A dipole magnet, a combined magnet and a particle accelerator

Abstract

The utility model relates to the technical field of particle acceleration, specifically relates to a dipole magnet, combined magnet and particle accelerator. The dipole magnet, including first saddle -shaped winding and second saddle -shaped winding, both opposite settings along the central ion beam flow direction, form main magnetic field structure, the pole head area of first saddle -shaped winding and second saddle -shaped winding respectively extend to the outside away from the central ion beam flow direction, constitute the archway shape cavity that penetrates the both ends of dipole magnet, the racetrack coil, including first racetrack winding and second racetrack winding, respectively located in the archway shape cavity with first saddle -shaped winding and second saddle -shaped winding corresponding setting, and its pole head area with the pole head area of saddle -shaped coil is adjacent, the utility model discloses the combination design of outside saddle -shaped coil and inside racetrack coil, guarantees the contribution of pole head position to the magnetic field of coil good field area simultaneously, significantly improves the wire turn number density of deflection section to strengthen the magnetic field intensity.

Description

Technical Field

[0001] This utility model relates to the field of particle acceleration technology, specifically to a diode magnet, a combined magnet, and a particle accelerator. Background Technology

[0002] In the field of particle accelerator technology, the pole region of a diode magnet is a critical component affecting the strength and uniformity of the magnetic field. Traditional designs commonly employ a saddle-shaped coil structure, where the pole region requires multiple bends to form an arched winding path. However, due to the brittleness of superconducting materials, a large radius of curvature must be maintained during the bending process, resulting in a severe shortage of wire turns within a limited space.

[0003] In existing technologies, the low efficiency of conductor arrangement in the pole region directly weakens the magnetic field strength. Although attempts have been made to improve this by increasing the number of coil layers or optimizing material properties, these solutions cannot overcome the physical limitations of the bending process: increasing the number of layers introduces higher-order magnetic field components, disrupting uniformity; and while material optimization can improve the current-carrying capacity of a single-turn conductor, it cannot compensate for the fundamental defect of insufficient number of turns.

[0004] Furthermore, in compact applications such as medical devices, the space in the pole head region is further compressed, making the winding efficiency problem of traditional saddle coils even more prominent. Existing designs are forced to compromise between magnetic field strength and device size, resulting in insufficient deflection capability or excessive system size, making it difficult to meet the requirements of efficient and compact accelerators.

[0005] In summary, the contradiction between the bending process of the conductors in the pole head region and the material properties of existing diode magnets leads to insufficient turns density and difficulty in balancing magnetic field performance, which has become a key technical bottleneck restricting the development of compact accelerators. Utility Model Content

[0006] (I) The technical problem to be solved by this utility model is that in the existing dipole magnets, the pole head area of ​​the saddle coil is limited by the plastic deformation ability of the superconducting material due to repeated bending, resulting in insufficient wire turn density, which causes a significant reduction in magnetic field strength and deterioration in uniformity, making it difficult to meet the requirements of compact accelerators for high-performance magnets.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, one embodiment of this utility model provides a diode magnet for deflecting a central particle beam, comprising a saddle-shaped coil and a racetrack-shaped coil. The saddle-shaped coil includes a first saddle-shaped winding and a second saddle-shaped winding, which are arranged opposite to each other along the direction of the central particle beam to form a main magnetic field structure. The pole head regions of the first saddle-shaped winding and the second saddle-shaped winding extend outward away from the direction of the central particle beam, forming an arch-shaped cavity penetrating both ends of the diode magnet.

[0009] The racetrack-shaped coil includes a first racetrack-shaped winding and a second racetrack-shaped winding, which are respectively located in the arch-shaped cavity and are correspondingly arranged with the first saddle-shaped winding and the second saddle-shaped winding, and their pole regions are adjacent to the pole regions of the saddle-shaped coil.

[0010] The deflection segment of the racetrack-shaped coil is parallel to the deflection segment of the saddle-shaped coil. The current direction of the deflection segments of the racetrack-shaped coil on both sides of the central particle beam direction is consistent with that of the deflection segments of their corresponding saddle-shaped coils, which is used to generate an auxiliary magnetic field superimposed on the main magnetic field.

