阅读说明：本技术 一种液氦浸泡式大孔径实验类密绕高场复合超导磁体 (Liquid helium soaking type large-aperture experiment type close-wound high-field composite superconducting magnet ) 是由 周超 秦经刚 高鹏 薛圣泉 刘方 金环 刘华军 李建刚 于 2020-12-22 设计创作，主要内容包括：本发明提出一种液氦浸泡式大孔径实验类密绕高场复合超导磁体,包括多组由不同超导材料绕制的螺线管磁体线圈,超导抽头,磁体线圈电流引线,磁体上、下端板、磁体上盖板和排线板；所述多组由不同超导材料绕制的螺线管磁体线圈包括分别由高场Nb-3Sn、ITER TF Nb-3Sn、NbTi超导材料绕制的螺线管磁体线圈,以串联方式进行连接；所述超导抽头对每个螺线管磁体线圈进行分段,以便外接失超检测与保护系统；磁体线圈电流引线,用于串联不同螺线管磁体线圈,并为复合螺线管磁体线圈通流励磁；所述磁体上、下端板,通过紧固螺栓与不同螺线管磁体线圈连接；磁体上盖板与磁体上端板紧密连接；排线板通过螺杆与磁体上盖板连接,用于排布、固定连接超导抽头的电位线和磁体电流引线。(The invention provides a liquid helium soaking type large-aperture experimental close-wound high-field composite superconducting magnet, which comprises a plurality of groups of solenoid magnet coils wound by different superconducting materials, superconducting taps, magnet coil current leads, magnet upper and lower end plates, a magnet upper cover plate and a magnet wire arranging plate, wherein the solenoid magnet coils are arranged on the upper end plate and the lower end plate; the multiple groups of solenoid magnet coils wound by different superconducting materials respectively comprise high-field Nb 3 Sn、ITER TF Nb 3 A solenoid magnet coil wound of Sn, NbTi superconducting material connected in series; the superconducting tap segments each solenoid magnet coil so as to be externally connected with a quench detection and protection system; the magnetic coil current lead wire is used for being connected with different solenoid magnetic coils in series and is used for through-flow excitation of the composite solenoid magnetic coil; the upper and lower end plates of the magnet are connected with different screws through fastening boltsThe line pipe magnet coil is connected; the upper cover plate of the magnet is tightly connected with the upper end plate of the magnet; the wiring board is connected with the upper cover plate of the magnet through a screw rod and is used for arranging and fixedly connecting a potential wire of the superconducting tap and a current lead of the magnet.)

1. A liquid helium soaking type large aperture experiment type close-wound high field composite superconducting magnet is characterized in that: the superconducting magnet comprises a plurality of groups of solenoid magnet coils wound by different superconducting materials, superconducting taps, magnet coil current leads, upper and lower magnet end plates, an upper magnet cover plate and a wire arranging plate; the multiple groups of solenoid magnet coils wound by different superconducting materials respectively comprise high-field Nb₃Sn、ITER TF Nb₃The solenoid magnet coil is wound by Sn, NbTi superconducting materials, and different solenoid magnet coils are connected in series; the superconducting tap segments each solenoid magnet coil so as to be externally connected with a quench detection and protection system; the magnet coil current lead wire is used for being connected with different solenoid magnet coils in series and is used for through-flow excitation of the composite solenoid magnet coil; the upper end plate and the lower end plate of the magnet are connected with different solenoid magnet coils through fastening bolts to limit the solenoid magnet coils and ensure the concentric coaxial characteristic of a plurality of groups of solenoid magnet coils; the upper cover plate of the magnet is tightly connected with the upper end plate of the magnet through a fastening bolt to encapsulate the residual space at the upper end of the magnet; the wire arrangement board is connected with the upper cover plate of the magnet through a screw rod and used for arranging and fixedly connecting a potential wire of the superconducting tap and a current lead of the magnet.

2. The liquid helium immersion type large aperture experimental group of claim 1The close-wound high-field composite superconducting magnet is characterized in that: the multiple groups of solenoid magnet coils wound by different superconducting materials comprise solenoid magnet coils wound by an odd-even close winding method and with different sizes, and the high-field Nb coils are respectively wound from inside to outside₃Sn wound solenoidal magnet coil, from ITER TF Nb₃A Sn-wound solenoidal magnet coil, a NbTi-wound solenoidal magnet coil; the multiple groups of solenoid magnet coils are combined in a concentric and coaxial mode, and from inside to outside, the two ends of the multiple groups of solenoid magnet coils are arranged in a step mode.

3. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 2, characterized in that: the solenoid magnet coil comprises a magnet framework straight cylinder, an upper flange, a lower flange, a straight cylinder insulating layer, an end insulating layer, a superconducting coil and a pre-tightening coil; the magnet framework straight cylinder, the upper flange and the lower flange are made of stainless steel, the wall thickness of the magnet at the innermost side is less than or equal to 5mm, through holes are formed in the centers of the upper flange and the lower flange of the magnet framework, the aperture of the through holes is equal to the outer diameter of the magnet framework straight cylinder, and the upper flange and the lower flange of the magnet framework are welded at two ends of the magnet framework straight cylinder; semi-circular through holes are uniformly distributed on the outer ring surfaces of the upper flange and the lower flange of the magnet framework and used for providing a liquid through-flow path, and non-through threaded holes are uniformly distributed on the outer surfaces of the upper flange and the lower flange of the magnet framework; the upper flange of the magnet framework is of an open-loop structure, and the open loop is provided with the wire inlet end and the wire outlet end of the superconducting coil; and two ends of the outer surface of the open ring of the flange on the magnet framework are provided with non-through threaded holes for fixing the superconducting tap and the current lead of the magnet coil.

4. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 3, characterized in that: the straight insulating layer, Nb₃The material used in the Sn solenoid magnet coil is mica glass fiber, the material used in the NbTi solenoid magnet coil is Teflon glass fiber, and the Teflon glass fiber is wound on the outer wall of the straight cylinder of the magnet framework; the end insulating layer, Nb₃The material used in the Sn solenoidal magnet coil is mica, the material used in the NbTi solenoidal magnet coil is G10, and the endThe outer diameter of the partial insulating layer is the same as the outer diameters of the upper flange and the lower flange of the magnet framework; the superconducting wire is made of high-field Nb₃Sn，ITER TF Nb₃Sn and NbTi are tightly wound along the outer wall of the straight-tube insulating layer through the coil inlet and outlet ends, the number of turns of even layers is one turn less than that of odd layers, the pre-tightening coil is made of stainless steel wires, the coil inlet and outlet ends are tightly wound along the outer wall of the superconducting coil, and the outer diameter of the pre-tightening coil is less than or equal to the outer diameter of the upper flange and the lower flange of the magnet framework.

5. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 1, characterized in that: the superconducting tap comprises a superconducting tap support and a superconducting wire, Nb₃The superconducting tap support of the Sn solenoid magnet coil is made of stainless steel, the superconducting tap support of the NbTi solenoid magnet coil is G10 and comprises a base, an upright post and a limiting block, the base and the upright post are of an integral structure, and the Nb is₃The superconducting tap base of the Sn solenoid magnet coil is fixed on the outer surface of the open ring position of the flange on the magnet framework by a fastening bolt through an aluminum nitride insulating block, and the superconducting tap base of the NbTi solenoid coil is directly fixed on the outer surface of the open ring position of the flange on the magnet framework by the fastening bolt; the surface of the upright post is provided with a U-shaped groove, and the superconducting wire is wired along the U-shaped groove; the limiting block is connected with the stand column through a fastening bolt and used for limiting the superconducting wire in the U-shaped groove on the surface of the stand column.

6. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 1, characterized in that: magnet coil current lead wire, including magnet coil current lead wire inlet wire and leading-out terminal, the material is oxygen-free copper, superconducting material inlet wire and leading-out terminal, including base and stand, structure as an organic whole, magnet coil current lead wire base through "falling T" shape aluminium nitride insulating block, fixes flange ring-opening department surface on the magnet skeleton through fastening bolt, magnet coil current lead wire stand surface processing is fluted for fixed superconducting current lead wire.

7. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 1, characterized in that: the upper end plate and the lower end plate of the magnet are made of stainless steel, the upper end plate and the lower end plate of the magnet are of a circular multi-step convex structure, a circular through hole is formed in the center, the aperture of the circular through hole is equal to the inner diameter of the solenoid composite magnet, the upper end plate of the magnet is of an open-loop structure, and the open-loop position corresponds to the positions of a superconducting tap and a current lead of a magnet coil.

8. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 1, characterized in that: the upper cover plate of the magnet is made of stainless steel, the upper cover plate of the magnet is of a non-closed circular ring structure, and the inner diameter of the circular ring is equal to that of the solenoid composite magnet; the open loop position corresponds to the positions of the superconducting tap and the current lead of the magnet coil; the upper cover plate of the magnet is tightly connected with the upper end plate of the magnet through evenly distributed fastening bolts.

9. The liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to claim 1, characterized in that: the flat cable plate material is G10, the flat cable plate is of a non-closed circular ring structure, and the inner diameter of the circular ring is equal to that of the solenoid composite magnet; the open loop position corresponds to the positions of the superconducting tap and the current lead of the magnet coil; the wire arranging plate is fixed on the upper cover plate of the magnet through a screw and a nut.

