Quench heater assembly for superconducting magnet and superconducting magnet assembly thereof

Abstract

The application relates to a heater assembly for quenching of a superconducting magnet and a superconducting magnet assembly, the heater assembly comprising a heating conductor and an insulator; the heating conductor comprises a stainless steel sheet and a connecting copper bar; the inner side of the two side vertical surfaces of the stainless steel sheet is provided with the connecting copper bar; the inner side insulator and the outer side insulator are connected together and wrap the lower area of the two side vertical surfaces of the stainless steel sheet; and the auxiliary insulator is attached to the two sides of the bottom edge. The superconducting magnet assembly is provided with the heater assembly for quenching of a superconducting magnet between the coil outer layer insulation and the structure reinforcing layer of the superconducting coil; the gap of the ring surface where the bottom edge and the auxiliary insulator are located is provided with a filling layer, and the outside is provided with a structure reinforcing layer. The application provides a specific structure design of the heater assembly, which can be reliably applied to the superconducting magnet assembly, ensures that the heater assembly can intervene in time when the superconducting coil quenches at low temperature, accelerates the coil quench, and thus guarantees the safety and cyclic use of the whole superconducting magnet.

Description

Technical Field

[0001] This invention relates to a heater assembly applied to a superconducting magnet composed of solenoid coils wound on the same frame and separated from each other, to accelerate its quenching process, and to a superconducting magnet assembly formed using the heater assembly, belonging to the field of superconducting magnet technology. Background Technology

[0002] Superconducting magnets, at ultra-low temperatures (approximately 4K, -269.15℃), utilize superconducting conductors that exhibit zero resistance, allowing them to carry much higher currents than conventional conductors and generate much higher magnetic fields, as well as magnetic energy storage far exceeding that of conventional magnets.

[0003] The quenching process of a superconducting magnet or coil refers to the gradual transition of a superconducting conductor from a fully superconducting state to a fully conductive state (the state of resistance in a conventional conductor). During quenching, the magnetic energy within the superconducting magnet or coil is converted into thermal energy in the conductive state. If the quenching process is completed quickly, the generated heat energy can be released relatively evenly within the coil, and there is no risk of overheating at any part of the coil. However, in reality, the quenching of the coil always begins in a localized point area. If other parts of the coil cannot quench in time to disperse the heat energy, that point area will burn out due to a rapid increase in temperature, rendering the entire superconducting magnet unusable.

[0004] Therefore, for superconducting coils or coil groups where quench propagation is hindered, especially those superconducting coil groups that are connected in series in the circuit but spatially separate, protective measures are needed to accelerate the quench process and prevent coil burnout accidents. A commonly used measure is to place a high-resistivity metal sheet on the coil surface as a heater during the quench process. The principle is that when a localized area of ​​the coil is triggered to quench, an external current is introduced, or the internal current of the superconducting coil is shunted and input into the high-resistivity metal sheet. The energized metal sheet generates Joule heat, which heats the superconducting coil, triggering quench in more areas and accelerating the entire quench process, thus preventing coil burnout accidents caused by localized quench.

[0005] Since its principle is to use a high-resistivity metal sheet to heat the superconducting coil, an insulating layer needs to be set between the metal sheet of the heater and the superconducting coil. However, (1) from the perspective of thermal conductivity, the thin insulating layer allows the heat emitted by the metal sheet to be quickly transferred to the superconducting coil, thereby accelerating the quenching process; (2) from the perspective of voltage withstand capability, the thick insulating layer is beneficial for isolating the high voltage between the metal sheet and the superconducting coil. On the one hand, this high voltage comes from the quenching process of the superconducting coil, and on the other hand, it may also come from the external pulse power supply of the metal sheet heater. Therefore, the setting of the metal sheet, especially the setting of the insulating layer between the metal sheet and the superconducting coil, directly affects the reliability of the quenching protection.

[0006] In addition, the high resistivity metal sheet must be tightly attached to the superconducting coil, which locally alters the original multi-layered structure composed of the skeleton, coil, and structural reinforcement layer. At the same time, there is an electromagnetic force inside the energized superconducting coil, which causes the coil to expand outward, thereby squeezing the metal sheet and affecting the reliability of the insulation layer of the metal sheet heater.

