JP2022108794A - Superconducting coil device - Google Patents

Abstract

To suppress wire movement that may occur during operation of a superconducting coil.SOLUTION: A superconducting coil device 10 includes a superconducting coil 12 formed by winding a tape-shaped wire, a set of coil support members, one of which is joined to one end surface of the superconducting coil 12 and the other of which is joined to the other end surface of the superconducting coil 12, and a tensioning mechanism 20 connected to the set of coil support members and applying a tensile force to at least one of the set of coil support members so as to generate tensile stress in the width direction of the tape-shaped wire.SELECTED DRAWING: Figure 1

Description

The present invention relates to a superconducting coil device.

2. Description of the Related Art Conventionally, a high-temperature superconducting coil formed by winding a tape-shaped high-temperature superconducting wire is known. During operation, the superconducting coil exerts a strong electromagnetic force outward in the radial direction of the coil due to the interaction between the high magnetic field generated and the large current flowing through the coil. This electromagnetic force exerts a force (hoop stress) to stretch the tape-like wire in the circumferential direction of the coil. Hoop stress can be comparable to the tensile strength of the wire in some cases. Therefore, it has been proposed to cover the superconducting coil with a coil case in which a frame material surrounding the outer circumference of the superconducting coil and side plates provided on the upper and lower surfaces of the coil are joined to reinforce the superconducting coil with this case.

Cryogenic Engineering, Vol. 48, No. 5, p. 213-219

In the superconducting coil described above, there is a slight gap between the wires wound and laminated in the radial direction of the coil or between the wire and the case. Therefore, when a strong electromagnetic force is applied to the wire during operation of the superconducting coil, the wire moves somewhat. Wire movement can adversely affect the operation of superconducting coils.

For example. Most superconducting coils are equipped with a mechanism to detect thermal runaway (quench). This often employs voltage-based sensing. When a quench is detected, the superconducting coil will transition to a state different from normal operation, such as stopping operation or performing protective actions aimed at recovery from the quench. The movement of the wire due to the strong electromagnetic force changes the inductance of the superconducting coil, and there is a risk that the superconducting coil will generate a large voltage due to electromagnetic induction. There is concern that the quench detection mechanism may erroneously detect a quench from this abnormal voltage and erroneously terminate normal operation of the superconducting coil. Another concern is the risk that the movement of the wire will cause friction between the wires and the resulting frictional heat will actually cause quenching.

One exemplary objective of certain aspects of the present invention is to suppress wire movement that may occur during operation of a superconducting coil.

According to one aspect of the present invention, a superconducting coil device includes a superconducting coil formed by winding a tape-shaped wire, one coil supporting member joined to one end face of the superconducting coil, and the other coil supporting member being superconducting. A set of coil support members joined to the other end face of the coil, and a set of coil support members connected to the set of coil support members so as to generate tensile stress in the width direction of the tape-shaped wire. a tensioning mechanism for applying a tensile force to at least one of the coil supports.

ADVANTAGE OF THE INVENTION According to this invention, the movement of the wire which may arise during operation|movement of a superconducting coil can be suppressed.

1 is a diagram schematically showing a superconducting coil device according to an embodiment; FIG. 2 schematically shows an exemplary configuration of the superconducting coil shown in FIG. 1; FIG. FIG. 3 is a schematic diagram showing stress stiffening of the high-temperature superconducting wire shown in FIG. 2; FIG. 4 is a diagram schematically showing another example of the superconducting coil device according to the embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description and drawings, the same or equivalent components, members, and processes are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. The scales and shapes of the illustrated parts are set for convenience in order to facilitate explanation, and should not be construed as limiting unless otherwise specified. The embodiment is an example and does not limit the scope of the present invention. All features and combinations thereof described in the embodiments are not necessarily essential to the invention.