10. A method for manufacturing a liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet is characterized by comprising the following steps:

step 1, carrying out insulation treatment on each magnet coil framework; reserving a magnet coil current lead wire with enough length, and winding a section of superconducting wire on a winding tool in a forward rotation manner; through the inlet end of the upper flange of the magnet framework, the superconducting wire is wound along the outer wall of the straight cylinder insulating layer of the magnet framework in a positive rotation manner until the superconducting wire is wound to the lower flange of the magnet framework, and the first layer winding of the magnet coil is finished; carrying out layer-spanning treatment on the superconducting magnet coil, positively winding a second layer of magnet coil along a first layer of inter-turn gap track of the magnet coil until the second layer of magnet coil is wound to the flange on the magnet framework and reaches a gap between a first layer of first turn and a second turn of the magnet coil, and finishing the winding of the second layer of magnet coil; carrying out layer-spanning treatment on the superconducting magnet coil, and positively winding a third layer of coil along a second layer of inter-turn gap track of the magnet coil, wherein the first turn of the third layer of magnet coil is arranged between the flange on the magnet framework and the first turn of the second layer of the magnet coil; the steps are repeated, so that the odd-even compact winding of the magnet coil is realized;

step 2, after the winding reaches the specified layer number, manufacturing a superconducting tap, wiring the superconducting wire along a U-shaped path along a groove on the surface of the upright post of the superconducting tap support, and locking the relative position of the superconducting wire and the superconducting tap support by using a limiting block; after the superconducting wire returns to the position of the solenoid magnet coil along the path, odd-even winding is repeated until the number of layers of the magnet coil reaches the designated number of layers, the tail end of the winding returns to the flange end on the magnet framework, the solenoid magnet coil is wound by glass fiber cloth, the appearing end of the solenoid magnet coil is locked by a hose clamp, and the leading-out end of the magnet coil is fixed on a winding device;

step 3, fixing one end of a stainless steel wire on a winding tool, enabling the stainless steel wire to rotate forwards along the outer wall of the magnet coil covered by the glass fiber through a flange inlet end on the magnet framework to be tightly wound until the stainless steel wire is wound to a flange on the lower part of the magnet framework, and finishing the first-layer winding of the pre-tightening coil; carrying out cross-layer treatment on the pre-tightening coils, and winding a second layer of pre-tightening coils in a forward rotation manner along a first layer of inter-turn gap track of the pre-tightening coils until the second layer of pre-tightening coils are wound to the upper flange of the magnet framework; repeating the steps until the number of layers of the pre-tightening coil reaches the designated number of layers, returning the tail end of the winding to the upper flange end of the magnet framework, locking the appearing end of the solenoid magnet coil by using a hose clamp, and fixing the wire outlet end of the magnet coil on a winding tool;

step 4, respectively carrying out high-temperature heat treatment on the wound Nb3Sn solenoid magnet coils; then, respectively welding superconducting tap potential lines and a magnet current lead NbTi extension line on the solenoid magnet coil; respectively loading the magnet coils into a packaging tool, injecting the prepared low-temperature epoxy resin under the preset temperature and vacuum environment, and stopping injecting when the page reaches the upper flange of the magnet framework; after the low-temperature epoxy resin is heated and cured, a solenoid superconducting magnet coil is formed;

step 5, connecting a plurality of groups of superconducting magnet coils with the upper end plate and the lower end plate of the magnet; encapsulating the upper cover plate of the magnet; additionally arranging a wiring board, and adjusting the height of the wiring board according to the positions of the superconducting taps and the magnet current lead outlets; and connecting a plurality of groups of superconducting magnet coils in series, fixing a connecting wire on a wiring board, and fixing a superconducting tap point bit line and a magnet coil current lead extension wire through the wiring board to form the composite superconducting magnet.

Technical Field

The invention relates to the technical field of experimental high-field superconducting magnets, in particular to a liquid helium soaking type large-aperture experimental close-wound high-field composite superconducting magnet.

Background

Superconducting magnets are ideal tools for providing a strong magnetic field environment, and have been widely used in the fields of controlled thermonuclear fusion reactors, high-energy particle accelerators, steady-state strong magnetic fields, nuclear magnetic resonance (NMR, MRI), energy storage, wind power generation, magnetic separation/magnetic separation, and the like. So far, most superconducting magnets are made of NbTi or Nb₃Sn, and the magnetic field intensity is generally less than or equal to 14T. In the future, in order to improve fusion power and particle collision energy, expand the scientific frontier and improve the medical diagnosis imaging resolution, the magnetic field intensity (15-25T) which is higher in the requirements of large scientific devices, energy research and medical diagnosis is required. Therefore, the development of high-field superconducting magnet technology is urgently needed, and the development of high-field superconducting magnet technology depends on the research and development of material science to a great extent. Therefore, different types of physical property researches need to be carried out on superconducting materials under low temperature and high magnetic field, an experimental high-field superconducting magnet is basic equipment for providing a high-field environment for the researches, and the larger the magnet aperture is, the more comprehensive the achievable test function is; the higher the magnetic field intensity, the higher the material physical property measurement accuracy. The experimental superconducting magnet wound by the NbTi superconducting wire has certain limitation on the magnetic field intensity (B)_maxLess than or equal to 10T), adopting ITER TF Nb₃Experimental superconducting magnets made from Sn are also at large apertures (D)_magn.Not less than 50mm) and high magnetic field (B)_maxNot less than 15T). Therefore, a large aperture (D) was developed_magn.Not less than 70mm) experimental high field (B)_maxNot less than 15T) superconducting magnets have certain challenges.

