A superconducting magnet skeleton, a superconducting magnet and a single crystal furnace device

Abstract

The application relates to the technical field of superconducting magnets, and particularly discloses a superconducting magnet framework, a superconducting magnet and a single-crystal furnace device. The framework comprises a support frame and upper and lower winding frameworks. The upper and lower winding frameworks are detachably connected to the upper and lower end faces of the support frame. The upper winding framework is provided with a first upper side blocking portion and a first lower side blocking portion which extend in the radial direction. The lower winding framework is provided with a second upper side blocking portion and a second lower side blocking portion which extend in the radial direction. An upper winding cavity and a lower winding cavity are formed between the first upper side blocking portion and the first lower side blocking portion and between the second upper side blocking portion and the second lower side blocking portion. The first upper side blocking portion and the second lower side blocking portion protrude in the radial direction from the first lower side blocking portion and the second upper side blocking portion. First pull rods are connected to the first upper side blocking portion and the second lower side blocking portion at both ends. The arrangement improves the structural strength and stability of the framework. Meanwhile, the superconducting magnet is provided with a cold conducting component and a magnet suspension, so that the heat dissipation performance, the structural stability of the superconducting magnet and the magnetic field uniformity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of superconducting magnets, and in particular to a superconducting magnet framework, a superconducting magnet and a single crystal furnace device. BACKGROUND

[0002] A superconducting magnet is a device that uses the characteristic of superconducting material having zero resistance at low temperature to generate a strong magnetic field. The superconducting magnet has the advantages of low energy consumption, high magnetic field strength and good uniformity, and is widely used in magnetic resonance imaging (MRI), high-energy physics experiments, magnetic levitation trains, nuclear fusion research, single crystal growth and other fields. A superconducting magnet framework is an important support structure of a superconducting magnet, which can provide mechanical support for superconducting coils and other components, ensure the structural stability of the superconducting magnet, and avoid deformation and displacement of the superconducting coils under stress, so as to ensure that the superconducting magnet can operate stably and reliably.

[0003] In related technologies, a superconducting magnet includes an I-shaped integral framework for winding superconducting coils on the upper and lower parts of the framework. However, such an integral framework is difficult to produce in the manufacturing process, and it is difficult to ensure the dimensional accuracy and shape accuracy of each part of the framework. Moreover, the heat dissipation performance of the superconducting magnet is poor, which can easily lead to an increase in temperature of the superconducting magnet during long-term operation, affecting the stability and service life of the superconducting magnet. In addition, since the cooling component is arranged close to the superconducting coils, the superconducting magnet can be slightly deformed during transportation or under stress, affecting the magnetic field uniformity and stability of the superconducting magnet. SUMMARY

[0004] The present application aims to provide a superconducting magnet framework, a superconducting magnet and a single crystal furnace device to at least solve the technical problems of the prior art that the I-shaped integral framework is difficult to produce and has poor heat dissipation effect, and the corresponding superconducting magnet has poor internal structural stability and poor heat dissipation performance.

[0005] In a first aspect, the embodiments of the present application provide a superconducting magnet framework, comprising:

[0006] a support frame, a projection profile of the support frame in a first direction is circular ring-shaped, and the support frame has an upper mounting portion and a lower mounting portion oppositely arranged in the first direction;

[0007] an upper winding framework; and

[0008] The upper winding frame and the lower winding frame are respectively detachably connected to the upper mounting portion and the lower mounting portion, the upper winding frame is provided with a first upper side blocking portion and a first lower side blocking portion extending radially along the support frame, the lower winding frame is provided with a second upper side blocking portion and a second lower side blocking portion extending radially along the support frame, an upper winding cavity and a lower winding cavity are respectively formed between the first upper side blocking portion and the first lower side blocking portion and between the second upper side blocking portion and the second lower side blocking portion, and the first upper side blocking portion and the second lower side blocking portion protrude radially from the first lower side blocking portion and the second upper side blocking portion.

[0009] The first pull rod is connected at two ends thereof to the first upper side blocking portion and the second lower side blocking portion along the first direction.

[0010] In some embodiments, the upper winding frame and the lower winding frame have a circular ring shape in a projection profile along the first direction, a plurality of the first pull rods are arranged along a circumferential direction of the upper winding frame and the lower winding frame and connected at two ends thereof to the first upper side blocking portion and the second lower side blocking portion respectively.

[0011] In some embodiments, the first upper side blocking portion and the second lower side blocking portion protrude from surfaces of the first lower side blocking portion and the second upper side blocking portion respectively, and are provided with a first connecting hole and a second connecting hole for connecting the first pull rod, the first connecting hole and the second connecting hole are coaxially arranged along the first direction.

[0012] In some embodiments, the upper winding cavity and the lower winding cavity have a circular ring shape in a projection profile along the first direction, and a ratio of an inner diameter R of the circular ring shape to a distance L between the upper winding cavity and the lower winding cavity along the first direction satisfies 2.5 < R / L < 2.7.

