JP2020051917A - Inspection apparatus and inspection method for cylindrical superconductor - Google Patents

Abstract

To provide an inspection apparatus capable of inspecting soundness of superconducting state of a cylindrical superconductor.SOLUTION: The inspection apparatus comprises: a shield magnetic field detection sensor disposed facing a cylindrical circumferential surface of a superconducting cylindrical superconductor 7; an axis direction mobile unit moving the shield magnetic field detection sensor in an axis direction of the cylindrical superconductor; a rotation unit rotating the shield magnetic field detection sensor about a central axis of the cylindrical superconductor; and a magnet disposed in a position where its N-pole faces the cylindrical circumferential surface of the cylindrical superconductor across the shield magnetic field detection sensor, and movable along with the shield magnetic field detection sensor. The shield magnetic field detection sensor detects a shield magnetic field formed by shielding a magnetic field applied to the cylindrical superconductor from the magnet while moving along the cylindrical circumferential surface of the cylindrical superconductor by driving of the axis direction mobile unit and the rotation unit. This allows inspection of soundness of the superconducting state of the cylindrical superconductor in the cylindrical circumferential surface.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an inspection device and an inspection method for a cylindrical superconductor.

  Development of a small-sized NMR superconducting magnet using a superconducting bulk magnet in which a bulk superconductor is magnetized to capture a magnetic field has been advanced. For example, Patent Literature 1 discloses a superconducting magnet (magnetic field generator) in which a cylindrical inner superconductor is coaxially arranged inside a cylindrical outer superconductor. According to the superconducting magnet described in Patent Document 1, these superconductors are cooled to a superconducting critical temperature (Tc) or less while a uniform external magnetic field is applied in the direction of the central axis of the outer superconductor and the inner superconductor. , The applied magnetic field is set to zero. Thereby, the superconductor is magnetized, and a uniform magnetic field space is formed in the bore (inner space) of the outer superconductor. At this time, a superconducting current is induced in the cylindrical surface of the inner superconductor so as to compensate for the applied magnetic field distribution that the outer superconductor could not hold. That is, the inner superconductor is magnetized so as to compensate for the disturbance of the magnetic field formed by the outer superconductor. For this reason, a more uniform magnetic field is formed in the bore. By inserting a measurement sample and a measurement probe into the bore in which a uniform magnetic field is formed, and obtaining an NMR spectrum from a signal detected by the measurement probe, a structure analysis of the sample with relatively high accuracy can be performed.

  In the cylindrical inner superconductor described in Patent Literature 1, the superconducting current flows in the cylindrical peripheral surface as described above. For this reason, if the soundness of the superconducting state in the cylindrical peripheral surface is impaired due to a defect occurring in the cylindrical peripheral surface, a desired superconducting current cannot be formed in the cylindrical peripheral surface. Can occur. In this case, the disturbance of the magnetic field formed by the outer superconductor cannot be sufficiently compensated for by the inner superconductor. Therefore, it is preferable that the soundness of the superconducting state of the inner superconductor is good, and it is necessary to check in advance that the soundness of the superconducting state of the inner superconductor is good.

  However, conventionally, an inspection apparatus and an inspection method capable of inspecting the soundness of the superconducting state of such a cylindrical superconductor have not been developed. Non-Patent Document 1 describes a method for inspecting the magnetic field state of a superconducting wire, but does not mention an inspection device and an inspection method for a cylindrical superconductor. It is unclear how the method may be applied to cylindrical superconductors.

JP-A-2006-6826

Applied Physics Letters 90, 032506 (2007), "Assessment of the local supercurrent densities in long superconducting coated conductors", M. Zehetmayer, R. Fuger, M. Eistere, F. Hengstberger, and H. W. Weber

(Problems to be solved by the invention)
An object of the present invention is to provide an inspection apparatus and an inspection method capable of inspecting the soundness of a superconducting state of a cylindrical superconductor.

(Means for solving the problem)
According to the present invention, a shielded magnetic field detection sensor (53) arranged facing a cylindrical peripheral surface of a cylindrical superconductor (7) in a superconducting state, and the shielded magnetic field detection sensor are moved along the axial direction of the cylindrical superconductor. And a rotation unit (30) configured to rotate the shielded magnetic field detection sensor around the central axis of the cylindrical superconductor. It has two magnetic poles (N pole, S pole), and one magnetic pole is disposed at a position facing the cylindrical peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween, and is movably shielded together with the shielding magnetic field detection sensor. And a magnet (55) connected to the magnetic field detection sensor, wherein the shielded magnetic field detection sensor shields the magnetic field applied to the cylindrical superconductor from one of the magnetic poles of the magnet to the cylindrical peripheral surface of the cylindrical superconductor. By The superconducting state within the cylindrical surface of the cylindrical superconductor is detected by detecting the shielding magnetic field generated while moving along the cylindrical surface of the cylindrical superconductor by driving the axial moving unit and the rotating unit. Provided is an inspection device (1) for a cylindrical superconductor configured to be able to inspect the performance.

  When the cylindrical superconductor is cooled below its superconducting critical temperature Tc, the cylindrical superconductor is brought into a superconducting state. When a magnetic field is applied by bringing one magnetic pole of the magnet close to the cylindrical surface of the cylindrical superconductor in the superconducting state, the superconductive current (shielding current) is applied to the cylindrical surface of the cylindrical superconductor so that the magnetic field does not enter inside. ) Is induced. The shielding current shields the applied magnetic field from entering the cylindrical superconductor. By shielding the applied magnetic field in this manner, the magnetic field is removed from the space between the cylindrical superconductor and the magnet. For this reason, the magnetic field (shielding magnetic field) formed between the cylindrical superconductor and the magnet becomes weak. However, when a defect is present on the cylindrical peripheral surface of the cylindrical superconductor, a shielding current is not sufficiently induced at that portion, so that the applied magnetic field penetrates the cylindrical superconductor through the defective portion. When the applied magnetic field passes through the cylindrical superconductor in this manner, the shielding magnetic field becomes strong because the magnetic field enters between the cylindrical superconductor and the magnet. In addition, when there is a locally weak portion of the critical current density Jc, which is one of the superconducting characteristics of the superconductor, the shielding current is reduced, and the shielding magnetic field is thereby increased. Therefore, by detecting the shielding magnetic field along the cylindrical surface of the cylindrical superconductor, the soundness of the superconducting state within the cylindrical surface of the cylindrical superconductor (existence of defects, variation of critical current density, etc.) is inspected. can do.

  According to the present invention, the shielding magnetic field detection sensor is arranged facing the cylindrical peripheral surface of the cylindrical superconductor, and one magnetic pole faces the cylindrical peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween. , A magnet is arranged. For this reason, the shielding magnetic field detection sensor detects a shielding magnetic field formed when the applied magnetic field from the magnet is shielded by the cylindrical peripheral surface of the cylindrical superconductor. In the inspection device according to the present invention, the shielding magnetic field detection sensor detects the shielding magnetic field while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the axial moving unit and the rotating unit. Therefore, the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor can be inspected.

  In the present invention, the inspection of the soundness of the superconducting state is used in the sense of inspecting whether or not the cylindrical superconductor can uniformly form a shielding current (superconducting current) in the peripheral surface of the cylinder. . The soundness of the superconducting state is evaluated by the shielding magnetic field detected by the shielding magnetic field sensor along the cylindrical peripheral surface of the cylindrical superconductor or the uniformity of a transmitted magnetic field described later. It is represented by the magnitude of the magnetic field or the presence or absence of a change in the magnitude of the transmitted magnetic field. Specifically, if the region where the shielding magnetic field (or transmission magnetic field) is weak continues, it can be determined that the superconducting state is sound (that is, the shielding current can be formed uniformly), and the shielding magnetic field (or transmission magnetic field) is strong. If there is a region, it can be determined that the superconducting state is unhealthy (that is, the shielding current cannot be formed uniformly) due to the presence of a defect or a decrease in the critical current density. Therefore, when the shielding magnetic field (transmission magnetic field) is uniformly weak (small) along the cylindrical peripheral surface of the cylindrical superconductor, it can be evaluated that the superconducting state of the cylindrical superconductor is uniformly sound. Further, when there is a region where the shielding magnetic field (transmission magnetic field) is locally strong (large), by specifying the locally strong region, the difference due to the presence / absence and position of the defect or the position of the critical current density Jc is determined. Can be detected.

  Further, according to the present invention, in order to detect a magnetic field (shielding magnetic field) weakened by the shielding current of the cylindrical superconductor, the soundness of the superconducting state of the surface of the cylindrical peripheral surface mainly facing the magnet is effectively inspected. can do.

  The area of the area where the shielding magnetic field detection sensor (specifically, the magnetic sensing part of the shielding magnetic field detection sensor) faces the cylindrical peripheral surface of the cylindrical superconductor is defined by the cylindrical superconductor cylinder with the magnet sandwiching the shielding magnetic field detection sensor. It is preferably smaller than the area of the region facing the peripheral surface. According to this, the shielding magnetic field region detected by the shielding magnetic field detection sensor is reduced, so that the inspection accuracy can be improved.

  As an example, the magnet and the shield magnetic field detection sensor are disposed in the inner peripheral space of the cylindrical superconductor as shown in a fourth embodiment described later. In this case, the shielding magnetic field detection sensor is disposed on the inner peripheral surface of the cylindrical superconductor, and the magnet is disposed at a position where one magnetic pole faces the inner peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween. You. With this configuration, it is possible to inspect the soundness of the superconducting state mainly on the inner peripheral surface of the cylindrical superconductor. In addition, since the shielding magnetic field detection sensor and the magnet are provided in the inner peripheral space of the cylindrical superconductor, the inspection device can be made compact. For this reason, for example, when inspecting the soundness of the cylindrical superconductor incorporated in the superconducting magnet for NMR, the inspection can be performed with the cylindrical superconductor incorporated in the superconducting magnet.

  When the shielding magnetic field detection sensor is provided in the inner peripheral space of the cylindrical superconductor, the shielding magnetic field detection sensor includes a first sensor (43A) and a second sensor (43) as described in a seventh embodiment described later. 43B). In this case, the magnet is arranged such that one magnetic pole (for example, N pole) faces the inner peripheral surface of the cylindrical superconductor with the first sensor interposed therebetween, and the other magnetic pole (for example, S pole) of the magnet sandwiches the second sensor. It is preferable to be disposed at a position facing the inner peripheral surface of the cylindrical superconductor. Then, the first sensor detects a shielding magnetic field formed by the magnetic field applied to the cylindrical superconductor from one magnetic pole being shielded by the cylindrical peripheral surface of the cylindrical superconductor, and the second sensor detects the shielding magnetic field formed by the other sensor. The magnetic field applied from the magnetic pole to the cylindrical superconductor is preferably shielded by the peripheral surface of the cylindrical superconductor to detect a shield magnetic field. Further, it is preferable that the first sensor and the second sensor are arranged at positions different by 180 ° in the circumferential direction of the cylindrical superconductor. According to this, since two locations on the inner peripheral surface of the cylindrical superconductor can be inspected at the same time, the inspection time can be reduced.

  Further, as another example, the magnet and the shielding magnetic field detection sensor may be provided in the outer peripheral space of the cylindrical superconductor as shown in a first embodiment described later. In this case, the shielding magnetic field detection sensor is disposed facing the outer peripheral surface of the cylindrical superconductor, and the magnet is disposed at a position where one magnetic pole is disposed facing the outer peripheral surface of the cylindrical superconductor with the shielding magnetic field detecting sensor interposed therebetween. You. According to this, it is possible to inspect the soundness of the superconducting state mainly on the outer peripheral surface of the cylindrical superconductor.

  Further, the present invention provides a transmission magnetic field detection sensor (43) disposed on the cylindrical peripheral surface of a cylindrical superconductor (7) in a superconducting state, and a transmission magnetic field detection sensor along the axial direction of the cylindrical superconductor. An axial moving unit (20) configured to be movable, and a rotating unit (30) configured to rotate the transmitted magnetic field detection sensor around a central axis of the cylindrical superconductor; It has two different magnetic poles (N-pole, S-pole), one of which is disposed at a position facing the transmitted magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor, and can move together with the transmitted magnetic field detection sensor And a magnet (55) connected to the transmission magnetic field detection sensor, wherein the transmission magnetic field detection sensor transmits a magnetic field applied to the cylindrical superconductor from one of the magnetic poles of the magnet through the cylindrical peripheral surface of the cylindrical superconductor. To do By detecting the transmitted magnetic field formed along the cylindrical surface of the cylindrical superconductor by driving the axially moving unit and the rotation unit, the superconducting state in the cylindrical surface of the cylindrical superconductor is detected. Provided is a cylindrical superconductor inspection device (1) configured to be able to inspect soundness.

  As described above, when a magnetic field is applied by bringing one magnetic pole of the magnet close to the cylindrical peripheral surface of the cylindrical superconductor in the superconducting state, the applied magnetic field is shielded by the cylindrical peripheral surface of the cylindrical superconductor by the shielding current. . However, as the applied magnetic field is increased, part of the applied magnetic field passes through the cylindrical peripheral surface of the cylindrical superconductor. However, the magnetic field formed by the transmission (transmission magnetic field) is weak when the superconducting state of the cylindrical superconductor is sound. However, when a defect is present on the cylindrical peripheral surface of the cylindrical superconductor, a shielding current is not sufficiently induced at that portion, so that the applied magnetic field penetrates the cylindrical superconductor through the defective portion. When the applied magnetic field passes through the cylindrical superconductor in this way, the transmitted magnetic field becomes strong. In addition, if there is a portion where the critical current density Jc, which is one of the superconducting characteristics of the superconductor, is locally weak, the shielding current is reduced, and the transmitted magnetic field is also increased. Therefore, by detecting the transmitted magnetic field along the cylindrical peripheral surface of the cylindrical superconductor, the soundness of the superconducting state within the cylindrical peripheral surface of the cylindrical superconductor (existence of defects, variation of the critical current density Jc, etc.) is improved. Can be inspected.

  According to the present invention, the transmitted magnetic field detection sensor is disposed facing the cylindrical peripheral surface of the cylindrical superconductor, and one magnetic pole faces the transmitted magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor. A magnet is provided at the location. That is, the transmitted magnetic field detection sensor and the magnet are arranged facing each other with the cylindrical peripheral surface of the cylindrical superconductor sandwiched therebetween. For this reason, the transmitted magnetic field detection sensor detects a transmitted magnetic field formed when the applied magnetic field from the magnet passes through the cylindrical peripheral surface of the cylindrical superconductor. In the inspection apparatus according to the present invention, the transmitted magnetic field detection sensor detects the transmitted magnetic field while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the axial moving unit and the rotating unit. Therefore, the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor can be inspected. Further, by detecting a magnetic field that passes through the cylindrical peripheral surface of the cylindrical superconductor, it is possible to inspect the soundness of the superconducting state over the entire cylindrical superconductor in the thickness direction.