Disclosure of Invention

In order to solve the technical problems, break through the limitations of low magnetic field, small aperture and the like of the existing experimental superconducting magnet and expand the low-temperature physical property measurement function of different materials, the invention provides a liquid helium immersion type large aperture experimental close-wound high-field composite superconducting magnet and a manufacturing method thereof. Considering that in recent years, with Nb₃The critical performance of Sn under a high field (B is more than or equal to 15T) is improved, the Sn has great application value in a 15-20T magnetic field interval in the field of high-field superconducting magnets, and meanwhile, the Sn provides possibility for the development of large-aperture experimental high-field superconducting magnets. Therefore, in order to fully exert the advantages of practical superconducting materials with different performance levels in corresponding magnetic field regions and reduce the manufacturing cost of the magnet as much as possible, the high-field superconducting magnet related by the invention is formed by combining a plurality of magnet coils which are wound by different superconducting wires in a concentric and coaxial structure, and is called as a high-field composite superconducting magnet. In order to further compress the overall dimension of the magnet and improve the contribution rate of the magnetic field of each coil, the experimental high-field composite superconducting magnet coil is wound in an odd-even compact winding mode.

The technical scheme of the invention is as follows: a liquid helium soaking type large-aperture experimental close-wound high-field composite superconducting magnet comprises a plurality of groups of solenoid magnet coils, superconducting taps, magnet coil current leads, upper and lower magnet end plates, an upper magnet cover plate and a wire arranging plate, wherein the solenoid magnet coils are wound by different superconducting materials; the multiple groups of solenoid magnet coils wound by different superconducting materials respectively comprise high-field Nb₃Sn、ITER TF Nb₃The solenoid magnet coil is wound by Sn, NbTi superconducting materials, and different solenoid magnet coils are connected in series; the superconducting tap segments each solenoid magnet coil so as to be externally connected with a quench detection and protection system; the magnet coil current lead wire is used for being connected with different solenoid magnet coils in series and is used for through-flow excitation of the composite solenoid magnet coil; on the magnetThe lower end plate is connected with different solenoid magnet coils through fastening bolts to limit the solenoid magnet coils and ensure the concentric and coaxial characteristics of a plurality of groups of solenoid magnet coils; the upper cover plate of the magnet is tightly connected with the upper end plate of the magnet through a fastening bolt to encapsulate the residual space at the upper end of the magnet; the wire arrangement board is connected with the upper cover plate of the magnet through a screw rod and used for arranging and fixedly connecting a potential wire of the superconducting tap and a current lead of the magnet.

Furthermore, the multiple groups of solenoid magnet coils wound by different superconducting materials comprise solenoid magnet coils wound by an odd-even close winding method and with different dimensions, and the high-field Nb coils are respectively wound from inside to outside₃Solenoid magnet coil wound with Sn superconducting wire, from ITER Nb₃The solenoid magnet coil is wound by NbTi superconducting wires, and the aperture, the size and the number of the solenoid magnet coils are determined by the aperture, the size and the quality of a required magnet and the outer diameter limit of a composite magnet coil. The multiple groups of solenoid magnet coils are combined in a concentric and coaxial mode, from inside to outside, two ends of the multiple groups of solenoid magnet coils are arranged in a step mode, and the height of each solenoid magnet coil is determined by the axial length of a central uniform field required by the composite magnet coil. The solenoid magnet coil comprises a magnet framework straight cylinder, an upper flange, a lower flange, a straight cylinder insulating layer, an end insulating layer, a superconducting coil and a pre-tightening coil. The magnet framework straight cylinder, the upper flange and the lower flange are made of stainless steel, the wall thickness of the magnet at the innermost side is less than or equal to 5mm, through holes are formed in the centers of the upper flange and the lower flange of the magnet framework, the aperture of the through holes is equal to the outer diameter of the magnet framework straight cylinder, and the upper flange and the lower flange of the magnet framework are welded at two ends of the magnet framework straight cylinder; semi-circular through holes are uniformly distributed on the outer ring surfaces of the upper flange and the lower flange of the magnet framework and used for providing a liquid through-flow path, and non-through threaded holes are uniformly distributed on the outer surfaces of the upper flange and the lower flange of the magnet framework; the upper flange of the magnet framework is of an open-loop structure, and the open loop is provided with the wire inlet end and the wire outlet end of the superconducting coil; and two ends of the outer surface of the open ring of the flange on the magnet framework are provided with non-through threaded holes for fixing the superconducting tap and the current lead of the magnet coil. The straight insulating layer, Nb₃The material used in the Sn solenoid magnet coil isThe material used in the mica glass fiber and NbTi solenoid magnet coil is Teflon glass fiber which is wound on the outer wall of the straight cylinder of the magnet framework. The end insulating layer, Nb₃The material used for the Sn solenoid magnet coil is mica, the material used for the NbTi solenoid magnet coil is G10, and the outer diameters of the end insulating layers are the same as the outer diameters of the upper flange and the lower flange of the magnet framework. The superconducting wire is made of high-field Nb₃Sn，ITER TF Nb₃Sn and NbTi are tightly wound along the outer wall of the straight-tube insulating layer through the coil inlet and outlet ends, and the number of turns of even layers is one turn less than that of odd layers. The pre-tightening coil is made of stainless steel wires, the coil inlet and outlet ends are tightly wound along the outer wall of the superconducting coil, and the outer diameter of the pre-tightening coil is less than or equal to the outer diameter of the upper flange and the lower flange of the magnet framework.