[0011] This invention utilizes a combination of an outer saddle-shaped coil and an inner racetrack-shaped coil. While ensuring the contribution of the pole head position to the magnetic field in the coil's best field region, it fully utilizes the space of the arch-shaped cavity to significantly increase the wire turn density in the deflection section, thereby enhancing the magnetic field strength. The design of the racetrack-shaped coil's deflection section being parallel to the saddle-shaped coil and having the same current direction ensures that the auxiliary magnetic field and the main magnetic field are superimposed in the same direction, avoiding mutual cancellation. Simultaneously, by adjusting the position and number of turns of the racetrack-shaped coil, higher-order magnetic field components can be precisely controlled, suppressing magnetic field distortion and improving uniformity. The synergistic effect of these two components achieves dual optimization of magnetic field strength and distribution within a limited space, without relying on multi-layer coil stacking or additional correction magnets. This results in a more compact magnet structure, significantly reduced manufacturing costs, and provides a reliable solution for the efficient operation of compact accelerators.

[0012] According to one embodiment of the present invention, the deflection segment of the saddle-shaped coil extends along a first direction, and the deflection segment of the racetrack-shaped coil extends along a second direction parallel to the first direction, together defining a bracket-shaped symmetrical cross section of the deflection segment of the diode magnet.

[0013] This structure achieves efficient utilization of the winding space in the pole area through the geometric adaptation of the arc extension of the saddle-shaped coil and the straight section of the racetrack-shaped coil. This avoids the redundant gaps caused by bending conflicts in traditional designs, and enhances the magnetic field strength in the central area through the superposition of magnetic fields under parallel current directions. At the same time, the bracket-shaped cross-section effectively constrains the magnetic field diffusion path through symmetrical distribution, reduces magnetic leakage and improves magnetic field uniformity, thus balancing magnetic field performance and equipment miniaturization requirements in a compact layout.

[0014] According to one embodiment of the present invention, the diode magnet further includes a window-shaped iron core, which surrounds the saddle-shaped portion of the first saddle-shaped winding and the second saddle-shaped winding, and extends to cover the outer side of the arch-shaped cavity. The inner wall of the window-shaped iron core is in clearance fit with the saddle-shaped portion of the saddle-shaped coil, and the opening direction is towards the central particle beam path.

[0015] Through the magnetic guiding effect of the window-shaped iron core, the magnetic field lines of the main magnetic field are concentrated and confined within the superimposed region of the saddle-shaped coil and the racetrack-shaped coil, significantly improving excitation efficiency. Simultaneously, the shielding effect of the iron core on the edge magnetic field reduces the leakage magnetic field strength to less than 30% of that in traditional coreless designs. The gap fit avoids mechanical stress caused by direct contact between the iron core and the coil, further reduces magnetic field loss by optimizing the reluctance path, ensuring efficient conversion of magnetic field energy into beam deflection force, and reserving space for the subsequent integration of dynamic adjustment mechanisms, thus achieving a balance between magnet performance and extended functionality.

[0016] According to one embodiment of the present invention, the diode magnet further includes a moving device, which is fixed to the inner wall of the window-shaped iron core and used to adjust the position of the racetrack-shaped coil; the moving device includes a fixing frame and a lifting mechanism.

[0017] The fixing frame is fixed to the inner wall of the iron core by bolt connection or welding.

[0018] The lifting mechanism is connected to the fixed frame and is used to move the racetrack-shaped coil along a direction perpendicular to the central particle beam.

[0019] The lifting mechanism adjusts the magnetic field gradient or uniformity by driving the racetrack-shaped coil away from or closer to the central particle beam path, thereby changing the distance between the racetrack-shaped coil and the saddle-shaped coil.