  The area of the area where the transmitted magnetic field detection sensor (specifically, the magnetic sensing part of the transmitted magnetic field detection sensor) faces the cylindrical peripheral surface of the cylindrical superconductor is the area of the area where the magnet faces the cylindrical peripheral surface of the cylindrical superconductor. It is preferably smaller than the area. According to this, the inspection accuracy can be improved by reducing the transmission magnetic field area detected by the transmission magnetic field detection sensor.

  As an example, the transmitted magnetic field detection sensor is disposed in the inner peripheral space of the cylindrical superconductor as shown in a first embodiment described later. In this case, the transmission magnetic field detection sensor is disposed facing the inner peripheral surface of the cylindrical superconductor, and the magnet has a cylindrical shape such that one magnetic pole faces the transmission magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor. It is arranged facing the outer peripheral surface of the superconductor. With this configuration, it is possible to inspect the soundness of the superconducting state mainly on the inner peripheral surface of the cylindrical superconductor.

  As another example, the transmitted magnetic field detection sensor may be provided in the outer peripheral space of the cylindrical superconductor as shown in a modified example 2 described later. In this case, the transmission magnetic field detection sensor is disposed facing the outer peripheral surface of the cylindrical superconductor, and the magnet is arranged so that one magnetic pole faces the transmission magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor. It is arranged facing the inner peripheral surface of the body. According to this, it is possible to inspect the soundness of the superconducting state mainly on the outer peripheral surface of the cylindrical superconductor.

  Further, a yoke (46) may be provided on the back surface of the transmitted magnetic field detection sensor. According to this, since the transmitted magnetic field is concentrated on the yoke, the detection sensitivity of the transmitted magnetic field detection sensor is improved.

  In addition, the inspection device of the present invention is disposed between the magnet and the cylindrical superconductor in addition to the transmitted magnetic field detection sensor, and is disposed to face the transmitted magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor. And a shielding magnetic field detection sensor (53) configured to be movable together with the transmitted magnetic field detection sensor by driving the axial movement unit and the rotation unit. Then, the shielded magnetic field detection sensor, the shield magnetic field formed by the magnetic field applied to the cylindrical superconductor from one magnetic pole of the magnet is shielded on the cylindrical peripheral surface of the cylindrical superconductor, the axial moving unit and The soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor may be inspected by detecting while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the rotating unit. According to this, the transmission magnetic field and the shielding magnetic field can be detected simultaneously, and the inspection accuracy is further improved.

  Further, the magnet used in the inspection device according to the present invention may be a permanent magnet. By using a permanent magnet, an applied magnetic field can be formed without requiring additional equipment such as a power supply. For this reason, the structure of the inspection device can be simplified.

  Further, the magnet used in the inspection device according to the present invention may be a coil or an electromagnet. By using a coil or an electromagnet, the magnitude and direction of a current applied to the cylindrical superconductor can be changed by changing the magnitude and direction of a current flowing through the coil or the electromagnet. Therefore, it is possible to adjust the applied magnetic field and set the optimum inspection conditions.

  Further, the cylindrical superconductor is formed in a cylindrical shape by a cylindrical base material (71) formed in a cylindrical shape and a superconducting wire spirally wound on the inner or outer peripheral surface of the cylindrical base material. And a superconducting layer (72, 73). In this case, the axial movement unit and the rotation unit are controlled such that the shielded magnetic field detection sensor and / or the transmitted magnetic field detection sensor move on the cylindrical peripheral surface of the cylindrical superconductor along the spiral winding direction of the superconducting wire. Good.

  In order to inspect the soundness of the superconducting state of the cylindrical peripheral surface of the cylindrical superconductor in which the superconducting wire is spirally wound, for example, first, the axial moving unit is driven to inspect the cylindrical superconductor along the axial direction. Then, the rotation unit is driven to rotate the inspection area by a predetermined angle. Then, the cylindrical superconductor is inspected along the axial direction by driving the axial moving unit. By repeating this, the inspection can be performed over the entire cylindrical peripheral surface. However, in this case, in order to specify the position of the unhealthy part, it may be necessary to map the result of inspection along the axial direction at each rotation angle. On the other hand, by inspecting the cylindrical superconductor along the spiral winding direction as in the present invention, the rotation angle and the axial position continuously change, so that the superconducting state of the superconducting state can be monitored in real time without mapping. Sex and unhealthy parts can be specified.

  Further, the present invention has a shielded magnetic field detection sensor (53) arranged facing the cylindrical peripheral surface of the cylindrical superconductor (7) in a superconducting state, and two different magnetic poles (N pole, S pole). A sweeping step of sweeping a magnet (55) having a magnetic pole disposed at a position facing the cylindrical peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween, in the axial direction and the circumferential direction of the cylindrical superconductor; The shielding magnetic field detection sensor sweeps a shielding magnetic field formed by a magnetic field applied to the cylindrical superconductor from one of the magnetic poles of the magnet being shielded by the cylindrical peripheral surface of the cylindrical superconductor in a sweeping process. And a shielding magnetic field detecting step of detecting.

  According to the inspection method of the present invention, the shielding magnetic field detection sensor detects the shielding magnetic field while being swept along the cylindrical peripheral surface of the cylindrical superconductor. Therefore, the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor can be inspected.

  Further, the present invention has a transmission magnetic field detection sensor (43) disposed facing the cylindrical peripheral surface of a cylindrical superconductor (7) in a superconducting state, and two different magnetic poles (N pole and S pole). A sweeping step of sweeping a magnet (55) whose magnetic pole is disposed at a position facing the transmitted magnetic field detection sensor across the cylindrical peripheral surface of the cylindrical superconductor, in an axial direction and a circumferential direction of the cylindrical superconductor; The transmitted magnetic field detection sensor detects the transmitted magnetic field formed by the magnetic field applied to the cylindrical superconductor from one magnetic pole of the magnet passing through the cylindrical peripheral surface of the cylindrical superconductor while being swept in the sweep process A method for detecting a cylindrical superconductor, comprising:

  According to the inspection method of the present invention, the transmitted magnetic field detection sensor detects the transmitted magnetic field while being swept along the cylindrical peripheral surface of the cylindrical superconductor. Therefore, the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor can be inspected.

  In the above-described inspection method, the cylindrical superconductor is formed by spirally winding a superconducting wire on a cylindrical base material (71) and an inner or outer peripheral surface of the cylindrical base material. And a superconducting layer (72, 73) formed in a shape. In this case, in the sweeping step, the shielding magnetic field detection sensor and / or the transmitted magnetic field detection sensor may be swept so as to move on the cylindrical peripheral surface of the cylindrical superconductor along the spiral winding direction of the superconducting wire. . According to this, the soundness of the superconducting state of the cylindrical superconductor and the unhealthy part can be specified in real time.

FIG. 1 is a schematic partial cross-sectional view showing a cylindrical superconductor inspection apparatus according to the first embodiment. FIG. 2 is a schematic cross-sectional view showing a connection configuration of the rotation unit, the inner inspection unit, and the outer inspection unit. FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 4 is a schematic perspective view of the cylindrical superconductor. FIG. 5 is a schematic sectional view of the cylindrical superconductor cut along a plane including the axial center thereof. FIG. 6 is a view separately showing the spirally wound inner superconducting layer and outer superconducting layer. FIG. 7 is a schematic sectional view of a container having a cylindrical superconductor disposed therein. FIG. 8 is a diagram showing an arrangement relationship between the cylindrical superconductor in the container and the inspection device at the start of the inspection. FIG. 9 is a schematic diagram showing the arrangement of the inner Hall element, the outer Hall element, and the outer permanent magnet with respect to the cylindrical superconductor. FIG. 10 is a conceptual diagram showing a magnetic field detected by the outer Hall element. FIG. 11 is a conceptual diagram showing a magnetic field detected by the inner Hall element. FIG. 12 is a diagram conceptually showing the relationship between the shielding magnetic field detected by the outer Hall element and the presence or absence of a defect in the cylindrical superconductor. FIG. 13 is a diagram conceptually showing the relationship between the transmitted magnetic field detected by the inner Hall element and the presence or absence of a defect in the cylindrical superconductor. FIG. 14A shows a cylindrical superconductor having an inner superconducting layer and an outer superconducting layer with intentionally formed defects. FIG. 14B is a diagram showing a state in which a superconducting wire constituting the inner superconducting layer and a superconducting wire constituting the outer superconducting layer are respectively developed. FIG. 15 is a developed view of a cylindrical body in which an inner superconducting layer and an outer superconducting layer are overlapped. FIG. 16 is a diagram showing a measurement result of the shielding magnetic field detected by the outer Hall element. FIG. 17 is a diagram showing a measurement result of a transmission magnetic field detected by the inner Hall element. FIG. 18 is a diagram showing the measurement result of the shielding magnetic field shown in FIG. 16 mapped to a developed view of the cylindrical superconductor. FIG. 19 is a diagram showing the measurement result of the transmission magnetic field shown in FIG. 17 mapped to a developed view of the cylindrical superconductor. FIG. 20 is a graph showing the relationship between the rotation angle and the strength of the magnetic field when the position of the cylindrical peripheral surface of the cylindrical superconductor formed by spirally winding the superconducting wire is represented by the rotation angle. FIG. 21 is a schematic cross-sectional view illustrating a connection configuration of a rotation unit, an inner inspection unit, and an outer inspection unit of the inspection device according to the second modification. FIG. 22 is a diagram illustrating an arrangement relationship between an inspection device and a cylindrical superconductor when inspecting a cylindrical superconductor set in a container using the inspection device according to the second modification. FIG. 23 is a schematic diagram showing an example of sweeping an outer Hall element having two Hall elements in a spiral direction according to the second embodiment. FIG. 24 is a diagram showing an arrangement relationship between the outer Hall element and the inner and outer superconducting layers of the cylindrical superconductor. FIG. 25 is a diagram illustrating a state in which the cylindrical superconductor cooled by the refrigerator is inspected by the inspection device according to the third embodiment. FIG. 26 is a schematic diagram illustrating an arrangement relationship among a refrigerator, a cylindrical superconductor, an inner Hall element, an outer Hall element, and an outer permanent magnet. FIG. 27 is a diagram illustrating a state where the cylindrical superconductor incorporated in the superconducting magnet of the NMR apparatus is inspected by the inspection apparatus according to the fourth embodiment. FIG. 28 is a diagram showing a superconducting magnet in which a cylindrical superconductor is incorporated. FIG. 29 is a diagram illustrating an example of inspection using the inspection device according to the fifth embodiment. FIG. 30 is a diagram illustrating an example of inspection using the inspection device according to the sixth embodiment. FIG. 31 is a diagram illustrating an example of inspection using the inspection device according to the seventh embodiment. FIG. 32 is a diagram illustrating an example of an inspection using the inspection device according to the eighth embodiment. FIG. 33 is a diagram illustrating an example of an inspection using the inspection device according to the ninth embodiment.

(1st Embodiment)
Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a schematic partial sectional view showing an inspection device (hereinafter simply referred to as an inspection device) 1 for a cylindrical superconductor according to a first embodiment. As shown in FIG. 1, the inspection device 1 includes a manual lifting / lowering operation unit 10, an axial movement unit 20, a rotation unit 30, an inner inspection unit 40, an outer inspection unit 50, and a controller (not shown).

  The manual lifting operation unit 10 includes a support guide 11, an upper plate 12, a ball screw rod 13, a ball nut 14, and a manual handle 15, and is mounted on a base plate P made of, for example, aluminum.

  The support guide 11 is a long plate-shaped member whose lower end is fixed to the base plate P and extends upward from the base plate P. An upper plate 12 is fixed to an upper end of the support guide 11. The upper plate 12 has a fixed portion 12a fixed to the support guide 11, and an extended portion 12b extending from the fixed portion 12a to the left in FIG. The upper end portion of the ball screw rod 13 is rotatably supported by the extending portion 12b of the upper plate 12. The ball screw rod 13 extends vertically downward from the upper plate 12. The lower end of the ball screw rod 13 is rotatably supported by a bearing member (not shown) provided on the base plate P.

  A male screw is formed on the outer periphery of the ball screw rod 13. Then, the ball nut 14 is attached to the outer periphery of the ball screw rod 13 so as to be screwed around a male screw formed on the outer periphery of the ball screw rod 13 so as not to rotate around the axis.

  A manual handle 15 is provided above the upper plate 12. The manual handle 15 is connected to the upper end of the ball screw rod 13 through the upper plate 12. The manual handle 15 is rotatable about a vertical axis, and is configured such that the ball screw rod 13 can rotate about the axis by rotating. When the ball screw rod 13 rotates around the axis, the ball nut 14 screwed to the ball screw rod 13 moves up and down.

  The axial movement unit 20 includes a joint block 21, a support case 22, a first electric motor 23, a ball screw rod 24, and an axial movement stage 25.

  The joint block 21 is connected to the ball nut 14 of the manual lifting operation unit 10. A support case 22 is connected to the joint block 21. The support case 22 has a lower plate 221 and a support rod 222. The support rod 222 extends in the vertical direction as shown in FIG. 1, and is connected to the joint block 21 at a lower portion thereof. The lower plate 221 is fixed to the lower end of the support rod 222. The lower plate 221 has a fixed portion 221a for fixing the support rod 222, and an extended portion 221b extending from the fixed portion 221a to the left in FIG.

  The first electric motor 23 is fixed to the upper end of the support rod 222. The first electric motor 23 is supported by the support rod 222 such that its output shaft faces downward. The upper end of a ball screw rod 24 is coaxially connected to the output shaft of the first electric motor 23. Therefore, when the first electric motor 23 is driven, the ball screw rod 24 rotates around the axis. The lower end of the ball screw rod 24 is rotatably supported by the extending portion 221b of the lower plate 221. The driving of the first electric motor 23 is controlled by the controller.

  A male screw is formed on the outer periphery of the ball screw rod 24. Further, an axial movement stage 25 is attached to the outer periphery of the ball screw rod 24 so as not to rotate around the axis. The axial movement stage 25 has a through hole through which the ball screw rod 24 penetrates. In this through hole, a female screw to be screwed with a male screw formed on the outer periphery of the ball screw rod 24 is formed. Therefore, when the ball screw rod 24 is rotated by the driving of the first electric motor 23, the axial movement stage 25 moves up and down along the axial direction of the ball screw rod 24, that is, the vertical direction.

  The rotation unit 30 has a case 31, a second electric motor 32, and a rotation stage 33. The case 31 is formed in a rectangular parallelepiped shape having a space inside, and its upper wall is connected to the axial movement stage 25 of the axial movement unit 20 via an L-shaped bracket 34. Further, a second electric motor 32 is provided in the case 31.

