A multi-coil jointless superconducting magnet and method of winding

Abstract

The application discloses a multi-coil jointless superconducting magnet and a winding method, which comprises a superconducting framework, an upper flange plate, a lower flange plate, a main coil part, an upper compensation coil part, a lower compensation coil part, a main transition slip, an upper transition slip, a lower transition slip, superconducting wires and an insulating film, the upper and lower ends of the superconducting framework are fixed with the upper flange plate and the lower flange plate respectively, the inner surface of the lower flange plate is provided with wire inlet notches and wire outlet notches, the superconducting framework is provided with the main coil part, the upper and lower ends of the main coil part are further provided with the upper compensation coil part and the lower compensation coil part respectively, and the main transition slip is provided with a transition wire slot. The application has the advantages that there is no connecting joint between the superconducting coils, the number of original superconducting magnet joints is reduced, the energy loss of the superconducting magnet is reduced, the long-time operation stability of the magnet is improved, and the operation risk of the superconducting magnet joints in repeated welding and disassembly is reduced.

Description

Technical Field

[0001] This invention relates to the field of superconducting magnet technology, specifically to a multi-coil seamless superconducting magnet and its winding method. Background Technology

[0002] Highly efficient superconducting magnet technology and cryogenic refrigeration technology have been widely applied in national economy, scientific experiments, national defense, nuclear magnetic resonance, magnetic levitation, and other scientific and technological fields. As a technology with near-zero resistance and zero energy consumption, superconducting magnets can achieve high current and strong magnetic fields at relatively low voltages, making them widely applicable and valuable for scientific research in fields such as integrated circuits, semiconductors, biomedicine, and new materials. The main reason why superconducting magnets cannot achieve completely zero resistance is that the superconducting joint itself is an open-circuit connection structure. Currently, no superconducting welding materials have been found internationally, therefore, the superconducting joint cannot achieve a zero-resistance superconducting state at 4K (-269℃). This situation results in a constant low-resistance heat loss in the entire current loop, causing the current in the loop to continuously decrease over time.

[0003] In a superconducting magnet system, a superconducting connector is a fixing device that connects the two ends of multiple superconducting wires, or a fixing lead-out device in the transition section between the superconducting magnet's inlet / outlet connectors and the external high-temperature zone.

[0004] In existing superconducting magnet technology, after each coil is wound, two connectors appear: an input connector and an output connector. For example, Chinese patent document CN114360846A discloses a high-field superconducting magnet with multiple coils and its manufacturing method. Each coil has two connectors. After these connectors are soldered, they are not superconducting at low temperatures but instead exhibit a heating resistance. For conduction-cooled superconducting magnets, the cooling power of a single refrigerator in the 4K temperature range is only 0.8W~1.5W. The heat loss from multiple soldered superconducting connectors generally accounts for more than half of the overall heat loss of the superconducting magnet. This is especially true in closed-loop superconducting magnet systems (such as nuclear magnetic resonance imaging, nuclear magnetic resonance spectrometers, proton accelerators, etc.). Due to the continuous decay of the current, the magnetic field also exhibits a linear decay change, increasing the energy loss of the superconducting magnet and making it impossible to achieve stable magnetic field operation for a long time. Furthermore, there are certain risks associated with repeated soldering and disassembly of superconducting magnet connectors. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to provide a superconducting magnet that reduces the number of superconducting magnet joints, reduces the energy loss of the superconducting magnet, improves the long-term operational stability of the magnet, and reduces the operational risks of superconducting magnet joints during repeated welding and disassembly.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A multi-coil, jointless superconducting magnet includes a superconducting frame, an upper flange plate, a lower flange plate, a main coil section, an upper compensation coil section, a lower compensation coil section, a main transition slip, an upper transition slip, a lower transition slip, a superconducting wire, and an insulating film. The upper flange plate and the lower flange plate are fixed to the upper and lower ends of the superconducting frame, respectively. An inlet slot and an outlet slot are formed on the inner surface of the lower flange plate. The main coil section is provided on the superconducting frame. The upper compensation coil section and the lower compensation coil section are also provided at the upper and lower ends of the main coil section, respectively. A transition slot is provided on the main transition slip. The tap of the superconducting wire enters the main coil section through the inlet slot and is wound to form the main coil before entering the upper compensation coil section. An insulating film is laid on the main coil before the main transition wrench is installed. After the superconducting wire is wound to form the upper compensation coil in the upper compensation coil section, its tap enters the lower compensation coil section through the transition slot. An insulating film is laid on the upper compensation coil before the upper transition wrench is installed. After the superconducting wire is wound to form the lower compensation coil in the lower compensation coil section, its tap is led out through the outlet slot. An insulating film is laid on the lower compensation coil before the lower transition wrench is installed.