Further, the superconducting tap comprises a superconducting tap holder and a superconducting wire, Nb₃The superconducting tap support of the Sn solenoid magnet coil is made of stainless steel, and the superconducting tap support of the NbTi solenoid magnet coil is G10 and comprises a base, a stand column and a limiting block. The base and the upright post are of an integral structure, Nb₃The superconducting tap base of the Sn solenoid magnet coil is fixed on the outer surface of the open ring position of the flange on the magnet framework by a fastening bolt through an aluminum nitride insulating block, and the superconducting tap base of the NbTi solenoid coil is directly fixed on the outer surface of the open ring position of the flange on the magnet framework by the fastening bolt; the surface of the upright post is provided with a U-shaped groove, and the superconducting wire is wired along the U-shaped groove; the limiting block is connected with the stand column through a fastening bolt and used for limiting the superconducting wire in the U-shaped groove on the surface of the stand column.

Furthermore, the magnet coil current lead comprises an inlet wire and an outlet wire end of the magnet coil current lead, and the magnet coil current lead is made of oxygen-free copper. The superconducting material inlet wire and outlet wire end comprises a base and a stand column, and the superconducting material inlet wire and outlet wire end is of an integrated structure. The current lead wire base of the magnet coil is fixed on the outer surface of the open ring position of the flange on the magnet framework through an inverted T-shaped aluminum nitride insulating block by a fastening bolt. And grooves are processed on the surfaces of the magnetic coil current lead columns and used for fixing the superconducting current leads.

Furthermore, the upper end plate material and the lower end plate material of the magnet are made of stainless steel. The upper end plate and the lower end plate of the magnet are of a circular multi-step convex structure, a circular through hole is formed in the center, and the aperture is equal to the inner diameter of the solenoid composite magnet.

The outer diameter of the convex step depends on the inner diameter of each solenoid magnet coil, and the height of the convex step depends on the height difference of the adjacent solenoid magnet coils. The upper end plate of the magnet is of an open-loop structure, and the open-loop position corresponds to the positions of the superconducting taps and the current leads of the magnet coil.

Furthermore, the upper cover plate of the magnet is made of stainless steel, the upper cover plate of the magnet is of a non-closed circular ring structure, and the inner diameter of the circular ring is equal to that of the solenoid composite magnet; the open loop position corresponds to the positions of the superconducting tap and the current lead of the magnet coil; the upper cover plate of the magnet is tightly connected with the upper end plate of the magnet through evenly distributed fastening bolts.

Furthermore, the flat cable plate material is G10, the flat cable plate is in a non-closed circular ring structure, and the inner diameter of the circular ring is equal to that of the solenoid composite magnet; the open loop position corresponds to the positions of the superconducting tap and the current lead of the magnet coil; the wire arranging plate is fixed on the upper cover plate of the magnet through a screw and a nut, and the fixed height depends on the superconducting tap and the top wire outlet position of the current lead of the magnet coil.

According to another aspect of the present invention, a method for manufacturing a liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet is provided, which comprises the following steps:

1. insulating each magnet coil framework; reserving a magnet coil current lead wire with enough length, and winding a section of superconducting wire on a winding tool in a forward rotation manner; through the inlet end of the upper flange of the magnet framework, the superconducting wire is wound along the outer wall of the straight cylinder insulating layer of the magnet framework in a positive rotation manner until the superconducting wire is wound to the lower flange of the magnet framework, and the first layer winding of the magnet coil is finished; carrying out layer-spanning treatment on the superconducting magnet coil, positively winding a second layer of magnet coil along a first layer of inter-turn gap track of the magnet coil until the second layer of magnet coil is wound to the flange on the magnet framework and reaches a gap between a first layer of first turn and a second turn of the magnet coil, and finishing the winding of the second layer of magnet coil; carrying out layer-spanning treatment on the superconducting magnet coil, and positively winding a third layer of coil along a second layer of inter-turn gap track of the magnet coil, wherein the first turn of the third layer of magnet coil is arranged between the flange on the magnet framework and the first turn of the second layer of the magnet coil; the steps are repeated, so that the odd-even compact winding of the magnet coil is realized;