  A disk-shaped rotary stage 33 is embedded in the lower wall of the case 31. The rotary stage 33 is attached to the case 31 so as to be rotatable around a vertical axis via a bearing member such as a bearing. The rotary stage 33 is connected to the output shaft of the second electric motor 32 in the case 31 so as to be coaxially rotatable. Therefore, when the second electric motor 32 is driven, the rotary stage 33 rotates around the vertical axis. The driving of the second electric motor 32 is controlled by the controller.

  The inner inspection unit 40 is connected to the rotating unit 30, and the outer inspection unit 50 is connected to the inner inspection unit 40. FIG. 2 is a schematic cross-sectional view showing a connection configuration of the rotation unit 30, the inner inspection unit 40, and the outer inspection unit 50. As shown in FIG. 2, the inner inspection unit 40 has an inner rod portion 41, an inner inspection plate 42, an inner Hall element 43, and an inner spacer 44.

  The inner rod portion 41 is a columnar member that is long in the vertical direction. The inner rod portion 41 has a head portion 41a having an enlarged diameter and an upper end portion, and a main body portion 41b extending downward from the head portion 41a in FIG. An engagement member 35 is connected to a portion of the lower surface of the rotation stage 33 of the rotation unit 30 near the outer periphery by a bolt. The engagement member 35 includes a cylindrical body 35a extending downward from a portion near the outer periphery of the disk-shaped rotary stage 33, and a flange 35b extending radially inward from a lower end of the body 35a. Have. Then, the lower surface of the head portion 41a of the inner rod portion 41 is engaged with the upper surface of the flange portion 35b of the engaging member 35. In this state, the head 41a of the inner rod portion 41 is sandwiched between the rotating stage 33 and the engaging member 35 by fastening the engaging member 35 to the rotating stage 33 with the bolt. The inner rod portion 41 is fixed to the rotating unit 30 by such holding. In this fixed state, the central axis of the rotary stage 33 coincides with the central axis in the longitudinal direction of the main body 41b of the inner rod 41. Therefore, when the rotation stage 33 rotates, the inner rod portion 41 rotates around the axis integrally therewith.

  Further, as can be seen from FIG. 2, a connection notched surface 41c which is cut inward in a radial direction is formed in a part of the upper portion of the main body 41b of the inner rod portion 41. Further, an inner notch surface 41d cut inward in a radial direction is formed in a lower portion of the main body portion 41b of the inner rod portion 41. The formation position of the connection notch surface 41c and the formation position of the inner notch surface 41d in the circumferential direction of the main body portion 41b of the inner rod portion 41 substantially coincide with each other.

  The inner inspection plate 42 is disposed on the inner notch surface 41d of the inner rod portion 41 so as to contact the surface. Then, the inner inspection plate 42 is fixed to the lower cutout surface 41d by bolts. The inner inspection plate 42 is disposed so as to protrude further downward from the lower end of the main body portion 41b of the inner rod portion 41 while being fixed to the inner notch surface 41d. Further, the inner inspection plate 42 has a mounting surface 42a facing outward in a radial direction of the main body portion 41b of the inner rod portion 41 in a fixed state, and an inner spacer 44 formed of an insulating material is provided on the mounting surface 42a. The inner Hall element 43 is attached through the intermediary. The inner Hall element 43 functions as a magnetic field sensor that detects a magnetic field formed by a magnetic flux passing therethrough. As can be seen from FIG. 2, the inner spacer 44 and the inner Hall element 43 are attached to a lower portion of the inner test plate 42.

  The outer inspection unit 50 has an outer rod portion 51, an outer inspection plate 52, an outer Hall element 53, an outer spacer 54, and an outer permanent magnet 55.

  The outer rod portion 51 is also formed to be long in the vertical direction similarly to the inner rod portion 41, and has a rectangular cross section cut in the horizontal direction. The outer rod portion 51 has a head portion 51a forming the upper end portion thereof, and a main body portion 51b extending downward from FIG. 2 from the head portion 51a. The head 51a is formed so as to protrude leftward in FIG. 2 from the main body 51b. Then, the outer rod portion 51 is in contact with the inner rod portion 41 such that the left end surface of the head portion 51a is in contact with the connection notch surface 41c formed in the upper portion of the main body portion 41b of the inner rod portion 41. Is arranged. Then, the head portion 51a is fixed to the connection notch surface 41c of the inner rod portion 41 via a fastening member such as a bolt. In a state where the head 51a is fixed to the notch 41c for connection, the main body 51b of the outer rod portion 51 is arranged in parallel with the main body portion 41b of the inner rod portion 41 with a certain gap. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2 and shows a connection state between the main body 41 b of the inner rod 41 and the head 51 a of the outer rod 51.

  Further, an outer cutout surface 51c is formed in a portion of the lower portion of the main body portion 51b of the outer rod portion 51 facing the inner cutout surface 41d formed in the main body portion 41b of the inner rod portion 41. The outer inspection plate 52 is disposed on the outer notch surface 51c so as to contact the surface. Then, the outer inspection plate 52 is fixed to the outer notch surface 51c by the bolt. The outer inspection plate 52 is disposed so as to protrude further downward from the lower end of the main body portion 51b of the outer rod portion 51 while being fixed to the outer notch surface 51c. Further, the outer inspection plate 52 has a mounting surface 52a facing a mounting surface 42a of the inner inspection plate 42 fixedly attached to the inner rod portion 41 with a predetermined gap therebetween. Then, an outer Hall element 53 is attached via an outer spacer 54 formed of an insulating material. The outer Hall element 53 functions as a magnetic field sensor that detects a magnetic field formed by a magnetic flux passing therethrough. As can be seen from FIG. 2, the outer spacer 54 and the outer Hall element 53 are attached to a lower portion of the outer test plate 52.

  An outer permanent magnet 55 is embedded at a position below the outer inspection plate 52 and facing the outer Hall element 53 via the outer spacer 54. In the present embodiment, a neodymium magnet (NdFeB magnet) is used as the outer permanent magnet 55. The outer permanent magnet 55 has two different magnetic poles (N-pole and S-pole), and is embedded in the outer inspection plate 52 such that the N-pole faces the outer Hall element 53 with the outer spacer 54 interposed therebetween. .

  As can be seen from FIG. 2, the inner inspection plate 42 and the outer inspection plate 52 are arranged so as to face each other. The inner Hall element 43 attached to the inner inspection plate 42 faces the outer Hall element 53 attached to the outer inspection plate 52. The main body 41b of the inner rod 41 and the components attached thereto (the inner inspection plate 42, the inner Hall element 43, and the inner spacer 44) are disposed in the inner peripheral space of the cylindrical superconductor to be inspected. Dimensioned so that you can When the main body 41b of the inner rod 41 and the components attached thereto are disposed in the inner peripheral space of the cylindrical superconductor, the main body 51b of the outer rod 51 and the main body 51b are attached thereto. These components are dimensioned such that the components (the outer inspection plate 52, the outer Hall element 53, the outer spacer 54, and the outer permanent magnet 55) are disposed on the outer peripheral side of the cylindrical superconductor. That is, when the main body portion 41b of the inner rod portion 41 and the components attached thereto are disposed in the inner peripheral space of the cylindrical superconductor, the main body portion 41b of the inner rod portion 41 and the main body portion 51b of the outer rod portion 51 are The inner inspection unit 40 and the outer inspection unit 50 are configured such that the cylindrical peripheral surface of the cylindrical superconductor is sandwiched in the gap.

  As well shown in FIGS. 2 and 3, a plurality of grooves 41 e that are recessed radially inward are formed on the outer periphery of the main body 41 b of the inner rod 41 along the axial direction. In the present embodiment, four grooves 41 e are formed at equal intervals along the circumferential direction on the outer periphery of the main body 41 b of the inner rod 41. A signal line having one end connected to the inner Hall element 43 is routed in the groove 41e. As shown in FIG. 2, the signal line having one end connected to the outer Hall element 53 is connected to the surface of the main body 51b of the outer rod 51 (specifically, the surface facing the main body 41b of the inner rod 41). ) Will be arranged on. The other ends of these signal lines are electrically connected to a controller (not shown).

  In the inspection apparatus 1 having the above configuration, when the axial movement unit 20 (the first electric motor 23) is driven, the rotation unit 30, the inner inspection unit 40, and the outer inspection unit 50 move integrally in the vertical direction. That is, the inner Hall element 43 included in the inner inspection unit 40, and the outer Hall element 53 and the outer permanent magnet 55 included in the outer inspection unit 50 are connected so as to move integrally by driving the axial movement unit 20. Will be. When the rotation unit 30 (second electric motor 32) is driven, the inner inspection unit 40 and the outer inspection unit 50 integrally rotate around the central axis of the main body 41b of the inner rod 41. That is, the inner Hall element 43 included in the inner inspection unit 40, and the outer Hall element 53 and the outer permanent magnet 55 included in the outer inspection unit 50 are connected so as to be integrally rotated by driving the rotation unit 30. Will be.

  Next, the cylindrical superconductor to be inspected will be described. FIG. 4 is a schematic perspective view of the cylindrical superconductor 7. FIG. 5 is a schematic cross-sectional view of the cylindrical superconductor 7 cut along a plane including the central axis. As shown in FIGS. 4 and 5, the cylindrical superconductor 7 has a cylindrical base material 71, an inner superconducting layer 72, and an outer superconducting layer 73.

  The cylindrical substrate 71 is formed in a cylindrical shape by, for example, copper or the like. An inner superconducting layer 72 is formed on the outer peripheral surface of the cylindrical base material 71. The inner superconducting layer 72 is formed in a cylindrical shape by spirally winding an elongated superconducting wire (superconducting tape) around the outer peripheral surface of the cylindrical base material 71. An outer superconducting layer 73 is formed on the outer periphery of an inner superconducting layer 72 formed into a cylindrical shape by spirally winding a superconducting wire. Similarly to the inner superconducting layer 72, the outer superconducting layer 73 is formed in a cylindrical shape by spirally winding an elongated superconducting wire (superconducting tape) around the outer peripheral surface of the cylindrical inner superconducting layer 72. That is, the cylindrical superconductor 7 is formed by laminating a cylindrical superconductor made of two layers of superconducting wires on the outer periphery of the cylindrical base material 71.

  FIGS. 6A and 6B are diagrams showing the spirally wound inner superconducting layer 72 and the outer superconducting layer 73 separately. FIG. 6A shows the inner superconducting layer 72, and FIG. 6B shows the outer superconducting layer 73. Is shown. As can be seen from FIG. 6 (a), the inner superconducting layer 72 is formed in a cylindrical shape by spirally winding the superconducting wire, and the side edges of the superconducting wires adjacent in the axial direction are brought into contact with no gap. Therefore, a boundary line (hereinafter referred to as a spiral boundary) B1 between adjacent side edges of the spirally wound superconducting wire is formed in a spiral shape. Further, as can be seen from FIG. 6B, the outer superconducting layer 73 is also formed in a cylindrical shape by spirally winding the superconducting wire, and the side edges of the superconducting wires adjacent in the axial direction are brought into contact with no gap. For this reason, a boundary line (hereinafter referred to as a spiral boundary) B2 between adjacent side edges of the spirally wound superconducting wire is formed in a spiral shape.

  As can be seen by comparing FIGS. 6A and 6B, the position of the spiral boundary B1 formed in the inner superconducting layer 72 and the position of the spiral boundary B2 formed in the outer superconducting layer 73 are determined. The formation position is shifted in the axial direction, specifically, so that the spiral boundary B1 and the spiral boundary B2 are farthest in the axial direction. In other words, the spiral boundary B1 and the spiral boundary B2 are １ ／ in the axial direction. Both are formed so as to be shifted in pitch. Therefore, in a state where the outer superconducting layer 73 is laminated on the inner superconducting layer 72, the spiral boundary B1 in the inner superconducting layer 72 is located at the center position in the width direction of the superconducting wire constituting the outer superconducting layer 73. In other words, the spiral boundary B2 of the outer superconducting layer 73 is located at the center position in the width direction of the superconducting wire constituting the inner superconducting layer 72.

  The reason why the spiral boundary B1 of the inner superconducting layer 72 and the spiral boundary B2 of the outer superconducting layer 73 are shifted in the axial direction is as follows. This cylindrical superconductor 7 is used as an inner superconductor disclosed in Patent Document 1. In this case, the cylindrical superconductor 7 is configured such that a superconducting current loop (shielding current) can be formed along the circumferential direction. Here, a superconducting current loop cannot be formed across the spiral boundary B1 of the inner superconducting layer 72 and the spiral boundary B2 of the outer superconducting layer 73. Therefore, when the spiral boundary B1 of the inner superconducting layer 72 matches the spiral boundary B2 of the outer superconducting layer 73, a desired superconducting current loop to be formed across these spiral boundaries B1 and B2 is formed. Can not do. In this regard, if the helical boundary B1 of the inner superconducting layer 72 and the helical boundary B2 of the outer superconducting layer 73 are displaced in the axial direction, for example, the helical boundary B1 like the superconducting current loop L1 shown in FIG. A superconducting current loop that cannot be formed in the inner superconducting layer 72 due to straddling can be formed in the outer superconducting layer 73 without straddling the spiral boundary B2 as shown in FIG. 6B. Similarly, for example, a superconducting current loop that cannot be formed in the outer superconducting layer 73 because it crosses the spiral boundary B2 as in the superconducting current loop L2 shown in FIG. 6B is formed in the inner superconducting layer 72 as shown in FIG. It can be formed without straddling the spiral boundary B2. In this way, the spiral boundary B1 of the inner superconducting layer 72 and the spiral boundary B2 of the outer superconducting layer 73 are shifted in the axial direction for the purpose of freely forming a superconducting current loop on the cylindrical peripheral surface of the cylindrical superconductor 7. ing. For details, refer to Patent Document 1.

  When inspecting the cylindrical superconductor 7 by the inspection device 1, the cylindrical superconductor 7 (specifically, the inner superconducting layer 72 and the outer superconducting layer 73) is brought into a superconducting state. In order to bring the cylindrical superconductor 7 into a superconducting state, it is necessary to cool the cylindrical superconductor 7 below the superconducting critical temperature Tc. For this purpose, in the present embodiment, the cylindrical superconductor 7 is disposed in a container filled with liquid nitrogen.

  FIG. 7 is a schematic sectional view of a container 81 in which the cylindrical superconductor 7 is disposed. As shown in FIG. 7, the container 81 has a disc-shaped bottom wall 82 and a cylindrical side wall 83 erected upward from the periphery of the bottom wall 82, and has a bottomed cylindrical shape with an open upper surface. Present. A support disk 84 is mounted in the container 81. The outer diameter of the support disk 84 is the same as the inner diameter of the side wall 83, and is fixed parallel to the bottom wall 82 at a position slightly above the bottom wall 82. An annular groove 841 is formed at the center of the support disk 84, and an inner through hole 842 and an outer through hole 843 are formed inside and outside the annular groove 841, respectively. The inner and outer diameters of the annular groove 841 correspond to the inner and outer diameters of the cylindrical superconductor 7. Then, the cylindrical superconductor 7 is disposed in the container 81 with its lower end inserted into the annular groove 841. Thereby, the cylindrical superconductor 7 is arranged in the container 81 coaxially with the container 81.

