A warm iron superconducting dipole magnet for large angle and high uniformity spectrometer

Abstract

The present invention relates to a warm iron superconducting dipole magnet for a large opening angle and high uniformity spectrometer, comprising: an iron core, which adopts an H-shaped structure with a truncated cone-shaped pole head, and the two ends of the iron core are cut along the beam direction to form a notch, and the notch is at a distance from the outer edge of the iron core; a coil, which is symmetrically arranged in the wire slots at the upper end and the lower end of the iron core. The present invention can achieve a large opening angle and high uniformity at the same time. The present invention can be applied in the field of superconducting magnet technology.

Description

Technical Field

[0001] The invention relates to the technical field of superconducting magnets, in particular to a warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer used in a low-temperature high-density nuclear 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 charged particles in the magnetic field, it can achieve full-space detection and identification of the products of medium-energy heavy ion collisions. Compared with conventional iron with low receptivity, superconducting magnets with high receptivity can make better use of various detection equipment, expand and enhance the research scope and capabilities of the spectrometer. The increase in the magnetic field distribution space can increase the spatial receptivity of the reaction products, and the increased effective field space allows the detector to be built-in, greatly enhancing the detection and identification capabilities of various products.

[0003] The large-scale spectrometer magnets currently in operation in the world include the superconducting dipole magnets of RIKEN-SAMURAI and the superconducting dipole magnets in FAIR-CBM. The common feature of these large-scale spectrometers is that in order to achieve a large opening angle or a large internal space of the magnet, most of the magnetic field uniformity is sacrificed, and the internal non-uniformity of the magnet is even more than 20%. When faced with special physical requirements of high uniformity at a large opening angle, this type of magnet is not suitable. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide a warm iron superconducting dipole magnet for a large opening angle and high uniformity spectrometer, which can achieve a large opening angle and high uniformity at the same time.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer, comprising: an iron core, which adopts an H-shaped structure with a truncated cone-shaped pole head, and the two ends of the iron core are cut along the beam direction to form an incision, and the incision is at a distance from the outer edge of the iron core; coils are symmetrically arranged in the wire slots at the upper and lower ends of the iron core.

[0006] Furthermore, the iron core is a room temperature iron core made of electrical pure iron.

[0007] Furthermore, passivation grooves are symmetrically arranged at the cutouts at the upper end and the lower end of the iron core.

[0008] Furthermore, the cross section of the passivation groove adopts a combined structure of a trapezoid and a rectangle, and the long side of the trapezoid is equal to the long side of the rectangle.

[0009] Furthermore, the height of the short side of the passivation groove is consistent with the height of the pole head.

[0010] Furthermore, upper and lower symmetrical pole pads are respectively provided at the pole corners of the iron core.

[0011] Furthermore, the cross-section of the pole pad adopts a combined structure of a rectangle and a trapezoid, the trapezoid is arranged at a vertex of the rectangle, and the length of the long side of the trapezoid is much smaller than the length of the long side of the rectangle.

[0012] Furthermore, the coil is a low-temperature superconducting coil having a solenoid structure.

[0013] Furthermore, the coil is composed of a superconducting wire and a glass ribbon wrapped outside the superconducting wire, and the superconducting wire is woven into a mesh structure.

[0014] Furthermore, the superconducting wire adopts a NbTi inlaid flat tape with a large copper ratio.

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

[0016] 1. The present invention adopts a room temperature iron core with a truncated cone-like H-shaped structure, and the magnetic field distribution inside the magnet can be adjusted through the detailed structure of the iron core. While achieving a large opening angle, the required regional uniformity is reduced to less than 1% according to the actual application scenario. The overall topological structure of the iron core structure is simple, the processing technology is mature, and it is easy to produce.