2. after the winding reaches the specified layer number, manufacturing a superconducting tap, wiring the superconducting wire along a U-shaped path along a groove on the surface of the upright post of the superconducting tap support, and locking the relative position of the superconducting wire and the superconducting tap support by using a limiting block; after the superconducting wire returns to the position of the solenoid magnet coil along the path, odd-even winding is repeated until the number of layers of the magnet coil reaches the designated number of layers, the tail end of the winding returns to the flange end on the magnet framework, the solenoid magnet coil is wound by glass fiber cloth, the appearing end of the solenoid magnet coil is locked by a hose clamp, and the leading-out end of the magnet coil is fixed on a winding device;

3. fixing one end of a stainless steel wire on a winding tool, leading the stainless steel wire to pass through an inlet end of an upper flange of a magnet framework, rotating the stainless steel wire forward along the outer wall of a magnet coil covered by glass fiber to be tightly wound until the stainless steel wire is wound to a lower flange of the magnet framework, and finishing the first-layer winding of a pre-tightening coil; carrying out cross-layer treatment on the pre-tightening coils, and winding a second layer of pre-tightening coils in a forward rotation manner along a first layer of inter-turn gap track of the pre-tightening coils until the second layer of pre-tightening coils are wound to the upper flange of the magnet framework; repeating the steps until the number of layers of the pre-tightening coil reaches the designated number of layers, returning the tail end of the winding to the upper flange end of the magnet framework, locking the appearing end of the solenoid magnet coil by using a hose clamp, and fixing the wire outlet end of the magnet coil on a winding tool;

4. nb to be wound₃Respectively carrying out high-temperature heat treatment on the Sn solenoid magnet coils; then, respectively welding superconducting tap potential lines and a magnet current lead NbTi extension line on the solenoid magnet coil; respectively loading the magnet coils into a packaging tool, injecting prepared low-temperature epoxy resin at a certain temperature in a vacuum environment, and stopping injecting when the page reaches the upper flange of the magnet framework; after the low-temperature epoxy resin is heated and cured, a solenoid superconducting magnet coil is formed;

5. connecting a plurality of groups of superconducting magnet coils with the upper end plate and the lower end plate of the magnet; encapsulating the upper cover plate of the magnet; additionally arranging a wire arranging plate, and adjusting the height of the wire arranging plate according to the positions of the superconducting taps and the magnet current lead wire outlets; and connecting a plurality of groups of superconducting magnet coils in series, fixing a connecting wire on a wiring board, and fixing a superconducting tap point bit line and a magnet coil current lead extension wire through the wiring board to form the composite superconducting magnet.

Has the advantages that:

the liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet provided by the invention can generate a central magnetic field of more than or equal to 15T in a 4.2K liquid helium temperature zone under the condition of 120A stable through-flow, and the aperture of the composite magnet is more than or equal to 70 mm. The invention adopts the odd-even winding method to wind the close-wound coil, effectively controls the turn interval of the close-wound coil and ensures the tightness and the flatness of the coil. The invention adopts a coaxial concentric assembly mode and a mode that various superconducting wire wound coils are matched with each other, reduces the size scale of the composite magnet coil and improves the magnetic field intensity and the central aperture of the magnet compared with the prior superconducting magnet technology. According to different critical characteristics of the superconducting wire, the composite magnet coil structure is used for tightly winding the experimental high-field superconducting magnet, so that the utilization rate of different types of superconducting materials is improved, and the manufacturing cost of the high-field superconducting magnet is reduced.

Drawings

FIG. 1 is a schematic diagram of a three-dimensional structure of a liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to the present invention;

FIG. 2 is a left half-sectional plan view of a liquid helium immersed large-aperture experimental close-wound high-field composite superconducting magnet according to the present invention;

FIG. 3 is a three-dimensional schematic diagram of an NbTi superconducting coil of a liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet according to the present invention;

FIG. 4 shows Nb of the liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet of the invention₃A three-dimensional schematic diagram of the Sn superconducting coil;

FIG. 5 is a three-dimensional schematic view of a superconducting tap of the liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet of the present invention;

FIG. 6 is a schematic diagram of a magnet coil current lead of the liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet of the present invention;

fig. 7 is a magnet coil close-wound schematic diagram of the liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet of the invention.

