Superconducting magnet system

Abstract

The invention relates to the technical field of superconducting magnets, in particular to a superconducting magnet system. The superconducting magnet system provided by the invention comprises a plurality of superconducting coil units and a connecting structure, the superconducting coil units are connected in series through connecting structures to form an annular magnet structure; the connecting structure comprises a connecting plate, a flexible connecting piece and fixing ends, the connecting plate is provided with a connecting groove, the flexible connecting piece is fixed to the connecting groove, the two ends of the flexible connecting piece are fixed to the two fixing ends, and the two superconducting coil units are connected through the two fixing ends. The superconducting coil units are connected through the flexible connecting pieces so as to adapt to infinitesimal displacement of the connecting interface caused by thermal shrinkage difference, stress concentration is avoided, and fretting wear of the connecting interface is prevented.

Description

Technical Field

[0001] This application relates to the field of superconducting magnet technology, and more particularly to a superconducting magnet system. Background Technology

[0002] Bi2212 (bismuth-strontium-calcium-copper-oxygen) superconducting material has become a core material for fabricating high-field superconducting magnets due to its high critical transition temperature (approximately 80K), extremely high upper critical magnetic field (over 200T), and excellent current-carrying capacity under high magnetic fields. Its unique isotropic circular wire structure (i.e., Bi2212 wire can be drawn into a circular cross-section rather than a flat strip) significantly simplifies the fabrication process of superconducting cables and coils, making it widely applicable in fields requiring strong magnetic fields (≥10T), such as nuclear magnetic resonance imaging (MRI), magnetic levitation trains, and controlled nuclear fusion devices (such as tokamak). In MRI equipment, Bi2212 magnets need to operate stably at low temperatures (4.2K liquid helium environment) while withstanding current loads of up to hundreds of kiloamperes; in magnetic levitation trains, superconducting magnets need to maintain the mechanical stability of the connection structure under dynamic loads and vibration environments; in controlled nuclear fusion devices, superconducting magnets need to withstand extreme magnetic fields and thermal cycling stresses over long periods.

[0003] In existing technologies, superconducting coils are mostly connected using rigid connection methods, such as bolt crimping or metal block welding. Taking bolt crimping as an example, the Bi2212 coil end is fixed to the metal connecting block (such as oxygen-free copper) by mechanical fastening, relying on external pressure to ensure the conductivity of the contact interface.

[0004] However, existing superconducting coil connection methods are prone to problems such as thermal stress concentration, fretting wear at the contact interface, and increased contact resistance in low-temperature and strong magnetic field environments. Summary of the Invention

[0005] This application provides a superconducting magnet system to solve the technical problems that existing superconducting coil connection methods easily lead to thermal stress concentration, fretting wear at the contact interface, and increased contact resistance under low temperature and strong magnetic field environments.

[0006] Please provide a superconducting magnet system, including multiple superconducting coil units and a connecting structure; the superconducting coil units are connected in series through the connecting structure to form a ring magnet structure; the connecting structure includes a connecting plate, a flexible connector, and fixed ends, the connecting plate has a connecting groove, the flexible connector is fixed in the connecting groove, the two ends of the flexible connector are fixed to two fixed ends, and two superconducting coil units are connected through the two fixed ends.

[0007] The superconducting magnet system connection structure provided in this application realizes the series connection of superconducting coil units. The flexible connector is embedded in the connection groove of the connecting plate, and its two ends are fixedly connected to the fixed end. The fixed end is connected to the wires of the adjacent superconducting coil unit to form a current transmission channel. When the superconducting magnet is running in a low-temperature environment, the flexibility of the flexible connector allows it to adapt to the small displacement caused by the difference in thermal contraction between the superconducting coil and the fixed end, avoiding stress concentration at the fixed position.

[0008] As an alternative implementation, the superconducting coil unit includes a housing and a superconducting coil, with the superconducting coil looped inside the housing.

[0009] The fixed end is located on the outside of the housing, and the coil end of the superconducting coil is fixedly connected to the fixed end.

[0010] This configuration allows the superconducting coil to be housed within the casing, while also providing mounting points for the fixed ends.

[0011] As an optional implementation, the fixed end is provided with a connecting hole, and the flexible connector and the coil end of the superconducting coil are both inserted into the connecting hole and connected to each other.

[0012] This design allows the connection between the flexible connector and the coil end of the superconducting coil to be accommodated through the connecting hole, making the connection structure more stable and less prone to breakage.