[0007] The article "A Review of Queue Protection for MRI and NMR Cryogenic Superconducting Magnets" published in the February 2012 issue of the Journal of Low Temperature Physics (Vol. 34, No. 1) also introduced the hazards of the aforementioned quench process and the method of using heaters (heating plates) to accelerate quench, but did not involve specific heaters and insulation structures. In fact, there are currently no publicly available heater assemblies with complete insulation structures that are used in superconducting coils during the production of MRI and NMR superconducting magnets.

[0008] Therefore, in response to the above requirements, it is necessary to design a special heater assembly with a complete insulation structure for superconducting magnets such as MRI and NMR, which consist of solenoid coils wound on the same frame and separated from each other, to ensure the high reliability of such superconducting magnets. Summary of the Invention

[0009] The purpose of this invention is to provide a heater assembly for superconducting magnet quenching and a superconducting magnet assembly thereof, in order to provide active protection against the quenching process of multi-sole superconducting magnets. It provides a heater assembly with a complete insulation structure and applies it to superconducting magnets, thereby heating the superconducting coil during the quenching process of the superconducting magnet, accelerating the quenching process, and avoiding coil burnout caused by localized quenching.

[0010] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a heater assembly for superconducting magnet quenching, comprising a heating conductor and an insulator;

[0011] The heating conductor consists of a thin stainless steel sheet and copper busbars.

[0012] The stainless steel sheet has an overall longitudinal section that is U-shaped.

[0013] The bottom edge of the stainless steel sheet is arc-shaped, and the entire bottom edge is covered with insulating material.

[0014] The stainless steel sheet has copper busbars on the inner sides of both sides of its facade; the copper busbars have through holes in the inner sides of the stainless steel sheet.

[0015] Insulators include inner insulators, outer insulators, and auxiliary insulators;

[0016] The inner insulator is attached to the inner side of both sides of the stainless steel sheet and is located below the copper busbar.

[0017] The outer insulator is attached to the outer side of both sides of the stainless steel sheet.

[0018] The inner insulator and the outer insulator are connected together and wrap around the lower area of ​​both sides of the stainless steel sheet.

[0019] The auxiliary insulator is attached to both sides of the open edge of the bottom edge of the stainless steel sheet. The thickness of the auxiliary insulator is the same as the thickness of the bottom edge of the stainless steel sheet, and the auxiliary insulator and the bottom edge of the stainless steel sheet form an arc shape with a continuous thickness.

[0020] The two ends of the auxiliary insulator are in contact with the bottom surface of the inner insulator.

[0021] As a further improvement of the present invention, the stainless steel sheet has a thickness of 0.3~0.6mm and a width of 30mm~60mm.

[0022] As a further improvement of the present invention, the insulating material provided throughout the bottom edge of the stainless steel sheet is an insulating varnish sprayed on, and the thickness of the insulating material is 50μm~100μm.

[0023] As a further improvement of the present invention, the bottom edge of the stainless steel sheet is connected to the two side facades by a bent arc transition.

[0024] The bottom outer side of the inner insulator is chamfered to allow for the transition of the bent arc.

[0025] As a further improvement of the present invention, the thickness of the inner insulator is greater than the thickness of the side surface of the stainless steel sheet;

[0026] The inner insulator has a first groove on its outward surface, and the side face of the stainless steel sheet is fitted into the first groove of the inner insulator.

[0027] Furthermore, a second groove is also provided on the inner insulator;

[0028] The second groove is located outside the first groove;

[0029] The outer insulator is an insulating thin plate, and the two sides of the outer insulator are embedded in the second groove.

[0030] Furthermore, the top of the outer insulator extends beyond the top of the inner insulator by a distance of 3-5 mm;

[0031] The side edges of the outer insulator extend beyond the side edges of the stainless steel sheet by a distance of 3-5 mm.

[0032] The distance between the bottom edge of the copper busbar and the top of the inner insulator is 3mm to 5mm.

[0033] In a second aspect, the present invention provides a superconducting magnet assembly, including a frame, a superconducting coil, and a structural reinforcement layer;

[0034] A superconducting magnet quench heater assembly, as described above, is provided between the outer insulation layer and the structural reinforcement layer of the superconducting coil.

[0035] The heater assembly is projected along the axial direction of the superconducting magnet assembly, covering the entire axis of the region where the superconducting coil is located;

[0036] One or two heater assemblies are provided along the circumference of the superconducting coil;

[0037] The heater assembly, projected along the diameter of the superconducting magnet assembly, covers only a portion of the circumference of the superconducting coil.