FIG. 1 is a diagram schematically showing a superconducting coil device 10 according to an embodiment. The superconducting coil device 10 includes a superconducting coil 12, and is configured to generate a strong magnetic field by energizing the superconducting coil 12 while the superconducting coil 12 is cooled to an extremely low temperature below the superconducting transition temperature. The superconducting coil device 10 is installed in high magnetic field utilization equipment as a magnetic field source for, for example, an NMR system, an MRI system, an accelerator such as a cyclotron, a high energy physical system such as a nuclear fusion system, or other high magnetic field utilization equipment (not shown). and can generate the high magnetic fields required by the instrument. In this embodiment, the superconducting coil device 10 is not an immersion cooling system in which the superconducting coils 12 are cooled by immersing them in a cryogenic liquid coolant such as liquid helium. It is configured as conduction cooled with direct cooling at 32 .

The superconducting coil 12 is, for example, a high-temperature superconducting coil formed by winding a tape-shaped high-temperature superconducting wire. An exemplary high temperature superconducting coil is described below with reference to FIG.

The superconducting coil device 10 includes a coil reinforcing case 14 arranged to surround the superconducting coil 12 so as to reinforce the superconducting coil 12 . The superconducting coil device 10 also includes a tensioning mechanism 20 that applies a tensile force to the coil reinforcing case 14 so as to generate tensile stress in the width direction (vertical direction in FIG. 1) of the tape-shaped wire. Although details will be described later, in this embodiment, the tensioning mechanism 20 is configured to mechanically apply a tensioning force.

The coil reinforcement case 14 includes a case outer frame 14a and a pair of coil support members (14b, 14c). Case outer frame 14 a is arranged adjacent to the outer peripheral surface of superconducting coil 12 . The case upper plate 14b, which is one of the coil supporting members, is arranged adjacent to one end face (upper end face) of the superconducting coil 12, and the other coil supporting member, the case lower plate 14c, is arranged on the other side of the superconducting coil 12. It is arranged adjacent to the end surface (lower end surface). Case upper plate 14 b is joined to the upper end surface of superconducting coil 12 , and case lower plate 14 c is joined to the lower end surface of superconducting coil 12 . Case outer frame 14 a supports the outer peripheral surface of superconducting coil 12 , case upper plate 14 b supports the upper end surface of superconducting coil 12 , and case lower plate 14 c supports the lower end surface of superconducting coil 12 .

The end face of the coil support member and the superconducting coil 12 may be adhered using an adhesive, for example. The adhesive is preferably of a material that is compatible with cryogenic temperatures (eg, a resinous material that does not or is less prone to low temperature embrittlement at the cooling temperatures used). Representative examples of such adhesives include particle-dispersed composite epoxy resin adhesives such as STYCAST manufactured by Emerson & Cuming (for example, Stycast 2850). The surface to which the adhesive is applied may be roughened to enhance adhesion. Alternatively, other suitable bonding methods may be used.

The outer periphery of the case upper plate 14b is connected to the upper end of the case outer frame 14a, and the outer periphery of the case lower plate 14c is connected to the lower end of the case outer frame 14a. Various methods can be used for this connection, and for example, it may be mechanically connected with fastening parts such as bolts, or it may be connected by welding.

When superconducting coil 12 has an annular shape, coil reinforcing case 14 may be a cylindrical box that just accommodates superconducting coil 12 . Therefore, the case outer frame 14a may be an annular frame extending along the outer peripheral surface of the superconducting coil 12 in the coil's circumferential direction. The case upper plate 14b and the case lower plate 14c may be circular disc-shaped plates extending along the upper end surface and the lower end surface of the superconducting coil 12, respectively.

A strong electromagnetic force acts on the superconducting coil 12 during excitation, causing the superconducting coil 12 to bulge in the radial direction due to interaction between a large current flowing through itself and a high magnetic field generated thereby. Coil reinforcement case 14 is formed of a metallic material, such as stainless steel, or other suitable high-strength material to provide the mechanical strength required to reinforce superconducting coil 12 against this electromagnetic force. be. Other suitable high strength materials include fiber and resin composites such as, for example, glass fiber reinforced plastic (GFRP).