[0013] Compared with the prior art, the technical solution provided by the first aspect of the present application has at least the following beneficial effects or advantages:

[0014] The superconducting magnet framework provided by the application is arranged to include a support frame, an upper winding framework and a lower winding framework, the support frame, the upper winding framework and the lower winding framework are detachably connected, thus, the parts of the superconducting magnet framework can be manufactured and processed separately, the volume of each part produced separately is small, the production difficulty is reduced, the dimensional accuracy and shape accuracy of the production of each part of the framework are improved, and the structure is more flexible, facilitating assembly and disassembly, thereby simplifying the installation and maintenance process of the superconducting magnet; the upper and lower winding frameworks are provided with different radial protruding upper side stop portions and lower side stop portions, and the first pull rods are arranged, the first pull rods are connected with the upper side stop portions of the upper winding framework and the lower side stop portions of the lower winding framework respectively, on the one hand, the upper and lower winding frameworks are tightly pressed against the support frame by the plurality of first pull rods, the structural strength, rigidity and stability of the entire superconducting magnet framework are improved, on the other hand, the first pull rods can better protect the coils between the upper and lower side stop portions; in addition, the upper winding framework and the lower winding framework can wind the upper coil and the lower coil separately, the winding period of the coil wound on the framework is reduced, and the production efficiency is improved; most importantly, the coil solidification can also be carried out separately, the required paraffin is reduced, the solidification time is shortened, the production cost is reduced, and the production efficiency is improved.

[0015] In a second aspect, the embodiments of the application provide a superconducting magnet, comprising:

[0016] A vacuum Dewar, the vacuum Dewar is a closed hollow circular ring column structure, the center of the vacuum Dewar is surrounded by a through hole;

[0017] A cold screen, the cold screen is accommodated in the vacuum Dewar, and the cold screen is a hollow circular ring column structure;

[0018] The superconducting magnet framework as claimed in any one of the preceding claims, the superconducting magnet framework is accommodated in the cold screen;

[0019] An upper coil and a lower coil, which are respectively spirally wound in the upper winding cavity and the lower winding cavity;

[0020] A cold conducting assembly, the cold conducting assembly is accommodated in the cold screen, the cold conducting assembly comprises a cold conducting copper plate arranged on the top surface of the upper winding framework, a copper sheet arranged on the surface of the upper coil and the lower coil, and a main cold conducting member connected with the copper sheet and the cold conducting copper plate respectively;

[0021] A refrigerator, the refrigerator is provided with a primary cold head and a secondary cold head penetrating the vacuum Dewar and the cold screen, the primary cold head is in cold conducting connection with the cold screen, and the secondary cold head is in cold conducting connection with the main cold conducting member;

[0022] The diameter D of the through hole and the center distance L1 between the upper coil and the lower coil along the first direction satisfy 0.88 < D / L1 < 0.93.

[0023] In some embodiments, a top surface of the cold-carrying copper plate is provided with a first copper foil, the secondary cold head is connected with the cold-carrying copper plate through the first copper foil, and the main cold-carrying member extends to the lower wire winding skeleton and is connected with the bottom end surface of the lower wire winding skeleton through a second copper foil; the cold-carrying assembly further comprises an arc-shaped cold-carrying copper plate connected with the copper sheet, and the arc-shaped cold-carrying copper plate is connected with the main cold-carrying member.

[0024] In some embodiments, the superconducting magnet further comprises a magnet suspension arranged in the vacuum Dewar, the magnet suspension comprises a second pull rod and an epoxy side lifting rod, the second pull rod is sequentially connected with the vacuum Dewar, the cold shield, the first upper side blocking part and the second lower side blocking part along the first direction, and one end of the epoxy side lifting rod is connected with the outer side wall of the support frame, and the other end penetrates the cold shield along the radial direction and is connected with the inner side wall of the vacuum Dewar.

[0025] In some embodiments, a plurality of the second pull rods and the epoxy side lifting rods are arranged in a circumferential direction of the support frame, and the second pull rods and the epoxy side lifting rods are arranged in a staggered manner.

[0026] In some embodiments, the magnet suspension further comprises an epoxy pull rod arranged along the first direction, and a plurality of the epoxy pull rods are sequentially connected with the inner wall of the upper cover plate of the vacuum Dewar, the upper cover plate of the cold shield, the first upper side blocking part and the second lower side blocking part along the first direction.

[0027] Compared with the prior art, the technical scheme provided by the second aspect of the above-mentioned application has at least the following beneficial effects or advantages:

[0028] The superconducting magnet provided by the application can achieve the beneficial effects of the superconducting magnet framework through the vacuum Dewar, the cold shield, the superconducting magnet framework arranged in the cold shield and the cold conducting assembly arranged in the cold shield; the cold conducting assembly comprises a cold conducting copper plate arranged on the top surface of the upper winding framework, copper sheets arranged on the surfaces of the upper coil and the lower coil, and main cold conducting components connected with the copper sheets and the cold conducting copper plate respectively; when the refrigerator connected with the cold conducting assembly is operated, the heat dissipation performance of the superconducting magnet can be significantly improved, the temperature of the superconducting magnet can be stabilized during long-time operation, and the service life of the superconducting magnet is prolonged; meanwhile, the optimized design of the cold conducting assembly also considers the structural stability and the magnetic field uniformity of the superconducting magnet, so that the superconducting magnet can be stably and reliably operated, and strong magnetic field support is provided for single crystal growth and other applications; the setting of the cold conducting assembly in combination with the pull rod can avoid slight deformation during transportation or under stress, and the magnetic field uniformity and stability of the superconducting magnet are improved.