[0038] The end plates on both sides of the skeleton are pre-machined with receiving grooves; the receiving grooves are recessed in the axial direction of the skeleton to form a cavity for accommodating the two sides of the stainless steel sheet, the inner insulator and the outer insulator; the cavity of the receiving groove is located on the inner side of the end plate and communicates with the cavity on the skeleton that accommodates the superconducting coil.

[0039] The length of the bottom edge of the stainless steel sheet is matched with the spacing between the two receiving grooves;

[0040] The heater assembly is embedded in the receiving slots on both sides, and the outer surface of the outermost outer insulator on both sides of the heater assembly is close to the chamber facade of the receiving slot.

[0041] The inner surface of the inner insulator on both sides is not higher than the inner surface of the end plate;

[0042] A superconducting coil is wound around the skeleton, and an outer layer of insulation is provided around the superconducting coil;

[0043] The outer insulation of the coil extends from the edge of the receiving groove into the receiving groove.

[0044] The arc shape of the bottom edge of the stainless steel sheet of the heater assembly matches the arc shape of the outer surface of the coil's outer insulation layer;

[0045] The bottom edge of the stainless steel sheet of the heater assembly is in close contact with the auxiliary insulator on the outer surface of the outer insulation of the coil;

[0046] A filling layer is provided in the gaps within the bottom edge of the stainless steel sheet and the annular surface where the auxiliary insulator is located;

[0047] The filler layer is connected to the auxiliary insulator;

[0048] The thickness of the filling layer, the thickness of the bottom edge, and the thickness of the auxiliary insulator are all the same;

[0049] An insulating film is attached to the outer surface of the bottom edge of a stainless steel sheet; the insulating film completely covers the bottom edge of the stainless steel sheet and extends beyond the bottom edge on all sides;

[0050] A structural reinforcement layer is set outside the ring formed by the bottom edge of the stainless steel sheet, the auxiliary insulator, and the filler layer;

[0051] The outer surface of the structural reinforcement layer is lower than the top surface of the inner insulator.

[0052] As a further improvement of the present invention, the receiving groove is recessed in the diameter direction of the skeleton, and the recess extends through the end plate of the entire skeleton.

[0053] The copper busbar is located inside the recess;

[0054] The copper busbar protrudes from the solid end plate.

[0055] As a further improvement of the present invention, the bottom surface of the outer insulator is in contact with the portion of the outer insulation of the coil that extends into the receiving groove.

[0056] As a further improvement of the present invention, the filling layer is a flexible material;

[0057] For applications requiring high thermal conductivity, metallic materials such as copper foil and stainless steel foil are preferred.

[0058] For applications where thermal conductivity is not critical, non-metallic materials, such as fiberglass sheets, can be used.

[0059] As a further improvement of the present invention, the insulating film covering the outer surface of the bottom edge of the stainless steel sheet is a polyimide film;

[0060] The four sides of the insulating film extend outward, exceeding the bottom edge by 5mm.

[0061] The superconducting magnet quench heater assembly and the superconducting magnet assembly of the present invention have the following advantages:

[0062] 1. The heater assembly itself has a relatively independent and complete structure, which facilitates prefabrication and mass production, and makes it easy to install and use;

[0063] 2. Only an annular structure composed of the bottom edge of a stainless steel sheet, an auxiliary insulator, and a filler layer was added between the outer insulation layer and the structural reinforcement layer of the existing superconducting coil. This minimizes changes to the original structure of the cold mass of the superconducting coil and ultimately maintains the overall structure as robust and reliable as possible. Furthermore, the stainless steel sheet, which serves as the heating element, directly contacts the superconducting coil over a large area through the outer insulation layer, ensuring efficient heat conduction.

[0064] 3. A comprehensive insulation protection system is set up around the core component of the heating conductor, the stainless steel sheet, to ensure sufficient creepage distance in all directions between the heating conductor and the frame, the superconducting coil, and the structural reinforcement layer; and to fully eliminate the risk of tip discharge, with no protruding structures such as solder joints within the coverage of the electrical insulation material; the bottom edge of the stainless steel sheet is covered with insulating material (insulating varnish) and several insulators to form two layers of shielding, strictly ensuring the electrical insulation performance of the quench trigger heater assembly during use.