  Next, a method for inspecting the cylindrical superconductor 7 using the inspection device 1 will be described. First, the inspection apparatus 1 is assembled as shown in FIG. Next, the joint handle 21 is moved to the uppermost position by rotating the manual handle 15 of the assembled inspection apparatus 1. Thereby, the axial moving unit 20 connected to the manual lifting operation unit 10 moves to the uppermost position. Next, the first electric motor 23 of the axial moving unit 20 is controlled to move the axial moving stage 25 to the uppermost position. Thereby, the rotation unit 30 connected to the axial movement unit 20 via the L-shaped bracket 34, the inner inspection unit 40 connected to the rotation unit 30, and the outer inspection unit 50 connected to the inner inspection unit 40 are: Move integrally to the top position.

  As shown in FIG. 7, one end (lower end) of the cylindrical superconductor 7 to be inspected is fixed to the annular groove 841 of the support disk 84 in the container 81. Next, the container 81 to which the cylindrical superconductor 7 is fixed is disposed immediately below the inner inspection unit 40 and the outer inspection unit 50 of the inspection device 1. Thereafter, the manual handle 15 of the manual lifting operation unit 10 is rotated to lower the inner inspection unit 40 and the outer inspection unit 50. At this time, with the center axis of the main body 41b of the inner rod 41 of the inner inspection unit 40 aligned with the center axis of the cylindrical superconductor 7 in the container 81, the main body 41b and the components attached thereto ( The inner inspection plate 42, the inner Hall element 43, and the inner spacer 44) enter the inner peripheral space of the cylindrical superconductor 7, and the main body 51b of the outer rod 51 of the outer inspection unit 50 and the components attached thereto. Manually adjust the position of the container 81 with respect to the inspection device 1 so that the (outer inspection plate 52, outer Hall element 53, outer spacer 54, outer permanent magnet 55) faces the outer periphery of the cylindrical superconductor 7 in the container 81. I do.

  After the completion of the position adjustment, the second electric motor 32 is controlled to fix the rotation unit 30 at a preset rotation position at a rotation angle of 0 °. Next, the first electric motor 23 is controlled to change the axial position of the axial moving unit 20 so that the inner Hall element 43 and the outer Hall element 53 face the peripheral surface of the lowermost end of the cylindrical superconductor 7. Set. Thereafter, in order to prevent the magnetic field of the outer permanent magnet 55 from being captured by the cylindrical superconductor 7, the first electric motor 23 is controlled so that the outer permanent magnet 55 is axially outside the cylindrical superconductor 7 ( The inner inspection unit 40 and the outer inspection unit 50 are temporarily moved upward so as to be above the upper end). Next, the container 81 is filled with liquid nitrogen, and the process waits until the boiling of the liquid nitrogen stops. After the boiling of the liquid nitrogen stops, the first electric motor 23 is controlled again to lower the inner inspection unit 40 and the outer inspection unit 50 to the previously set axial position. Then, the inspection is started. FIG. 8 is a diagram illustrating an arrangement relationship between the cylindrical superconductor 7 in the container 81 and the inspection device 1 at the start of the inspection. As shown in FIG. 8, the cylindrical superconductor 7 is completely immersed in the liquid nitrogen in the container 81. For this reason, the cylindrical superconductor 7 is cooled below the superconducting critical temperature Tc, whereby the cylindrical superconductor 7 (the inner superconducting layer 72 and the outer superconducting layer 73) is brought into a superconducting state. An inner inspection unit 40 is disposed on the inner peripheral side of the cylindrical superconductor 7, and an outer inspection unit 50 is disposed on the outer peripheral side of the cylindrical superconductor 7. Accordingly, the inner Hall element 43 of the inner inspection unit 40 is disposed on the inner peripheral side of the cylindrical superconductor 7, and the outer Hall element 53 and the outer permanent magnet 55 of the outer inspection unit 50 are disposed on the outer peripheral side of the cylindrical superconductor 7. Is done.

  FIG. 9 is a schematic diagram showing an arrangement relationship of the inner Hall element 43, the outer Hall element 53, and the outer permanent magnet 55 with respect to the cylindrical superconductor 7. As shown in FIGS. 8 and 9, the inner Hall element 43 is arranged facing the inner peripheral surface (cylindrical peripheral surface) of the cylindrical superconductor 7. As described above, since the innermost periphery of the cylindrical superconductor 7 is constituted by the cylindrical base 71, the inner Hall element 43 is connected to the inner superconductor of the cylindrical superconductor 7 via the cylindrical base 71. It will face layer 72. The inner Hall element 43 according to the present embodiment corresponds to the transmitted magnetic field detection sensor of the present invention.

  The outer Hall element 53 is disposed on the outer peripheral surface (cylindrical peripheral surface) of the cylindrical superconductor 7, specifically, on the outer superconducting layer 73 of the cylindrical superconductor 7. The outer Hall element 53 according to the present embodiment corresponds to a shielded magnetic field detection sensor of the present invention.

  Further, as shown in FIG. 9, the outer permanent magnet 55 is disposed at a position where its N pole faces the outer peripheral surface (cylindrical peripheral surface) of the cylindrical superconductor 7 with the outer Hall element 53 interposed therebetween. The outer permanent magnet 55 is disposed at a position where the N pole side of the inner Hall element 43 faces the inner Hall element 43 with the cylindrical peripheral surface of the cylindrical superconductor 7 interposed therebetween. The outer permanent magnet 55 according to the present embodiment corresponds to the magnet of the present invention.

  Further, as shown in FIG. 9, the inner Hall element 43 has a magnetic sensing part 43a (active area), and the outer Hall element 53 has a magnetic sensing part 53a (active area). The inner Hall element 43 detects a magnetic field applied to the magnetic sensing part 43a, and the outer Hall element 53 detects a magnetic field applied to the magnetic sensing part 53a. The area of the portion where these magnetic sensing portions 43a and 53a face the cylindrical peripheral surface of the cylindrical superconductor 7, that is, the area of the active area is larger than the area where the N pole surface of the outer permanent magnet faces the cylindrical superconductor 7. Is also small.

  In this inspection, first, the first electric motor 23 is controlled to move the axial moving unit 20 upward. When the axial moving unit 20 is moved upward, the rotating unit 30 connected to the axial moving unit 20, the inner inspection unit 40 connected to the rotating unit 30, and the outer inspection unit 50 connected to the inner inspection unit 40 are integrated. Specifically, it moves upward from the position shown in FIG. Thereby, the inner Hall element 43 of the inner inspection unit 40 moves upward (sweep) along the inner peripheral surface of the cylindrical superconductor 7 while changing the facing position in the axial direction, and the outer Hall element 53 of the outer inspection unit 50. Moves upward (sweep) along the outer peripheral surface of the cylindrical superconductor 7 while changing the facing position in the axial direction. At this time, the inner Hall element 43 moves upward while maintaining a constant radial distance between the inner peripheral surface of the cylindrical superconductor 7 and the outer Hall element 53 moves upward with the outer peripheral surface of the cylindrical superconductor 7. Move upward while maintaining a constant radial distance between. Further, the outer permanent magnet 55 moves axially along the outer peripheral surface of the cylindrical superconductor 7 together with the inner Hall element 43 and the outer Hall element 53 while maintaining the relative positional relationship with the inner Hall element 43 (the sweeping step). ).

  The inner Hall element 43 detects the magnitude of the magnetic field while moving in the axial direction along the inner peripheral surface of the cylindrical superconductor 7, and the outer Hall element 53 moves along the outer peripheral surface of the cylindrical superconductor 7. The magnitude of the magnetic field is detected while moving in the axial direction.

  FIG. 10 is a conceptual diagram showing a magnetic field detected by the outer Hall element 53. As shown in FIG. 10, the outer Hall element 53 is disposed facing the outer peripheral surface of the cylindrical superconductor 7 in a superconducting state. The outer permanent magnet 55 is disposed at a position where its N pole faces the outer peripheral surface of the cylindrical superconductor 7 with the outer Hall element 53 interposed therebetween. Therefore, the outer permanent magnet 55 applies a magnetic field to the cylindrical superconductor 7 from its N pole. Here, since the cylindrical superconductor 7 is in a superconducting state, a superconducting current (shielding current) is induced in the cylindrical superconductor 7 so as to prevent an applied magnetic field from entering the inside. The shielding current shields the applied magnetic field from entering the cylindrical superconductor. By shielding the applied magnetic field in this manner, a shielding magnetic field is formed between the cylindrical superconductor 7 and the outer permanent magnet 55. Therefore, the outer Hall element 53 located between the cylindrical superconductor 7 and the outer permanent magnet 55 detects the magnitude of the shielding magnetic field.

  FIG. 11 is a conceptual diagram showing the magnetic field detected by the inner Hall element 43. As shown in FIG. 11, the inner Hall element 43 is arranged facing the inner peripheral surface of the cylindrical superconductor 7 in a superconducting state. Further, the outer permanent magnet 55 is disposed at a position where the N pole of the outer permanent magnet 55 faces the inner Hall element 43 with the cylindrical peripheral surface of the cylindrical superconductor 7 interposed therebetween. That is, the inner Hall element 43 and the outer permanent magnet 55 are opposed to each other with the cylindrical superconductor 7 interposed therebetween. Here, as described above, the magnetic field applied to the cylindrical superconductor 7 from the N-pole side of the outer permanent magnet 55 is shielded by the cylindrical superconductor 7. The portion penetrates the cylindrical peripheral surface of the cylindrical superconductor 7 and reaches the inner peripheral side of the cylindrical superconductor 7. Thus, the transmitted magnetic field is formed on the inner peripheral side of the cylindrical superconductor 7 by the magnetic field transmitted through the cylindrical peripheral surface of the cylindrical superconductor 7. Therefore, the inner Hall element 43 disposed facing the inner peripheral surface of the cylindrical superconductor 7 detects the magnitude of the transmitted magnetic field.

  Thus, the outer Hall element 53 detects the shielding magnetic field while moving along the axial direction of the cylindrical superconductor 7 by driving the axial moving unit 20 (shielding magnetic field detection step), and the inner Hall element 43 The transmitted magnetic field is detected while moving along the axial direction of the cylindrical superconductor 7 by driving the axial moving unit 20 (transmitted magnetic field detecting step).

  When the rotation (the sweep) of the inner Hall element 43 and the outer Hall element 53 along the axial direction of the cylindrical superconductor 7 is completed when the rotation angle is 0 °, the inner Hall element 43 and the outer Hall element 53 become cylindrical superconductive. The upper end of the body 7 faces the cylindrical peripheral surface. Next, the second electric motor 32 is controlled to rotate the rotation unit 30 from the rotation angle of 0 ° to a rotation position rotated by a predetermined angle, for example, 30 °. As a result, the inner Hall element 43 and the outer Hall element 53 rotate around the central axis of the cylindrical superconductor 7, and the inner Hall element 43 faces the inner peripheral surface of the cylindrical superconductor 7, and The position where the Hall element 53 faces the outer peripheral surface of the cylindrical superconductor 7 changes in the circumferential direction. Here, since the central axis of the inner inspection unit 40 and the central axis of the cylindrical superconductor 7 coincide with each other, the distance between the inner Hall element 43 before rotation and the inner peripheral surface of the cylindrical superconductor 7 is rotated. The distance between the rear inner Hall element 43 and the inner peripheral surface of the cylindrical superconductor 7 is equal, and the outer Hall element 53 before rotation, the outer peripheral surface of the cylindrical superconductor 7, the outer Hall element 53 after rotation, and the cylinder The distance between the outer peripheral surface of the superconductor 7 is equal. Next, the first electric motor 23 is controlled to move the axial moving unit 20 downward. When the axial moving unit 20 is moved downward, the rotating unit 30 connected to the axial moving unit 20, the inner inspection unit 40 connected to the rotating unit 30, and the outer inspection unit 50 connected to the inner inspection unit 40 are integrated. And move downward. As a result, the inner Hall element 43 of the inner inspection unit 40 moves downward (sweep) along the inner peripheral surface of the cylindrical superconductor 7 while changing the facing position in the axial direction, and the outer Hall element 53 of the outer inspection unit 50. Moves downward (sweep) along the outer peripheral surface of the cylindrical superconductor 7 while changing the facing position in the axial direction. Further, the outer permanent magnet 55 moves axially along the outer peripheral surface of the cylindrical superconductor 7 together with the outer Hall element 53. At this time, the inner Hall element 43 detects the transmitted magnetic field while moving downward along the axial direction of the cylindrical superconductor 7, and the outer Hall element 53 shields while moving downward along the axial direction of the cylindrical superconductor 7. Detect the magnetic field.

  As described above, the movement and rotation of the inner Hall element 43 along the axial direction of the cylindrical superconductor 7, and the movement and movement of the outer Hall element 53 and the outer permanent magnet 55 along the axial direction of the cylindrical superconductor 7. The rotation is repeatedly performed, and the inspection is completed when the inner Hall element 43 and the outer Hall element 53 make one round in the circumferential direction of the cylindrical superconductor 7. Thereby, the transmitted magnetic field and the shielding magnetic field over the entire area of the cylindrical peripheral surface of the cylindrical superconductor 7 are detected. During the inspection, the main body portion 41b of the inner rod portion 41 of the inner inspection unit 40 and the components connected thereto move up and down in the inner circumferential space of the cylindrical superconductor 7, but with this, the inside of the container 81 Liquid nitrogen flows into and out of the inner peripheral space of the cylindrical superconductor 7 through the inner through hole 842 and the outer through hole 843 formed in the support disk 84 of FIG. Due to such inflow and outflow of liquid nitrogen, pressure fluctuation in the inner peripheral space of the cylindrical superconductor 7 is suppressed.

  FIG. 12 is a diagram conceptually showing the relationship between the shielding magnetic field detected by the outer Hall element 53 and the presence or absence of a defect in the cylindrical superconductor 7. As shown in FIG. 12A, a region indicated by oblique lines facing the outer Hall element 53 in the cylindrical superconductor 7 is an inspection region R. If no defect exists in the inspection region R, a shielding current of a required magnitude is induced in the inspection region R in an attempt to shield the magnetic field applied from the N pole side of the outer permanent magnet 55. For this reason, the shielding current is shielded so that the applied magnetic field does not enter the cylindrical superconductor 7. Therefore, the magnetic flux generated from the N pole of the outer permanent magnet 55 bends so as to be deflected from the outer Hall element 53 located between the inspection region R and the outer permanent magnet 55, and passes through the magneto-sensitive portion 53a of the outer Hall element 53. The generated magnetic flux is small. That is, when there is no defect in the inspection region R, the magnetic field is removed from the space between the outer permanent magnet 55 and the cylindrical superconductor 7, and is detected by the outer Hall element 53 located in the space therebetween. The shielding magnetic field is weak.