In FIG. 1, the electromagnetic force 50 exerted in the radial direction on the superconducting coil 12 during excitation is indicated by thick arrows, and the upper case plate 14b and the lower case plate 14c of the coil reinforcing case 14 are formed to resist the electromagnetic force 50. A thin arrow indicates a mechanical internal stress 52 acting on the . Thus, the coil reinforcement case 14 reinforces the superconducting coil 12 , and the entire structure including the superconducting coil 12 and the coil reinforcement case 14 can provide mechanical support against the strong electromagnetic force 50 .

Superconducting coil 12 is installed in vacuum vessel 30 . Vacuum vessel 30 is configured to separate vacuum region 16 from external environment 18 . A vacuum region 16 is defined within a vacuum vessel 30 . To enhance the thermal insulation performance of the vacuum vessel 30, insulating material may be provided along the surfaces of, or within the wall members of, the vacuum vessel 30 that separate the vacuum region 16 from the external environment 18. Vacuum vessel 30 may be, for example, a cryostat. A tension mechanism 20 and a cryogenic refrigerator 32 are installed in the vacuum vessel 30 .

The tensioning mechanism 20 includes a tensioning device 22 that produces a tensioning force applied to the coil stiffening case 14 and connects the tensioning device 22 to the case top plate 14b so as to transfer this tensioning force from the tensioning device 22 to the case top plate 14b. and a connection member 24 that

The tensioning device 22 is located outside the vacuum vessel 30, ie in the external environment 18, and comprises, by way of example, an actuating member 22a, a drive 22b and a bellows 22c. The actuating member 22a is connected to the wall (for example, the upper wall) of the vacuum vessel 30 via a bellows 22c and constitutes a part of the vacuum vessel 30. As shown in FIG. The actuating member 22a may be a flange or block to which the ends of the connecting member 24 are fixed and is made of a metallic material such as stainless steel or other suitable high strength material (eg a composite material such as GFRP). . The bellows 22c has vacuum flanges at both ends which are connected to the actuating member 22a and the vacuum vessel 30 respectively so as to keep the vacuum area 16 airtight. Thus, the space within bellows 22 c becomes part of vacuum region 16 . The drive device 22b is installed in the vacuum container 30 and connected to the operating member 22a so as to move the operating member 22a up and down with respect to the vacuum container 30 . The driving device 22b may have an appropriate driving source such as hydraulic pressure, pneumatic pressure, electric motor, electromagnet, or the like. Note that the tensioning device 22 may be arranged inside the vacuum vessel 30 .

The connecting member 24 has one end fixed to the operating member 22a within the bellows 22c and the other end fixed to the case upper plate 14b. The connecting member 24 has an elongated rod-like shape and extends from the actuating member 22 a through the bellows 22 c and through the wall of the vacuum vessel 30 to the vacuum region 16 . A flange portion may be provided at the end of the connection member 24 fixed to the case upper plate 14b, and this flange portion may be fixed to the case upper plate 14b. Connecting member 24 is formed of a metallic material, such as stainless steel, or other suitable high-strength material. In order to suppress heat input from the external environment 18 to the superconducting coil 12 through the connecting member 24, the connecting member 24 is preferably made of a heat insulating material. Therefore, the connection member 24 is preferably made of, for example, glass fiber reinforced plastic (GFRP) in terms of having both high strength and heat insulating performance.

The case bottom plate 14c is connected to the wall (for example, the bottom wall) of the vacuum vessel 30 by a support member 26. As shown in FIG. Like the connection member 24, the support member 26 may have an elongated rod-like shape and may have flanges at both ends. Support member 26 may be formed of a metallic material, such as stainless steel, or other suitable high-strength material (eg, GFRP, etc.).

Therefore, when the tension device 22 pulls up the connection member 24 (arrow 28 in FIG. 1), the case upper plate 14b is pulled in the coil center axis direction with respect to the case lower plate 14c. Thereby, the tensioning mechanism 20 generates tensile stress in the width direction (the same direction as the coil central axis direction) of the tape-shaped wire forming the superconducting coil 12 .