[0017] 2. The present invention adopts a solenoid structure coil, the winding process is mature, and it is easy to optimize and customize production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1a It is a schematic diagram of the overall structure of a two-pole magnet in one embodiment of the present invention;

[0019] Figure 1b It is a schematic diagram of the overall structure of a two-pole magnet with a passivation groove in one embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the structure of a passivation tank in one embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a pole head shim according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of a superconducting solenoid in one embodiment of the present invention;

[0023] Figure 5 is a schematic cross-sectional view of a coil solenoid in one embodiment of the present invention;

[0024] Reference numerals:

[0025] 1. Iron core, 2. Coil, 3. End cut, 4. Passivation groove, 5. Pole pad, 6. Superconducting wire, 7. Glass ribbon. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] The invention discloses a warm iron superconducting dipole magnet for a large opening angle and high uniformity spectrometer, comprising: an iron core, which adopts an H-shaped structure with a truncated cone-shaped pole head, and the two ends of the iron core are cut along the beam direction to form a notch, and the notch is at a distance from the outer edge of the iron core; and a coil, which is symmetrically arranged in the wire slots at the upper and lower ends of the iron core. The invention can achieve a large opening angle and high uniformity at the same time.

[0029] In one embodiment of the present invention, a warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer is provided. In this embodiment, Figure 1a , Figure 1b As shown, the two-pole magnet includes:

[0030] The core 1 adopts an H-shaped structure with a truncated cone-shaped pole. Both ends of the core 1 are cut along the beam direction to form a cutout 3. The cutout 3 has a distance from the outer edge of the core 1. In this embodiment, the distance is preferably 0.6 meters.

[0031] The coil 2 is symmetrically arranged in the wire slots at the upper and lower ends of the iron core 1.

[0032] In the above embodiment, the iron core 1 is a room temperature iron core, and the magnetic core 1 is made of electrical pure iron. The H-shaped structure thereof optimizes the magnetic field distribution to achieve a highly uniform magnetic field.

[0033] In the above embodiment, Figure 2 As shown, the passivation grooves 4 are symmetrically arranged at the cutouts 3 at the upper and lower ends of the core 1. In this embodiment, the cross section of the passivation groove 4 can adopt a combination structure of a trapezoid and a rectangle, and the long side of the trapezoid is equal to the long side of the rectangle, that is, the passivation groove 4 is a combination structure of a cylinder and a truncated cone. The height of the short side of the passivation groove 4 is consistent with the height of the pole head, as shown in FIG. Figure 1b shown.

[0034] In the above embodiment, Figure 3 As shown, pole pads 5 are provided at the pole corners of the core 1 in a symmetrical manner. In this embodiment, the cross section of the pole pad 5 adopts a combination of a rectangular and a trapezoidal structure, and the trapezoid is provided at a vertex of the rectangle, that is, the length of the long side of the trapezoid is much smaller than the length of the long side of the rectangle. By setting the height of the pole pad 5, the large aperture and large opening angle can be effectively improved.

[0035] In the above embodiment, the coil 2 is a low-temperature superconducting coil, which adopts a solenoid structure and reduces the coil size and energy consumption through high current carrying capacity.

[0036] Among them, Figure 4 , Figure 5 As shown, the coil 2 is composed of a superconducting wire 6 and a glass ribbon 7 wrapped around the outside of the superconducting wire 6, and the superconducting wire 6 is woven into a mesh structure.

[0037] In this embodiment, the superconducting wire 6 is a NbTi inlaid flat tape with a large copper ratio.

[0038] Example:

[0039] In this embodiment, the radius of the core 1 is 2.2 meters, the height of the core 1 is 2.9 meters, the air gap is 1.3 meters, the central aperture is 1.2 meters, the good field range is 0.9 meters × 1.2 meters × 0.8 meters (length × width × height), the magnetic field of the good field is 0.5T, and the uniformity of the good field is <±1%. The cross section is used as a reference to illustrate the warm iron superconducting dipole magnet for a large angle high uniformity spectrometer. The magnet structure is shown in schematic diagram 1. The magnet as a whole includes two major parts: a superconducting coil 2 of a solenoid structure and a room temperature core 1. Among them, the room temperature core 1 adopts an H-type structure with a truncated cone-shaped pole head. The outer diameter of the core 1 is 4.4 meters, the inner diameter of the pole head is 2.7 meters, and the material of the magnetic core 1 is electrical pure iron of the grade DT4. In order to ensure the central aperture of 1.2 meters and increase the large angle, the two ends of the core 1 are cut along the beam direction to form a cut 3, and the cut 3 is 0.6 meters away from the outer edge of the magnetic core 1. The magnet optimizes the magnetic field mainly through its external structure including the passivation groove 4 and the pole head pad 5, so as to realize a high uniformity magnetic field in the good field area.