[0020] By driving the racetrack-shaped coil closer to or away from the beam path, changing its distance from the saddle-shaped coil, the magnetic field gradient distribution can be directly controlled. When the racetrack-shaped coil is closer to the beam path, the magnetic field gradient is enhanced, suitable for high-energy particle deflection requirements; when it is farther away, the magnetic field distribution tends to be uniform, suitable for stable transmission of low-energy beams. This design breaks through the limitations of traditional fixed magnet structures, realizing online dynamic optimization of magnetic field parameters without disassembling the magnet or interrupting accelerator operation, significantly improving the flexibility and efficiency of equipment control. The compact layout of the moving device and the coordinated design of the opening direction of the window-shaped iron core ensure that the particle beam path is unobstructed during adjustment, while avoiding mechanical interference with the main magnetic field frame, balancing magnetic field performance and operational safety.

[0021] According to one embodiment of the present invention, the fixing frame includes a right-angled trapezoidal main frame, with its inclined side facing the central particle beam path. The right-angled side is adjacent to and fixedly connected to the inner wall of the window-shaped iron core. The main frame is arranged perpendicular to the winding plane of the racetrack-shaped coil and is located between the two deflection segments of the racetrack-shaped coil. By adapting the inclined side to the straight extension direction of the beam path, the rigid connection between the bottom right-angled side and the iron core ensures the overall support stability while avoiding encroachment on the space of the winding plane.

[0022] The lifting mechanism includes:

[0023] The driving component is fixed to the upper bottom side frame located on the inner side of the main frame;

[0024] The lifting arm consists of two parallel and symmetrically arranged V-shaped connecting rods. One end of the V-shaped connecting rod is rotatably connected to the output end of the drive unit, and the other end is hinged to the acute angle end of the main frame. When the drive unit is running, the V-shaped connecting rod drives the support plate at the bottom to rise and fall along the direction perpendicular to the beam direction, thereby realizing the vertical displacement of the racetrack-shaped coil.

[0025] The moving device also includes a support clamp and a spreading device. The support clamp includes two clamping units, which respectively fix the deflection segment of the racetrack-shaped coil to ensure that the coil does not twist or shift during movement. These units are hinged to the bottom ends of the two V-shaped connecting rods to fix the deflection segment of the racetrack-shaped coil.

[0026] The spreading device is disposed between the two supporting clamps and is used to spread or retract the supporting clamps in the horizontal direction to adjust the length-to-width ratio of the deflection section and the bending section of the racetrack-shaped coil.

[0027] Through the combined motion of vertical lifting and horizontal expansion, the magnetic field gradient and uniformity are simultaneously optimized under a single driving source. The vertical displacement adjusts the main magnetic field strength, and the horizontal expansion compensates for higher-order magnetic field distortion, thereby completing the dynamic matching of multi-dimensional magnetic field parameters in a compact space.

[0028] According to one embodiment of the present invention, the clamping unit is U-shaped, and the inner surface of the clamping unit is provided with a rolling mechanism, the rolling mechanism including a roller, and the rolling direction of the roller is consistent with the winding direction of the racetrack-shaped coil.

[0029] When the racetrack-shaped coil is adjusted in position due to lifting or spreading, the roller rolls freely along the winding direction, providing the coil with a unidirectional sliding degree of freedom. This not only eliminates the local stress concentration caused by traditional rigid clamping, but also ensures that the coil maintains the preset winding geometry accuracy during deformation.

[0030] According to one embodiment of the present invention, the other end of the two V-shaped connecting rods is hinged to the acute-angle end of the main frame via a rotating shaft;

[0031] The V-shaped connecting rod is provided with a limiting rod on the side near the central particle beam path, and the limiting rod is fixedly connected to the main frame.

[0032] The limiting rod contacts the side wall of the V-shaped connecting rod to limit the maximum unfolding angle of the V-shaped connecting rod, thereby limiting the minimum distance between the supporting clamp and the central particle beam path. The minimum distance is the critical threshold for adjusting the aspect ratio of the racetrack-shaped coil deflection section and bending section, to avoid degradation of the critical current caused by excessive stretching or compression of the superconducting tape.

[0033] According to one embodiment of the present invention, at least one of the saddle-shaped coil or racetrack-shaped coil is a superconducting material, which further enhances the magnetic field strength.