[0007] This superconducting magnet uses a single superconducting wire to wind multiple superconducting coils, enabling the combination or nesting of multiple layered solenoid coils. It is not limited to a single coil and can produce magnets with different magnetic field distribution requirements. Furthermore, there are no connecting joints between the superconducting coils, reducing the number of joints in the original superconducting magnet, reducing the energy loss of the superconducting magnet, thereby improving the long-term operational stability of the magnet and reducing the operational risks of repeated welding and disassembly of the superconducting magnet joints.

[0008] Furthermore, by combining multiple coils, it is possible not only to meet the requirements of high uniformity winding of nuclear magnetic resonance superconducting magnets, gradient magnets, and conductive cooling magnets, but also to achieve interpolation combinations of the same material with different numbers of layers and turns, thus meeting the winding requirements of various types of superconducting magnets.

[0009] Preferably, the main transition slip has a first annular lead-out groove on its top inner wall and top surface, and a second annular lead-out groove on its bottom inner wall and bottom surface, with the upper and lower ends of the transition groove communicating with the first annular lead-out groove and the second annular lead-out groove, respectively.

[0010] Preferably, the upper transition slot is provided with an upper transition groove that communicates with the transition groove, the upper transition slot has a third annular lead-out groove on the top inner wall and top surface, and the upper transition slot has a fourth annular lead-out groove on the bottom inner wall and bottom surface. The upper and lower ends of the upper transition groove are respectively connected to the third annular lead-out groove and the fourth lower annular lead-out groove, and the first annular lead-out groove and the fourth annular lead-out groove are respectively provided.

[0011] Preferably, the arc of the first annular lead-out groove, the second annular lead-out groove, the third annular lead-out groove, and the fourth lower annular lead-out groove on the outside of the copper lead-out tile is not less than 30 times the diameter of the superconducting wire, the width of the transition groove and the upper transition groove is not less than 2.5 times the diameter of the superconducting wire, and the depth of the transition groove and the upper transition groove is greater than the diameter of the superconducting wire.

[0012] Preferably, the lower transition slot is provided with a lower transition groove, and the upper inner wall and top surface of the lower transition slot are provided with a fifth annular lead-out groove. The upper and lower ends of the lower transition groove are respectively connected to the fifth annular lead-out groove and the outlet groove.

[0013] Preferably, the arc of the fifth annular lead-out groove on the outside of the copper lead-out tile is not less than 30 times the diameter of the superconducting wire, the width of the lower transition groove is not less than 2.5 times the diameter of the superconducting wire, and the depth of the lower transition groove is greater than the diameter of the superconducting wire.

[0014] Preferably, the arc of the fifth annular lead-out groove on the outside of the copper lead-out tile is not less than 30 times the diameter of the superconducting wire, the width of the lower transition groove is not less than 2.5 times the diameter of the superconducting wire, and the depth of the lower transition groove is greater than the diameter of the superconducting wire.

[0015] Preferably, both the upper flange and the lower flange are oxygen-free copper cold-conducting flanges.

[0016] Preferably, the main transition slip, upper transition slip, and lower transition slip are made of non-magnetic metal or thermally conductive composite materials with high heat transfer efficiency.

