a magnetic field with high spatial uniformity can be formed.

  Further, in order to solve the above problems, the present invention is a method for producing a superconducting coil in which a tape-shaped superconducting wire is wound in a solenoid shape in a state where its thickness direction is directed in the radial direction of the spiral, A step of forming a predetermined layer of the superconducting coil by winding a single tape-shaped unit wire in the solenoid shape, and a unit wire having the predetermined layer formed at the end of the superconducting coil in the axial direction of the coil The superconducting wire is constructed by connecting the ends of the tape-shaped unit wires constituting the outer layer in the radial direction so as to overlap each other in the thickness direction. Winding a unit wire on the predetermined layer to form the outer layer.

  According to this configuration, the end of the single unit wire constituting the radially inner layer (predetermined layer) and the outer layer thereof are configured at the end in the coil axial direction of the superconducting coil wound in multiple layers. By superimposing and connecting the end portions of the single unit wire material, a superconducting coil in which the disturbance of the superconducting wire material due to the thickness of the connection portion is suppressed is formed.

  As described above, according to the present invention, a superconducting coil that can form a magnetic field with high spatial uniformity using a superconducting wire connected with a plurality of tape-like unit wires, a superconducting magnet using this coil, and the manufacture of the superconducting coil A method can be provided.

It is a front view of the superconducting magnet which concerns on this embodiment. It is a front view of the winding frame of the superconducting magnet. It is a figure for demonstrating a superconducting wire. It is the elements on larger scale for demonstrating the connection part in the said superconducting wire. It is a figure for demonstrating the position of the circumferential direction of each connection part in a superconducting coil. It is a partial expanded sectional view for demonstrating the position of the circumferential direction of each connection part in a superconducting coil. It is a partial expanded sectional view for demonstrating the state where the connection part overlapped in radial direction. It is a figure for demonstrating the process of forming the nth layer of the said superconducting coil. It is a figure for demonstrating the process of forming the n + 1th layer of a superconducting coil, after forming a connection part. It is a figure for demonstrating a dummy line. It is a figure for demonstrating the conventional superconducting magnet. It is a partially expanded sectional view which shows the winding disorder by the connection part of a superconducting wire. It is a figure for demonstrating the position in which the connection part of the superconducting wire in a superconducting coil is formed.

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

  FIG. 1 is a front view of the superconducting magnet according to the present embodiment. FIG. 2 is a front view of the winding frame of the superconducting magnet. FIG. 3 is a view for explaining a superconducting wire, and FIG. 4 is a partially enlarged view for explaining a connecting portion in the superconducting wire. FIG. 5 is a view for explaining the circumferential position of each connecting portion in the superconducting coil, and FIG. 6 is a partially enlarged sectional view for explaining the circumferential position of each connecting portion in the superconducting coil. . FIG. 7 is a partially enlarged cross-sectional view for explaining a state in which the connection portions overlap in the radial direction.

  A superconducting magnet 10 according to the present embodiment includes a winding frame 12 and a superconducting coil 20.

  The winding frame 12 includes a body portion 14 and a pair of flange portions 16 and 16. The trunk | drum 14 has a cylindrical shape and is formed with a nonmagnetic material. The flange portion 16 is provided at both ends in the axial direction of the body portion 14 (both ends in the left-right direction in FIG. 2), and protrudes radially outward from the outer peripheral surface of the body portion 14. As for the trunk | drum 14 of this embodiment, the distance between the inner surfaces of the flange part 16 is 200 mm, for example, and an outer diameter is 600 mm, for example.

  The superconducting coil 20 is formed by winding a tape-like superconducting wire 22 in a solenoid shape in a state where its thickness direction is directed in the radial direction of the spiral. Specifically, the outer peripheral surface of the body portion 14 in the state where the tape-shaped superconducting wire 22 is oriented in the radial direction of the winding frame 12 (flatwise state) in the region between the pair of flange portions 16, 16. The superconducting coil 20 is constructed by winding up multiple layers like a solenoid above.

  The superconducting wire 22 is formed by connecting a plurality of tape-like unit wires 24, 24,... In series. Each unit wire 24 is formed of a Bi (bismuth) -based or Y (yttrium) -based oxide material, and has a length of about 400 m, a width of 4 mm, and a thickness of 0.5 mm, for example.