[0065] This invention not only provides a structural design for a heater assembly for superconducting magnets that quenches, facilitating prefabrication and advance preparation; but also provides a setting method and precautions for the superconducting coil used in superconducting magnets, ensuring reasonable setup and eliminating the risk of electrical breakdown. This ensures that the heater assembly can intervene in time when the superconducting coil quenches at low temperatures, generating heat to heat the coil and accelerate the quenching process, thereby ensuring the safety and cyclical use of the entire superconducting magnet. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the overall structure of the heater assembly for superconducting magnet quenching according to the present invention;

[0067] Figure 2 for Figure 1 Exploded views of components

[0068] Figure 3 for Figure 1 Overall sectional view;

[0069] Figure 4 for Figure 2 A schematic diagram of the overall structure of the heating conductor;

[0070] Figure 5 for Figure 2 A schematic diagram of the overall structure of the inner insulator;

[0071] Figure 6 for Figure 1 Side view;

[0072] Figure 7 for Figure 3 A magnified view of a portion of the image;

[0073] Figure 8 This is a schematic diagram of the overall structure of the superconducting magnet assembly of the present invention;

[0074] Figure 9 for Figure 8 A partial half-section diagram;

[0075] Figure 10 for Figure 9 A magnified view of a portion of the image;

[0076] Figure 11 for Figure 8 A schematic diagram of the front section;

[0077] Figure 12 for Figure 11 A magnified view of a portion of the image. Detailed Implementation

[0078] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0079] The heater assembly for superconducting magnet quenching of the present invention has the following overall structure: Figure 1 As shown, the components involved are as follows Figure 2 As shown, the overall sectional view is as follows Figure 3 As shown, one of the core components, the heating conductor, is as follows: Figure 4 As shown, one of the core components, the inner insulator, is as follows: Figure 5 As shown, Figure 6 , Figure 7 This demonstrates the key dimensions between the core components.

[0080] The superconducting magnet quench heater assembly of the present invention is mainly composed of a heating conductor 1 and an insulator.

[0081] The heating conductor 1 is primarily a U-shaped stainless steel sheet 11 with a thickness of 0.3~0.6mm. Stainless steel has low magnetic susceptibility, preventing interference with the magnetic field generated by the superconducting coil. Furthermore, the stainless steel sheet has high resistivity, large specific heat capacity, and is easy to manufacture and process. When energized, it generates significant heat to heat the superconducting coil. The width of the stainless steel sheet 11 is set between 30mm and 60mm to achieve suitable resistance for heating.

[0082] The bottom edge 111 of the “U”-shaped stainless steel sheet 11 is the key area for heating the superconducting coil. It is set in an arc shape with the arc R matching the outer diameter of the superconducting coil and is tightly attached to the superconducting coil. To achieve insulation, insulating material, such as sprayed insulating paint, is applied to the bottom edge 111 of the stainless steel sheet 11, with a thickness of 50μm~100μm, to form electrical insulation.

[0083] A copper busbar 12 is provided on both sides of the U-shaped stainless steel sheet 11 of the heating conductor 1. Preferably, it is fixed to the inside of the side of the stainless steel sheet 11 by brazing. A through hole 13 is provided on the copper busbar 12 for connecting multiple heater assemblies in parallel or for accommodating connecting conductors from different directions.

[0084] The two sides of the “U”-shaped stainless steel sheet 11 are connected to the bottom edge 111 by a bent arc transition 112, which avoids stress concentration and tip discharge.

[0085] Several insulators are provided along the heating conductor 1.

[0086] The insulator first includes an inner insulator 2, which is a thick insulating plate with a specific shape and structure. It is positioned inside the heating conductor 1, specifically attached to the inner sides of the two vertical surfaces of the "U"-shaped stainless steel sheet 11, and located below the copper busbar 12. The thickness of the inner insulator 2 is greater than the thickness of the side surfaces of the stainless steel sheet 11. A first groove 21 is provided on the outward-facing surface of the inner insulator 2 to accommodate the side surfaces of the stainless steel sheet 11. A chamfer 23 is also provided at the bottom of the first groove 21 to allow for the bend radius transition 112 of the stainless steel sheet 11. The two can be fitted together or have a gap, such as... Figure 7 As shown. The inner insulator 2 is also provided with a second groove 22, which is located outside the first groove 21, and the second groove 22 is used to accommodate the outer insulator 3.