  On the other hand, as shown in FIG. 12B, when a defect D exists in the inspection region R, a shielding current of a magnitude necessary for shielding the applied magnetic field is not induced in the inspection region R, and as a result, Without sufficiently removing the applied magnetic field, a part of the magnetic flux generated from the N pole side of the outer permanent magnet 55 proceeds so as to pass through the defect D in the inspection region R. Since such a magnetic flux passes through the magnetic sensing portion 53a of the outer Hall element 53 located between the inspection region R and the outer permanent magnet 55, the shielding magnetic field detected by the outer Hall element 53 indicates that the defect D Stronger than when it does not exist in the inspection region R. That is, when a defect or the like exists in a region of the cylindrical peripheral surface of the cylindrical superconductor 7 facing the outer Hall element 53, the defect is detected by the outer Hall element 53 as compared with the case where no defect exists. The shielding magnetic field becomes stronger.

  As described above, the magnitude of the shielding magnetic field detected by the outer Hall element 53 changes depending on the presence or absence of a defect in the inspection region R. Specifically, when the defect D exists, the shielding magnetic field detected by the outer Hall element 53 becomes stronger. Accordingly, by detecting the shielding magnetic field with the outer Hall element 53 while sweeping the outer Hall element 53 (while the outer Hall element 53 moves) along the cylindrical peripheral surface of the cylindrical superconductor 7, the presence or absence of a defect or the like is determined. Of the superconducting state of the cylindrical superconductor 7 which is affected by the above.

  FIG. 13 is a diagram conceptually showing the relationship between the transmitted magnetic field detected by the inner Hall element 43 and the presence or absence of a defect in the cylindrical superconductor 7. As shown in FIG. 13A, an area indicated by oblique lines facing the inner Hall element 43 in the cylindrical superconductor 7 is an inspection area R. When there is no defect in the inspection region R, a shielding current that attempts to shield a magnetic field applied from the N pole side of the outer permanent magnet 55 is induced in the inspection region R. Therefore, the possibility that the magnetic flux generated from the N pole of the outer permanent magnet 55 is detected by the inner Hall element 43 located on the opposite side of the inspection region R from the outer permanent magnet 55 is low. As described above, when the applied magnetic field from the outer permanent magnet 55 is increased, a part of the magnetic flux penetrates the inspection region R, but is formed on the inner peripheral side of the cylindrical superconductor 7 by the transmission. Transmitted magnetic field is weak. That is, when no defect exists in the inspection region R, the transmitted magnetic field detected by the inner Hall element 43 is weak.

  On the other hand, as shown in FIG. 13B, when the defect D exists in the inspection region R, a part of the magnetic flux generated from the N pole side of the outer permanent magnet 55 passes through the defect D and passes through the inner Hall element 43. Is likely to pass through the magnetic sensing part 43a. Therefore, when a defect or the like exists in the inspection region R, the transmitted magnetic field detected by the inner Hall element 43 becomes stronger than when no defect exists.

  Thus, the magnitude of the transmitted magnetic field detected by the inner Hall element 43 changes depending on the presence or absence of a defect in the inspection region R. Specifically, when the defect D exists, the transmitted magnetic field detected by the inner Hall element 43 increases. Therefore, by detecting the transmitted magnetic field with the inner Hall element 43 while sweeping the inner Hall element 43 along the cylindrical peripheral surface of the cylindrical superconductor 7 (while the inner Hall element 43 moves), the presence or absence of a defect or the like is determined. The soundness of the cylindrical superconductor 7 affected by the above can be inspected.

  In the present embodiment, since the applied magnetic field is generated using the permanent magnet (outer permanent magnet 55), no additional equipment such as a power supply for generating the applied magnetic field is required. For this reason, the structure of the inspection device 1 can be simplified.

<Experiment for confirming defect detection>
Using the inspection device 1 according to the present embodiment, whether or not a defect intentionally formed in the inner superconducting layer 72 and the outer superconducting layer 73 of the cylindrical superconductor 7 can be detected, that is, the cylindrical superconductor 7 was conducted to confirm whether the superconducting state can be checked for soundness. FIG. 14A shows a cylindrical superconductor 7 having an inner superconducting layer 72 and an outer superconducting layer 73 in which defects are intentionally formed. 14A (a) is a top view of the cylindrical superconductor 7, FIG. 14A (b) is a view in the direction of arrow A in FIG. 14A (a), and FIG. 14A (c) is a view in FIG. 14A (a). It is an arrow B view. FIGS. 14A (b) and 14A (c) are side views of the cylindrical superconductor 7 viewed from opposite directions. In these drawings, the helical boundary B1 of the inner superconducting layer 72 is indicated by a broken line. The spiral boundary B2 of the outer superconducting layer 73 is indicated by a solid line. In the following description, a defect formed in outer superconducting layer 73 will be described with reference to FIG. 14A (c), and a defect formed in inner superconducting layer 72 will be described with reference to FIG. 14A (b).

  As shown in FIG. 14A (c), the outer superconducting layer 73 is configured such that the superconducting wire SCout whose both ends are represented by solid lines is viewed from above from the uppermost winding start position S2 (see FIG. 14A (a)). It is formed cylindrical by spirally winding downward about 12 turns counterclockwise (as viewed from the direction shown). Then, a defect Dout is formed at the end position of the fourth turn and the end position of the eighth turn from the upper side. Here, when the circumferential position of the outer superconducting layer 73 is represented by a rotation angle at which the rotation angle changes from 0 ° to 360 ° by one turn of helical winding with the rotation start position S2 being 0 °, The positions of the defects Dout formed in the layer 73 are the end of the fourth turn from the top and the rotation angle of 0 °, and the end of the eighth turn from the top and the position of the rotation angle of 0 °.

  Also, as shown in FIG. 14A (b), the inner superconducting layer 72 looks at the superconducting wire SCin whose both ends are indicated by broken lines from above from the winding start position S1 on the upper end side (FIG. 14A (a)). It is formed into a cylindrical shape by spirally winding downward about 12 turns in a counterclockwise direction (as viewed from the direction shown in (a)). Then, a defect Din is formed at the end position of the fourth turn and the end position of the eighth turn from the upper side. Here, as shown in FIG. 14A (a), the winding start position S1 of the inner superconducting layer 72 is shifted by 180 ° from the winding start position S2 of the outer superconducting layer 73. Therefore, based on the rotation angle of the outer superconducting layer 73 (that is, assuming that the rotation angle of the position S1 is 0 °), the position of the defect Din formed in the inner superconducting layer 72 is at the end of the fourth turn from the top. There is a position where the rotation angle is 180 ° and a position where the rotation angle is 180 ° at the end of the eighth turn from the top. FIG. 14A shows the axial position (z-direction position) of each superconducting layer shown in FIGS. 14A (b) and 14A (c). The position where the axial position z ≒ 8 mm is the upper end position of each superconducting layer, and the position where the axial position z ≒ 147 mm is the lower end position of each superconducting layer.

  FIG. 14B is a diagram showing a state in which the superconducting wire SCin forming the inner superconducting layer 72 and the superconducting wire SCout forming the outer superconducting layer 73 are developed. As shown in FIG. 14B, in the inner superconducting layer 72, a defect Din is located at a position at the end of the fourth turn (turn 4) and an end of the eighth turn (eighth turn) from the winding start position S1. Is formed. Further, in the outer superconducting layer 73, defects Dout are formed at the end position of the fourth turn (4th turn) and the end position of the 8th turn (8th turn) from the winding start position S2.

  FIG. 15 is a developed view of a cylindrical body in which the inner superconducting layer 72 and the outer superconducting layer 73 are overlapped. In FIG. 15, the helical boundary B1 of the inner superconducting layer 72 is indicated by a broken line, and the helical boundary B2 of the outer superconducting layer 73 is indicated by a solid line. The defect Din formed in the inner superconducting layer 72 is formed between the pair of spiral boundaries B1 of the part constituting the end of the fourth turn from the top and the pair of spiral boundaries B1 of the part constituting the end of the eighth turn from the top. In between, each is formed. The defect Dout formed in the outer superconducting layer 73 is formed between the pair of spiral boundaries B2 of the part constituting the end of the fourth turn from the upper side and the pair of spiral boundaries B2 of the part constituting the end of the eighth turn from the upper side. In between, each is formed. Further, as can be seen from FIG. 15, the spiral boundary B1 of the inner superconducting layer 72 is shifted from the spiral boundary B2 of the outer superconducting layer 73 by １ ／ pitch in the axial direction. Therefore, the defect Din formed in the inner superconducting layer 72 is formed on the spiral boundary B2 of the outer superconducting layer 73, and the defect Dout formed in the outer superconducting layer 73 is changed to the spiral boundary of the inner superconducting layer 72. It will be formed on B1.

  As the superconducting wire constituting the inner superconducting layer 72 and the outer superconducting layer 73, a Gd-Ba-Cu-O-based superconducting material was used. The superconducting wire has a width of 12 mm and a thickness of 0.12 mm. Further, each of the defects Din and Dout is formed by bending the superconducting wire in a U-shape on the front side and the back side of the superconducting wire so as to have a radius smaller than an allowable bending radius.

  The cylindrical superconductor 7 including the inner superconducting layer 72 and the outer superconducting layer 73 having the above configuration was inspected using the inspection apparatus 1. Here, the size of the outer permanent magnet 55 is a column having a diameter of 5 mm and a height of 15 mm, and is arranged such that an N pole surface formed on one end face thereof faces the outer superconducting layer 73. Note that the size of the outer permanent magnet 55, specifically, the diameter (5 mm) of the N pole face of the outer permanent magnet 55 is smaller than the width (12 mm) of the superconducting wire. The radial distance between the outer permanent magnet 55 and the outer superconducting layer 73 is 6 mm, the radial distance between the outer Hall element 53 and the outer superconducting layer 73 is 3 mm, and the inner Hall element 43 and the inner superconducting layer 72 The inner inspection unit 40 and the outer inspection unit 50 of the inspection apparatus 1 are arranged with respect to the cylindrical superconductor 7 such that the radial distance between the two is 3 mm.

  Then, after the cylindrical superconductor 7 is immersed in liquid nitrogen to bring the cylindrical superconductor 7 into a superconducting state, the inner inspection unit 40 and the outer inspection unit 50 are moved in the axial direction, and the inner Hall elements 43 and The outer Hall element 53 was swept in the axial direction along the cylindrical peripheral surface of the cylindrical superconductor. Further, the rotation angle of the rotation stage 33 is rotated by 30 °, and the sweep of each Hall element in the above-described axial direction is performed at each rotation angle. Detection was performed, and the shielding magnetic field in each inspection area was detected by the outer Hall element 53.

  FIG. 16 shows the measurement result of the shielding magnetic field detected by the outer Hall element 53, and FIG. 17 shows the measurement result of the transmission magnetic field detected by the inner Hall element 43. 16 and 17, the vertical axis represents the magnetic field strength (arbitrary unit), and the horizontal axis represents the axial position of the inspection region. Here, the axial position near z = 8 mm indicates the upper end position of each cylindrical superconducting layer, and the axial position near z = 147 mm indicates the lower end position of each cylindrical superconducting layer. FIGS. 16 and 17 each show twelve measurement graphs. These graphs show the Hall elements 43 and 53 in the axial direction with the rotation stage 33 fixed at a predetermined rotation angle. It represents the change in the magnetic field strength detected when the sweep is performed. The uppermost graph of the twelve measurement graphs shows a change in the magnetic field intensity when the rotation angle of the rotary stage 30 is 360 °, and thereafter, as the angle goes down, the rotation angle changes from 360 ° to 30 °. It shows the change in the magnetic field strength when it decreases. Here, when the rotation angle of the rotary stage 30 is 0 ° (= 360 °), the inner Hall element 43 and the outer Hall element 53 are located at the winding start position S2 of the upper end of the superconducting wire constituting the outer superconducting layer 73. The rotating position of the rotating stage 30 is adjusted so as to face each other. Here, when the circumferential position of the outer superconducting layer 73 is represented by a rotation angle, the rotation angle of the position S2 is 0 °. That is, the rotation angle of the rotation stage 30 and the rotation angle representing the circumferential position of the outer superconducting layer 73 match. Therefore, the rotation angle of each graph shown in FIGS. 16 and 17 indicates the rotation angle of the outer superconducting layer 73.

  16 and 17, a helical boundary B1 of the inner superconducting layer 72 is indicated by a broken line, and a helical boundary B2 of the outer superconducting layer 73 is indicated by a solid line. As can be seen from FIG. 16, at the fourth and eighth turns from the upper end position (z ≒ 8 mm) of each of the superconducting layers 72 and 73, the shielding magnetic field around 360 ° and 180 ° becomes strong. I have. Similarly, as can be seen from FIG. 17, at the fourth and eighth turns from the upper end position (z ≒ 8 mm) of each of the superconducting layers 72 and 73, the transmitted magnetic field around the rotation angle of 360 ° and around the rotation angle of 180 ° It is getting stronger. These positions where the shielding magnetic field and the transmitted magnetic field are strong coincide with the positions of the defects intentionally formed in the inner superconducting layer 72 and the outer superconducting layer 73. From this, by detecting the shielding magnetic field and / or the transmission magnetic field by the inspection apparatus 1 according to the present embodiment, the presence or absence of the defect of the cylindrical superconductor 7, that is, the soundness of the superconducting state of the cylindrical superconductor 7 is inspected. Prove that you can.

  FIG. 18 is a diagram showing the measurement result of the shielding magnetic field shown in FIG. 16 mapped to a development view of the cylindrical superconductor 7, and FIG. 19 is a diagram showing the measurement result of the transmission magnetic field shown in FIG. FIG. 5 is a diagram mapped to a development view of FIG. By mapping the strength of the magnetic field on the developed view of the cylindrical superconductor 7 as shown in these figures, the existence of a defect can be clearly grasped.

  In FIG. 18, a line that is thinly displayed along the oblique horizontal direction is the spiral boundary B2 of the outer superconducting layer 73, and a line that is thinly displayed obliquely in the lateral direction is the inner superconducting layer 72. It is a spiral boundary B1. In particular, as can be seen from FIG. 18, the defects Dout of the outer superconducting layer 73 represented near the rotation angles of 0 ° and 360 ° are formed between the spiral boundaries B2 of the vertically adjacent pair, and have a rotation angle of about 180 °. Are formed on the spiral boundary B2. As described above, since the spiral boundary B1 of the inner superconducting layer 72 is formed so as to be shifted from the spiral boundary B2 of the outer superconducting layer 73 by ピ ッ チ pitch in the axial direction, the defect Din of the inner superconducting layer 72 is When viewed from the outside, the outer superconducting layer 73 is located on the spiral boundary B2.