[0034] This utility model also provides a combined magnet, comprising: a dipolar magnet and a quadrupole coil as described in any of the above claims; the quadrupole coil is disposed inside the dipolar magnet and is coaxial with the racetrack-shaped coil and the saddle-shaped coil of the dipolar magnet.

[0035] The magnetic field component of the quadrupole coil is superimposed with the deflection magnetic field of the diode magnet to form a composite magnetic field. The gradient component of the composite magnetic field is used for beam focusing, and the uniformity component is used for particle path deflection.

[0036] This invention further provides a particle accelerator, comprising:

[0037] Dipole magnets or combined magnets as described in any of the above;

[0038] The diode magnet or combined magnet is arranged along the particle beam path to deflect and / or focus the particle beam.

[0039] (III) Beneficial Effects of this Invention: This invention, through the combined design of an outer saddle-shaped coil and an inner racetrack-shaped coil, significantly increases the wire turn density in the deflection section while ensuring the contribution of the pole head position to the magnetic field of the coil's good field region, thereby enhancing the magnetic field strength. Simultaneously, the racetrack-shaped coil, through flexible adjustment of its position and number of turns, precisely compensates for higher-order magnetic field components, improving magnetic field uniformity. The synergistic effect of both achieves dual optimization of magnetic field strength and distribution within a limited space, eliminating the need for complex multi-layered coils or additional correction magnets, significantly reducing magnet volume and manufacturing costs, and providing a high-performance magnet solution for compact accelerators. Attached Figure Description

[0040] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 A three-dimensional structural diagram of a diode magnet in a first state according to an embodiment of the present invention;

[0042] Figure 2 A three-dimensional structural diagram of the first state of the diode magnet after removing the window-type iron core, according to an embodiment of the present invention;

[0043] Figure 3 for Figure 2 Front view diagram;

[0044] Figure 4 A schematic diagram of the cross-sectional structure of the deflection segment of a diode magnet in a first state according to an embodiment of the present invention;

[0045] Figure 5 A three-dimensional structural diagram of the second state of the diode magnet after removing the window-type iron core, according to an embodiment of the present invention;

[0046] Figure 6 for Figure 5 Front view diagram;

[0047] Figure 7 A schematic diagram of the cross-sectional structure of the deflection segment of a diode magnet in a second state according to an embodiment of the present invention;

[0048] Figure 8 A three-dimensional structural diagram of a moving device for a diode magnet provided in one embodiment of the present invention;

[0049] Figure 9 This is a schematic diagram of a three-dimensional structure of a combined magnet provided in one embodiment of the present invention.

[0050] Figure 10 This is a three-dimensional structural diagram of the combined magnet when removing the iron core, according to one embodiment of the present invention.

[0051] Figure 11 This is a schematic diagram of a three-dimensional structure of a diode magnet provided in one embodiment of the present invention.

[0052] Icons: 1. Saddle-shaped coil; 11. First saddle-shaped winding; 12. Second saddle-shaped winding; 14. Arch-shaped cavity; 2. Racetrack-shaped coil; 21. First racetrack-shaped winding; 22. Second racetrack-shaped winding; 301. Pole head area; 302. Deflection section; 4. Window-shaped iron core; 5. Moving device; 51. Fixed frame; 511. Main frame; 512. Limiting rod; 52. Lifting mechanism; 521. Driving component; 522. Lifting arm; 523. Spreading device; 524. Supporting clamp; 5241. Clamping unit; 5242. Rolling mechanism; 6. Four-pole coil. Detailed Implementation

[0053] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0054] Example 1:

[0055] like Figures 1 to 8 As shown, this embodiment provides a diode magnet for deflecting a central particle beam, including a saddle-shaped coil 1, a racetrack-shaped coil 2, a moving device 5, and a window-shaped iron core 4.

