A racetrack cross-section coil-dominated superconducting magnet for spectrometer

Abstract

The present invention relates to a racetrack-shaped cross-section coil-dominated superconducting magnet for a spectrometer, comprising: an iron core, which adopts a hollow rectangular structure, the cross section of its inner wall surface is a racetrack-shaped structure, the two sides of the racetrack are semicircular arc segments, and the middle section is platform-shaped; and the corners of the rectangular structure adopt a chamfered structure; a superconducting coil, which is arranged on the inner wall surface of the iron core and has a distance between it and the inner wall surface, and the cross section of the superconducting coil is the same as the racetrack-shaped cross section of the inner wall surface. The present invention can simultaneously meet the requirements of large aperture, large opening angle and high uniformity, and under the same physical parameters, reduce the size and weight of the magnet, and increase the internal space and external opening angle. The present invention can be applied in the field of superconducting magnet technology.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting magnets, in particular to a racetrack cross-section coil-dominated superconducting magnet for a material measurement spectrometer. Background Art

[0002] The material measurement spectrometer uses a dipole magnet to deflect charged particles, and by measuring the trajectory, velocity, energy loss and other information of the charged particles in the magnetic field, it can detect and identify the products of medium-energy heavy ion collisions in the entire space. Large opening angle and large space have always been the basic requirements for this type of dipole magnet. For specific physical requirements, some devices even need to meet the requirements of large opening angle and large internal space, while still requiring the magnet to provide a large range of highly uniform magnetic fields.

[0003] Similar devices currently available in the world are often huge in size. However, their huge size makes the processing of the warm iron superconducting magnet difficult and risky, and the huge electromagnetic force between the large-section superconducting coils separated from each other poses great technical challenges to the design and processing of the magnet dewar. In addition, according to physical requirements, it is necessary to provide a larger internal space and receiving angle as much as possible. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a racetrack-shaped cross-section coil-dominated superconducting magnet for a spectrometer, which can simultaneously meet the requirements of large aperture, large opening angle and high uniformity, and under the same physical parameters, reduce the size and weight of the magnet, and increase the internal space and external opening angle.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a racetrack-shaped cross-section coil-dominated superconducting magnet for a spectrometer, comprising: an iron core, which adopts a hollow rectangular structure, the cross-section of its inner wall surface is a racetrack-shaped structure, the two sides of the runway are semicircular arc segments, and the middle section is platform-shaped; and the corners of the rectangular structure adopt a chamfered structure; a superconducting coil, which is arranged on the inner wall surface of the iron core and has a distance between it and the inner wall surface, and the cross-section of the superconducting coil is the same as the racetrack-shaped cross-section shape of the inner wall surface.

[0006] Furthermore, first shims are respectively provided at the top and bottom of the iron core near the edge, and second shims are respectively provided at the ends of the inner wall surface of the iron core.

[0007] Furthermore, an iron core side plate is provided on the outer side of the iron core at a position corresponding to the arc segment of the runway.

[0008] Furthermore, passivation grooves are provided on the bottom and the top of the inner wall of the iron core.

[0009] Furthermore, the iron core is a room temperature iron core, and the iron core is made of electrical pure iron.

[0010] Furthermore, the superconducting coil includes a superconducting cable and a skeleton; the skeleton is arranged on the inner wall surface of the iron core, and the shape of the skeleton is arranged corresponding to the shape of the inner wall surface of the iron core; wire grooves are arranged on the skeleton according to the preset required current distribution, and the superconducting cable is wound in the wire grooves to form the superconducting coil.

[0011] Furthermore, the superconducting cable adopts a seven-strand cable composed of superconducting wires and copper wires.

[0012] Furthermore, one strand of the copper wire is located at a central position, and six strands of the superconducting wires are evenly distributed around the copper wire, and the superconducting wires and the copper wires are twisted together to form the seven-strand cable.

[0013] Furthermore, the skeleton adopts a multi-layer structure.

[0014] Furthermore, two layers of the superconducting coils are wound on the single-layer frame, the first layer of the superconducting coils is wound from the outside of the superconducting cable to the inside, and the second layer of the superconducting coils is wound from the inside of the superconducting cable to the outside.

[0015] The present invention adopts the above technical solution, which has the following advantages:

[0016] 1. The present invention adopts a racetrack-shaped structure. Under the premise of the same design requirements, compared with warm iron superconducting magnets, the racetrack-shaped cross-section coil-dominated superconducting magnet can greatly reduce the overall size and weight of the magnet, and greatly increase the internal space and external angle of the magnet.