  That is, when a defect is found between the adjacent spiral boundaries B2 of the outer superconducting layer 73, it is understood that the defect is formed in the outer superconducting layer 73. When a defect is found on the spiral boundary B2 of the outer superconducting layer 73, it is understood that the defect is formed in the inner superconducting layer 72. Thus, according to the present embodiment, from the relationship between the defect position and the spiral boundary, it is also possible to determine which layer of the cylindrical superconductor formed in a plurality of layers by the spiral winding of the superconducting wire has the defect. , Can be determined.

  FIG. 20 shows the rotation angle and the strength of the magnetic field when the position of the cylindrical peripheral surface of the cylindrical superconductor 7 (the inner superconducting layer 72 and the outer superconducting layer 73) formed by spirally winding the superconducting wire is represented by the rotation angle. 6 is a graph showing a relationship with (size). In FIG. 20, the vertical axis represents the strength of the magnetic field, and the horizontal axis represents the rotation angle θ representing the position of the peripheral surface of the cylinder. The rotation angle θ is -360 ° at the winding start position S2 of the outer superconducting layer 73, the first turn is expressed as a rotation angle of −360 ° to 0 °, and the second turn is expressed as a rotation angle of 0 ° to The rotation angle is expressed as 360 °, and the rotation angle is continuously increased for the subsequent turns. In this case, the rotation angle θ of the winding start position S1 of the inner superconducting layer 72 is −180 °. FIG. 20 shows two graphs A and B, both of which are created based on the mapping results shown in FIG. Here, graph A shows the strength of the magnetic field on the line following the center position in the width direction of the two adjacent spiral boundaries B2 shown in FIG. 18 along the spiral direction, and the position of A0 in FIG. And plotted corresponding to the rotation angle θ. From the graph A, the presence or absence of a defect in the outer superconducting layer 73 is determined. Graph B shows the strength of the magnetic field on the line following the position on the helical boundary B2 shown in FIG. 18 along the helical direction along the rotation angle θ with the position of B0 in FIG. Created by plotting. From the graph B, the presence or absence of a defect in the inner superconducting layer 72 is determined.

  As can be seen from FIG. 20, in the graph A, the magnetic field is strong at the position where the rotation angle θ is 1080 ° and at the position where the rotation angle θ is 2520 °. The rotational position of the defect Dout intentionally formed in the outer superconducting layer 73 is a position at 1080 ° and a position at 2520 ° from the position A0 in FIG. 15, and the result of the graph A agrees with this. In the graph B, the magnetic field is strong at the positions where the rotation angle θ is 1260 ° and 2700 ° (the position advanced by 180 ° from the rotation position of the defect Dout). The rotational positions of the defect Din intentionally formed in the inner superconducting layer 72 are the positions of 1260 ° and 2700 ° from the position B0 in FIG. 15, and the result of the graph B agrees with this. In this way, by using the inspection device 1 according to the present embodiment, it is possible to inspect the cylindrical superconductor 7 for a defect.

(Modification 1)
In the first embodiment, the axial movement unit 20 is driven at a predetermined rotation position where the rotation angle of the rotation unit 30 is fixed. Thus, the outer Hall element 53 and the inner Hall element 43 detect the shielding magnetic field and the transmitted magnetic field while being moved (swept) in the axial direction. Then, after the movement (sweep) in the axial direction is completed, the rotation angle is changed, and the outer Hall element 53 and the inner Hall element 43 are again moved in the axial direction (while being swept) at the changed rotation position. Detect the shielding magnetic field and the transmitted magnetic field. That is, the shielding magnetic field and the transmitted magnetic field are detected while the outer Hall element 53 and the inner Hall element 43 are swept in the axial direction at a plurality of rotation positions. However, in a state where the axial position is fixed, the outer Hall element 53 and the inner Hall element 43 are rotationally moved by driving the rotation unit 30, and the outer Hall element 53 and the inner Hall element 43 are rotated and moved while the shielding magnetic field and the transmission are blocked. A magnetic field may be detected. Then, after the rotational movement is completed, the axial position is changed, and at the changed axial position, the shielding magnetic field and the transmitted magnetic field are detected while the outer Hall element 53 and the inner Hall element 43 rotate (sweep) again. You may. That is, the shielding magnetic field and the transmitted magnetic field may be detected while the outer Hall element 53 and the inner Hall element 43 are rotationally moved (swept) at a plurality of axial positions.

(Modification 2)
In the first embodiment, an example in which the transmitted magnetic field is detected by the inner Hall element 43 and the shielding magnetic field is detected by the outer Hall element 53 has been described. However, the shielding magnetic field can be detected by the inner Hall element 43 and the transmitted magnetic field can be detected by the outer Hall element 53. In this case, an inner permanent magnet disposed on the inner peripheral side of the superconducting cylindrical body 7 is used instead of the outer permanent magnet 55 shown in the first embodiment. FIG. 21 is a schematic cross-sectional view showing a connection configuration of the rotation unit 30, the inner inspection unit 40, and the outer inspection unit 50 of the inspection device 1 according to the second modification. As shown in FIG. 21, the inner permanent magnet 45 is embedded at a position below the inner inspection plate 42 of the inner inspection unit 40 and at a position facing the inner Hall element 43 via the inner spacer 44. The inner permanent magnet 45 has two different magnetic poles (N pole and S pole), and is embedded in the inner inspection plate 42 such that the N pole faces the inner Hall element 43 with the inner spacer 44 interposed therebetween. As the inner permanent magnet 45, a neodymium magnet (NdFeB magnet) can be used. Further, the outer permanent magnet 45 is omitted. In the configuration of the inspection apparatus according to the present example, the configuration of the other parts than the above is the same as the configuration of the inspection apparatus according to the first embodiment.

  FIG. 22 is a diagram showing an arrangement relationship between the inspection device 1 and the cylindrical superconductor 7 when inspecting the cylindrical superconductor 7 set in the container 81 using the inspection device 1 according to the present example. . As shown in FIG. 22, the inner inspection unit 40 of the cylindrical superconductor 7 is provided in the inner peripheral space of the cylindrical superconductor 7. Therefore, the inner permanent magnet 45 and the inner Hall element 43 provided in the inner inspection unit 40 are also arranged in the inner peripheral space of the cylindrical superconductor 7. Then, the inner Hall element 43 is disposed facing the inner peripheral surface of the cylindrical superconductor 7. Further, the inner permanent magnet 45 is arranged such that the N pole side faces the inner peripheral surface of the cylindrical superconductor 7 with the inner Hall element 43 interposed therebetween. The outer Hall element 53 is arranged on the outer peripheral side of the cylindrical superconductor 7 and is arranged facing the outer peripheral surface of the cylindrical superconductor 7. Here, the inner permanent magnet 45 is arranged such that the N pole faces the outer Hall element 53 such that the N pole faces the outer Hall element 53 with the cylindrical peripheral surface of the cylindrical superconductor 7 interposed therebetween. It is arranged to face.

  According to the inspection device 1 according to the second modification, the magnetic field applied from the N pole of the inner permanent magnet 45 to the cylindrical superconductor 7 from the inner peripheral side thereof is shielded by the cylindrical peripheral surface of the cylindrical superconductor 7. Thereby, a shielding magnetic field is formed on the inner peripheral side of the cylindrical superconductor 7. The shielding magnetic field thus formed is detected by the inner Hall element 43 disposed facing the inner peripheral surface of the cylindrical superconductor 7. The inner Hall element 43 detects the shielding magnetic field while moving along the cylindrical peripheral surface (inner peripheral surface) of the cylindrical superconductor 7 by driving the axial moving unit 20 and the rotating unit 30. That is, the inner Hall element 43 is used as a shielding magnetic field detection sensor.

  Further, a magnetic field applied from the N pole of the inner permanent magnet 45 to the cylindrical superconductor 7 from the inner peripheral side thereof penetrates the cylindrical peripheral surface of the cylindrical superconductor 7 so that the magnetic field is applied to the outer peripheral side of the cylindrical superconductor 7. A transmission magnetic field is formed. The transmitted magnetic field thus formed is detected by the outer Hall element 53 disposed on the outer peripheral surface of the cylindrical superconductor 7 so as to face each other. The outer Hall element 53 detects the transmitted magnetic field while moving along the cylindrical peripheral surface (outer peripheral surface) of the cylindrical superconductor 7 by driving the axial moving unit 20 and the rotating unit 30. That is, the outer Hall element 53 is used as a transmitted magnetic field detection sensor.

(Second embodiment)
In the first embodiment, the example in which the axial movement unit 20 and the rotation unit 30 are separately driven has been described. Specifically, an example in which the axial movement unit 20 is driven when the rotation unit 30 is stopped has been described. In the present embodiment, an example in which the axial movement unit 20 and the rotation unit 30 are driven simultaneously will be described.

  In this embodiment, the drive of both units 30 and 20 is interlocked and controlled by the controller such that the rotation unit 30 is driven to rotate in one direction and the axial movement unit 20 is moved in the axial direction in one direction. When the two units 30 and 20 are thus controlled in an interlocked manner, the inner inspection unit 40 and the outer inspection unit 50 move spirally. Therefore, the inner Hall element 43 attached to the inner inspection unit 40 and the outer Hall element 53 and the outer permanent magnet 55 attached to the outer inspection unit 50 also move spirally. As described above, the inner Hall element 43 and the outer Hall element 53 are spirally moved along the cylindrical peripheral surface of the cylindrical superconductor 7, so that the entire cylindrical peripheral surface of the cylindrical superconductor 7 is efficiently moved. The integrity of the superconducting state can be inspected.

  In particular, when the cylindrical superconductor 7 to be inspected includes the inner superconducting layer 72 and the outer superconducting layer 73 formed in a cylindrical shape by spirally winding a superconducting wire as shown in the first embodiment. The rotation unit 30 and the axial movement unit 20 may be controlled so that the inner Hall element 43 and the outer Hall element 53 move along the spiral winding direction. According to this, the inspection can be performed along the longitudinal direction of the superconducting wire.

  When the cylindrical superconductor 7 has the above-described inner superconducting layer 72 and outer superconducting layer 73, the inner Hall element 43 and / or the outer Hall element 53 are preferably formed of two Hall elements, respectively.

  FIG. 23 is a schematic diagram showing an example in which an outer Hall element 531 having two Hall elements is swept in a spiral direction. As shown in FIG. 23, the outer Hall element 531 includes a first outer Hall element 532 and a second outer Hall element 533. These Hall elements 532 and 533 are configured to be integrally movable.

  FIG. 24 is a diagram showing an arrangement relationship between the outer Hall element 531 and the inner superconducting layer 72 and the outer superconducting layer 73 of the cylindrical superconductor 7. As shown in FIG. 24, the first outer Hall element 532 is arranged facing the spiral boundary B1 of the inner superconducting layer 72, and the second outer Hall element 533 is arranged facing the spiral boundary B2 of the outer superconducting layer 73. Here, the spiral boundary B1 is located at the center in the width direction of the superconducting wire constituting the outer superconducting layer 73, and the spiral boundary B2 is located at the center in the width direction of the superconducting wire constituting the inner superconducting layer 72. . Therefore, the first outer Hall element 532 faces the center position in the width direction of the superconducting wire constituting the outer superconducting layer 73, and the second outer Hall element 533 extends in the width direction of the superconducting wire constituting the inner superconducting layer 72. You will face the central position. Further, an outer permanent magnet 55 is disposed facing the outer peripheral surface of the cylindrical superconductor 7 with the outer Hall element 531 interposed therebetween, and its N pole has a cylindrical peripheral surface of the cylindrical superconductor 7 with the outer Hall element 531 interposed therebetween. Face to face.

  The outer Hall element 531 having the above configuration is spirally swept along the spiral boundaries B1 and B2. At this time, the shielding magnetic field formed by shielding the magnetic field applied to the cylindrical superconductor 7 from the N pole of the outer permanent magnet 55 by the outer superconducting layer 73 is mainly detected by the first outer Hall element 532. You. In addition, a shield magnetic field formed by shielding the magnetic field applied to the cylindrical superconductor 7 from the N pole of the outer permanent magnet 55 to the cylindrical superconductor 7 is mainly detected by the second outer Hall element 533. .

  Accordingly, by continuously plotting the magnetic field strength detected by the spirally moving first outer Hall element 532, the graph A of FIG. 20 is created in real time, and the spirally moving second outer Hall element 532 is generated. By continuously plotting the magnetic field strength detected by the element 533, the graph B of FIG. 20 is created in real time. In this way, by creating the graph shown in FIG. 20 in real time, an inspection result can be obtained without performing the mapping operation and the like shown in the first embodiment, and the inspection procedure can be simplified. .

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the first embodiment, the cylindrical superconductor 7 is immersed in liquid nitrogen to cool the cylindrical superconductor 7 to a superconducting state. An example of checking the soundness was given. In the present embodiment, an example will be described in which the superconducting state of the cylindrical superconductor is inspected using the inspection apparatus 1 in a state where the cylindrical superconductor is cooled to a superconducting state using a refrigerator.

  FIG. 25 is a diagram illustrating a state where the inspection device 1 inspects the cylindrical superconductor 7A cooled by the refrigerator. As shown in FIG. 25, an inner inspection unit 40 is disposed on the inner peripheral side of the cylindrical superconductor 7A cooled by the refrigerator 6, and an outer inspection unit 50 is disposed on the outer peripheral side of the cylindrical superconductor 7A. You. In this state, the inspection device 1 is driven to inspect the cylindrical superconductor 7A.

  FIG. 26 shows the refrigerator 6, the cylindrical superconductor 7 </ b> A cooled by the refrigerator 6, the inner Hall element 43 attached to the inner inspection unit 40 of the inspection device 1, and the outer hall attached to the outer inspection unit 50. It is the schematic which shows the arrangement | positioning relationship with the Hall element 53 and the outer permanent magnet 55. As shown in FIG. 26, the refrigerator 6 has a refrigerator main body 61, an extension 62, and a cold stage 63. Freezing is generated inside the refrigerator main body 61. The generated refrigeration is transmitted to the cold stage 63 via the extension 62. Therefore, when the refrigerator 6 is driven, the cold stage 63 is cooled to a predetermined temperature, for example, a temperature equal to or lower than the superconducting critical temperature Tc of the cylindrical superconductor 7A.