[0056] The saddle-shaped coil 1 includes a first saddle-shaped winding 11 and a second saddle-shaped winding 12, which are symmetrically arranged along the direction of the central particle beam to form the main magnetic field structure. The pole regions 301 of the first saddle-shaped winding 11 and the second saddle-shaped winding 12 extend outward away from the direction of the central particle beam, forming an arch-shaped cavity 14 penetrating both ends of the magnet. The cross-section of the cavity is symmetrically arched, and the path of the central particle beam passes through the central axis of the arch-shaped cavity, intersecting perpendicularly with the plane of the deflection segment 302 of the saddle-shaped coil 1, ensuring that the particle beam deflects along a preset trajectory under the action of the magnetic field. The racetrack-shaped coil 2 includes a first racetrack-shaped winding 21 and a second racetrack-shaped winding 22, which are respectively embedded in the arch-shaped cavity 14 and adjacent to the corresponding pole region 301 of the saddle-shaped coil 1. The spacing is controlled within the millimeter range through precision assembly, and the winding direction of its pole region 301 is at a certain vertical distance from and parallel to the saddle-shaped coil 1.

[0057] The deflection section 302 of the saddle-shaped coil 1 extends along a first direction (i.e., the beam deflection plane) and is wound with niobium-titanium (NbTi) superconducting wire. The arc-shaped bending section of its pole region 301 is formed by segmented welding to avoid damage to the superconducting layer caused by overall bending. The deflection section 302 of the racetrack-shaped coil 2 extends along a second direction parallel to the first direction and uses yttrium barium copper oxide (YBCO) coated conductor. The winding is densely filled with serpentine reciprocating arrangement and leaves gaps with the saddle-shaped coil 1. The current directions of the deflection sections 302 of both are consistent, so that the auxiliary magnetic field generated by the racetrack-shaped coil 2 is superimposed in the same direction as the main magnetic field of the saddle-shaped coil 1, and the central magnetic field strength can reach 5-6T. The arc segment of saddle-shaped coil 1 and the straight segment of racetrack-shaped coil 2 together define a bracket-shaped symmetrical cross section—the outer side is the continuous arc profile of saddle-shaped coil 1, and the inner side is the straight winding area of ​​racetrack-shaped coil 2 (deflection segment 302). This geometric design, through the magnetic field converging effect of the arc segment and the uniform diffusion characteristics of the straight segment, forms a high-intensity and uniformly distributed magnetic field region around the central beam path, extending the good field area space range to 1.5 times that of the traditional design.

[0058] like Figure 11 As shown, the diode magnet in this embodiment can also be configured to be bent, and it can be used independently without the moving device 5.

[0059] The window-shaped iron core 4 surrounds the saddle-shaped portion of the saddle-shaped coil 1 and extends to cover the outside of the arch-shaped cavity 14. Its opening direction is strictly aligned with the beam path, and leakage magnetic flux is reduced through a gap fit design. The moving device 5 is integrated into the inner wall of the iron core and is used to drive the racetrack-shaped coil 2 to move vertically to dynamically adjust the magnetic field gradient. The synergistic effect of the selection of superconducting materials (such as the high current-carrying capacity of NbTi and the flexible processing characteristics of YBCO) and the coil geometry design achieves dual optimization of magnetic field strength and uniformity within a limited space, meeting the high-precision deflection requirements of compact accelerators.

[0060] Furthermore, the window-shaped iron core 4 surrounds the saddle-shaped portions of the first saddle-shaped winding 11 and the second saddle-shaped winding 12, and extends to cover the outer side of the arch-shaped cavity 14. The inner wall of the window-shaped iron core 4 is in clearance fit with the saddle-shaped portion of the saddle-shaped coil 1 (e.g., Figure 4 As shown in the figure, the opening is oriented toward the central particle beam path to enhance excitation efficiency and shield the leakage magnetic field.

[0061] Furthermore, in this embodiment, there are four sets of moving devices 5, which are fixed to the inner wall of the window-shaped iron core 4 and correspond one-to-one with the four bent sections of the racetrack-shaped coil 2. Each set of moving devices 5 includes a fixing frame 51, a lifting mechanism 52, a supporting clamp 524, and a spreading device 523.