[0017] Preferably, a method for winding a multi-coil jointless superconducting magnet is also provided, comprising the following steps: Step 1: Fix the upper flange plate and the lower flange plate to the upper and lower ends of the superconducting skeleton respectively, and lay an insulating film on the inner surface of the upper flange plate and the lower flange plate and the surface of the superconducting skeleton. Step 2: The tap of the superconducting wire enters the main coil section through the inlet slot and is wound to form the main coil before entering the upper compensation coil section. Then, an insulating film is laid on the main coil and the main transition clip is set. Step 3: Lay an insulating film on the upper and lower surfaces of the main transition slip; Step 4: After the superconducting wire is wound into the upper compensation coil to form the upper compensation coil, its tap enters the lower compensation coil through the transition groove. Then, an insulating film is laid on the upper compensation coil and the upper transition clip is set. Step 5: After the superconducting wire is wound into the lower compensation coil to form the lower compensation coil, its tap is led out through the outlet slot. Then, an insulating film is laid on the lower compensation coil and the lower transition clip is set.

[0018] Compared with the prior art, the beneficial effects of the present invention are: This superconducting magnet uses a single superconducting wire to wind multiple superconducting coils, enabling the combination or nesting of multiple layered solenoid coils. It is not limited to a single coil and can produce magnets with different magnetic field distribution requirements. Furthermore, there are no connecting joints between the superconducting coils, reducing the number of joints in the original superconducting magnet, reducing the energy loss of the superconducting magnet, thereby improving the long-term operational stability of the magnet and reducing the operational risks of repeated welding and disassembly of the superconducting magnet joints.

[0019] Furthermore, by combining multiple coils, it is possible not only to meet the requirements of high uniformity winding of nuclear magnetic resonance superconducting magnets, gradient magnets, and conductive cooling magnets, but also to achieve interpolation combinations of the same material with different numbers of layers and turns, thus meeting the winding requirements of various types of superconducting magnets. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 This is a partial schematic diagram of an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the superconducting wire after winding according to an embodiment of the present invention; Figure 4 This is a partial structural diagram of the superconducting wire after winding according to an embodiment of the present invention; Figure 5 This is another partial structural diagram of the superconducting wire after winding according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the main transition slip in an embodiment of the present invention; Figure 7 This is a schematic diagram of the transition slip structure in an embodiment of the present invention; Figure 8 This is a schematic diagram of the transition chuck structure in an embodiment of the present invention. Detailed Implementation

[0021] To facilitate understanding of the technical solution of the present invention by those skilled in the art, the technical solution of the present invention will now be further described in conjunction with the accompanying drawings.

[0022] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of 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.

[0023] In this application, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited.

[0024] See Figures 1 to 3 This embodiment discloses a multi-coil seamless superconducting magnet, including a superconducting frame 1, an upper flange plate 2, a lower flange plate 3, a main coil section 4, an upper compensation coil section 5, a lower compensation coil section 6, a main transition slip 7, an upper transition slip 8, a lower transition slip 9, a superconducting wire 10, and an insulating film (not shown in the figure). The superconducting frame 1 is a core cylinder structure with a through hole in the middle. The flanges at both ends of the superconducting frame 1 are slightly larger than the inner diameter of the upper flange plate 2 and the lower flange plate 3. The flange plate 2 and the lower flange plate 3 are fixed by bolts respectively. In this embodiment, the upper flange plate 2 and the lower flange plate 4 are both oxygen-free copper heat-conducting flange plates. The flange plate 2 and the lower flange plate 3 play the role of fixing the superconducting magnet coils and pressing against each layer of superconducting wire 10 and the interlayer transition section during winding. Oxygen-free copper has a higher thermal conductivity than non-magnetic stainless steel at a deep low temperature of 4K (-269℃) to cool the internal superconducting coils and achieve a more uniform cooling temperature.