The pulling mechanism 20 may be configured to pull the case lower plate 14c instead of the case upper plate 14b. In this case, the connecting member 24 may connect the tensioning device 22 to the case bottom plate 14c such that the tensioning device 22 generates a tension force from the tensioning device 22 to the case bottom plate 14c. Alternatively, the pulling mechanism 20 may be configured to pull the case upper plate 14b and the case lower plate 14c in opposite directions. A set of tensioning devices 22 and connecting members 24 may be provided, one tensioning device 22 and connecting member 24 pulling the case top plate 14b and the other tensioning device 22 and connecting member 24 pulling the case bottom plate 14c. .

Cryogenic refrigerator 32 includes a single cooling stage 32 a and a dual cooling stage 32 b located within vacuum vessel 30 . The cryogenic refrigerator 32 includes a compressor (not shown) for a working gas (for example, helium gas) and an expander also called a cold head, and the compressor and the expander constitute a refrigeration cycle of the cryogenic refrigerator 32. , thereby cooling the single cooling stage 32a and the double cooling stage 32b, respectively, to the desired cryogenic temperatures. The first-stage cooling stage 32a is cooled to, for example, 50K to 80K, and the two-stage cooling stage 32b is cooled to, for example, 3K to 20K. The single-cooling stage 32a and the double-cooling stage 32b are made of a metallic material such as copper or other material with high thermal conductivity.

Cryogenic refrigerator 32 is, by way of example, a two-stage Gifford-McMahon (GM) refrigerator, but may also be a pulse tube refrigerator, Stirling refrigerator, or other type of cryogenic refrigerator. may Cryogenic refrigerator 32 may be a single stage GM refrigerator or other type of cryogenic refrigerator.

Also, the vacuum vessel 30 may be provided with a heat shield 34 that is thermally coupled to the first-stage cooling stage 32a and cooled to the cooling temperature of the first-stage cooling stage 32a. The heat shield 34 is arranged so as to surround the superconducting coil device 10, the two-stage cooling stage 32b of the cryogenic refrigerator 32, or other low-temperature portions that are cooled to a lower temperature, and protects these low-temperature portions from external radiant heat. can be thermally protected. Heat shield 34 is formed of a metallic material such as copper or other material with high thermal conductivity.

The heat shield 34 is directly attached to the first cooling stage 32a or attached via an appropriate heat transfer member. As illustrated, the heat shield 34 has an opening (for example, a through hole) through which the connection member 24 is inserted and an opening through which the support member 26 is inserted.

The coil reinforcing case 14 is thermally coupled with the two-stage cooling stage 32b and cooled to the cooling temperature of the two-stage cooling stage 32b. The coil reinforcing case 14 may be thermally coupled with the two-stage cooling stage 32b via a heat transfer member 36 made of a high heat conductive material such as copper. The heat transfer member 36 may be a rigid heat transfer member, or it may be a flexible heat transfer member, such as formed as a bundle of wires or a laminate of foils so as to be flexible. . Alternatively, the coil stiffening case 14 may be attached directly to the two-stage cooling stage 32b.

The current leads 38 are brought out of the vacuum vessel 30 through vacuum feedthroughs provided in the vacuum vessel 30 to connect the superconducting coil 12 to a power source (not shown) external to the vacuum vessel 30 .

In this manner, the superconducting coil 12 is cooled to the cooling temperature of the two-stage cooling stage 32b of the cryogenic refrigerator 32 via the heat transfer member 36 and the coil reinforcing case 14 by the two-stage cooling stage 32b. By energizing the superconducting coil 12 through the current lead portion 38, the superconducting coil device 10 can generate a strong magnetic field.