[0062] like Figure 8 As shown, the specific structure is as follows:

[0063] Fixing frame 51: A right-angled trapezoidal main frame 511 is adopted, with its inclined side facing the central particle beam path and parallel to the beam deflection plane; the right-angled side of the bottom surface is rigidly connected to the inner wall of the iron core by bolts to ensure support stability. The main frame 511 is set perpendicular to the winding plane of the racetrack-shaped coil 2 and is located between the two deflection sections 302 of the coil to avoid encroaching on the winding space.

[0064] The lifting mechanism 52 consists of a drive component 521 and a lifting arm 522, wherein the lifting arm 522 is a V-shaped connecting rod. The drive component 521 (such as a stepper motor) is fixed to the inner side of the bottom edge of the main frame 511, and its output end is connected to the top of one of the V-shaped connecting rods through a rotating shaft; the other end of the V-shaped connecting rod is hinged to the acute angle end of the main frame 511, forming a double-support linkage structure. When the drive component 521 is running, the bottom end of the V-shaped connecting rod drives the bottom end supporting clamp 524 to rise and fall along the direction perpendicular to the beam direction, realizing the vertical displacement of the racetrack-shaped coil 2 and adjusting its distance from the saddle-shaped coil 1. The specific lifting trajectory can be controlled according to the included angle of the V-shaped connecting rod. In this embodiment, the running trajectory is an upward and inward arc lifting, which leaves space for the subsequent expansion of the bending section of the racetrack-shaped coil.

[0065] Supporting clamp 524 and spreading device 523: The supporting clamp 524 consists of two U-shaped clamping units 5241, which are hinged to the bottom end of the V-shaped connecting rod, and are used to fix the deflection section 302 of the racetrack-shaped coil 2. The inner surface of the U-shaped clamping unit 5241 is provided with a rolling mechanism 5242—polytetrafluoroethylene-coated rollers arranged at equal intervals along the winding direction, and their rotation axis is perpendicular to the extension direction of the coil. When the coil deforms due to lifting or spreading, the rollers roll freely along the winding direction to eliminate local stress concentration. The spreading device 523 is horizontally arranged between the two supporting clamps 524. It can use a bidirectional screw to drive the sliding block to move towards each other, and drive the clamping unit 5241 to horizontally spread or retract through the connecting rod assembly, adjusting the length-to-width ratio of the coil deflection section 302 and the bending section (e.g., from 10:1 to 9:1).

[0066] Limiting protection mechanism: A limiting rod 512 is provided on the side of the V-shaped connecting rod closest to the beam path, with both ends fixed to the junction of the acute and right angle sides of the main frame 511. When the V-shaped connecting rod is extended to a preset angle, the limiting rod 512 limits its maximum extension angle through physical contact, locking the minimum distance between the supporting clamp 524 and the beam path to a critical threshold (e.g., 10mm), corresponding to the aspect ratio adjustment limit (≤1:1.8), to prevent the superconducting tape from degrading due to excessive deformation.

[0067] Movement process and magnetic field state switching of mobile device 5:

[0068] In this embodiment, the moving device 5 achieves dynamic adjustment of the position and geometry of the runway-shaped coil 2 through a combination of vertical lifting and horizontal spreading motions. The specific motion process is as follows:

[0069] First state (high gradient deflection mode):

[0070] like Figures 5 to 7 As shown, the drive unit 521 drives the V-shaped connecting rod to lift, causing the supporting clamp 524 to rise along an upward and inward arc trajectory, bringing the runway-shaped coil 2 closer to the central beam path. At this time:

[0071] Vertical displacement: The distance between the racetrack-shaped coil 2 and the saddle-shaped coil 1 is reduced, and the magnetic field gradient in the pole region 301 is increased from 10 T / m to 15 T / m, which is suitable for the strong deflection requirements of high-energy particles (such as 200 MeV proton beams).

[0072] Horizontal expansion: The expansion device 523 drives the support clamp 524 to expand horizontally, adjusting the aspect ratio of the coil deflection section 302 to the bending section from 10:1 to 9:1, suppressing the hexagonal magnetic field component (reduction ≥40%), and reducing beam dispersion.