[0040] There are two vertically symmetrical passivation grooves 4 in the center of the iron core 1, and vertically symmetrical pole pads 5 are provided at the pole corners. A two-dimensional cross-sectional schematic diagram of the passivation groove 4 is shown in FIG. Figure 2As shown, the optimization effect of the trapezoidal plus rectangular passivation groove structure is better than that of the single rectangular passivation groove structure. At the same time, the shape factor is used to set the cross section of the passivation groove during the optimization process. After the two-dimensional cross section is rotated, the passivation groove 4 is a cylindrical plus truncated cone structure. At the same time, in order to facilitate processing, the upper surface of the passivation groove 4 is highly consistent with the pole head. In the magnet in Figure 1, the top diameter of the passivation groove 4 is 452 mm, the bottom is 199 mm, and the overall height of the passivation groove 4 is 178 mm, of which the height of the cylinder is 17 mm, the height of the truncated cone is 161 mm, and the bottom of the passivation groove 4 is 22 mm away from the lower surface of the pole head.

[0041] The pole pad 5 is also composed of a multi-parameter structure, and its cross-sectional structure is as follows: Figure 3 As shown, the pole head shim 5 is a trapezoidal structure. The two-dimensional structure is formed by rotating around the center of the magnet, and the top of the shim is 487 mm long and the bottom is 388 m long. In order to improve the large aperture and large opening angle, the height of the pole head shim 5 is preferably 50 mm.

[0042] The magnet coil 2 is a low temperature superconducting coil, and its structure is shown in the figure Figure 4 As shown. It is fixed in the wire slot of the core 1 symmetrically through the coil box. The outer diameter of the single parallel coil is 2.88 meters, and the height of the coil from the center of the magnet is 0.73 meters.

[0043] The conductor of coil 2 adopts NbTi inlaid flat tape with large copper ratio, high magnetic stability, high safety requirements, and large copper (7.7). The optional superconducting flat tape has a width of 2.553 mm, a thickness of 1.765 mm, and a core number of 55. The coil structure adopts a solenoid structure, which mainly reduces the coil size and energy consumption through high current carrying capacity. The cross section of the coil is as follows Figure 5 As shown. Each layer of coil has 30 turns, 30 layers in total. Each coil has 900 turns, and the coil is insulated with 2mm glass ribbon.

[0044] 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 warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer, characterized in that: include: The iron core adopts an H-shaped structure with a truncated cone-shaped pole head. The two ends of the iron core are cut along the beam direction to form a notch, and the notch is at a distance from the outer edge of the iron core to ensure that the central aperture is 1.2 meters while increasing the large opening angle; Coils are symmetrically arranged in the wire slots at the upper and lower ends of the iron core; Passivation grooves are symmetrically arranged at the cutouts at the upper and lower ends of the iron core; The pole corners of the iron core are respectively provided with pole shims which are symmetrical up and down; The cross section of the pole pad adopts a combined structure of a rectangle and a trapezoid, the trapezoid is arranged at a vertex of the rectangle, and the length of the long side of the trapezoid is much smaller than the length of the long side of the rectangle.

2. The warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer according to claim 1, characterized in that: The iron core is a room temperature iron core made of electrical pure iron.

3. The warm iron superconducting dipole magnet for a large angle and high uniformity spectrometer according to claim 1, characterized in that: The cross section of the passivation groove adopts a combined structure of a trapezoid and a rectangle, and the long side of the trapezoid is equal to the long side of the rectangle.

4. The warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer as claimed in claim 3, characterized in that: The height of the short side of the passivation groove is consistent with the height of the pole head.

5. The warm iron superconducting dipole magnet for a large angle high uniformity spectrometer as claimed in claim 1, characterized in that: The coil is a low-temperature superconducting coil and adopts a solenoid structure.

6. The warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer as claimed in claim 5, characterized in that: The coil is composed of a superconducting wire and a glass ribbon wrapped outside the superconducting wire, and the superconducting wire is woven into a mesh structure.

7. The warm iron superconducting dipole magnet for a large-angle high-uniformity spectrometer as claimed in claim 6, characterized in that: The superconducting wire adopts a NbTi inlaid flat ribbon with a large copper ratio.

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