In addition, when the coil reinforcement case 14 covers the entire superconducting coil 12, the coil reinforcement case 14 may be an airtight container. Alternatively, the coil reinforcement case 14 may have openings that communicate the interior of the case with the vacuum region 16 within the vacuum vessel 30 . For example, the coil reinforcement case 14 may not have the case outer frame 14a. In this case, the case upper plate 14b and the case lower plate 14c are respectively joined to the end surfaces of the superconducting coil 12, but are not connected to each other. good too. At least one of the case upper plate 14b and the case lower plate 14c may not cover the entire end surface of the superconducting coil 12, and may be a plate having an opening.

FIG. 2 is a diagram schematically showing an exemplary configuration of superconducting coil 12 shown in FIG. The left part of FIG. 2 shows a schematic perspective view of the superconducting coil 12, and the right part shows a cross section of the wire on a plane perpendicular to the longitudinal direction of the wire. In this cross-sectional view, the width direction of the wire corresponds to the up-down direction, and the thickness direction corresponds to the left-right direction.

In this embodiment, the superconducting coil 12 is a single pancake coil formed by winding tape-shaped high-temperature superconducting wires 40, also called REBCO wires, so as to stack them in the radial direction of the coil.

The high-temperature superconducting wire 40 has a superconducting layer 40c formed on a substrate 40a with an intermediate layer 40b interposed therebetween, a first stabilizing layer 40d formed on the superconducting layer 40c, and a second stabilizing layer 40d on the outer periphery thereof. The layer 40e is covered and constructed.

The substrate 40a is made of a metal such as nickel alloy (Hastelloy), silver, or silver alloy and has a thickness of 100 μm and a width of 10 mm, for example. Hastelloy is an alloy containing nickel as a main component and chromium, molybdenum, etc., and is excellent in heat resistance, mechanical strength, and the like. The intermediate layer 40b is made of gadolinium/zirconium oxide (Gd/Zr oxide), magnesium oxide (MgO), yttrium-stabilized zirconium (YSZ), barium/zirconium oxide (Ba/Zr oxide), and cerium oxide (CeO2). etc., to have a thickness of 500 nm and a width of 10 mm, for example.

The superconducting layer 40c is formed to have a thickness of about 1 μm and a width of 10 mm, for example, by CVD (chemical vapor deposition) of a rare earth oxide superconductor. Rare earth elements include lanthanum (La), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), dysprosium (Dy), holmium (Ho), erbium (Er), yttrium (Y), Ytterbium (Yb) and the like can be mentioned. Examples of rare earth oxides include RE, Ba, Cu, O, and the like. However, RE represents a rare earth element. Specific examples of the superconducting layer 40c include yttrium-barium-copper oxide (Y-Ba-Cu oxide) and lanthanum-barium-copper oxide (La-Ba-Cu oxide).

The first stabilizing layer 40d is formed to have a thickness of about 15 μm and a width of 10 mm, for example, by sputtering a metal such as silver. The second stabilizing layer 40e is formed to have a thickness of about 50 μm, for example, by plating with a metal such as copper.

Thus, the high-temperature superconducting wire 40 includes a multilayer structure 42 including a superconducting layer 40c and a covering layer (eg, second stabilizing layer 40e) covering the multilayer structure 42. FIG. As shown, the coating layer covers the entire periphery of the multilayer structure 42 in the cross section perpendicular to the longitudinal direction of the wire, so that the multilayer structure 42 is covered with the coating layer on the front surface (for example, the substrate 40a). and the rear surface (for example, the first stabilizing layer 40d) are coated, as well as both edges in the width direction. Therefore, the coating layer has an edge portion 44 outside the multilayer structure 42 in the width direction of the wire. Edge 44 is the portion formed from the material of the cover layer and not including multilayer structure 42 .

In this embodiment, the covering layer consists of the second stabilizing layer 40e. However, if desired, the covering layer may further comprise at least one layer. For example, the covering layer may include additional layers (eg, insulating layers) provided outside the second stabilizing layer 40e and covering all or part of the second stabilizing layer 40e.