[0073] Magnetic field characteristics: The central magnetic field strength is maintained at 5.5T, but the gradient is increased, and the good field area is slightly reduced to 65% of the magnet cross-section to ensure the accurate deflection of the high-energy beam.

[0074] like Figures 1 to 4 The second state (high uniformity transmission mode):

[0075] The drive unit 521 reverses its direction, the bottom end of the V-shaped connecting rod moves downward, and the supporting clamp 524 moves along a downward and outward arc trajectory, causing the racetrack-shaped coil 2 to move away from the beam path. At this time:

[0076] Vertical displacement: The distance between the racetrack-shaped coil 2 and the saddle-shaped coil 1 is increased, the magnetic field gradient is reduced to 8 T / m, the magnetic field distribution tends to be flat, and the uniformity is improved by 20%, which is suitable for the stable transmission of low-energy particle beams (such as 50 MeV proton beams).

[0077] Horizontal retraction: The spreading device 523 drives the supporting clamp 524 to retract, restoring the aspect ratio to 10:1, reducing coil deformation stress, and ensuring that the strain of the superconducting strip is ≤0.05%;

[0078] Magnetic field characteristics: The central magnetic field strength remains at 5.2T, the good field area is expanded to 80% of the magnet cross-section, and the proportion of the uniformity component is increased to 95%.

[0079] Coordination mechanism for state switching

[0080] Motion trajectory design:

[0081] The upward and inward arc-shaped lifting trajectory of the V-link (e.g.) Figure 8 As shown, the space reserved for the expansion of the bending section is to avoid interference between the bending section of the runway-shaped coil and the bending section of the saddle-shaped coil 1; at the same time, the limit rod 512 locks the minimum spacing to ensure that the length-to-width ratio adjustment does not exceed the material safety threshold.

[0082] Rolling mechanism 5242 protection:

[0083] During the lifting and spreading process, the rollers of the U-shaped clamping unit 5241 roll freely along the winding direction of the racetrack-shaped coil 2, with a friction coefficient ≤0.08, eliminating damage to the superconducting layer caused by mechanical resistance; the polytetrafluoroethylene coating (thickness 0.3mm) of the rollers simultaneously provides insulation protection to prevent leakage current from causing local temperature rise.

[0084] Magnetic field response verification:

[0085] First state: The measured magnetic field gradient of the 301 pole head region of the Hall probe is 15.2 T / m, the proportion of the quadrupole component is ≤3%, and the beam deflection radius error is ≤0.3mm;

[0086] Second state: The standard deviation of magnetic field uniformity is reduced from 5% to 2%, the proportion of hexapole components is ≤1%, and the beam transmission efficiency is improved by 25%.

[0087] Simplified form without mobile device 5

[0088] like Figure 11 As shown, the diode magnet in this embodiment can also be set to a fixed bent state (excluding the moving device 5), in which case the distance and aspect ratio between the racetrack-shaped coil 2 and the saddle-shaped coil 1 are fixed. This configuration is suitable for applications with constant magnetic field parameters (such as synchrotron radiation sources). By optimizing the initial assembly position (such as a distance of 12mm and an aspect ratio of 10:1), a balanced performance of a central magnetic field strength of 5T and a uniformity standard deviation of 3% can be achieved.

[0089] Example 2

[0090] like Figure 9 Figure 10 As shown, this embodiment integrates a quadrupole coil 6 on the basis of the dipole magnet in embodiment 1 to form a composite magnetic field structure, specifically including the following design:

[0091] Integrated layout of quadrupole coil 6:

[0092] The quadrupole coil 6 is coaxially nested inside the diode magnet, with its pole head region 301 embedded in the arch-shaped cavity 14 of the diode magnet. The distance between the quadrupole coil 6 and the straight section of the racetrack-shaped coil 2 is controlled within the range of 2-3 mm. The quadrupole coil 6 is wound with niobium-titanium (NbTi) superconducting wire, and the winding direction is orthogonal to the racetrack-shaped coil 2 of the diode magnet, forming a quadrupole symmetrical magnetic field distribution. The magnetic field gradient direction of the quadrupole coil 6 is perpendicular to the deflection magnetic field of the diode magnet. After the two are superimposed, a composite magnetic field is formed around the central beam path—the diode magnetic field provides a deflection force perpendicular to the beam direction, and the quadrupole magnetic field provides a radial focusing force.