  The superconducting wire 22 has a plurality of connecting portions 26 that are portions where the end portions of the unit wire 24 are connected to each other. The connection portion 26 has a structure in which the end portions of the unit wire 24 are overlapped with each other in the thickness direction via the solder 28 (interposing), and an insulating tape 30 is wound around the end portion. For this reason, in the superconducting wire 22, the connection portion 26 has a thickness (thickness dimension) that is twice or more that of other portions. Moreover, in order to suppress the electrical resistance in the connection part 26, in this embodiment, the solder 28 containing silver is used for the connection of the edge parts of the unit wire material 24, and the edge parts of the unit wire material 24 are 5 cm or more in a longitudinal direction. The substantially entire surfaces that are overlapped and opposed to each other are connected by solder 28.

  Each layer of the superconducting coil 20 is constituted by a single unit wire 24. That is, in the superconducting coil 20, the connection portion 26 is provided at the end of each layer in the coil axis direction, and the connection portion 26 is not formed in the middle (intermediate position) of each layer in the coil axis direction.

  Specifically, each connection portion 26 has a radial inner side (n-th layer and (n + 1) -th layer) adjacent to the upper and lower sides (inside and outside in the radial direction) at the end in the coil axial direction of the superconducting coil 20. The end of the unit wire 24 constituting the n-th layer which is the lower layer and the end of the unit wire 24 constituting the (n + 1) th layer which is the outer (upper) layer are in the thickness direction of each other. It is formed by being connected in a superposed state.

  This connection part 26 may be provided in each layer at the end of the superconducting coil 20 in the coil axial direction, or may be provided in several layers.

  The plurality of connecting portions 26, 26,... Are distributed at both ends in the coil axis direction of the superconducting coil 20 (both ends in the left-right direction in FIG. 1). As described above, the connection portion 26 is distributed to both end portions in the coil axial direction, so that it is possible to prevent the winding thickness of the outer diameter biased to only one end portion of the superconducting coil 20. For example, when even layers are continuously formed by one unit wire 24, the connection portion 26 is formed only at one end in the coil axis direction of the superconducting coil 20, and therefore the outer diameter of the end is the other. It becomes thicker than the outer diameter of the end portion (winding thickening occurs at one end portion). On the other hand, when the odd-numbered layers are continuously formed by one unit wire 24, the connecting portions 26 are formed at both ends of the superconducting coil 20, so that the outer diameter is thickened only at one end. Does not occur.

  In addition, when the connection part 26 is distributed and provided in the both ends of the superconducting coil 20, the number of the connection parts 26 provided in each edge part does not need to be the same. As long as the spatial uniformity of the magnetic field formed by the superconducting coil 20 is within an allowable range, the number of connection portions 26 distributed to both ends of the superconducting coil 20 may be different.

  Further, the plurality of connecting portions 26, 26,... Are provided at different positions (shifted positions) in the circumferential direction so as not to overlap the radial direction of the superconducting coil 20 at each end of the superconducting coil 20. Specifically, for example, as shown in FIG. 5 and FIG. 6, when the connection portions 26 are provided in each layer, they do not overlap when viewed toward the center side in the radial direction, that is, the outer layer. There is a gap between the downstream end (the lower end in FIG. 5) in the current flow direction of the connecting portion 26 and the upstream end (the upper end in FIG. 5) of the inner layer connecting portion 26. Arranged to occur or match. Thereby, the site | part (connection part) 26 which generate | occur | produces at the time of electricity supply can be disperse | distributed to the circumferential direction, As a result, the disconnection of the superconducting wire 22 resulting from the said heat_generation | fever can be prevented. That is, since the connecting portion 26 generates heat during energization (during excitation) due to the electrical resistance of the solder 28, if the connecting portions 26 and 26 overlap in the radial direction as shown in FIG. Although it may be difficult to disconnect the part due to high temperature, the connection part 26 is provided at different positions in the circumferential direction so as not to overlap in the radial direction as described above. Therefore, disconnection due to the heat generation can be prevented.