[0025] The inner surface of the lower flange plate 3 is provided with an inlet slot 301 and an outlet slot 302. The superconducting skeleton 1 is provided with a main coil part 4. The upper and lower ends of the main coil part 4 are respectively provided with an upper compensation coil part 5 and a lower compensation coil part 6. The main transition slip 7 is provided with a transition slot 701.

[0026] See Figures 3 to 5 The tap of the superconducting wire 10 enters the main coil section 4 through the inlet slot 301 and is wound to form the main coil before entering the upper compensation coil section 5. An insulating film is laid on the main coil before the main transition clamp 7 is installed. After the superconducting wire 10 is wound to form the upper compensation coil in the upper compensation coil section 5, its tap enters the lower compensation coil section 6 through the transition slot 701. An insulating film is laid on the upper compensation coil before the upper transition clamp 8 is installed. After the superconducting wire 10 is wound to form the lower compensation coil in the lower compensation coil section 6, its tap is led out through the outlet slot 302. An insulating film is laid on the lower compensation coil before the lower transition clamp 9 is installed.

[0027] This superconducting magnet uses a single superconducting wire to wind multiple superconducting coils, enabling the combination or nesting of multiple layered solenoid coils. It is not limited to a single coil and can produce magnets with different magnetic field distribution requirements. Furthermore, there are no connecting joints between the superconducting coils, reducing the number of joints in the original superconducting magnet, reducing the energy loss of the superconducting magnet, thereby improving the long-term operational stability of the magnet and reducing the operational risks of repeated welding and disassembly of the superconducting magnet joints.

[0028] Furthermore, by combining multiple coils, it can not only meet the requirements for high uniformity winding of nuclear magnetic resonance superconducting magnets, gradient magnets, and conductive cooling magnets, but also achieve interpolation combinations of the same material with different numbers of layers and turns, thus meeting various winding requirements for superconducting magnets. Specifically, it can be applied to solenoid-type coils with axisymmetric structures, such as externally concave coils, mountain-shaped coils, long coil pairs, split coil pairs, hollow cylindrical coils, and gradient coil pairs, as well as L-shaped coils, but not to disc-shaped coils.

[0029] Additionally, it should be noted that multiple pairs of superconducting coils are generally designed with a symmetrical structure. To ensure that the magnetic field center is located at the exact center of the coil pair to obtain a high central magnetic field strength or high central magnetic field uniformity, the number of compensation coils usually appears in pairs, such as 2, 4, or 6 compensation coils, depending on the actual needs. In this embodiment, the number of compensation coils is 2, but it is not limited to 2. Multiple compensation coils can be wound on the main coil, the main transition chuck is divided into multiple chucks, and chucks are set on the additional compensation coils.

[0030] Furthermore, the superconducting framework 1 is made of a material with a certain structural strength. For superconducting magnets that require heat treatment, it should also meet the requirements of high-temperature heat treatment. Its coefficient of thermal expansion should be less than or equal to the coefficient of thermal expansion of the superconducting wire, including but not limited to 5083 series aluminum alloy, 6061 series aluminum alloy, 304, 304L, 316L, 316LN, Ti6AlV4, Cr-based alloy, Ni-based alloy or other types of materials with high structural strength.

[0031] Furthermore, both the upper flange plate 2 and the lower flange plate 3 are provided with vertical through-slits, causing the upper flange plate 2 and the lower flange plate 3 to form a half structure, eliminating the eddy current loss effect generated during the excitation of the superconducting coil. The optical holes on the upper flange plate 2 and the lower flange plate 3 are used for the connection of the external support structure of the magnet body, and the two pairs of 2x2 bolt holes are used to fix the external cooling connectors and cool the superconducting wire.

[0032] Furthermore, the main transition slip 7, upper transition slip 8, and lower transition slip 9 are made of non-magnetic metal materials or thermally conductive composite materials with high heat transfer efficiency, possessing a high 4K low-temperature thermal conductivity (-269℃), with a reference value not less than 300W / (m·K)@4K, and a thermal expansion coefficient close to that of the superconducting wire 10. These materials include, but are not limited to, TU00 high-conductivity oxygen-free copper, TU0 high-conductivity oxygen-free copper, TU1 high-conductivity oxygen-free copper, silver-based alloys, and gold-based alloys. In this embodiment, the main transition slip 7, upper transition slip 8, and lower transition slip 9 all employ oxygen-free copper tiles to achieve non-liquid helium conductive cooling and meet the conductive cooling requirements of highly conductive materials.