Further, high-temperature superconducting wire 40 may have at least one layer different from at least one of the layers specifically mentioned in the above description. Additionally or alternatively, high-temperature superconducting wire 40 may further have at least one layer in addition to the layers specifically mentioned in the above description.

Conventionally, low-temperature superconducting coils made of low-temperature superconducting wires such as NbTi are often impregnated with a resin material such as epoxy resin when the coils are manufactured. The resin material impregnated between the wires wound in a coil is hardened, and the wires can be strongly fixed to each other, thereby increasing the mechanical strength of the coil. The impregnated resin is useful for suppressing deformation of the coil that may be caused by strong electromagnetic force generated inside the coil during coil excitation. In addition, the impregnated resin uniformly forms a heat transfer path that thermally couples the wires inside the coil, and is useful for improving the thermal stability of the coil.

However, such an impregnation treatment is not suitable for the superconducting coil 12 formed of the high-temperature superconducting wire 40 . Compared with the peel strength between the layers of the high-temperature superconducting wire 40, the adhesion between the wires by the impregnated resin material tends to be too strong. Internal stress that may occur during use of the superconducting coil 12 concentrates inside the high-temperature superconducting wire 40, which is inferior in strength, and causes delamination between the layers of the high-temperature superconducting wire 40, which is inferior in strength to the impregnated resin portion, and finally There is concern that the high-temperature superconducting wire 40 will be destroyed.

Therefore, the superconducting coil 12 is not impregnated in the manufacturing process. Therefore, superconducting coil 12 does not have an impregnating material between laminated high-temperature superconducting wires 40 . Like the superconducting coil 12, a superconducting coil formed of a superconducting wire that is not insulated can also be referred to as a no-insulation (NI) superconducting coil. Even if a normal-conducting portion is locally generated for some reason during excitation, the current can be detoured to the adjacent wire, which has the advantage of enabling stable excitation. In addition, high current density is possible.

On the other hand, as described at the beginning of this document, in such a non-impregnated superconducting coil 12, the high-temperature superconducting wires 40 wound and laminated in the radial direction of the coil are separated from each other, or between the high-temperature superconducting wires 40 and the coil. There is a slight gap between the reinforcing cases 14. - 特許庁Therefore, when a strong electromagnetic force 50 is applied to the high temperature superconducting wire 40 during operation of the superconducting coil 12, the high temperature superconducting wire 40 moves somewhat. Movement of high-temperature superconducting wire 40 can adversely affect the operation of superconducting coil 12 .

For example. The superconducting coil 12 is usually provided with a mechanism for detecting thermal runaway (quench). This often employs voltage-based sensing. When a quench is detected, the superconducting coil 12 will transition to a state different from normal operation, such as stopping operation or performing protective actions aimed at recovery from the quench. The movement of the high-temperature superconducting wire 40 due to the strong electromagnetic force 50 changes the inductance of the superconducting coil 12, which may generate a large voltage in the superconducting coil 12 due to electromagnetic induction. There is concern that the quench detection mechanism may erroneously detect quench from this abnormal voltage and erroneously terminate the normal operation of the superconducting coil 12 . Another concern is the risk that movement of the high temperature superconducting wire 40 will cause friction between the wires and the resulting frictional heat will actually cause quenching.

The superconducting coil device 10 according to the embodiment can increase the strength of the high-temperature superconducting wire 40 against the electromagnetic force 50 in the coil radial direction by using an effect called stress stiffening.

FIG. 3 is a schematic diagram showing stress stiffening of the high-temperature superconducting wire 40 shown in FIG. According to stress stiffening, the application of tensile stress in the in-plane direction increases the stiffness against forces acting in the out-of-plane direction (compared to the case where such tensile stress is not applied). In this embodiment, tensile stress 54 is applied to high-temperature superconducting wire 40 by tension mechanism 20, thereby increasing the rigidity of high-temperature superconducting wire 40 against electromagnetic force 50 acting in the radial direction of the coil. 40 movement can be suppressed. Therefore, it is possible to prevent or alleviate the disturbance of the normal operation of the superconducting coil 12 due to the movement of the high-temperature superconducting wire 40 . For example, false quench detection can be prevented. The friction between the high-temperature superconducting wires 40 and the resulting frictional heat can be suppressed, and the risk of quenching can be reduced.