[0029] In a third aspect, the embodiments of the application further provide a single crystal furnace device, comprising the superconducting magnet according to any one of the second aspect, and a single crystal furnace arranged at the center of the superconducting magnet, wherein the superconducting magnet is used to generate a hook-shaped magnetic field and act on a silicon melt contained in a crucible in the single crystal furnace, and during single crystal growth, the zero magnetic surface of the hook-shaped magnetic field satisfies that the zero magnetic surface is located below the liquid surface of the silicon solution and the distance between the zero magnetic surface and the liquid surface is 0-100 mm in the first direction.

[0030] Compared with the prior art, the technical scheme provided by the third aspect of the application at least has the following beneficial effects or advantages:

[0031] The single crystal furnace device provided by the application comprises a superconducting magnet and a single crystal furnace arranged at the center of the superconducting magnet, wherein the upper coil and the lower coil in the superconducting magnet are used to generate a hook-shaped magnetic field and act on a silicon melt contained in a crucible in the single crystal furnace, and the distance between the zero magnetic surface of the hook-shaped magnetic field and the interface of the silicon solution is set as 0-100 mm, which has the advantages that during the directional solidification growth of the silicon melt, the influence of the zero magnetic surface on the heat convection of the silicon melt can be avoided, and the silicon melt can be subjected to a relatively uniform magnetic field during solidification, so that the quality and stability of single crystal growth are improved; meanwhile, the inner diameter R of the superconducting coil and the distance L between the two superconducting coils satisfy 2.5

[0032] Additional aspects and advantages of the application will be made apparent by the following description and the appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0034] Figure 1 is a sectional view of the superconducting magnet skeleton along the central axis according to an embodiment of the present application;

[0035] Figure 2 is a top view of the superconducting magnet skeleton according to an embodiment of the present application;

[0036] Figure 3 is a partial sectional view of the superconducting magnet skeleton according to an embodiment of the present application;

[0037] Figure 4 is another sectional view of the superconducting magnet skeleton along the central axis according to an embodiment of the present application;

[0038] Figure 5 is a partial sectional view of the superconducting magnet along the central axis according to an embodiment of the present application;

[0039] Figure 6 is a structural schematic diagram of the cold conducting assembly according to an embodiment of the present application;

[0040] Figure 7 is a structural schematic diagram of the superconducting magnet according to an embodiment of the present application;

[0041] Figure 8 is another partial sectional view of the superconducting magnet along the central axis according to an embodiment of the present application;

[0042] Figure 9 is a sectional schematic diagram of the single crystal furnace device along the central axis according to an embodiment of the present application.

[0043] LIST OF REFERENCE NUMERALS

[0044] 10, superconducting magnet skeleton; 11, support frame; 111, upper mounting portion; 112, lower mounting portion; 12, upper winding skeleton; 121, first upper side blocking portion; 1211, first connecting hole; 122, first lower side blocking portion; 123, upper winding cavity; 13, lower winding skeleton; 131, second upper side blocking portion; 132, second lower side blocking portion; 1321, second connecting hole; 133, lower winding cavity; 14, first pull rod;

[0045] 100, superconducting magnet; 101, vacuum dewar; 102, cold shield; 1021, upper cover plate; 1022, lower cover plate; 103, upper coil; 104, lower coil; 105, refrigerator; 1051, primary cold head; 1052, secondary cold head;

[0046] 20, cold conducting assembly; 21, cold conducting copper plate; 211, first copper foil; 212, positive copper lead wire; 213, negative copper lead wire; 22, copper sheet; 23, main cold conducting member; 231, second copper foil; 24, arc conducting copper plate; 241, third copper foil; 30, magnet suspension; 31, second pull rod; 32, epoxy side ejector pin; 33, epoxy pull rod;

[0047] 1000, single crystal furnace device; 1001, zero magnetic surface; 1002, silicon solution interface; 1011, shielding layer; 200, crucible;

[0048] A, first direction. DETAILED DESCRIPTION

[0049] Embodiments of the present application are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein, and wherein the same or similar numerals indicate the same or similar elements throughout the several views. The embodiments described herein are merely exemplary and are not intended to limit the present application.