[0033] For further details, please refer to [link / reference]. Figure 6 The main transition slip 7 has a first annular lead-out groove (not shown in the figure) on its top inner wall and top surface, and a second annular lead-out groove 702 on its bottom inner wall and bottom surface. The upper and lower ends of the transition groove 701 are respectively connected to the first annular lead-out groove and the second annular lead-out groove 702.

[0034] See Figure 7 The upper transition slip 8 is provided with an upper transition groove 801 that communicates with the transition groove 701. The upper transition slip 8 has a third annular lead-out groove 802 on its top inner wall and top surface, and a fourth annular lead-out groove (not shown in the figure) on its bottom inner wall and bottom surface. The upper and lower ends of the upper transition groove 801 are respectively connected to the third annular lead-out groove 802 and the fourth lower annular lead-out groove. The first annular lead-out groove and the fourth annular lead-out groove are provided correspondingly.

[0035] After the upper compensation coil is wound, to reduce the number of superconducting joints, the tap of the superconducting wire 10 is not led out from the upper flange plate 2, but is transferred to the lower compensation coil section 6 through the outer transition groove 701 of the main transition slip 7 for further winding. For details, please refer to [link to relevant documentation]. Figure 4 and Figure 5 When the number of winding layers of the upper compensation coil in the upper compensation coil section 5 is even, the superconducting wire 10 is led out from the third annular lead-out groove 802 to the upper transition groove 801 and then enters the transition groove 701; when the number of winding layers of the upper compensation coil in the upper compensation coil section 5 is odd, the superconducting wire 10 is led out from the fourth annular lead-out groove and the first annular lead-out groove to the transition groove 701.

[0036] See Figure 8 The lower transition slip 9 is provided with a lower transition groove 901. The upper inner wall and top surface of the lower transition slip 9 are provided with a fifth annular lead-out groove 902. The upper and lower ends of the lower transition groove 901 are respectively connected to the fifth annular lead-out groove 902 and the lead-out groove 302.

[0037] For details, please refer to Figure 3When the number of winding layers of the lower compensation coil in the lower compensation coil section 6 is even, the superconducting wire 10 is led out from the fifth annular lead-out slot 902 to the lower transition wire slot 901 and then led out from the exit slot 302; when the number of winding layers of the lower compensation coil in the lower compensation coil section 6 is odd, the superconducting wire 10 is directly led out from the exit slot 302.

[0038] Furthermore, the first annular lead-out groove, the second annular lead-out groove 702, the third annular lead-out groove 802, the fourth lower annular lead-out groove, and the fifth annular lead-out groove 902 have the same shape. The arc of the first annular lead-out groove, the second annular lead-out groove 702, the third annular lead-out groove 802, the fourth lower annular lead-out groove, and the fifth annular lead-out groove 902 on the outer side of the copper tile is not less than 30 times the diameter of the superconducting wire 10, and it is a large-radius transition. The length of the annular lead-out section of the last turn of the superconducting coil is not less than 1 / 4 of the circumference of the copper tile to avoid cutting or twisting the superconducting wire 10; the transition The width of the wire groove 701, the upper transition wire groove 801, and the lower transition wire groove 901 is not less than 2.5 times the diameter of the superconducting wire 10. The depth of the transition wire groove 701, the upper transition wire groove 801, and the lower transition wire groove 901 is greater than the diameter of the superconducting wire 10, ensuring that there is sufficient space in the transition wire groove 701, the upper transition wire groove 801, and the lower transition wire groove 901 to fill with potting compound. Specifically, Stycast low-temperature thermally conductive adhesive (type AB) is used to pot the wire grooves to ensure that the superconducting wire 10 is electrically insulated from the copper tile, and that the superconducting wire 10 is not higher than the outer surface of the copper tile, to prevent the superconducting wire 10 from being damaged by the outer binding wire during winding.