  Moreover, since the thickness of the connection portion 26 in the superconducting wire 22 is more than twice the thickness of other portions, the plurality of connection portions 26, 26, ... are provided so as not to overlap in the radial direction. It can prevent that the shape of the said part (coil axial direction edge part of the superconducting coil 20) seeing in the coil axial direction is distorted. That is, when a plurality of connecting portions 26, 26,... Overlap in the radial direction, the diameter of the position becomes larger than the diameter of other positions in the circumferential direction, but it is specified by dispersing the connecting portions 26 in the circumferential direction. It is possible to prevent only the diameter of the material from becoming large.

  Next, a method for manufacturing the superconducting magnet 10 will be described with reference to FIGS. FIG. 8 is a diagram for explaining a process of forming the nth layer of the superconducting coil. FIG. 9 is a diagram for explaining a process of forming the (n + 1) th layer of the superconducting coil after the connection portion is formed. FIG. 10 is a diagram for explaining the dummy lines.

  A single unit wire 24 in the form of a tape is formed on the outer peripheral surface of the body 14 of the winding frame 12 from one end in the axial direction (left end in FIG. 8) to the other end (right end in FIG. 8). The first layer of the superconducting coil 20 is configured in this manner.

  When the unit wire 24 is wound up to the other end of the body portion 14, the remaining part of the unit wire 24 is cut. In addition, if the single unit wire 24 has a length capable of continuously forming a plurality of layers, the remaining unit wire is not cut even if the first layer has been wound. Two layers, a third layer,... May be formed continuously. That is, a plurality of layers (first layer, second layer, third layer,...) May be continuously formed by the single unit wire 24.

  Solder 28 is applied to the radially outer surface of the end portion of the unit wire rod 24 of the first layer (the right end portion in FIG. 8). The end portion of the unit wire rod 24 for constituting the second layer is overlapped on the portion where the solder 28 is applied, and is connected (soldered) by applying heat. Thereafter, the soldered portion is covered with an insulating coating (for example, covered with an insulating tape 30), whereby the unit wire 24 constituting the first layer and the unit wire 24 constituting the second layer are connected in series. The

  Subsequently, the single unit wire material 24 constituting the second layer is arranged on the radially outer side (upper side) of the first layer from the other end (right end in FIG. 9) to one end ( The second layer of the superconducting coil 20 is formed by winding it in a flat-wise solenoid shape toward the left end in FIG.

  When the second layer has been wound, the connection portion 26 is formed by connecting the end of the unit wire 24 constituting the first layer and the end of the unit wire 24 constituting the second layer to form a surplus. And the end of the unit wire 24 constituting the second layer and the end of the unit wire 24 constituting the third layer are connected.

  The unit wire material 24 constituting the connected third layer is arranged on the radially outer side (upper side) of the second layer from the one end in the axial direction (left end in FIG. 9) to the other end (in FIG. 9). The third layer of the superconducting coil 20 is formed by winding it in a flat-wise solenoid shape toward the right end).

  By repeating the above, the superconducting wire 22 (wire to which a plurality of unit wires 24, 24,... Are connected) is wound to form a plurality of solenoidal superconducting coils 20. At this time, for example, when the connection portion 26 is provided at the end of winding of the n-th layer, in the case where it overlaps with the connection portion 26 of the lower (radially inner side) layer (n-1th layer) in the radial direction, The unit wire 24 constituting the n-th layer is cut at a position before the connecting portion 26 of the lower layer in the winding direction, and at this position, the unit wire 24 that is cut (configures the n-th layer) is cut. The end and the end of the unit wire constituting the (n + 1) th layer are connected. In this case, between the end of the unit wire rod 24 constituting the nth layer (the cut position) and the end of winding of the nth layer, as shown in FIG. A dummy line 32 having a length corresponding to the distance from the n-layer winding end position is arranged. As a result, even if the connection portion 26 is formed before the n-th layer is wound, it is possible to prevent a gap from being formed inside the superconducting coil 20, and to prevent winding disturbance caused by the gap.

  The dummy wire 32 is a tape-like member having the same width and thickness as the unit wire 24. In this embodiment, for example, the same wire as the unit wire 24 constituting the superconducting coil 20 is cut to a predetermined length. It is used as.