[0050] It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is to be understood that the terms "approximately" and "substantially" are used herein to represent the insubstantial difference in the precision of a numerical value, and the insubstantial difference in the shape, position, and / or the like of a geometric figure.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] Reference will now be made to Figures 1 to 4The embodiment provides a superconducting magnet framework, which comprises a support frame 11, an upper winding frame 12, a lower winding frame 13 and a first pull rod 14; the projection profile of the support frame 11 along a first direction A is circular ring-shaped, and the support frame 11 has an upper mounting part 111 and a lower mounting part 112 oppositely arranged along the first direction A. It is to be explained that the upper mounting part 111 and the lower mounting part 112 can be mounting surfaces arranged on the upper and lower end faces of the support frame 11, and the mounting surfaces can be circular ring-shaped planes, so as to be used for mounting the upper winding frame 12 and the lower winding frame 13 respectively. The upper winding frame 12 and the lower winding frame 13 are detachably connected to the upper mounting part 111 and the lower mounting part 112 respectively. Specifically, screw holes can be formed in the bottom of the upper winding frame 12, the top of the lower winding frame 13, the upper mounting part 111 and the lower mounting part 112, and detachable connection is realized through bolts. Figure 1 For the convenience of description, the height direction of the support frame 11 is defined as the first direction A. For the upper mounting part 111 and the lower mounting part 112, the mounting surfaces can be circular ring-shaped planes, so as to be used for mounting the upper winding frame 12 and the lower winding frame 13 respectively. The upper winding frame 12 and the lower winding frame 13 are detachably connected to the upper mounting part 111 and the lower mounting part 112 respectively. Specifically, screw holes can be formed in the bottom of the upper winding frame 12, the top of the lower winding frame 13, the upper mounting part 111 and the lower mounting part 112, and detachable connection is realized through bolts.

[0053] Further, the upper winding frame 12 is provided with a first upper side blocking part 121 and a first lower side blocking part 122 extending along the radial direction of the support frame 11, and the lower winding frame 13 is provided with a second upper side blocking part 131 and a second lower side blocking part 132 extending along the radial direction of the support frame 11. The first upper side blocking part 121 and the first lower side blocking part 122, and the second upper side blocking part 131 and the second lower side blocking part 132 form an upper winding cavity 123 and a lower winding cavity 133 respectively. The first upper side blocking part 121 and the second lower side blocking part 132 protrude radially from the first lower side blocking part 122 and the second upper side blocking part 131. The first pull rod 14 is connected to the first upper side blocking part 121 and the second lower side blocking part 132 at both ends along the first direction A.

[0054] It is to be explained that, as shown in FIG. 1, Figure 1 The projection profile of the first upper side blocking part 121, the first lower side blocking part 122, the second upper side blocking part 131 and the second lower side blocking part 132 along the first direction A is circular ring-shaped. The circular ring profile of the first lower side blocking part 122 can be arranged to be the same as the profile of the upper mounting part 111, and the circular ring profile of the second upper side blocking part 131 can be arranged to be the same as the profile of the lower mounting part 112. In order to facilitate installation, the first lower side blocking part 122 and the second upper side blocking part 131 are provided with bolt holes, and the bolt holes are reserved at a certain distance from the side walls of the upper winding cavity 123 and the lower winding cavity 133. In this way, after the winding of the coil is completed, the installation of the upper winding frame 12, the lower winding frame 13 and the support frame 11 is facilitated.

[0055] Similarly, the first upper side stop 121 and the second lower side stop 132 protrude radially from the first lower side stop 122 and the second upper side stop 131. It can be understood that the diameters of the circles on which the side end faces of the first upper side stop 121 and the second lower side stop 132 are located are greater than the diameters of the circles on which the side end faces of the first lower side stop 122 and the second upper side stop 131 are located. In this way, a cavity is formed between the first upper side stop 121 and the second lower side stop 132 in the vertical direction, and the first pull rod 14 can be conveniently installed and fixed.

[0056] It should also be noted that the axis of the bolt connecting the upper winding framework 12 and the upper mounting portion 111 and the lower winding framework 13 and the lower mounting portion 112 is arranged to be offset from the axis of the first pull rod 14, the ratio of the number of pull rods to the number of bolts can be 1:3, the outer diameter of the pull rod is greater than the outer diameter of the bolt; the upper winding cavity 123 and the lower winding cavity 133 are circular cavities; and the superconducting magnet framework 10 of the embodiment can be made of stainless steel material, which is more flexible in structure on the basis of ensuring the structural strength and rigidity of the framework.

[0057] In the superconducting magnet framework 10 of the embodiment, the support frame 11, the upper winding framework 12, and the lower winding framework 13 are arranged to be detachably connected, so that each part of the superconducting magnet framework 10 can be manufactured and processed separately, and the size precision and shape precision of each part produced are improved due to the small volume of each part produced separately, the production difficulty is reduced, and the structure is more flexible, facilitating assembly and disassembly, thereby simplifying the installation and maintenance process of the superconducting magnet; the upper winding framework 12 and the lower winding framework 13 are provided with upper side stops and lower side stops protruding in different radial directions, and the first pull rod 14 is arranged to connect the upper side stops of the upper winding framework 12 and the lower side stops of the lower winding framework 13, thereby improving the structural strength, rigidity, and stability of the entire superconducting magnet framework 10, and the first pull rod 14 can better protect the coils between the upper and lower side stops.