[0039] Furthermore, the outer diameter of the main transition valve 7 is larger than the outer diameters of the upper and lower compensation coils.

[0040] Furthermore, the superconducting wire 10 can be in the form of round wire, rectangular wire, or small cable composed of composite multi-strand wire, including but not limited to low-temperature or high-temperature superconducting materials such as NbTi / Cu, Nb3Sn, Bi2212, iron-base wire, Bi2223, and YBCO.

[0041] This embodiment also provides a method for winding a multi-coil, jointless superconducting magnet, which specifically includes the following steps: Step 1: Fix the upper flange plate 2 and the lower flange plate 3 to the upper and lower ends of the superconducting frame 1 respectively with bolts, and lay an insulating film on the inner surface of the upper flange plate 2 and the lower flange plate 3 and the surface of the superconducting frame 1. Step 2: The tap of the superconducting wire 10 enters the main coil section 4 through the inlet slot 301 and is wound to form the main coil before entering the upper compensation coil section 5. Then, an insulating film is laid on the main coil and the main transition clip 7 is fixed. Step 3: Lay an insulating film on the upper and lower surfaces of the main transition slip 7; Step 4: The superconducting wire 10 is wound on the upper compensation coil section 5 to form an upper compensation coil. Then, an insulating film is laid on the upper compensation coil and an upper transition clamp 8 is set. When the number of winding layers of the upper compensation coil is even, the superconducting wire 10 is led out from the third annular lead-out groove 802 on the upper transition clamp 8 to the upper transition groove 801 and then from the transition groove 701 to the lower compensation coil section 6. When the number of winding layers of the upper compensation coil is odd, the superconducting wire 10 is led out from the fourth annular lead-out groove at the bottom of the upper transition clamp 8 and the first annular lead-out groove on the main transition clamp 7 to the transition groove 701 and then to the lower compensation coil section 6. Step 5: The superconducting wire 10 is wound on the lower compensation coil section 6 to form a lower compensation coil. Then, an insulating film is laid on the lower compensation coil and a lower transition clamp 9 is set. When the number of winding layers of the lower compensation coil in the lower compensation coil section 6 is even, the superconducting wire 10 is led out from the fifth annular lead-out groove 902 on the lower transition clamp 9 to the lower transition groove 901 and then led out from the outlet groove 302. When the number of winding layers of the lower compensation coil is odd, the superconducting wire 10 is directly led out from the outlet groove 302.

[0042] Through the above winding method and optimized coil winding process, multiple coils can be wound on a single wire, reducing the number of original superconducting joints, greatly reducing the energy loss of the superconducting magnet, improving the long-term operational stability of the magnet, and also reducing the operational risks of superconducting magnet joints during repeated welding and disassembly.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0044] The above embodiments are merely examples of implementation methods of the invention. The scope of protection of the present invention is not limited to the above embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A multi-coil, jointless superconducting magnet, characterized in that: The superconducting frame includes an upper flange plate, a lower flange plate, a main coil section, an upper compensation coil section, a lower compensation coil section, a main transition slip, an upper transition slip, a lower transition slip, a superconducting wire, and an insulating film. The upper flange plate and the lower flange plate are fixed at the upper and lower ends of the superconducting frame, respectively. An inlet slot and an outlet slot are formed on the inner surface of the lower flange plate. The main coil section is provided on the superconducting frame. The upper compensation coil section and the lower compensation coil section are also provided at the upper and lower ends of the main coil section, respectively. The main transition slip is provided with a transition wire groove. The tap of the superconducting wire enters the main coil section through the inlet slot and is wound to form the main coil before entering the upper compensation coil section. An insulating film is laid on the main coil before the main transition wrench is installed. After the superconducting wire is wound to form the upper compensation coil in the upper compensation coil section, its tap enters the lower compensation coil section through the transition slot. An insulating film is laid on the upper compensation coil before the upper transition wrench is installed. After the superconducting wire is wound to form the lower compensation coil in the lower compensation coil section, its tap is led out through the outlet slot. An insulating film is laid on the lower compensation coil before the lower transition wrench is installed.