[0087] The outer insulator 3 is an insulating thin plate, which is attached to the outer side of both sides of the "U"-shaped stainless steel thin plate 11 and embedded in the second groove 22.

[0088] The inner insulator 2 and the outer insulator 3 are glued to the two sides of the stainless steel sheet 11 and are bonded together to each other, completely covering the two sides of the stainless steel sheet 11. This ensures that after the superconducting magnet quench heater assembly of the present invention is applied to the superconducting magnet, there is a sufficient creepage distance between the heating conductor 1 and the frame.

[0089] Especially referencing Figure 6 , Figure 7 The distance between the top of the outer insulator 3 and the top of the inner insulator 2 is a; the distance between the side edges of the outer insulator 3 and the side edges of the stainless steel sheet 11 is b; the distance between the bottom edge of the copper busbar 12 and the top of the inner insulator 2 is c; the dimensions of a, b, and c are all 3mm to 5mm to ensure the external insulation distance of the heating conductor 1.

[0090] Furthermore, auxiliary insulators 4 are provided on both sides of the bottom edge 111 (non-side facade) of the stainless steel sheet 11. The auxiliary insulators 4 are insulating sheets with the same thickness as the bottom edge 111 of the stainless steel sheet 11. They are glued to both sides of the bottom edge 111 to form wing edges. The auxiliary insulators 4 can extend the creepage distance between the stainless steel sheet 11 and the superconducting coil, the frame and the structural reinforcement layer, and can also eliminate the tip discharge phenomenon of the narrow edge of the stainless steel sheet 11.

[0091] The two ends of the auxiliary insulator 4 are in contact with the bottom surface of the inner insulator 2 and can be fixed by adhesive.

[0092] The aforementioned superconducting magnet quench heater assembly can be prefabricated according to the structural dimensions of the superconducting magnet. After the superconducting coil on the superconducting magnet is wound, and before applying the structural reinforcement layer, the superconducting magnet quench heater assembly is placed and fixed, as can be referred to... Figures 8-12 The specific implementation method is as follows:

[0093] Receiving grooves 52 are pre-machined on the end plates 51 on both sides of the frame 5. The receiving grooves 52 are recessed in the axial direction of the frame 5 to accommodate the two vertical surfaces of the stainless steel sheet 11 of the heater assembly, and the inner insulator 2 and outer insulator 3 applied to both sides of the vertical surfaces; the receiving grooves 52 are located on the inner side and communicate with the cavity accommodating the superconducting coil. The length of the bottom edge 111 of the stainless steel sheet 11 (i.e., the distance between the two vertical surfaces) matches the distance between the receiving grooves 52 on both sides. When the heater assembly is placed in the receiving grooves 52 in the frame 5, the outer surface of the outermost outer insulator 3 on both sides is close to the vertical surface of the receiving groove 52; at the same time, the inner surface of the inner insulator 2 on both sides is not higher than the inner surface of the end plate 51 (i.e., does not protrude from the receiving groove 52), preferably both are flush. Meanwhile, the receiving groove 52 is recessed in the diameter direction of the frame 5, and the recess preferably extends through several end plates 51 on the entire frame 5. The wiring copper busbar 12 is located in the recess, that is, protruding from the solid of the end plate 51, which facilitates wiring; however, if it protrudes directly from the maximum outer circle of the end plate 51, the overall outer diameter will be too large, increasing the overall size of the equipment.

[0094] After the superconducting coil 6 is wound onto the skeleton 5, an outer layer insulation 8 is provided around the superconducting coil 6. The outer layer insulation 8 is generally a high-molecular polymer insulating film, which is tightly wrapped around the outer layer of the superconducting coil 6. Preferably, the bottom of the receiving groove 52 along its diameter is arc-shaped, flush with the outer wall of the wound superconducting coil 6. During winding, the outer layer insulation 8 extends into the receiving groove 52 from both sides (e.g., ...). Figure 10 As shown), it covers the bottom surface of the receiving groove 52.