[0058] Continuing to refer to Figures 1 to 3In some embodiments, the plurality of first pull rods 14 are arranged along the circumference of the upper winding frame 12 and the lower winding frame 13, and are connected to the first upper side block 121 and the second lower side block 132 at two ends respectively. In the present embodiment, the number of first pull rods 14 can be selected according to specific requirements. Meanwhile, the plurality of first pull rods 14 can be arranged equidistantly or unequidistantly along the circumference of the upper winding frame 12 or the lower winding frame 13, and are preferably arranged equidistantly. In this way, due to the connection of the first pull rods 14 with the first upper side block 121 and the second lower side block 132, the top end surface of the upper winding frame 12 and the bottom end surface of the lower winding frame 13 are subjected to relative pulling force. Since the plurality of pulling forces are distributed along the upper winding frame 12 or the lower winding frame 13, the strength and stability of the superconducting magnet frame 10 structure are further improved.

[0059] Optionally, the plurality of first pull rods 14 are preferably distributed on the same circumferential contour. The first upper side block 121 and the second lower side block 132 protrude from the surfaces of the first lower side block 122 and the second upper side block 131, and are respectively provided with first connecting holes 1211 and second connecting holes 1321 for connecting the first pull rods 14. The first connecting holes 1211 and the second connecting holes 1321 are coaxially arranged along the first direction A. It should be understood that the number of first connecting holes 1211 or second connecting holes 1321 is the same as the number of first pull rods 14. The first connecting holes 1211 and the second connecting holes 1321 are distributed on the same diameter circumferential contour. In this way, threads or other fastening structures can be arranged at both ends of the first pull rods 14. Both ends pass through the first connecting holes 1211 and the second connecting holes 1321 and are fixed by nuts, facilitating the installation of the first pull rods 14.

[0060] Continuing to refer to Figure 4 In some embodiments, the projection profile of the upper winding cavity 123 and the lower winding cavity 133 along the first direction A is a circular ring, and the ratio of the inner diameter R of the circular ring to the distance L between the upper winding cavity 123 and the lower winding cavity 133 along the first direction A satisfies the range of 2.5 < R / L < 2.7. It should be noted that in actual superconducting magnet frames 10, the volume of the upper winding frame 12 and the lower winding frame 13 is actually much larger than the volume of the upper winding cavity 123 and the lower winding cavity 133. For example, the distance between the central axis shown by the dashed line in the figure and the inner side wall of the upper winding frame or the inner side wall of the upper winding cavity 123 is negligible. The distance L between the upper winding cavity 123 and the lower winding cavity 133 along the first direction A can be defined as the distance between the middle position of the upper winding cavity 123 along the first direction A and the middle position of the lower winding cavity 133 along the first direction A.

[0061] It should be noted that by setting the ratio of the inner diameter R of the upper winding cavity 123 and the lower winding cavity 133 to the spacing L between the two superconducting coils in the first direction A to be in the range of 2.5 < R / L < 2.7, the inner diameter R of the wound superconducting coil and the spacing L between the two superconducting coils can satisfy 2.5 < R / L < 2.7. In specific embodiments, the ratio of the inner diameter R of the superconducting coil to the spacing L between the two superconducting coils is related to the magnetic field strength and the magnetic field distribution requirements. When the ratio of the inner diameter R of the superconducting coil to the spacing L between the two superconducting coils is within the above range, the distribution of the magnetic field in the superconducting magnet can be optimized, so that when the radial distance from the mid-plane of the superconducting magnet to the central axis of the superconducting magnet satisfies a certain range, the magnetic field strength and the magnetic field distribution can meet the conditions required for single crystal growth.

[0062] Please refer to Figures 5 to 8 The present embodiment provides a superconducting magnet, which comprises a vacuum dewar 101, a cold shield 102, a superconducting magnet framework 10, upper and lower coils 103 and 104, a cold conducting assembly 20, and a refrigerator 105. The vacuum dewar 101 is a closed hollow circular cylindrical structure. The cold shield 102 is accommodated in the vacuum dewar 101 and is also a hollow circular cylindrical structure. The superconducting magnet framework 10 is accommodated in the cold shield 102. The upper and lower coils 103 and 104 are respectively spirally wound in the upper and lower winding cavities 123 and 133. The cold conducting assembly 20 is accommodated in the cold shield 102 and comprises a cold conducting copper plate 21 arranged on the top surface of the upper winding framework 12, a copper sheet 22 arranged on the surfaces of the upper and lower coils 103 and 104, and a main cold conducting member 23 connected with the copper sheet 22 and the cold conducting copper plate 21, respectively. The refrigerator 105 is provided with a primary cold head 1051 and a secondary cold head 1052 penetrating the vacuum dewar 101 and the cold shield 102. The primary cold head 1051 is in cold conducting connection with the cold shield 102, and the secondary cold head 1052 is in cold conducting connection with the top end of the main cold conducting member 23.