[0017] 2. Since the present invention adopts a coil-dominated structure, it is subsequently upgradeable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of a racetrack-shaped cross-section coil-dominated superconducting magnet in one embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of the core structure in one embodiment of the present invention;

[0020] Figure 3 is a schematic diagram of the structure of a superconducting coil in one embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of a seven-strand cable in one embodiment of the present invention;

[0022] Figure 5 is a schematic cross-sectional view of a skeleton in one embodiment of the present invention;

[0023] Reference numerals:

[0024] 1. Iron core, 2. Superconducting coil, 3. First shim, 4. Passivation groove, 5. Second shim, 6. Iron core side plate, 7. Superconducting wire, 8. Copper wire, 9. Seven-strand cable, 10. Skeleton. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] The racetrack-shaped cross-section coil-dominated superconducting magnet for a spectrometer of the present invention comprises: an iron core, which adopts a hollow rectangular structure, the cross section of its inner wall surface is a racetrack-shaped structure, the two sides of the racetrack are semicircular arc segments, and the middle section is platform-shaped; and the corners of the rectangular structure adopt a chamfered structure; a superconducting coil is arranged on the inner wall surface of the iron core, and the cross section of the superconducting coil is the same as the racetrack-shaped cross section of the inner wall surface. The present invention can simultaneously meet the requirements of large aperture, large opening angle and high uniformity, and under the same physical parameters, reduce the size and weight of the magnet, and increase the internal space and external opening angle.

[0028] In one embodiment of the present invention, a racetrack-shaped cross-section coil-dominated superconducting magnet for a spectrometer is provided. In this embodiment, according to the general characteristics of magnets for spectrometers, the cross-section is set to a racetrack-shaped structure, such as Figure 1 As shown, the superconducting magnet comprises:

[0029] The iron core 1 adopts a hollow rectangular structure, and the cross-section of its inner wall is a runway-shaped structure. The two sides of the runway are semicircular arc segments, and the middle section is platform-shaped. Compared with the circular section, the runway-shaped cross-section can greatly save space, and the middle platform section can be easier to install; and the corners of the rectangular structure adopt a chamfered structure to reduce the weight of the magnet; the structure of the iron core 1 can effectively improve the internal magnetic field strength of the magnet.

[0030] The superconducting coil 2 is arranged on the inner wall surface of the iron core 1, and there is a distance between the superconducting coil 2 and the inner wall surface. The cross section of the superconducting coil 2 is the same as the racetrack cross section of the inner wall surface.

[0031] In the above embodiment, Figure 2 As shown, first shims 3 are respectively provided at the top and bottom of the core 1 near the edge, and second shims 5 are respectively provided at the ends of the inner wall surface of the core 1. Core side plates 6 are provided on the outer side of the core 1 at positions corresponding to the arc segments of the runway, which can effectively ensure that the magnetic field distribution inside the core 1 is relatively uniform and avoid magnetic field saturation.

[0032] In the above embodiment, the passivation grooves 4 are provided on the bottom and the top of the inner wall of the iron core 1, and the magnetic field inside the magnet is adjusted by the passivation grooves 4 to ensure that the magnetic field in the inner space is uniform.

[0033] In the above embodiment, the iron core 1 is a room temperature iron core, and the iron core 1 is made of electrical pure iron.

[0034] In the above embodiment, Figures 3 to 5 As shown, the superconducting coil 2 includes a superconducting cable and a skeleton 10. The skeleton 1 is arranged on the inner wall surface of the iron core 1, and the shape of the skeleton 10 is arranged corresponding to the shape of the inner wall surface of the iron core 1; a wire slot is arranged on the skeleton 1 according to the preset required current distribution, and the superconducting cable is wound in the wire slot to form the superconducting coil 2. In this embodiment, the skeleton 10 is preferably a G10 skeleton. When in use, the skeleton 10 can provide accurate current distribution and improve the magnetic field quality in the good field area.

[0035] The superconducting cable adopts a seven-strand cable 9 composed of superconducting wires 7 and copper wires 8. Figure 4 One copper wire 8 is located at the center, and six superconducting wires 7 are evenly distributed around the copper wire 8. The superconducting wires 7 and the copper wires 8 are twisted to form a seven-strand cable 9. When in use, the copper wires 8 can provide quench-back protection.

[0036] The skeleton 10 may adopt a multi-layer structure. Two layers of superconducting coils 2 are wound on a single-layer skeleton 10, the first layer of superconducting coils 2 is wound from the outside to the inside of the superconducting cable, and the second layer of superconducting coils 2 is wound from the inside to the outside of the superconducting cable, and a single superconducting cable can be wound into two layers of superconducting coils 2.

[0037] In summary, the coil-dominated superconducting magnet of the present invention is a type of magnet that mainly relies on spatial current distribution to generate a specific magnetic field, and has the advantages of light structure, variable field pattern, and magnetic field linearity. The specific magnetic field needs to be generated by analytically / numerically solving the spatial current distribution.