[0013] As an optional implementation, the flexible connector is welded to the coil end of the superconducting coil.

[0014] This setup allows for improved connection stability between the flexible connector and the coil end of the superconducting coil through welding.

[0015] As an optional implementation, the flexible connector is made of high-temperature superconducting material, and the connecting groove is provided with multiple flexible connectors.

[0016] This design, by employing high-temperature superconducting materials, significantly improves the electrical performance of the device, avoiding the interfacial resistance problem between traditional metal connectors and superconductors. At the same time, the parallel design of multiple flexible connectors significantly improves the total current carrying capacity of the connection structure, preventing performance degradation caused by local overheating of individual connectors, and enhancing the stability of the connection structure in extreme environments.

[0017] As an optional implementation, the connection structure also includes an insulating support member disposed between the fixed end and the housing.

[0018] This design, through the installation of insulating support components, significantly improves the electrical safety of the connection, avoids short circuits caused by direct contact between the fixed end and the housing, and enhances the operational reliability of the superconducting magnet in complex environments.

[0019] As an optional implementation, the connecting groove is arc-shaped.

[0020] With this design, the stress distribution of the flexible connector is more uniform through the arc-shaped connecting groove. At the same time, the connection direction of the flexible connector in the connecting groove can be changed without bending.

[0021] As an optional implementation, the connection structure also includes fixing blocks, with fixing blocks provided at both ends of the connection plate along its length, and the fixing blocks being fixedly connected to the fixing ends.

[0022] This configuration, which uses a fixing block to secure the connecting plate to the fixed end, enhances connection stability.

[0023] As an alternative implementation, the housing has an opening, a pressure block is installed in the opening, the pressure block has an opening, the superconducting coil extends out of the opening and is connected to the fixed end.

[0024] This design allows the cable end of the superconducting coil to extend from inside the housing through the opening, while the pressure block serves to fix and insulate the cable, preventing it from shaking and from directly contacting the housing.

[0025] As an optional implementation, the superconducting magnet system also includes an intermediate core cylinder, and multiple superconducting coil units each have a straight segment. The straight segments of the superconducting coil units are fixedly connected to the intermediate core cylinder, and the multiple superconducting coil units are arranged at intervals around the intermediate core cylinder.

[0026] This configuration significantly improves the structural stability of the superconducting magnet system through the intermediate core, ensuring the fixed position of the coil unit in a strong magnetic field environment and the overall magnetic field uniformity and operational reliability of the magnet.

[0027] This application provides a superconducting magnet system, including multiple superconducting coil units and a connecting structure. The superconducting coil units are connected in series through the connecting structure to form a ring magnet structure. The connecting structure includes a connecting plate, a flexible connector, and fixed ends. The connecting plate has a connecting groove, the flexible connector is fixed to the connecting groove, and both ends of the flexible connector are fixed to two fixed ends, connecting two superconducting coil units through the two fixed ends. This application uses a flexible connector to connect the superconducting coil units to accommodate the minute displacements caused by thermal contraction differences at the connection interface, avoiding stress concentration and preventing fretting wear at the connection interface.

[0028] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that the superconducting magnet system provided by this application can solve, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific embodiments. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the superconducting magnet system provided in the embodiments of this application;

[0031] Figure 2 A top view of the superconducting magnet system provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram showing the connection of two superconducting coil units provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the structure of a single superconducting coil unit provided in an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 10-Superconducting magnet system;

[0036] 100 - Superconducting coil unit; 110 - Housing; 111 - Inner ring; 112 - Outer ring; 113 - Side structure; 114 - Opening; 115 - Pressing block; 116 - Cover plate; 120 - Superconducting coil; 121 - Coil end;

[0037] 200 - Connection structure; 210 - Connection plate; 211 - Connection groove; 220 - Fixed end; 221 - Communicating hole; 230 - Insulating support block; 240 - Fixed block;

[0038] 300 - Intermediate core; 310 - End cap; 320 - Lifting lug. Detailed Implementation

[0039] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0041] The terms "first," "second," and "third" (if any) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0042] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or maintenance tool that includes a series of steps or units, not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or maintenance tool.