  The cold stage 63 is formed in a disk shape, and is connected to the distal end (upper end) of the extending portion 62 such that one end surface (upper surface) faces upward. On this cold stage 63, a cylindrical superconductor 7A is coaxially arranged. In the present embodiment, the cylindrical superconductor 7A includes a cylindrical base 71A and a sheet-shaped superconductor 74. The cylindrical base material 71A has a cylindrical portion and a flange radially extending from one end (the lower end in FIG. 26) of the cylindrical portion, and the flange is mounted on the cold stage 63. Therefore, the cylindrical portion of the cylindrical substrate extends upward from the cold stage 63. In addition, a concave portion is formed in most of the outer peripheral surface of the cylindrical portion of the cylindrical base material 71A so that the superconductor 74 can be attached thereto. A sheet-like superconductor 74 is attached to the concave portion. Thereby, superconductor 74 is formed in a cylindrical shape.

  Further, a vacuum heat insulating container 64 is provided above the refrigerator main body 61. The vacuum heat insulating container 64 has a first container part 641, a disk-shaped member 642, and a second container part 643. The first container portion 641 has a cylindrical shape, and the lower end surface is air-tightly fixed to the upper surface of the refrigerator main body 61. Then, the first container portion 641 is disposed so as to stand upright from the upper surface of the refrigerator main body 61 and cover the extending portion 62 and the cold stage 63 of the refrigerator 6 from the outer peripheral side.

  A disc-shaped member 642 is provided at the upper end of the first container portion 641. The disk-shaped member 642 is disposed coaxially with the cold stage 63 at a position slightly higher than the cold stage 63, and the lower surface thereof is air-tightly fixed to the upper end of the first container portion 641. Further, a circular hole 642 a having a diameter slightly larger than the diameter of the cylindrical superconductor 7 is formed at the center of the disk-shaped member 642. The cylindrical superconductor 7A on the cold stage 63 extends upward through the circular hole 642a of the disk-shaped member 642.

  The second container portion 643 has an outer cylindrical portion 643a, an inner cylindrical portion 643b, an inner bottom portion 643c, and a ring-shaped upper wall portion 643d. The lower end portion of the outer peripheral surface of the outer peripheral side cylindrical portion 643a is hermetically fixed to the inner peripheral surface of the circular hole 642a of the disk-shaped member 642. The outer peripheral side cylindrical portion 643a extends upward from the inner peripheral wall of the circular hole 642a so as to cover the superconductor 74 attached to the cylindrical portion of the cylindrical base 71A of the cylindrical superconductor 7A from the outer peripheral side. . Therefore, the outer peripheral side cylindrical portion 643a is disposed on the outer peripheral side of the cylindrical superconductor 7A along the outer peripheral surface.

  The outer peripheral edge of the ring-shaped upper wall portion 643d is continuously provided on the upper end of the outer peripheral side cylindrical portion 643a. The ring-shaped upper wall portion 643d is arranged in a ring shape so as to cover the upper end of the cylindrical superconductor 7A. The upper end of the inner peripheral side cylindrical portion 643b is connected to the inner peripheral edge of the ring-shaped upper wall portion 643d. The inner peripheral side cylindrical portion 643b extends in the axial direction of the cylindrical superconductor 7A so as to face the inner peripheral surface of the cylindrical portion of the cylindrical base material 71A of the cylindrical superconductor 7A from the inner peripheral edge of the ring-shaped upper wall portion 643d. And extends downwardly along. Therefore, the inner peripheral side cylindrical portion 643b is disposed on the inner peripheral side of the cylindrical superconductor 7A along the inner peripheral surface. An inner peripheral bottom portion 643c is continuously provided at a lower end of the inner peripheral side cylindrical portion 643b. The inner peripheral bottom portion 643c is located slightly above the cold stage 63 and slightly below the lower end position of the superconductor 74 of the cylindrical superconductor 7A as shown in FIG.

  By providing the vacuum heat insulating container 64 as described above, an insulating space surrounded by the upper surface portion of the refrigerator main body 61, the first container portion 641, the disc-shaped member 642, and the second container portion 643 is formed. Is done. The extended portion 62 of the refrigerator 6 and the cold stage 63 are provided in a space surrounded by the first container portion 641 and the disk-shaped member 642 in the heat insulating space. The cylindrical superconductor 7A is disposed in a space between the outer cylindrical portion 643a and the inner cylindrical portion 643b of the second container portion 643 in the heat insulating space.

  When the refrigerator 6 having the above configuration is driven, the cold stage 63 is cooled, and further, the cylindrical superconductor 7A mounted on the cold stage 63 is cooled. As a result, the cylindrical superconductor 7A is cooled below the superconducting critical temperature Tc, and the cylindrical superconductor 7A is brought into a superconducting state.

  As shown in FIG. 26, the inner Hall element 43 of the inner inspection unit 40 included in the inspection apparatus 1 is provided on the inner peripheral surface of the cylindrical superconductor 7A with the inner peripheral side cylindrical portion 643b of the second container portion 643 interposed therebetween. The outer Hall element 53 of the outer inspection unit 50 provided in the inspection apparatus 1 is disposed to face the outer peripheral surface of the cylindrical superconductor 7A with the outer cylindrical portion 643a of the second container portion 643 interposed therebetween. In this state, the inner Hall element 43 and the outer Hall element 53 are swept along the cylindrical peripheral surface (inner peripheral surface and outer peripheral surface) of the cylindrical superconductor 7A, so that the transmitted magnetic field is detected by the inner Hall element 43. Then, the shielding magnetic field is detected by the outer Hall element 53. Thus, the soundness of the superconducting state of the cylindrical superconductor 7A is inspected. Thus, according to the present embodiment, the cylindrical superconductor cooled by the refrigerator can be inspected.

(Fourth embodiment)
FIG. 27 is a diagram illustrating a state where the cylindrical superconductor 7A incorporated in the superconducting magnet of the NMR apparatus is inspected by the inspection apparatus 1A. FIG. 28 is a diagram showing a superconducting magnet 100 in which the cylindrical superconductor 7A is incorporated. First, the configuration of the superconducting magnet 100 will be described with reference to FIG. As shown in FIG. 28, the superconducting magnet 100 has a refrigerator 110 and a magnetic field generator 120.

  The refrigerator 110 has a refrigerator main body 111, an extension part 112, and a cold stage 113, similarly to the refrigerator 6 described in the third embodiment. Then, the magnetic field generator 120 is mounted on the cold stage 113.

  The magnetic field generator 120 has an inner superconductor 121, an outer superconductor 122, a sample holder 123, a vacuum heat insulating container 124, and a room temperature bore container 125.

  The inner superconductor 121 corresponds to the cylindrical superconductor of the present invention. The inner superconductor 121 has the same configuration as the cylindrical superconductor 7A according to the second embodiment, and has a cylindrical base 121a and a superconductor 121b. The cylindrical substrate 121a has a cylindrical portion and a flange radially extending radially outward from one end (lower end) of the cylindrical portion. The flange is mounted on the upper surface of the cold stage 113 coaxially with the cold stage 113. Is done. Further, a sheet-like superconductor 121b is attached to a concave portion formed on a large part of the outer peripheral surface of the cylindrical portion of the cylindrical base material 121a. Thereby, superconductor 121b is formed in a cylindrical shape.

  The outer superconductor 122 is a member that generates a strong magnetic field by capturing an external magnetic field in a superconducting state. The outer superconductor 122 is formed in a cylindrical shape by laminating a plurality of ring-shaped superconducting bulks along the axial direction. An inner superconductor 121 is coaxially arranged around the inner periphery of the cylindrical outer superconductor 122.

  The cylindrical outer superconductor 122 is coaxially arranged with the inner superconductor 121 such that the lower end surface is placed on the flange of the cylindrical base 121a. Then, a sample holder 123 is arranged on these superconductors so as to cover the outer peripheral surface and the upper end surface of the outer superconductor 122 and the upper end surface of the inner superconductor 121.

  The sample holder 123 has a main body 123a, a flange 123b, and a cover 123c. The main body 123a is formed in a cylindrical shape and is disposed so as to cover the outer periphery of the outer superconductor 122. A flange portion 123b is continuously provided at a lower end of the main body portion 123a. The flange portion 123b is formed so as to expand radially outward from the lower end of the main body portion 123a, and the lower surface thereof is fixed to the upper surface of the cold stage 113. Further, a cover part 123c is continuously provided on an upper end of the main body part 123a. The cover portion 123c is formed in a circular shape so as to cover the upper end opening of the main body portion 123a, and is disposed so as to cover the upper end surface of the outer superconductor 122 and the upper end surface of the inner superconductor 121. Further, a circular hole having a diameter substantially equal to the inner peripheral diameter of the inner superconductor is formed at the center of the cover portion 123c.

  The vacuum insulated container 124 has a main body 124a, a flange 124b, and a cover 124c. The main body 124a has an inner diameter larger than the outer diameter of the cold stage 113, and is formed in a cylindrical shape. The extension part 112 and the cold stage 113 of the refrigerator 110, the inner superconductor 121, the outer superconductor 122, and the sample holder 123 are covered by the main body part 124a. Further, a flange portion 124b is continuously provided at a lower end of the main body portion 124a. The flange portion 124b is fixed to the upper surface of the refrigerator main body 111 of the refrigerator 110. Further, a cover 124c is continuously provided on the upper end of the main body 124a. The cover part 124c is formed in a disk shape so as to cover an upper end opening of the main body part 124a. The cover 124c is located slightly above the cover 123c of the sample holder 123. Further, a circular hole having a diameter smaller than the diameter of the circular hole formed in the cover portion 123c of the sample holder 123 is formed at the center of the cover portion 124c.

  The room temperature bore container 125 has a container part 125a and a lid part 125b. The container portion 125 a has a bottomed cylindrical shape, and is disposed coaxially with the inner superconductor 121 and the outer superconductor 122 in the inner peripheral space of the inner superconductor 121 with the bottom face down. An upper end portion of the container portion 125a protrudes upward from a circular hole formed in the cover portion 124c of the vacuum heat insulating container 124, and a lid portion 125b formed so as to radially spread radially outward from the upper end thereof. Is established. The lid 125b is placed on the upper surface of the cover 124c of the vacuum heat insulating container 124.

  The space above the refrigerator main body 111 is made a closed space by the vacuum heat insulating container 124 and the room temperature bore container 125. In the sealed space, the extension 112 and the cold stage 113 of the refrigerator 110, the outer superconductor 122, the inner superconductor 121, and the sample holder 123 are provided. This enclosed space is evacuated for heat insulation. The inner peripheral space of the container portion 125a of the room temperature bore container 125 is called a room temperature bore space.

  In the superconducting magnet 100 having the above configuration, when the refrigerator 110 is driven, the cold stage 113 is cooled, and the outer superconductor 122 and the inner superconductor 121 mounted on the cold stage 113 are further cooled. As a result, the outer superconductor 122 and the inner superconductor 121 are cooled below the superconducting critical temperature Tc, and are brought into a superconducting state.

  Further, as shown in FIG. 27, the inspection apparatus 1A according to the present embodiment has a configuration in which the outer inspection unit 50 is excluded from the inspection apparatus 1 according to the modification 2 shown in FIG. That is, the inspection apparatus 1A includes the inspection unit 40 having the inner Hall element 43 and the inner permanent magnet 45, and does not include the outer inspection unit. Then, the inner inspection unit 40 is inserted into the room temperature bore space of the superconducting magnet 100.

  As shown in FIG. 28, the inner Hall element 43 of the inner inspection unit 40 inserted into the room temperature bore space has the inner periphery of the inner superconductor 121 (cylindrical superconductor) sandwiching the container portion 125a of the room temperature bore container 125. Face to face. Further, the inner permanent magnet 45 is disposed facing the inner peripheral surface of the inner superconductor 121 with the inner Hall element 43 and the container portion 125 a of the room temperature bore container 125 interposed therebetween. Here, in the present embodiment, the inner permanent magnet 45 is arranged such that the N pole side faces the inner Hall element 43. In this state, the inner Hall element 43 is swept along the inner peripheral surface of the inner superconductor 121.

  In the present embodiment, a magnetic field is applied to the inner superconductor 121 from the N pole of the inner permanent magnet 45. Since the inner superconductor 121 is in a superconducting state, a shielding current is formed in the inner superconductor 121 so as to shield the applied magnetic field from the inner permanent magnet 45. Thereby, the applied magnetic field is shielded, and the shielded magnetic field (shielded magnetic field) is formed between the inner permanent magnet 45 and the inner superconductor 121 in the inner peripheral space of the inner superconductor 121. Therefore, the inner Hall element 43 between the inner permanent magnet 45 and the inner superconductor 121 detects the shielding magnetic field. Thus, in the present embodiment, the inner Hall element 43 functions as a shielding magnetic field detection sensor. Then, by detecting the shielding magnetic field while the inner Hall element 43 is swept (moved) along the inner peripheral surface of the inner superconductor 121, the soundness of the superconducting state of the inner superconductor 121 is inspected.

  According to this embodiment, the inner superconductor 121 which is a cylindrical superconductor incorporated in the superconducting magnet 100 for NMR can be directly inspected through the room-temperature bore container 125. For this reason, the cylindrical superconductor can be inspected without preparing a dedicated refrigerator or vacuum container for the inspection.

Hereinafter, various modifications for inspecting the soundness of the superconducting state of the cylindrical superconductor 7A cooled by the refrigerator 6 described in the third embodiment will be described.
(Fifth embodiment)
FIG. 29 is a diagram illustrating an example of inspection using the inspection device according to the fifth embodiment. As shown in FIG. 29, in the present embodiment, the back surface of the inner Hall element 43 (the surface of the inner Hall element 43 opposite to the surface facing the inner peripheral surface of the cylindrical superconductor 7A) is made of a magnetic material. Yoke 46 is provided. In this embodiment, the outer permanent magnet 55 is provided, but the outer Hall element is not provided. The other configuration is the same as the configuration of the inspection device 1 shown in the first embodiment.

  Since the yoke 46 is provided on the back surface of the inner Hall element 43, the magnetic flux generated from the N pole of the outer permanent magnet 55 and transmitted through, for example, a defect of the cylindrical superconductor 7A concentrates on the yoke 46. Since the yoke 46 is attached to the back of the inner Hall element 43, the magnetic flux concentrated on the yoke always passes through the inner Hall element 43. Therefore, the transmitted magnetic field detected by the inner Hall element 43 becomes stronger. That is, the detection sensitivity is improved, and even if the defect is a minute defect, the presence of the defect can be represented by a change in the intensity of the transmitted magnetic field. For this reason, the inspection accuracy can be further improved.

(Sixth embodiment)
FIG. 30 is a diagram illustrating an example of inspection using the inspection device according to the sixth embodiment. As shown in FIG. 30, in the inspection device according to the present embodiment, a yoke 46 is provided on the back surface of the inner Hall element 43, as in the fifth embodiment. Further, an outer Hall element 53 is provided between the outer permanent magnet 55 and the cylindrical superconductor 7A. The other configuration is the same as the configuration of the inspection device 1 described in the first embodiment.