[0038] Example:

[0039] In this embodiment, the magnet length is 4.0 meters, the magnet width is 4.4 meters, and the magnet height is 2.8 meters. The magnet cross section is distributed in a racetrack shape, the magnet center aperture height is 20 meters, and the aperture width is 36 meters (maximum) / 16 meters (straight edge section). The regional magnetic field is 0.5T, and the good field area range is 0.9 meters × 1.2 meters × 0.8 meters (length × width × height) as a reference, and the racetrack cross-section coil-dominated superconducting magnet for the spectrometer is further described.

[0040] like Figure 1 As shown, the magnet as a whole includes two parts: a superconducting coil 2 and a room temperature iron core 1. The room temperature iron core 1 adopts a rectangular structure, and the inner hole is a runway-shaped hole that is consistent with the runway-shaped cross-section of the coil. The aperture height is 2.0 meters, and the aperture width is 3.6 meters (maximum) / 1.6 meters (straight edge section). The long side of the iron core 1 is chamfered to partially reduce the weight of the magnet. The length of the iron core 1 is 4.0 meters, the magnet width is 4.4 meters, and the magnet height is 2.8 meters. The material of the magnetic core 1 is electrical pure iron of grade DT4.

[0041] The uniformity of the good field area can be adjusted and optimized through the iron core 1. According to the structure of the magnet itself, the first shim 3 is set at the top and bottom of the iron core 1, the passivation groove 4 is opened inside the iron core, and the second shim 5 is set at the end of the iron core 1. At the same time, the magnetic field distribution inside the iron core 1 is relatively uniform to avoid magnetic field saturation, and some iron core side plates 6 are added at the arc section of the runway (on both sides of the iron core).

[0042] like Figure 3 As shown, by optimizing the cross-sectional distribution of the coil 2, the magnetic field in the central good field area can be optimized. In this embodiment, two layers of coils 2 are placed on a single-layer frame 10, and a seven-strand cable (6+1) single cable is used. 4 layers of frame, total number of turns 100×4, single coil current 292A, total wire usage of about 50,000 meters.

[0043] like Figure 4 As shown, the 6+1 seven-strand cable used in this example has a diameter of about 3 mm and is made of 6 superconducting wires and 1 copper wire. The 6 outer wires are superconducting wires 7 and the central wire is a copper wire 8.

[0044] like Figure 5 The figure shows the winding of the skeleton 10. In this example, the G10 skeleton 10 is about 10 mm thick, the wire groove depth is 6 mm, and the single-layer skeleton is wound with two layers of coils. The first layer of coils is wound from the outside to the inside, and the second layer of coils is wound from the inside to the outside. A single superconducting cable is just wound with two layers of coils, which is convenient for inter-layer jumper.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A racetrack cross-section coil-dominated superconducting magnet for a spectrometer, characterized in that: include: The iron core adopts a hollow rectangular structure, and the cross section of its inner wall is a runway-shaped structure, with semicircular arc segments on both sides of the runway and a platform-shaped middle section; The corners of the rectangular structure are chamfered; A superconducting coil is arranged on the inner wall surface of the iron core and has a distance from the inner wall surface, and the cross section of the superconducting coil is the same as the racetrack cross section of the inner wall surface; A first shim is provided at the top and bottom of the iron core near the edge, and a second shim is provided at the end of the inner wall surface of the iron core; The superconducting coil comprises a superconducting cable and a frame; the frame is arranged on the inner wall surface of the iron core, and the shape of the frame is arranged corresponding to the shape of the inner wall surface of the iron core; a wire groove is arranged on the frame according to a preset required current distribution, and the superconducting cable is wound in the wire groove to form the superconducting coil; The frame adopts a multi-layer structure; two layers of superconducting coils are wound on the single-layer frame, the first layer of superconducting coils is wound from the outside to the inside of the superconducting cable, and the second layer of superconducting coils is wound from the inside to the outside of the superconducting cable.

2. The racetrack cross-section coil-dominated superconducting magnet for spectrometer according to claim 1, characterized in that: An iron core side plate is arranged on the outer side of the iron core at a position corresponding to the arc segment of the runway.

3. The racetrack cross-section coil-dominated superconducting magnet for spectrometer according to claim 1, characterized in that: The bottom and the top of the inner wall of the iron core are provided with passivation grooves.

4. The racetrack cross-section coil-dominated superconducting magnet for spectrometer according to claim 1, characterized in that: The iron core is a room temperature iron core, and the iron core is made of electrical pure iron.

5. The racetrack cross-section coil-dominated superconducting magnet for spectrometer according to claim 1, characterized in that: The superconducting cable adopts a seven-strand cable composed of superconducting wires and copper wires.

6. The racetrack cross-section coil-dominated superconducting magnet for spectrometer according to claim 5, characterized in that: One strand of the copper wire is located at the center, and six strands of the superconducting wires are evenly distributed around the copper wire. The superconducting wires and the copper wires are twisted together to form the seven-strand cable.

Images