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Bi2212 superconducting material, due to its high critical transition temperature, extremely high upper critical magnetic field, and excellent current-carrying capacity under high magnetic fields, has become a core material for fabricating high-field superconducting magnets. Its unique isotropic circular wire structure significantly simplifies the fabrication process of superconducting cables and coils, making it a promising candidate for applications in fields requiring strong magnetic fields, such as nuclear magnetic resonance imaging (NMR), magnetic levitation trains, and controlled nuclear fusion devices (e.g., tokamak). In NMR equipment, Bi2212 magnets need to operate stably at low temperatures while withstanding current loads of hundreds of kiloamperes; in magnetic levitation trains, superconducting magnets need to maintain the mechanical stability of the connection structure under dynamic loads and vibration environments; and in controlled nuclear fusion devices, superconducting magnets need to withstand extreme magnetic fields and thermal cycling stresses over long periods.

[0045] In existing technologies, superconducting coils are mostly connected using rigid connection methods, such as bolt crimping or metal block welding. Taking bolt crimping as an example, the Bi2212 coil end is fixed to the metal connecting block by mechanical fastening, relying on external pressure to ensure the conductivity of the contact interface.

[0046] However, the thermal expansion coefficients of superconducting materials and metal connectors differ significantly. When cooled from room temperature to 4.2K, the difference in shrinkage between the two can reach hundreds of micrometers, resulting in huge internal stress at the contact interface. This may cause coil end breakage or connection failure. Furthermore, rigid connections cannot adapt to the minute displacements caused by electromagnetic forces or thermal cycling in low-temperature environments, which can easily lead to fretting and slippage at the contact interface, resulting in the formation of oxide layers or contaminants. This significantly increases the contact resistance, which can lead to Joule heat accumulation. In low-temperature superconducting systems, this may cause local quenching failure, endangering the safe operation of the magnet.

[0047] To address the aforementioned technical problems, this application provides a superconducting magnet system, comprising a ring magnet structure formed by multiple superconducting coil units connected in series. The superconducting magnet system connection structure provided in this application realizes the series connection of the superconducting coil units. A flexible connector is embedded in the connection groove of the connecting plate, with both ends fixedly connected to fixed ends. The fixed ends are respectively connected to the wires of adjacent superconducting coil units, forming a current transmission channel. When the superconducting magnet operates in a low-temperature environment, the flexibility of the flexible connector allows it to adapt to the minute displacements caused by the thermal contraction differences between the superconducting coils and the fixed ends, avoiding stress concentration and preventing fretting wear.

[0048] Figure 1 This is a schematic diagram of the structure of the superconducting magnet system provided in the embodiments of this application; Figure 2 A top view of the superconducting magnet system provided in an embodiment of this application; Figure 3 This is a schematic diagram showing the connection of two superconducting coil units provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a single superconducting coil unit provided in an embodiment of this application.

[0049] See Figures 1 to 4 As shown, this application discloses a superconducting magnet system 10, which includes multiple superconducting coil units 100 and a connecting structure 200. The superconducting coil units 100 are connected in series through the connecting structure 200 to form a ring magnet structure. The connecting structure 200 includes a connecting plate 210, a flexible connector, and fixed ends 220. The connecting plate 210 has a connecting groove 211. The flexible connector is fixed to the connecting groove 211. The two ends of the flexible connector are fixed to two fixed ends 220, and two superconducting coil units 100 are connected through the two fixed ends 220.

[0050] Understandably, the flexible connector can connect two superconducting coil units 100 in series via two fixed ends 220. When the coil ends 121 of the superconducting coil unit 100 experience minute displacements and deformations during integration, cooling, and energization, the flexible connector can absorb and release these stresses, maintaining the stability of the contact section and preventing fretting wear. Furthermore, because the flexible connector has relatively low tolerance requirements and stronger stress management capabilities, it is expected to improve the success rate of the integration stage and the reliability of the final product, thereby reducing overall costs.

[0051] The superconducting magnet system 10 of this application connects multiple superconducting coil units 100 in series through a connecting structure 200 to form a ring magnet structure. Each superconducting coil unit 100 can be independently subjected to optimized heat treatment. If a superconducting coil unit 100 is damaged during production or testing, it can be replaced individually, which greatly reduces manufacturing costs and complexity.

[0052] The superconducting coil unit 100 includes a housing 110 and a superconducting coil 120, with the superconducting coil 120 annularly disposed inside the housing 110. The housing 110 is made of a metallic material, such as carbon steel, and includes an inner ring 111, an outer ring 112, and a side structure 113. The inner ring 111, outer ring 112, and side structure 113 together form a coil frame with an annular channel, within which a superconducting cable is wound to form the superconducting coil 120. The inner ring 111, outer ring 112, and side structure 113 can be welded together or bolted together; this embodiment does not impose specific limitations.