[0095] The arc shape (radius R) of the bottom edge 111 of the stainless steel sheet 11 matches the outer diameter of the wound coil outer insulation 8. After the coil outer insulation 8 is applied, the prefabricated superconducting magnet quench heater assembly is placed in the receiving groove 52 of the frame 5. The bottom edge 111 of the stainless steel sheet 11 is tightly attached to the coil outer insulation 8 and fixed by applying adhesive to the attached parts (between the outer surface of the outer insulator 3 and the vertical surface of the receiving groove 52, between the bottom edge 111 of the stainless steel sheet 11 and the outer surface of the coil outer insulation 8, and between the auxiliary insulators 4 on both sides of the stainless steel sheet 11 and the outer surface of the coil outer insulation 8). The bottom surface of the outer insulator 3 can contact the part of the coil outer insulation 8 that extends into the receiving groove 52 to achieve full-wrap insulation protection.

[0096] When a superconducting magnet experiences quenching at cryogenic temperatures, the quenching velocity along the circumference is much greater than that in the radial and axial directions. A quenching at any point in the superconducting coil will rapidly expand to a quenching velocity across the entire circumferential region. Therefore, when applying the heater assembly to the superconducting coil, it is not necessary to cover the entire outer surface of the coil. Only a small segment of the cylindrical surface of the superconducting coil needs to be selected for the heater assembly. That is, the projection of the heater assembly along the diameter of the entire superconducting magnet assembly only covers a portion of the circumference of the superconducting coil. However, along the axial direction, multiple heater assemblies can be placed to ensure that heater assemblies are present along the entire axial direction. That is, the projection of the heater assembly along the axial direction of the entire superconducting magnet assembly covers the entire axis of the region where the superconducting coil is located. When using... Figure 8 As shown, when using multi-segment superconducting coils, the heater assembly can also be arranged in segments. On a circumferential surface, when the outer diameter of the superconducting coil is large, it can be arranged as follows: Figure 11 The diagram shows the installation of two or more heater assemblies to heat multiple areas simultaneously, further improving the quench speed.

[0097] After the heater assembly is fixed in place according to the design, within the annular surface where the bottom edge 111 of the stainless steel sheet 11 and the auxiliary insulator 4 are located, such as Figure 12 As shown, a filler layer 44 is provided, connecting the filler layer 44 to the auxiliary insulator 4. The thickness of the filler layer 44 is approximately equal to the thickness of the bottom edge 111 and the auxiliary insulator 4. Thus, the bottom edge 111, the auxiliary insulator 4, and the filler layer 44 together form a ring around the superconducting coil 6 and the outer insulation layer 8, ensuring overall roundness, cylindricity, and coaxiality. The filler layer 44 is a flexible material. For applications requiring high thermal conductivity, metallic materials such as copper foil or stainless steel foil are preferred; while for applications with lower thermal conductivity requirements, non-metallic materials such as fiberglass sheets can be used.

[0098] One to three layers of insulating film 9, preferably polyimide film, are glued to the outer surface of the bottom edge 111 of the stainless steel sheet 11. The insulating film 9 completely covers the bottom edge 111, and the four-way edges 91 of the insulating film 9 extend outward by about 5 mm to increase the insulation area and increase the creepage distance.

[0099] Finally, the reinforcing layer 7 is wound around the structure; and then the peripheral components are installed to form the superconducting magnet assembly of the present invention.

[0100] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A heater assembly for superconducting magnet quenching, characterized in that, Includes heating conductors and insulators; The heating conductor consists of a thin stainless steel sheet and copper busbars. The stainless steel sheet has an overall longitudinal section that is U-shaped. The bottom edge of the stainless steel sheet is arc-shaped, and the entire bottom edge is covered with insulating material. The stainless steel sheet has copper busbars on the inner sides of both sides of its facade; the copper busbars have through holes in the inner sides of the stainless steel sheet. Insulators include inner insulators, outer insulators, and auxiliary insulators; The inner insulator is attached to the inner side of both sides of the stainless steel sheet and is located below the copper busbar. The outer insulator is attached to the outer side of both sides of the stainless steel sheet. The inner insulator and the outer insulator are connected together and wrap around the lower area of ​​both sides of the stainless steel sheet. The auxiliary insulator is attached to both sides of the open edge of the bottom edge of the stainless steel sheet. The thickness of the auxiliary insulator is the same as the thickness of the bottom edge of the stainless steel sheet, and the auxiliary insulator and the bottom edge of the stainless steel sheet form an arc shape with a continuous thickness. The two ends of the auxiliary insulator are in contact with the bottom surface of the inner insulator.

2. The heater assembly for superconducting magnet quenching as described in claim 1, characterized in that, The stainless steel sheet has a thickness of 0.3~0.6mm and a width of 30mm~60mm.