[0063] It should be noted that for the vacuum Dewar 101, it can include an inner cylinder, an outer cylinder, and upper and lower cover plates arranged at the upper and lower ends of the inner and outer cylinders, so as to form a hollow circular column, and the center of the vacuum Dewar is surrounded to form a through hole, wherein the ratio of the diameter D of the through hole to the center distance L1 between the upper coil and the lower coil in the first direction A satisfies the range of 0.88 < D / L1 < 0.93; within this ratio range, under other conditions unchanged, the magnetic field strength at the center of the superconducting magnet can be stronger, which is more conducive to suppressing the heat convection in the crucible and improving the crystal pulling quality. Similarly, for the cold shield 102, the upper cover plate 1021 and the lower cover plate 1022 are arranged in the first direction A, and the projection profile of the upper cover plate 1021 and the lower cover plate 1022 along the first direction A is a circular ring, and the upper cover plate 1021 and the lower cover plate 1022 are connected by the inner and outer cylinders along the radial inner and outer sides, that is, the structure of the cold shield 102 forms a relatively closed hollow circular column, so that through the arrangement of the vacuum Dewar 101 and the cold shield 102, the cryocooler 105 can better cool the superconducting magnet skeleton 10, the upper coil 103 and the lower coil 104 arranged in the cold shield 102, and improve the cooling efficiency of the upper coil 103 and the lower coil 104.

[0064] It can be understood that the cryocooler 105 can be obtained from the prior art, and the cryocooler 105 can be installed at the top of the superconducting magnet 100, and the output end extends into the cold shield 102, that is, the primary cold head 1051 and the secondary cold head 1052 are respectively connected to the top end surface of the cold shield 102 and the top end surface of the main cooling component 23 (or the upper winding skeleton 12); for the structure of the cooling assembly 20, on the one hand, it can significantly improve the cooling efficiency of the upper coil 103 and the lower coil 104, ensure the temperature stability of the superconducting magnet 100 during long-time operation, and prolong the service life of the superconducting magnet 100; at the same time, the optimized cooling assembly 20 also considers the structural stability and magnetic field uniformity of the superconducting magnet 100, so as to ensure that the superconducting magnet 100 can stably and reliably operate, and provide strong magnetic field support for single crystal growth and other applications.

[0065] Continuing to refer to Figure 6In some embodiments, the top surface of the cold lead copper plate 21 is provided with a first copper foil 211, the first-level cold head 1051 is connected with the cold lead copper plate 21 through the first copper foil 211, and one end of the main cold lead 23 extends to the lower winding skeleton 13 and is connected with the bottom end surface of the lower winding skeleton 13 through a second copper foil 231; the cold lead assembly 20 further comprises an arc-shaped cold lead copper plate 24 connected with the copper sheet 22, the arc-shaped cold lead copper plate 24 is connected with the main cold lead 23 through a third copper foil 241 arranged on the outer surface of the support frame 11; it should be noted that the first copper foil 211, the second copper foil 231 and the third copper foil 241 are arranged to realize the soft connection between the cold lead copper plate 21, the arc-shaped cold lead copper plate 24 and the main cold lead 23; the positive copper lead 212 and the negative copper lead 213 can also be arranged at both ends of the cold lead copper plate 21 to transmit current and cool the current lead.

[0066] In the present embodiment, the copper sheet 22 in the shape of a circular ring is arranged circumferentially on the upper coil 103 and the lower coil 104, the copper sheet 22 can be arranged to fit the upper coil 103 and the lower coil 104, thereby improving the cooling effect on the upper coil 103 and the lower coil 104; at the same time, the main cold lead 23 extends to the lower winding skeleton 13 along the first direction A, and when the refrigerator 105 is running, synchronous refrigeration of the upper winding skeleton 12 and the lower winding skeleton 13 is realized, thereby significantly improving the refrigeration efficiency of the upper coil 103 and the lower coil 104, ensuring the temperature stability of the superconducting magnet 100 during long-time operation, thereby prolonging the service life of the superconducting magnet 100.

[0067] Please refer to Figure 7 and Figure 8 In some embodiments, the superconducting magnet 100 further comprises a magnet suspension 30 arranged in the vacuum dewar 101, the magnet suspension 30 comprises a second pull rod 31, an epoxy pull rod 33 and an epoxy side top rod 32, the second pull rod 31 is sequentially connected with the inner wall of the lower cover plate of the vacuum dewar 101, the lower cover plate of the cold screen 102, the second lower side stop portion 132 and the first upper side stop portion 121 and the second lower side stop portion 132 along the first direction A; the epoxy pull rod 33 is sequentially connected with the inner wall of the upper cover plate of the vacuum dewar 101, the upper cover plate 1021 of the cold screen 102, the first upper side stop portion 121 and the second lower side stop portion 132 along the first direction A; one end of the epoxy side top rod 32 is connected with the outer side wall of the support frame 11, and the other end penetrates the cold screen 102 along the radial direction and is connected with the inner side wall of the vacuum dewar 101; a plurality of second pull rods 31, epoxy side top rods 32 and epoxy pull rods 33 are arranged in a spaced manner along the circumference of the support frame 11, and the second pull rod 31 is arranged in a staggered manner with the epoxy side top rod 32 and the epoxy pull rod 33.

[0068] Specifically, the lower cover plate of the vacuum Dewar 101 is connected with the lower cover plate 1022 of the cold shield 102, the top end of the upper winding frame 12 and the bottom end of the lower winding frame 13 through a plurality of second pull rods 31, the material of the second pull rods 31 can be made of titanium alloy, so as to further reduce the mass while ensuring the structural strength; the upper cover plate of the vacuum Dewar 101, the upper cover plate 1021 of the cold shield 102 and the top end of the upper winding frame 12 and the bottom end of the lower winding frame 13 are connected through a plurality of epoxy rods 33, which reduces the weight, ensures the structural strength and reduces the heat leakage; the middle support frame 11 is connected with the outer cylinder of the cold shield 102 and the inner wall of the outer cylinder of the vacuum Dewar 101 through a plurality of epoxy side top rods 32 along the circumferential direction of the middle support frame 11, which ensures the structural strength and the stability of the superconducting magnet structure during transportation.