[0053] The outer ring 112 of the housing 110 has an opening 114, on which a pressure block 115 is mounted. The shape of the pressure block 115 matches that of the opening 114. A through hole is provided on the pressure block 115, allowing the coil end 121 of the superconducting coil 120 to protrude from the through hole of the pressure block 115 for connection with the flexible connector. A cover plate 116 is provided above the pressure block 115. The cover plate 116 has a channel for the coil end 121 of the superconducting coil 120 to pass through. The cover plate 116 can fix the coil end 121 and protect the coil end 121 from being directly exposed to the outside.

[0054] The fixed end 220 is located on the outside of the housing 110, that is, fixed on the outer ring 112 of the housing 110, and the coil end 121 of the superconducting coil 120 is fixedly connected to the fixed end 220.

[0055] Both the pressure block 115 and the cover plate 116 can be made of epoxy insulation material, or low-temperature insulation material that can be extruded, such as cross-linked polyethylene or polytetrafluoroethylene. The fixing end 220 can be made of copper or oxygen-free copper, and can be tin-plated or silver-plated.

[0056] As one possible implementation, the fixed end 220 is provided with a connecting hole 221, which passes through the fixed end 220. The end of the flexible connector and the coil end 121 of the superconducting coil 120 are both inserted into the connecting hole 221 and connected to each other.

[0057] As one possible implementation, the flexible connector is made of a high-temperature superconducting material, such as YBCO (yttrium barium copper oxide) tape, whose structure is a combination of ceramic and metal, with a coefficient of thermal expansion between that of ceramic and metal. Superconducting coil 120 is made of Bi2212 (bismuth strontium calcium copper oxide) wire, whose structure is Ag and Bi2212 ceramic. Compared to Bi2212 wire and pure copper or silver, the difference in the coefficient of thermal expansion between Bi2212 wire and YBCO tape is smaller. During cooling from room temperature to 4.2K, the difference in shrinkage between the two is smaller, resulting in less thermal stress. This further protects the fragile connection interface and the Bi2212 wire itself. Although YBCO tape cannot be knotted like a rope, it possesses excellent flexibility in one dimension, allowing for easy bending and shaping. YBCO tape can absorb and release stress like a spring, maintaining the stability of the contact interface and greatly eliminating fretting wear.

[0058] In some embodiments, the connecting groove 211 is provided with a plurality of flexible connectors, the ends of which are inserted into the connecting holes 221 of the fixed end 220. The coil end 121 of the superconducting coil 120 can be inserted from the other end of the connecting hole 221, or it can be inserted from the same end of the connecting hole 221 together with the ends of the flexible connectors. Then, the connecting hole 221 is filled with solder to weld the ends of the flexible connectors and the coil end 121 of the superconducting coil 120, thereby achieving the connection between the two.

[0059] It should be noted that in the superconducting state, the resistance of the current flowing through the YBCO tape itself is almost zero. The resistance of the entire joint mainly comes from the Bi2212 / YBCO interface. By optimizing the welding process, the interface resistance can be made extremely low, far lower than that of traditional copper-copper or copper-silver interfaces. This minimizes Joule heating (I²R loss) and reduces the risk of quenching at the joint. At the same time, the YBCO tape itself has an extremely high critical current density (Jc). Even in the high magnetic field environment of the connection area, its current carrying capacity is much higher than that of oxygen-free copper of the same cross-section. This means that the jumper itself will not become a bottleneck for current transmission.

[0060] The connection structure 200 also includes an insulating support 230, which is disposed between the fixed end 220 and the housing 110. The insulating support 230 can insulatingly separate the fixed end 220 and the housing 110. The fixed end 220 and the insulating support 230 can be connected to the outer ring 112 of the housing 110 by bolts.

[0061] In some embodiments, the fixed end 220 can be a cuboid structure, and the connecting hole 221 of the fixed end 220 is provided through the length direction of the fixed end 220. The length of the insulating support 230 is equal to the length of the fixed end 220, and the width of the insulating support 230 is equal to the width of the fixed end 220. The contact surface between the insulating support 230 and the fixed end 220 is a plane, and the contact surface between the insulating support 230 and the housing 110 is an arc-shaped surface. The arc-shaped surface of the insulating support 230 matches the arc-shaped contour of the housing 110. In this way, the insulating support 230 can be tightly fitted to the surfaces of the fixed end 220 and the housing 110. Both the fixed end 220 and the insulating support 230 are provided with four bolt holes, and the bolt holes of the fixed end 220 and the bolt holes of the insulating support 230 are matched one-to-one. During installation, the bolts are passed through the fixed end 220 and the insulating support 230 and threadedly connected to the housing 110 to achieve a tight connection between the fixed end 220 and the insulating support 230 and the housing 110.