3. The heater assembly for superconducting magnet quenching as described in claim 1, characterized in that, The insulating material applied to the bottom edge of the stainless steel sheet is an insulating varnish with a thickness of 50μm to 100μm.

4. The heater assembly for superconducting magnet quenching as described in claim 1, characterized in that, The bottom edge of the stainless steel sheet is connected to the two side facades by a bent arc transition. The bottom outer side of the inner insulator is chamfered to allow for the transition of the bent arc.

5. The heater assembly for superconducting magnet quenching as described in claim 1, characterized in that, The thickness of the inner insulator is greater than the thickness of the side facade of the stainless steel sheet; The inner insulator has a first groove on its outward surface, and the side face of the stainless steel sheet is fitted into the first groove of the inner insulator.

6. The heater assembly for superconducting magnet quenching as described in claim 5, characterized in that, The inner insulator is also provided with a second groove; The second groove is located outside the first groove; The outer insulator is an insulating thin plate, and the two sides of the outer insulator are embedded in the second groove.

7. The heater assembly for superconducting magnet quenching as described in claim 1, 5, or 6, characterized in that, The top of the outer insulator extends beyond the top of the inner insulator by 3-5 mm. The side edges of the outer insulator extend beyond the side edges of the stainless steel sheet by a distance of 3-5 mm. The distance between the bottom edge of the copper busbar and the top of the inner insulator is 3mm to 5mm.

8. A superconducting magnet assembly, characterized in that, Includes the framework, superconducting coils, and structural reinforcement layers; A heater assembly for superconducting magnet quenching, as described in any one of claims 1-7, is provided between the outer insulation layer and the structural reinforcement layer of the superconducting coil. The heater assembly is projected along the axial direction of the superconducting magnet assembly, covering the entire axis of the region where the superconducting coil is located; One or two heater assemblies are provided along the circumference of the superconducting coil; The heater assembly, projected along the diameter of the superconducting magnet assembly, covers only a portion of the circumference of the superconducting coil. The end plates on both sides of the skeleton are pre-machined with receiving grooves; the receiving grooves are recessed in the axial direction of the skeleton to form a cavity for accommodating the two sides of the stainless steel sheet, the inner insulator and the outer insulator; the cavity of the receiving groove is located on the inner side of the end plate and communicates with the cavity on the skeleton that accommodates the superconducting coil. The length of the bottom edge of the stainless steel sheet is matched with the spacing between the two receiving grooves; The heater assembly is embedded in the receiving slots on both sides, and the outer surface of the outermost outer insulator on both sides of the heater assembly is close to the chamber facade of the receiving slot. The inner surface of the inner insulator on both sides is not higher than the inner surface of the end plate; A superconducting coil is wound around the skeleton, and an outer layer of insulation is provided around the superconducting coil; The outer insulation of the coil extends from the edge of the receiving groove into the receiving groove. The arc shape of the bottom edge of the stainless steel sheet of the heater assembly matches the arc shape of the outer surface of the coil's outer insulation layer; The bottom edge of the stainless steel sheet of the heater assembly is in close contact with the auxiliary insulator on the outer surface of the outer insulation of the coil; A filling layer is provided in the gaps within the bottom edge of the stainless steel sheet and the annular surface where the auxiliary insulator is located; The filler layer is connected to the auxiliary insulator; The thickness of the filling layer, the thickness of the bottom edge, and the thickness of the auxiliary insulator are all the same; An insulating film is attached to the outer surface of the bottom edge of a stainless steel sheet; the insulating film completely covers the bottom edge of the stainless steel sheet and extends beyond the bottom edge on all sides; A structural reinforcement layer is set outside the ring formed by the bottom edge of the stainless steel sheet, the auxiliary insulator, and the filler layer; The outer surface of the structural reinforcement layer is lower than the top surface of the inner insulator.

9. The superconducting magnet assembly as described in claim 8, characterized in that, The receiving groove is recessed in the diameter direction of the skeleton, and the recess extends through the end plate of the entire skeleton. The copper busbar is located inside the recess; The copper busbar protrudes from the solid end plate.

10. The superconducting magnet assembly as described in claim 8, characterized in that, The bottom surface of the outer insulator is in contact with the portion of the outer insulation of the coil that extends into the receiving groove.

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