[0069] Optionally, in combination with Figure 7 As shown in the drawings, the epoxy side top rods 32 are arranged along the radial direction, the second pull rods 31 and the epoxy rods 33 are arranged in a staggered manner, and a plurality of epoxy side top rods 32, second pull rods 31 and epoxy rods 33 can be arranged along the circumferential direction of the upper winding frame 12 or the lower winding frame 13, so as to improve the structural stability of the superconducting magnet 100 at each position along the circumferential direction.

[0070] In this way, through the multi-point connection of the second pull rods 31, the epoxy rods 33 and the epoxy side top rods 32 in the vacuum Dewar 101, not only the connection strength between the superconducting magnet 100 and the support structure is enhanced, but also the stress is effectively dispersed, the possibility of deformation is reduced, and thus the structural stability and the anti-seismic performance of the superconducting magnet 100 can be significantly improved.

[0071] The superconducting magnet 100 provided by each of the above embodiments, through the vacuum Dewar 101, the cold shield 102, the superconducting magnet frame 10 arranged in the cold shield 102 and the cold lead assembly 20, the beneficial effects that can be achieved by the superconducting magnet frame 10 contained therein can be referred to the description of the first aspect above; the cold lead assembly 20 includes a cold lead copper plate 21 arranged on the top surface of the upper winding frame 12, a copper sheet 22 arranged on the surfaces of the upper coil 103 and the lower coil 104, and a main cold lead 23 connected with the copper sheet 22 and the cold lead copper plate 21 respectively, when the refrigerator 105 connected with the cold lead assembly 20 is operated, the refrigeration efficiency of the superconducting coil can be significantly improved, the temperature stability of the superconducting magnet 100 during long-time operation is ensured, and thus the service life of the superconducting magnet 100 is prolonged; at the same time, the design of the optimized cold lead assembly 20 also considers the structural stability and the magnetic field uniformity of the superconducting magnet 100, which ensures that the superconducting magnet 100 can stably and reliably operate, and provides strong magnetic field support for single crystal growth and other applications; the setting of the cold lead assembly 20 in combination with the pull rod can avoid slight deformation during transportation or under stress, and ensure the magnetic field uniformity and stability of the superconducting magnet 100.

[0072] Please refer to Figure 9 In some embodiments, a single crystal furnace device is also provided, the single crystal furnace device 1000 comprises a superconducting magnet 100 and a single crystal furnace arranged at the center of the superconducting magnet 100, the outer wall of the vacuum dewar 101 of the superconducting magnet 100 is provided with a shielding layer 1011, the upper coil 103 and the lower coil 104 in the superconducting magnet 100 are used to generate a hook-shaped magnetic field and act on the silicon melt contained in the crucible 200 in the single crystal furnace, the zero magnetic surface 1001 of the hook-shaped magnetic field is located below the silicon solution interface 1002 at a distance H of 0-100 mm. It should be noted that the advantage of setting H to 0-100 mm is that during the directional solidification growth of the silicon melt, the influence of the zero magnetic surface 1001 on the thermal convection of the silicon melt can be avoided, and at the same time, it is ensured that the silicon melt is subjected to a relatively uniform magnetic field during the solidification process, thereby improving the quality and stability of single crystal growth.

[0073] Further, the distance L between the upper and lower coils and the radius R of the upper and lower coils also satisfy: 2.5 < R / L < 2.7; that is, the inner diameter R of the superconducting coil and the distance L between the two superconducting coils satisfy 2.5 < R / L < 2.7. Wherein, the inner diameter of the superconducting coil is set as the central diameter of the superconducting coil, and the distance between the two superconducting coils is set as the axial distance between the centers of the two superconducting coils; when the ratio of the inner diameter R of the superconducting coil and the distance L between the two superconducting coils is within the above range, the distribution of the magnetic field in the superconducting magnet 100 can be optimized, so that when the radial distance from the midplane of the superconducting magnet 100 and the central axis of the superconducting magnet 100 satisfies a certain range, the magnetic field strength and the magnetic field distribution can meet the requirements of single crystal growth.

[0074] In the single crystal furnace device 1000 of the present embodiment, by introducing a high-temperature superconducting magnet 100 with higher critical current density and critical magnetic field strength into the single crystal furnace device 1000 to generate a hook-shaped magnetic field for controlling single crystal growth, the energy consumption and manufacturing cost can be reduced, and the production cycle can be shortened, thereby providing a strong guarantee for the efficient operation and large-scale application of single crystal furnace equipment; at the same time, by accurately controlling the strength and distribution of the hook-shaped magnetic field, the single crystal growth process can be further optimized, the quality and yield of the single crystal can be improved, and the demand for high-quality single crystal materials in the fields of semiconductors, photovoltaics, etc. can be met.