[0062] It should be noted that two insulating supports 230 and two fixed ends 220 can be provided on the housing 110 of the same superconducting coil unit 100. The two insulating supports 230 and the two fixed ends 220 are connected one-to-one. The housing 110 is also provided with two openings 114, which are respectively provided one-to-one with the two fixed ends 220. The two coil ends 121 of the superconducting coil 120 extend out from the two openings 114 respectively. Since the two coil ends 121 of the superconducting coil 120 have opposite winding directions, one opening 114 can be set on the upper side of one fixed end 220 and the other opening 114 can be set on the lower side of the other fixed end 220, so that the two coil ends 121 of the superconducting coil 120 can be inserted into the connecting holes 221 of the two fixed ends 220 respectively, and the insertion directions are opposite. The two coil ends 121 of the same superconducting coil unit 100 can be connected to two flexible connectors, and connected to two adjacent superconducting coil units 100 through the flexible connectors. In this way, multiple superconducting coil units 100 can be connected in series. Among the multiple superconducting coil units 100 connected in series, the first and last superconducting coil units 100 are not connected.

[0063] It should be noted that the connecting groove 211 on the connecting plate 210 is set in an arc shape. Since the extension direction of the connecting plate 210 is perpendicular to the plane of the superconducting coil 120, the coil end 121 of the superconducting coil 120 naturally extends and is inserted into the connecting hole 221. The extension directions of both the connecting hole 221 and the coil end 121 of the superconducting coil 120 are perpendicular to the connecting plate 210. The flexible connector can be bent to a certain extent, but it cannot be directly bent. By setting the connecting groove 211 in an arc shape, the flexible connector can be inserted into the connecting hole 221 when bent and connected to the coil end 121 of the superconducting coil 120.

[0064] As one possible implementation, the connection structure 200 also includes a fixing block 240. The fixing blocks 240 are provided at both ends of the length direction of the connection plate 210, and the fixing blocks 240 are fixedly connected to the fixing end 220.

[0065] It should be noted that the fixed end 220 is also provided with a connecting hole, which is arranged parallel to the connecting hole 221. The fixed block 240 is connected to the fixed end 220 through the connecting hole by bolts. The fixed block 240 can also be connected to the fixed end 220 through the connecting hole by a rotating shaft. The end of the connecting plate 210 can be connected to the fixed block 240 by bolts. This realizes the connection between the connecting plate 210 and the fixed end 220, so that the connecting plate 210 can be fixed on the superconducting coil unit 100.

[0066] Reference Figure 3 , combined Figure 1 and Figure 2In some embodiments, the end of the connecting plate 210 is located near the opening 114 on the housing 110. To ensure that the coil end 121 of the superconducting coil 120 is inserted into the connecting hole 221, a notch can be provided on the connecting plate 210 to prevent the connecting plate 210 from obstructing the insertion of the coil end 121 of the superconducting coil 120 into the connecting hole 221. At the same time, an installation position is reserved for the cover plate 116.

[0067] As one possible implementation, the superconducting magnet system 10 also includes an intermediate core cylinder 300, with multiple superconducting coil units 100 arranged at intervals around the intermediate core cylinder 300.

[0068] For example, a total of six superconducting coil units 100 are arranged around the central core cylinder 300. The six superconducting coil units 100 are connected in series by five connecting structures 200, forming a ring shape. The first superconducting coil unit 100 and the last superconducting coil unit 100 are not connected.