2. The multi-coil seamless superconducting magnet according to claim 1, characterized in that: The main transition slip has a first annular lead-out groove on its top inner wall and top surface, and a second annular lead-out groove on its bottom inner wall and bottom surface. The upper and lower ends of the transition groove are respectively connected to the first annular lead-out groove and the second annular lead-out groove.

3. A multi-coil seamless superconducting magnet according to claim 2, characterized in that: The upper transition slot is provided with an upper transition groove that communicates with the transition groove. The upper transition slot has a third annular lead-out groove on its top inner wall and top surface, and a fourth annular lead-out groove on its bottom inner wall and bottom surface. The upper and lower ends of the upper transition groove are respectively connected to the third annular lead-out groove and the fourth lower annular lead-out groove. The first annular lead-out groove and the fourth annular lead-out groove are respectively provided.

4. A multi-coil seamless superconducting magnet according to claim 3, characterized in that: The arc of the first annular lead-out groove, the second annular lead-out groove, the third annular lead-out groove, and the fourth lower annular lead-out groove on the outside of the copper tile is not less than 30 times the diameter of the superconducting wire. The width of the transition groove and the upper transition groove is not less than 2.5 times the diameter of the superconducting wire. The depth of the transition groove and the upper transition groove is greater than the diameter of the superconducting wire.

5. A multi-coil seamless superconducting magnet according to claim 1, characterized in that: The lower transition slip is provided with a lower transition groove, and the upper inner wall and top surface of the lower transition slip are provided with a fifth annular lead-out groove. The upper and lower ends of the lower transition groove are respectively connected to the fifth annular lead-out groove and the outlet groove.

6. A multi-coil seamless superconducting magnet according to claim 5, characterized in that: The arc of the fifth annular lead-out groove on the outside of the copper tile is not less than 30 times the diameter of the superconducting wire, the width of the lower transition groove is not less than 2.5 times the diameter of the superconducting wire, and the depth of the lower transition groove is greater than the diameter of the superconducting wire.

7. A multi-coil seamless superconducting magnet according to claim 1, characterized in that: Both the upper and lower flanges are provided with vertical through-slits, resulting in a split structure between the upper and lower flanges.

8. A multi-coil seamless superconducting magnet according to claim 1, characterized in that: Both the upper and lower flanges are oxygen-free copper heat-conducting flanges.

9. A multi-coil seamless superconducting magnet according to claim 1, characterized in that: The main transition slip, upper transition slip, and lower transition slip are made of non-magnetic metal or thermally conductive composite materials with high heat transfer efficiency.

10. A method for winding a multi-coil seamless superconducting magnet according to any one of claims 1 to 9, characterized in that: Includes the following steps: Step 1: Fix the upper flange plate and the lower flange plate to the upper and lower ends of the superconducting skeleton respectively, and lay an insulating film on the inner surface of the upper flange plate and the lower flange plate and the surface of the superconducting skeleton. Step 2: The tap of the superconducting wire enters the main coil section through the inlet slot and is wound to form the main coil before entering the upper compensation coil section. Then, an insulating film is laid on the main coil and the main transition slip is set. Step 3: Lay an insulating film on the upper and lower surfaces of the main transition slip; Step 4: After the superconducting wire is wound into the upper compensation coil to form the upper compensation coil, its tap enters the lower compensation coil through the transition groove. Then, an insulating film is laid on the upper compensation coil and the upper transition clip is set. Step 5: After the superconducting wire is wound into the lower compensation coil to form the lower compensation coil, its tap is led out through the outlet slot. Then, an insulating film is laid on the lower compensation coil and the lower transition clip is set.

Images