[0075] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0076] In the description of the application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description of the application, the exemplary description of the above terms does not necessarily mean the same embodiment or example, but can mean different embodiments or examples.

[0077] It is obvious that the described embodiments are only a part of the embodiments of the application, not all the embodiments. In this paper, "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the application. The phrase appears at various places in the specification is not necessarily the same embodiment, nor is it an independent or alternative embodiment or a separate embodiment. Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0078] Although the embodiments of the application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the application, and the scope of the application is defined by the claims and their equivalents.

Claims

1. A superconducting magnet, characterized by, The application relates to a superconducting magnet device. The application comprises: a vacuum dewar which is a closed hollow circular column structure, and the center of the vacuum dewar is provided with a through hole; a cold shield which is accommodated in the vacuum dewar and is a hollow circular column structure; a superconducting magnet framework which is accommodated in the cold shield and comprises a support frame, an upper winding frame, a lower winding frame and a first pull rod, the support frame is connected with the upper winding frame and the lower winding frame at opposite ends along a first direction respectively, the upper winding frame is provided with a first upper side block and a first lower side block which extend radially along the support frame, the lower winding frame is provided with a second upper side block and a second lower side block which extend radially along the support frame, an upper winding cavity and a lower winding cavity are formed between the first upper side block and the first lower side block and between the second upper side block and the second lower side block respectively, and the first upper side block and the second lower side block protrude radially from the first lower side block and the second upper side block, and the first pull rod is connected with the first upper side block and the second lower side block at two ends along the first direction respectively; upper coils and lower coils which are wound in the upper winding cavity and the lower winding cavity respectively; a cold conducting assembly which is accommodated in the cold shield, the cold conducting assembly comprises a cold conducting copper plate arranged on the top surface of the upper winding frame, copper sheets arranged on the surfaces of the upper coils and the lower coils, and main cold conducting members connected with the copper sheets and the cold conducting copper plate respectively, the top surface of the cold conducting copper plate is provided with a first copper foil, a secondary cold head is connected with the cold conducting copper plate through the first copper foil, one end of the main cold conducting member extends to the vicinity of the lower winding frame and is connected with the bottom end surface of the lower winding frame through a second copper foil, the cold conducting assembly further comprises arc-shaped cold conducting copper plates connected with the copper sheets, and the arc-shaped cold conducting copper plates are connected with the main cold conducting members; a magnet suspension arranged in the vacuum dewar, the magnet suspension comprises a second pull rod which is connected with the vacuum dewar, the cold shield, the first upper side block and the second lower side block along the first direction in sequence, and an epoxy side top rod which is connected with the outer side wall of the support frame at one end and penetrates the cold shield along the radial direction and is connected with the inner side wall of the vacuum dewar at the other end; a refrigerator which is provided with a primary cold head and a secondary cold head penetrating the vacuum dewar and the cold shield, the primary cold head is connected with the cold shield for cold conduction, and the secondary cold head is connected with the main cold conducting member for cold conduction; 2. The superconducting magnet of claim 1, wherein, wherein the diameter D of the through hole and the center distance L1 between the upper coils and the lower coils along the first direction satisfy the condition of 0.88 < D / L1 < 0.

93. The projection profiles of the upper winding frame and the lower winding frame along the first direction are circular, a plurality of the first pull rods are arranged along the circumferential direction of the upper winding frame and the lower winding frame, and two ends of the first pull rods are connected with the first upper side block and the second lower side block respectively.

3. The superconducting magnet of claim 1, wherein, The first upper side blocking part and the second lower side blocking part are respectively provided with a first connecting hole and a second connecting hole for connecting with the first pull rod, and the first connecting hole and the second connecting hole are coaxially arranged along the first direction.

4. The superconducting magnet of claim 1, wherein, The projection profile of the upper winding cavity and the lower winding cavity along the first direction is a circular ring, and the ratio of the inner diameter R of the circular ring to the distance L between the upper winding cavity and the lower winding cavity along the first direction satisfies 2.5 < R / L < 2.

7.

5. The superconducting magnet of claim 1, wherein, A plurality of the second pull rods and the epoxy side ejector rod are arranged along the circumferential direction of the support frame, and the second pull rod and the epoxy side ejector rod are arranged in a staggered manner.

6. The superconducting magnet of claim 5, wherein, The magnet suspension further comprises epoxy pull rods arranged along the first direction, and a plurality of the epoxy pull rods are sequentially connected with the inner wall of the upper cover plate of the vacuum Dewar, the upper cover plate of the cold shield, the first upper side blocking part and the second lower side blocking part along the first direction.

7. A single crystal furnace apparatus characterized by comprising: The superconducting magnet comprises a single crystal furnace arranged at the center of the superconducting magnet, and the superconducting magnet is used to generate a hook-shaped magnetic field and act on a silicon solution contained in a crucible of the single crystal furnace, and during the single crystal growth process, the zero magnetic surface of the hook-shaped magnetic field satisfies that the zero magnetic surface is located below the liquid surface of the silicon solution and the distance between the zero magnetic surface and the liquid surface ranges from 0 mm to 100 mm.

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