[0069] It should be noted that each of the multiple superconducting coil units 100 has both straight and curved segments, making the superconducting coil unit 100 D-shaped, such as... Figure 1 and Figure 4 The straight segment of the superconducting coil unit 100 is fixedly connected to the intermediate core cylinder 300, while the curved segment faces away from the intermediate core cylinder 300. When a huge current flows through the coil and it is in a strong magnetic field, it will be subjected to a huge outward expansion force. For a circular coil, this stress is unevenly distributed throughout the coil, and stress concentration will occur at the points of maximum curvature on the inner and outer sides of the coil, making these points very fragile and easily damaged. However, the electromagnetic force of the straight segment of the "D"-shaped coil is mainly tensile stress rather than bending stress. Since the material's resistance to tension is much stronger than its resistance to bending, the entire superconducting coil 120 structure is more stable. In addition, the straight segment can increase the contact area between the superconducting coil unit 100 and the intermediate core cylinder 300, making the connection between the superconducting coil unit 100 and the intermediate core cylinder 300 more stable; the curved segment retains a part of the circle to maintain the required magnetic field shape.

[0070] As one possible implementation, the intermediate core cylinder 300 is provided with an end cap 310, which is connected to the intermediate core cylinder 300 by bolts. The end cap 310 is provided with a lifting lug 320, which is threadedly connected to the end cap 310. The end cap 310 and the lifting lug 320 are mainly used to lift the entire superconducting magnet system 10.

[0071] This application provides a superconducting magnet system 10, including multiple superconducting coil units 100 and a connecting structure 200. The superconducting coil units 100 are connected in series through the connecting structure 200 to form a ring magnet structure. The connecting structure 200 includes a connecting plate 210, a flexible connector, and fixed ends 220. The connecting plate 210 has a connecting groove 211, the flexible connector is fixed to the connecting groove 211, and both ends of the flexible connector are fixed to two fixed ends 220, connecting two superconducting coil units 100 through the two fixed ends 220. This application uses a flexible connector to connect the superconducting coil units 100 to accommodate the minute displacement caused by thermal contraction differences at the connection interface, avoid stress concentration, and prevent fretting wear at the connection interface.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A superconducting magnet system, characterized in that, It includes multiple superconducting coil units (100) and a connecting structure (200); the superconducting coil units (100) are connected in series through the connecting structure (200) to form a ring magnet structure; the connecting structure (200) includes a connecting plate (210), a flexible connector and a fixed end (220), the connecting plate (210) has a connecting groove (211), the flexible connector is fixed to the connecting groove (211), the two ends of the flexible connector are fixed to the two fixed ends (220), and the two superconducting coil units (100) are connected through the two fixed ends (220).

2. The superconducting magnet system according to claim 1, characterized in that, The superconducting coil unit (100) includes a housing (110) and a superconducting coil (120), the superconducting coil (120) being arranged around the inside of the housing (110); The fixed end (220) is fixed to the outside of the housing (110), and the coil end (121) of the superconducting coil (120) can extend out of the housing (110) and be fixedly connected to the fixed end (220).

3. The superconducting magnet system according to claim 2, characterized in that, The fixed end (220) is provided with a connecting hole (221), and the flexible connector and the coil end (121) of the superconducting coil (120) are both inserted into the connecting hole (221) and connected to each other.

4. The superconducting magnet system according to claim 3, characterized in that, The flexible connector is welded to the coil end (121) of the superconducting coil (120) within the communicating hole (221).

5. The superconducting magnet system according to claim 1, characterized in that, The flexible connector is made of high-temperature superconducting material, and the connecting groove (211) is provided with multiple flexible connectors.

6. The superconducting magnet system according to claim 2, characterized in that, The connection structure (200) further includes an insulating support (230) disposed between the fixed end (220) and the housing (110).

7. The superconducting magnet system according to claim 1, characterized in that, The connecting groove (211) is arc-shaped.

8. The superconducting magnet system according to claim 1, characterized in that, The connection structure (200) further includes a fixing block (240). The two ends of the connection plate (210) in the length direction are provided with fixing blocks (240), and the fixing blocks (240) are fixedly connected to the fixing end (220).

9. The superconducting magnet system according to claim 2, characterized in that, The housing (110) is provided with an opening (114), a pressure block (115) and a cover plate (116). The pressure block (115) fills the opening (114) and has an opening. The coil end (121) of the superconducting coil (120) extends out from the opening and is connected to the fixed end (220). The cover plate (116) is placed on the upper side of the opening (114) to protect the coil end (121) of the superconducting coil (120).

10. The superconducting magnet system according to claim 1, characterized in that, The superconducting magnet system (10) also includes an intermediate core cylinder (300), and each of the multiple superconducting coil units (100) has a straight segment. The straight segment of the superconducting coil unit (100) is fixedly connected to the intermediate core cylinder (300), and the multiple superconducting coil units (100) are arranged at intervals around the intermediate core cylinder (300).

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