In the figure: 1-NbTi solenoidal magnet coil, 2-ITER TF Nb₃Sn solenoidal magnet coil, 3-first high field Nb₃Sn solenoidal magnet coil, 4-second high field Nb₃The magnetic coil of the Sn solenoid, 5-superconducting taps, 6-current leads of the magnetic coil, 7-upper end plate of the magnet, 8-lower end plate of the magnet, 9-upper cover plate of the magnet, 10-wire arranging plate, 11-fastening screw and nut, 12-straight cylinder of the magnet framework, 13-upper flange of the magnet framework, 14-lower flange of the magnet framework, 15-end insulating layer of NbTi magnet framework, 16-straight cylinder insulating layer of NbTi magnet framework, 17-NbTi superconducting coils, 18-pre-tightening coils, 19-limiting blocks of the superconducting taps, and 20-Nb₃Insulating layer at end of Sn magnet skeleton, 21-Nb₃Straight insulating layer of Sn magnet skeleton, 22-Nb₃The superconducting magnet comprises a Sn superconducting coil, 23-a superconducting tap insulating gasket, 24-a magnet coil current lead insulating gasket, 25-a superconducting tap support, 26-a magnet coil current lead incoming end, 27-a magnet coil current lead outgoing end and 28-a superconducting wire.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention belong to the protection scope of the present invention without creative efforts.

According to an embodiment of the invention, a liquid helium immersed large-aperture experimental close-wound high-field composite superconducting magnet is provided, which is shown in the attached drawings 1-2 and comprises an NbTi solenoid magnet coil 1 and an ITER TF Nb₃Sn solenoidal magnet coil 2(ITER TF Nb)₃The critical current density of the Sn superconducting wire is 1000-2000A/mm²Between @12T and 4.2K), the first high field Nb₃Sn solenoidal magnet coil 3 (high field Nb)₃The critical current density of the Sn superconducting wire is more than or equal to 2000A/mm²@12T, 4.2K), second high field Nb₃Sn solenoid magnet coil 4, superconducting tap 5, magnet wireA coil current lead 6, a magnet upper end plate 7, a magnet lower end plate 8, a magnet upper cover plate 9 and a wire arranging plate 10.

Referring to fig. 3, the NbTi solenoid magnet coil 1 includes a magnet frame straight cylinder 12, a magnet frame upper flange 13, a magnet frame lower flange 14, an end insulating layer 15, a straight cylinder insulating layer 16, a superconducting coil 17, and a pre-tightening coil 18; the upper flange 13 of the magnet framework and the lower flange 14 of the magnet framework are welded at two ends of the straight cylinder 12 of the magnet framework, the insulating layer 16 of the straight cylinder is wound along the outer wall of the straight cylinder 12 of the magnet framework, the insulating layer 15 of the end part is fixed at the inner sides of the upper flange 13 of the magnet framework and the lower flange 14 of the magnet framework, the superconducting coil 17 is wound along the outer wall of the insulating layer 16 of the straight cylinder in a positive rotation mode through the wire inlet end of the upper flange 13 of the magnet framework, and as shown in figure 7, the pre-tightening coil 18 is wound on the.

See FIG. 4, Nb₃The Sn solenoid magnet coils 2-4 comprise a magnet framework straight cylinder 12, a magnet framework upper flange 13, a magnet framework lower flange 14, an end insulating layer 20, a straight cylinder insulating layer 21, a superconducting coil 22 and a pre-tightening coil 18; the upper flange 13 of the magnet framework and the lower flange 14 of the magnet framework are welded at two ends of the straight cylinder 12 of the magnet framework, the insulating layer 21 of the straight cylinder is wound along the outer wall of the straight cylinder 12 of the magnet framework, the insulating layer 20 of the end part is fixed at the inner sides of the upper flange 13 of the magnet framework and the lower flange 14 of the magnet framework, the superconducting coil 17 is wound along the outer wall of the insulating layer 16 of the straight cylinder in a positive rotation manner through the wire inlet end of the upper flange 13 of the magnet framework, and as shown in figure 7, the pre-tightening coil 18 is wound on the;

referring to fig. 5, the superconducting tap 5 comprises a superconducting tap support 25 and a superconducting wire 28, after the superconducting coil 17 is wound to a specified number of layers, the superconducting coil is wired along a U-shaped groove on the surface of the superconducting tap support 25 through an open loop of a flange 13 on a magnet framework, and the superconducting wire 17 in the U-shaped groove on the surface of the superconducting tap support 25 is limited and fixed by a limiting block 19; the superconducting tap 5 of the NbTi solenoid magnet coil 1 is fixed on a flange 13 on a magnet framework through a fastening bolt; see FIG. 6, Nb₃The superconducting tap 5 of the Sn solenoid magnet coil 2-4 is fixed on the flange 13 of the magnet framework through a superconducting tap insulating gasket 23 by a fastening bolt;

with further reference to fig. 6, the magnet coil current lead 6 includes a magnet coil current lead incoming end 26, a magnet coil current lead outgoing end 27, and a superconducting wire 28, wherein after the superconducting coil 17 is wound to a specified number of layers, the superconducting wire 28 is connected to the magnet coil current lead incoming end 26 and the magnet coil current lead outgoing end 27 through an open loop of the magnet frame upper flange 13; a magnet current lead wire inlet end 26 and a magnet current lead wire outlet end 27 are fixed on the magnet framework upper flange 13 through a magnet coil current lead wire insulating gasket 24 through fastening bolts;