  In this embodiment, as in the fifth embodiment, the magnetic flux transmitted through the defect of the cylindrical superconductor 7A concentrates on the yoke 46 provided on the back surface of the inner Hall element 43. For this reason, the detection sensitivity of the inner Hall element 43 and the outer Hall element 53 is improved, and the inspection accuracy can be improved. Further, similarly to the first embodiment, the transmission magnetic field can be detected by the inner Hall element 43 and the shielding magnetic field can be detected by the outer Hall element 53 simultaneously.

(Seventh embodiment)
FIG. 31 is a diagram illustrating an example of inspection using the inspection device according to the seventh embodiment. In this embodiment, an inspection apparatus similar to the inspection apparatus 1A shown in FIG. 27 described in the fourth embodiment is used. Therefore, the inspection apparatus according to the present embodiment includes the inner inspection unit 40 but does not include the outer inspection unit.

  In the inspection device according to the present embodiment, the inner inspection unit 40 includes the first inner Hall element 43A and the second inner Hall element 43B. The first inner Hall element 43A corresponds to a first sensor of the present invention, and the second inner Hall element 43B corresponds to a second sensor of the present invention. The first inner Hall element 43A has a magnetic sensing part 43a1, and is provided between the N pole surface of the inner permanent magnet 45 provided in the inner inspection unit 40 and the cylindrical superconductor 7A. The second inner Hall element 43B has a magnetic sensing portion 43a2, and is provided between the S-pole surface of the inner permanent magnet 45, that is, the pole surface opposite to the N-pole surface, and the cylindrical superconductor 7A. Note that a first inner spacer 44A is provided between the N pole surface of the inner permanent magnet 45 and the first inner Hall element 43A, and between the S pole face of the inner permanent magnet 45 and the second inner Hall element 43B. The second inner spacer 44B is provided. Further, the inner permanent magnet 45 is embedded in the inner rod portion 41 such that, for example, as shown in FIG. 31, the N-pole surface and the S-pole surface are exposed in the opposite directions from the outer peripheral surface of the inner rod portion 41. By doing so, it can be configured. Other configurations of the inspection apparatus according to the present embodiment are the same as those of the inspection apparatus 1A described in the fourth embodiment.

  According to the present embodiment, the first inner Hall element 43A detects the shielding magnetic field in the inspection area facing the same, and the second inner Hall element 43B detects the shielding magnetic field in the inspection area facing the same. That is, it is possible to simultaneously detect the shielding magnetic field in the two inspection areas. Therefore, the inspection time can be shortened. Note that, even when the S pole surface of the inner permanent magnet 45 faces the cylindrical peripheral surface of the cylindrical superconductor 7A as in the present embodiment, the N pole surface is formed on the cylindrical peripheral surface of the cylindrical superconductor 7A. In the same manner as when facing each other, the shielding magnetic field and the transmitted magnetic field can be detected.

(Eighth embodiment)
FIG. 32 shows an example of inspection to which the inspection device according to the eighth embodiment is applied. In this embodiment, a yoke 56 for concentrating magnetic flux is attached to the N pole surface of the outer permanent magnet 55. Other configurations are the same as those of the inspection apparatus 1 according to the first embodiment.

  According to the present embodiment, the magnetic field generated from the N-pole surface of the outer permanent magnet 55 concentrates on the yoke 56 and thereby concentrates on the inspection area of the cylindrical superconductor 7A. Therefore, when a defect exists, more magnetic flux passes through the outer Hall element 53 and the inner Hall element 43. Therefore, when a defect is present, the magnitude of the shielding magnetic field and the transmitted magnetic field is further increased, and the detection sensitivity and the position resolution are improved. As a result, the inspection accuracy is further improved.

(Ninth embodiment)
FIG. 33 shows an example of inspection using the inspection device according to the ninth embodiment. In this embodiment, an outer coil 57 is provided instead of the outer permanent magnet 55. Other configurations are the same as those of the inspection apparatus 1 according to the first embodiment.

  According to the present embodiment, the magnitude of the magnetic field applied from the outer coil 57 to the cylindrical superconductor 7A can be adjusted by controlling the amount of current supplied to the outer coil 57. Therefore, by changing the amount of current and the direction of current to the outer coil 57, it is possible to set optimal inspection conditions. If the current flowing through the outer coil 57 is small and the generated magnetic field is small, the presence or absence of defects on the surface of the cylindrical superconductor 7A and the evaluation of non-uniformity of the critical current density Jc, that is, the surface of the cylindrical superconductor 7A An inspection of the layer health can be performed. Further, when the energizing current is made very large and the generated magnetic field is made very large, the magnetic field gradually enters the inside of the cylindrical superconductor 7A from the surface thereof. Therefore, it is possible to inspect not only the surface of the cylindrical superconductor 7A but also the soundness of the superconducting state inside the cylindrical superconductor 7A (the presence or absence of a defect and the non-uniformity of the critical current density Jc).

  Although various embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the first embodiment, an example in which the shielded magnetic field is detected by the outer Hall element 53 and the transmitted magnetic field is detected by the inner Hall element 43 has been described, but only the shielded magnetic field or only the transmitted magnetic field may be detected. The inspection device may be configured as follows. In the ninth embodiment, the example in which the outer coil 57 is used has been described, but an electromagnet may be used instead of the coil. Further, the outer Hall element 53 and the outer permanent magnet 55 may be attached to the outer inspection unit 50, and the inner Hall element 43 and the inner permanent magnet 55 may be attached to the inner inspection unit 40. That is, magnets may be provided on both the inner and outer peripheral sides of the cylindrical superconductor. In this case, the state of the shielding magnetic field and the transmission magnetic field becomes complicated, but the shielding magnetic field and the transmission magnetic field are still changed depending on the presence or absence of a defect. Sex can be tested. Thus, the present invention can be modified without departing from the spirit thereof.

1, 1A: inspection device, 6: refrigerator, 7, 7A: cylindrical superconductor, 71, 71A: cylindrical substrate, 72: inner superconducting layer, 73: outer superconducting layer, 74: superconductor, 10: manual lifting Operation unit, 20: axial moving unit, 25: axial moving stage, 30: rotating unit, 33: rotating stage, 40: inner inspection unit, 41: inner rod part, 42: inner inspection plate, 43: inner Hall element (Transmission magnetic field detection sensor, shielding magnetic field detection sensor), 43A: first inner Hall element (first sensor), 43B: second inner Hall element (second sensor), 44: inner spacer, 45: inner permanent magnet (magnet) ), 46: yoke, 50: outer inspection unit, 51: outer rod portion, 52: outer inspection plate, 53, 531: outer Hall element (shielded magnetic field detection sensor, transmitted magnetic field detection sensor), 5 2 First outer Hall element, 533 Second outer Hall element, 54 Outside spacer, 55 Outside permanent magnet (magnet), 56 Yoke, 57 Outside coil (magnet), 81 Container, 100 Superconducting magnet , 110: refrigerator, 120: magnetic field generator, 121: inner superconductor (cylindrical superconductor), 121a: cylindrical substrate, 121b: superconductor, 122: outer superconductor, 123: sample holder, 124: vacuum insulation Container, 125: room temperature bore container, B1, B2: spiral boundary, D: defect, R: inspection area

Claims (14)

A shielding magnetic field detection sensor arranged on the cylindrical peripheral surface of the cylindrical superconductor in a superconducting state,
An axial moving unit configured to be able to move the shielding magnetic field detection sensor along the axial direction of the cylindrical superconductor,
A rotation unit configured to be able to rotate the shielding magnetic field detection sensor around a central axis of the cylindrical superconductor,
It has two different magnetic poles, and one magnetic pole is disposed at a position facing the cylindrical peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween, and is movable with the shielding magnetic field detection sensor. A magnet connected to the sensor,
With
The shielded magnetic field detection sensor, the magnetic field applied to the cylindrical superconductor from the one magnetic pole of the magnet is shielded by the cylindrical superconductor cylindrical peripheral surface formed by the shielded magnetic field, the axis Checking the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor by detecting while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the direction moving unit and the rotating unit; Inspection system for cylindrical superconductors configured to be able to The inspection apparatus for a cylindrical superconductor according to claim 1,
The magnet and the shielding magnetic field detection sensor are disposed in an inner peripheral space of the cylindrical superconductor,
The shielding magnetic field detection sensor is disposed facing the inner peripheral surface of the cylindrical superconductor,
The inspection apparatus for a cylindrical superconductor, wherein the magnet is disposed at a position where the one magnetic pole faces the inner peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween. An inspection device for a cylindrical superconductor according to claim 2,
The shielded magnetic field detection sensor has a first sensor and a second sensor,
The magnet is arranged such that the one magnetic pole faces the inner peripheral surface of the cylindrical superconductor with the first sensor interposed therebetween, and the other magnetic pole of the magnet has the cylindrical superconductor sandwiched with the second sensor. It is disposed at the position to face the inner peripheral surface of the
The first sensor detects a shielding magnetic field formed by a magnetic field applied to the cylindrical superconductor from the one magnetic pole being shielded by a cylindrical peripheral surface of the cylindrical superconductor, and the second sensor Is an inspection device for a cylindrical superconductor, which detects a shield magnetic field formed by shielding a magnetic field applied to the cylindrical superconductor from the other magnetic pole on a cylindrical peripheral surface of the cylindrical superconductor. The inspection apparatus for a cylindrical superconductor according to claim 1,
The magnet and the shielding magnetic field detection sensor are disposed in an outer peripheral space of the cylindrical superconductor,
The shielding magnetic field detection sensor is disposed facing the outer peripheral surface of the cylindrical superconductor,
The inspection apparatus for a cylindrical superconductor, wherein the magnet is disposed at a position where the one magnetic pole faces the outer peripheral surface of the cylindrical superconductor with the shielding magnetic field detection sensor interposed therebetween. A transmission magnetic field detection sensor arranged facing the cylindrical surface of the cylindrical superconductor in a superconducting state,
An axial moving unit configured to be able to move the transmitted magnetic field detection sensor along the axial direction of the cylindrical superconductor,
A rotation unit configured to be able to rotate the transmitted magnetic field detection sensor around a central axis of the cylindrical superconductor,
The transmission magnetic field has two different magnetic poles, and one of the magnetic poles is disposed at a position facing the transmission magnetic field detection sensor across a cylindrical peripheral surface of the cylindrical superconductor, and is movable with the transmission magnetic field detection sensor. A magnet connected to the detection sensor;
With
The transmitted magnetic field detection sensor, the magnetic field applied from the one magnetic pole of the magnet to the cylindrical superconductor is transmitted through the cylindrical peripheral surface of the cylindrical superconductor, the transmission magnetic field formed by the axial direction Inspection of the soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor by detecting while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the moving unit and the rotating unit. Inspection system for cylindrical superconductors configured to be able to The inspection apparatus for a cylindrical superconductor according to claim 5,
An inspection device for a cylindrical superconductor, wherein a yoke is provided on a back surface of the transmission magnetic field detection sensor. The inspection device for a cylindrical superconductor according to claim 5 or 6,
Driving of the axial moving unit and the rotating unit is disposed between the magnet and the cylindrical superconductor, and is disposed to face the transmitted magnetic field detection sensor with a cylindrical peripheral surface of the cylindrical superconductor sandwiched therebetween. A shielding magnetic field detection sensor configured to be movable together with the transmitted magnetic field detection sensor,
The shielded magnetic field detection sensor, the magnetic field applied to the cylindrical superconductor from the one magnetic pole of the magnet is shielded by the cylindrical superconductor cylindrical peripheral surface formed by the shielded magnetic field, the axis The soundness of the superconducting state in the cylindrical peripheral surface of the cylindrical superconductor is detected by detecting while moving along the cylindrical peripheral surface of the cylindrical superconductor by driving the direction moving unit and the rotating unit. Inspection system for cylindrical superconductors. An inspection device for a cylindrical superconductor according to any one of claims 1 to 7,
An inspection device for a cylindrical superconductor, wherein a yoke for focusing a magnetic field on the one magnetic pole of the magnet is provided. An inspection device for a cylindrical superconductor according to any one of claims 1 to 8,
An inspection device for a cylindrical superconductor, wherein the magnet is a permanent magnet. An inspection device for a cylindrical superconductor according to any one of claims 1 to 8,
An inspection device for a cylindrical superconductor, wherein the magnet is a coil or an electromagnet. In the inspection apparatus of the cylindrical superconductor according to any one of claims 1 to 10,
The cylindrical superconductor, a cylindrical substrate formed in a cylindrical shape,
A superconducting layer formed into a cylindrical shape by superconducting wire being spirally wound on the inner peripheral surface or outer peripheral surface of the cylindrical base material,
With
The axial movement unit and the rotation unit are controlled such that the shield magnetic field detection sensor and / or the transmission magnetic field detection sensor move on the cylindrical peripheral surface of the cylindrical superconductor along the spiral winding direction of the superconducting wire. Inspection equipment for cylindrical superconductors. A shielding magnetic field detection sensor disposed on the cylindrical peripheral surface of the cylindrical superconductor in a superconducting state, and two different magnetic poles, one magnetic pole of which is sandwiched by the shielding magnetic field detection sensor and the cylindrical peripheral surface of the cylindrical superconductor And a magnet disposed at a position facing, and a sweeping step of sweeping in the axial and circumferential directions of the cylindrical superconductor,
The sweeping magnetic field detection sensor sweeps a shielding magnetic field formed by shielding a magnetic field applied to the cylindrical superconductor from the one magnetic pole of the magnet to a cylindrical peripheral surface of the cylindrical superconductor. A shielding magnetic field detection step of detecting while being swept in the process,
A method for inspecting a cylindrical superconductor, comprising: A transmission magnetic field detection sensor disposed on a cylindrical peripheral surface of a cylindrical superconductor in a superconducting state, and a transmission magnetic field detection sensor having two different magnetic poles, one magnetic pole sandwiching the cylindrical peripheral surface of the cylindrical superconductor A magnet disposed at a position facing the, a sweeping step of sweeping in the axial direction and circumferential direction of the cylindrical superconductor,
The transmitted magnetic field detection sensor, the transmitted magnetic field formed by transmitting the magnetic field applied to the cylindrical superconductor from one magnetic pole of the magnet through the cylindrical peripheral surface of the cylindrical superconductor, in the sweeping step, A transmitted magnetic field detection step of detecting while being swept,
A method for inspecting a cylindrical superconductor, comprising: In the inspection method of the cylindrical superconductor according to claim 12 or 13,
The cylindrical superconductor, a cylindrical substrate formed in a cylindrical shape,
A superconducting layer formed into a cylindrical shape by superconducting wires being spirally wound on the inner peripheral surface or outer peripheral surface of the cylindrical base material,
With
In the sweeping step, the shielded magnetic field detection sensor and / or the transmitted magnetic field detection sensor are swept so as to move on a cylindrical peripheral surface of the cylindrical superconductor along a spiral winding direction of the superconducting wire. Inspection method for cylindrical superconductors.