  According to the superconducting magnet 10 manufactured as described above, the single layer constituting the inner layer (for example, the nth layer) at the end in the coil axial direction of the superconducting coil 20 in which the superconducting wire 22 is wound in multiple layers. By connecting the end portion of the unit wire rod 24 and the end portion of the single unit wire rod 24 constituting the outer layer (for example, the (n + 1) th layer) in an overlapping manner, the thickness of the connection portion 26 is increased. The resulting turbulence of the superconducting wire 22 can be suppressed. That is, when a connecting portion is provided in the middle portion in the coil axis direction, the superconducting wire constituting the outer layer (for example, the (n + 1) th layer) is formed by the difference in thickness between the connecting portion 26 and the other part of the superconducting wire 22. 22 is disturbed (see FIG. 12), but at the end of the superconducting coil 20 in the coil axial direction, the end of the unit wire 24 constituting the inner layer (for example, the nth layer) and the outer layer thereof By overlapping the end portions of the unit wire rods 24 (for example, the (n + 1) th layer) to form the connection portion 26 (see FIG. 13), the difference in thickness between the connection portion 26 and other parts is filled. Therefore, the turbulence of the superconducting wire 22 due to the thickness of the connecting portion 26 can be suppressed without inserting an insulating material or the like. As a result, according to the superconducting coil 20 (superconducting magnet 10 using the coil 20), a magnetic field with high spatial uniformity can be formed.

  The superconducting coil of the present invention, the superconducting magnet using this coil, and the method of manufacturing the superconducting coil are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Of course.

  In the above-described embodiment, the connection portion 26 is provided in each layer of the superconducting coil 20, but is not limited to this configuration, and may be provided in several layers. Even in this case, the plurality of connection portions 26, 26,... Are overlapped in the radial direction of the superconducting coil 20 in order to disperse the portions (connection portions) 26 that generate heat during energization in the circumferential direction and prevent disconnection due to the heat generation. It is preferable to be provided at different positions in the circumferential direction (displaced positions) that do not become necessary.

  Moreover, in the said embodiment, although the several connection part 26 is provided in the both ends of the coil axial direction in the superconducting coil 20, you may provide in only one edge part.

  The tape-like superconducting wire 22 of the above embodiment is formed of a Bi (bismuth) -based or Y (yttrium) -based oxide material (oxide superconducting conductor), but is formed of a metal-based superconducting conductor. May be.

DESCRIPTION OF SYMBOLS 10 Superconducting magnet 12 Reel 20 Superconducting coil 22 Superconducting wire 24 Unit wire 26 Connection part 28 Solder

Claims (5)

A superconducting coil in which a tape-like superconducting wire is wound in a multilayered manner like a solenoid with its thickness direction oriented in the radial direction of the spiral,
The superconducting wire is configured by connecting a plurality of tape-shaped unit wires in the longitudinal direction thereof,
Each layer of the coil is configured by winding a single unit wire in the solenoid shape,
The connecting portion of the superconducting wire to which the unit wires are connected is the end of the unit wire constituting the radially inner layer and the unit wire constituting the outer layer at the coil axial end of the coil. The superconducting coils are connected to each other in a state where the end portions thereof are overlapped with each other in the thickness direction. The superconducting coil according to claim 1,
The superconducting wire has a plurality of the connection portions, and at each connection portion, the end portions of the unit wire materials are connected to each other via solder, and the plurality of connection portions are ends on one side in the coil axis direction of the coil. Superconducting coils respectively provided at different positions in the circumferential direction of the coil so as not to overlap in the radial direction of the coil. The superconducting coil according to claim 2,
The plurality of connection portions are superconducting coils provided in a distributed manner at both ends of the coil in the coil axial direction. The superconducting coil according to any one of claims 1 to 3,
A superconducting magnet comprising: a winding frame around which the superconducting wire constituting the superconducting coil is wound. A method of manufacturing a superconducting coil in which a tape-shaped superconducting wire is wound in a solenoid shape in a state where its thickness direction is directed in the radial direction of the spiral,
Forming a predetermined layer of the superconducting coil by winding a single tape-shaped unit wire into the solenoid shape;
At the end in the coil axial direction of the superconducting coil, the end of the unit wire forming the predetermined layer is connected to the end of the tape-shaped unit wire constituting the radially outer layer in the thickness direction. A superconducting magnet manufacturing method comprising: forming the superconducting wire by overlapping and connecting, and forming the outer layer by winding the connected single unit wire on the predetermined layer. .

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