Note that FIG. 1 includes a partially enlarged view showing the joint between the high-temperature superconducting wire 40 and the coil reinforcing case 14 (for example, the case upper plate 14b). As shown, the case top plate 14b is bonded to the high-temperature superconducting wire 40 at the edge 44 of the coating layer by adhesion. Adhesive is applied to the surface of the upper case plate 14b to form an adhesive layer 46, and the upper case plate 14b is adhered to the edge 44 of the cover layer by the adhesive layer 46. FIG. The edge 42a of the multilayer structure 42 in the width direction of the high-temperature superconducting wire 40 is located farther from the surface of the case upper plate 14b in the width direction of the wire than the surface 46a of the adhesive layer 46 is. In other words, the high-temperature superconducting wire 40 is adhered to the upper case plate 14b at the portion not including the multilayer structure 42 (edge 44 of the coating layer). By bonding the high-temperature superconducting wire 40 only at the edge portion 44 in this manner, deterioration of the high-temperature superconducting wire 40 can be suppressed as compared with the case where the wire is impregnated as described above.

FIG. 4 is a diagram schematically showing another example of the superconducting coil device 10 according to the embodiment. In this embodiment, unlike the embodiment of FIG. 1, the tensioning mechanism 20 utilizes heat contraction to generate the tensioning force. Therefore, the tension device 22 arranged outside the vacuum vessel 30 becomes unnecessary.

The tensioning mechanism 20 includes a connection member 24 made of a material that heat-shrinks when cooled, and the connection member 24 is connected to at least one of the pair of coil support members (14b, 14c) (for example, a case upper plate). 14b) is connected to support 30a which has a higher temperature than the coil support. Support portion 30 a forms part of vacuum vessel 30 that accommodates superconducting coil 12 and coil reinforcing case 14 .

The connection member 24 is arranged inside the vacuum vessel 30 . The connecting member 24 has an elongated rod-like shape, one end of which is fixed to the support portion 30a, and the other end of which is fixed to the case upper plate 14b. A flange portion may be provided at the end of the connection member 24 fixed to the case upper plate 14b, and this flange portion may be fixed to the case upper plate 14b. Connecting member 24 is formed of a metallic material, such as stainless steel, or other suitable high-strength material. The case lower plate 14c is also connected to the wall (for example, the lower wall) of the vacuum vessel 30 by the connecting member 24. As shown in FIG.

Since the vacuum vessel 30 and support 30a are exposed to the external environment 18, they are at ambient temperature (eg, room temperature) and have a higher temperature than the superconducting coil 12 and coil reinforcement case 14 during operation. As described above, during operation of superconducting coil apparatus 10 , superconducting coil 12 and coil reinforcement case 14 are cooled to cryogenic temperatures by cryogenic refrigerator 32 . Since the connecting member 24 is connected to the coil reinforcing case 14, it is cooled by the coil reinforcing case 14 and thermally shrinks. Therefore, these two connecting members 24 apply tensile forces to the case upper plate 14b and the case lower plate 14c, respectively, whereby the tension mechanism 20 pulls the tape-shaped wire forming the superconducting coil 12 in the width direction. stress can be produced. Therefore, the superconducting coil device 10 according to the embodiment of FIG. 4 can also suppress the movement of the tape-shaped wire of the superconducting coil 12 by using stress stiffening as in the embodiment of FIG.

The connection member 24 may be connected to another part having a temperature higher than that of the coil reinforcement case 14 instead of the part having the ambient temperature such as the supporting part 30 a which is a part of the vacuum vessel 30 . For example, the connection member 24 may be connected to a portion such as the heat shield 34 that is cooled by the first stage cooling stage 32a.