the wound solenoid magnet coil 1-4 is fixed by an upper magnet end plate 7 and a lower magnet end plate 8 from outside to inside, namely an NbTi solenoid magnet coil 1 and an ITER Nb from outside to inside₃Sn solenoidal magnet coil 2, first high field Nb₃Sn solenoidal magnet coil 3, second high field Nb₃Sn solenoid magnet coil 4;

the upper magnet cover plate 9 is tightly connected with the upper magnet end plate 7 through a fastening bolt;

the power strip 10 is connected with the magnet upper cover plate 9 through a fastening screw and a nut 11, and the extension lines of the superconducting taps 5 and the magnet coil current leads 6 are arranged and fixed on the power strip 10.

According to an embodiment of the invention, a method for manufacturing a liquid helium immersion type large-aperture experimental close-wound high-field composite superconducting magnet is provided, which specifically comprises the following steps:

step 1, carrying out insulation treatment on each magnet coil framework; reserving a magnet coil current lead wire with enough length, and winding a section of superconducting wire on a winding tool in a forward rotation manner; through the inlet end of the upper flange of the magnet framework, the superconducting wire is wound along the outer wall of the straight cylinder insulating layer of the magnet framework in a positive rotation manner until the superconducting wire is wound to the lower flange of the magnet framework, and the first layer winding of the magnet coil is finished; carrying out layer-spanning treatment on the superconducting magnet coil, positively winding a second layer of magnet coil along a first layer of inter-turn gap track of the magnet coil until the second layer of magnet coil is wound to the flange on the magnet framework and reaches a gap between a first layer of first turn and a second turn of the magnet coil, and finishing the winding of the second layer of magnet coil; carrying out layer-spanning treatment on the superconducting magnet coil, and positively winding a third layer of coil along a second layer of inter-turn gap track of the magnet coil, wherein the first turn of the third layer of magnet coil is arranged between the flange on the magnet framework and the first turn of the second layer of the magnet coil; the steps are repeated, so that the odd-even compact winding of the magnet coil is realized;

step 2, after the winding reaches the specified layer number, manufacturing a superconducting tap, wiring the superconducting wire along a U-shaped path along a groove on the surface of the upright post of the superconducting tap support, and locking the relative position of the superconducting wire and the superconducting tap support by using a limiting block; after the superconducting wire returns to the position of the solenoid magnet coil along the path, odd-even winding is repeated until the number of layers of the magnet coil reaches the designated number of layers, the tail end of the winding returns to the flange end on the magnet framework, the solenoid magnet coil is wound by glass fiber cloth, the appearing end of the solenoid magnet coil is locked by a hose clamp, and the leading-out end of the magnet coil is fixed on a winding device;

step 3, fixing one end of a stainless steel wire on a winding tool, enabling the stainless steel wire to rotate forwards along the outer wall of the magnet coil covered by the glass fiber through a flange inlet end on the magnet framework to be tightly wound until the stainless steel wire is wound to a flange on the lower part of the magnet framework, and finishing the first-layer winding of the pre-tightening coil; carrying out cross-layer treatment on the pre-tightening coils, and winding a second layer of pre-tightening coils in a forward rotation manner along a first layer of inter-turn gap track of the pre-tightening coils until the second layer of pre-tightening coils are wound to the upper flange of the magnet framework; repeating the steps until the number of layers of the pre-tightening coil reaches the designated number of layers, returning the tail end of the winding to the upper flange end of the magnet framework, locking the appearing end of the solenoid magnet coil by using a hose clamp, and fixing the wire outlet end of the magnet coil on a winding tool;

step 4, respectively carrying out high-temperature heat treatment on the wound Nb3Sn solenoid magnet coils; then, respectively welding superconducting tap potential lines and a magnet current lead NbTi extension line on the solenoid magnet coil; respectively loading the magnet coils into a packaging tool, injecting the prepared low-temperature epoxy resin under the preset temperature and vacuum environment, and stopping injecting when the page reaches the upper flange of the magnet framework; after the low-temperature epoxy resin is heated and cured, a solenoid superconducting magnet coil is formed;

step 5, connecting a plurality of groups of superconducting magnet coils with the upper end plate and the lower end plate of the magnet; encapsulating the upper cover plate of the magnet; additionally arranging a wiring board, and adjusting the height of the wiring board according to the positions of the superconducting taps and the magnet current lead outlets; and connecting a plurality of groups of superconducting magnet coils in series, fixing a connecting wire on a wiring board, and fixing a superconducting tap point bit line and a magnet coil current lead extension wire through the wiring board to form the composite superconducting magnet.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.