In some embodiments, the tensioning mechanism 20 of the embodiment of FIG. 1 and the tensioning mechanism 20 of the embodiment of FIG. 4 may be used in combination. For example, connecting member 24 in tensioning mechanism 20 of the embodiment of FIG. 1 may be formed of a material that heat shrinks upon cooling. Alternatively, the tensioning mechanism 20 of the embodiment of FIG. 1 may be applied to one coil support of a set of coil supports, and the tensioning mechanism 20 of the embodiment of FIG. 4 may be applied to the other coil support. .

The present invention has been described above based on the examples. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that various design changes and modifications are possible, and that such modifications are within the scope of the present invention. By the way. Various features described in relation to one embodiment are also applicable to other embodiments. A new embodiment resulting from combination has the effects of each of the combined embodiments.

In the above-described embodiment, the case where the superconducting coil 12 is a single pancake coil formed from the high-temperature superconducting wire 40 is described as an example. 12 is not limited to having such a specific shape and material. For example, superconducting coil 12 may be a double pancake coil or other multi-layer pancake coil.

Further, in the above-described embodiments, the high-temperature superconducting wire 40 has been described as an example of the tape-shaped wire, but the present invention is similarly applicable to superconducting coils formed from other tape-shaped wires.

In the above-described embodiment, the superconducting coil device 10 is configured as conduction cooling, but other coil cooling methods may be applied. For example, the superconducting coil device 10 may be configured as an immersion cooling type in which the superconducting coil 12 is immersed in a cryogenic liquid coolant such as liquid helium for cooling. In this case, a set of coil supports (14b, 14c) along with the superconducting coil 12 are placed in a bath of cryogenic liquid coolant and submerged in the cryogenic liquid coolant. The connection of the tensioning mechanism 20 to the coil support may also be placed in a bath of cryogenic liquid coolant and submerged in the cryogenic liquid coolant. Cryogenic refrigerator 32 may be used to recondense the cryogenic liquid refrigerant.

Although the present invention has been described using specific terms based on the embodiment, the embodiment only shows one aspect of the principle and application of the present invention, and the embodiment does not include the claims. Many variations and rearrangements are permissible without departing from the spirit of the invention as defined in its scope.

10 superconducting coil device 12 superconducting coil 14 coil reinforcement case 20 tensioning mechanism 22 tensioning device 24 connecting member 30 vacuum container 40c superconducting layer 42 multilayer structure 44 edge 54 tensile stress.

Claims (6)

a superconducting coil formed by winding a tape-shaped wire;
a set of coil support members, one of which is joined to one end face of the superconducting coil and the other of which is joined to the other end face of the superconducting coil;
A tension unit connected to the set of coil support members and applying a tensile force to at least one of the set of coil support members so as to generate tensile stress in the width direction of the tape-shaped wire. A superconducting coil device comprising: a mechanism; The tensioning mechanism comprises a tensioning device for generating the tensioning force and a connecting member connecting the tensioning device to the one coil support so as to transmit the tensioning force from the tensioning device to the one coil support. 2. The superconducting coil device according to claim 1, comprising: The tensioning mechanism includes a connection member made of a material that heat-shrinks when cooled, and the connection member sets at least one of the pair of coil supports higher than the coil support. 3. The superconducting coil device according to claim 1, wherein the superconducting coil device is connected to a supporting portion having a temperature. 4. The superconducting coil device according to claim 3, wherein the support forms part of a vacuum vessel that houses the superconducting coil and the set of coil support members. 2. A coil reinforcement case comprising said set of coil support members and an outer peripheral frame disposed adjacent to the outer peripheral surface of said superconducting coil and connecting said set of coil support members. 5. The superconducting coil device according to any one of 1 to 4. The tape-shaped wire includes a multilayer structure including a superconducting layer and a coating layer covering the multilayer structure, and the coating layer has an edge outside the multilayer structure in the width direction of the tape-shaped wire. death,
6. The superconducting coil device according to claim 1, wherein the coil supporting member is joined to the tape-shaped wire at the edge of the coating layer.

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