[0093] Generation and control of composite magnetic fields:

[0094] The two-pole magnetic field dominates the deflection: the superimposed magnetic field strength of saddle-shaped coil 1 and racetrack-shaped coil 2 is 5-6T, which is used to control the deflection radius of the particle beam;

[0095] Quadrupole magnetic field enhances focusing: Quadrupole coil 6 generates a gradient magnetic field (20-25 T / m), which suppresses beam divergence and improves focusing efficiency by 40% compared to a single diode magnet;

[0096] Dynamic coordinated adjustment: The position of the racetrack coil 2 (vertical displacement ±5mm) and the current of the quadrupole coil 6 (±15%) are adjusted by the moving device 5 to achieve real-time matching between the deflection radius and the focusing intensity. For example, when the particle energy increases, the displacement of the racetrack coil 2 closer to the beam is increased simultaneously (to increase the deflection magnetic field gradient) and the current of the quadrupole coil 6 is enhanced (to increase the focusing force), thus maintaining the stability of the beam trajectory.

[0097] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A diode magnet for deflecting a central particle beam, characterized in that, include: The saddle-shaped coil includes a first saddle-shaped winding and a second saddle-shaped winding, which are arranged opposite to each other along the direction of the central particle beam to form the main magnetic field structure; The pole head regions of the first saddle-shaped winding and the second saddle-shaped winding extend outward away from the direction of the central particle beam, forming an arch-shaped cavity that runs through both ends of the diode magnet. The racetrack-shaped coil includes a first racetrack-shaped winding and a second racetrack-shaped winding, which are respectively located in the arch-shaped cavity and are correspondingly arranged with the first saddle-shaped winding and the second saddle-shaped winding, and their pole regions are adjacent to the pole regions of the saddle-shaped coil. The deflection segment of the racetrack-shaped coil is parallel to the deflection segment of the saddle-shaped coil. The current direction of the deflection segments of the racetrack-shaped coil on both sides of the central particle beam direction is consistent with that of the deflection segments of their corresponding saddle-shaped coils, which is used to generate an auxiliary magnetic field superimposed on the main magnetic field.

2. The diode magnet according to claim 1, characterized in that, The deflection segment of the saddle-shaped coil extends along a first direction, and the deflection segment of the racetrack-shaped coil extends along a second direction parallel to the first direction. Together, they define a bracket-shaped symmetrical cross-section of the deflection segment of the diode magnet.

3. The diode magnet according to claim 2, characterized in that, It also includes a window-shaped iron core, which surrounds the saddle-shaped portions of the first and second saddle-shaped windings and extends to cover the outer side of the arch-shaped cavity. The inner wall of the window-shaped iron core is in clearance fit with the saddle-shaped portion of the saddle-shaped coil, and the opening direction faces the central particle beam path to enhance excitation efficiency and shield leakage magnetic field.

4. The diode magnet according to claim 3, characterized in that, Also includes: A movable device, fixed to the inner wall of the window-shaped iron core, is used to adjust the position of the racetrack-shaped coil; The mobile device includes: The fixing frame is fixed to the inner wall of the window-shaped iron core by bolt connection or welding; A lifting mechanism, connected to the fixed frame, is used to move the racetrack-shaped coil along a direction perpendicular to the central particle beam. The lifting mechanism adjusts the magnetic field gradient or uniformity by driving the racetrack-shaped coil away from or closer to the central particle beam path, thereby changing the distance between the racetrack-shaped coil and the saddle-shaped coil.

5. The diode magnet according to claim 4, characterized in that, The fixing frame includes a right-angled trapezoidal main frame, with its hypotenuse facing the central particle beam path. The right-angled side frame is adjacent to and fixedly connected to the inner wall of the window-shaped iron core. The main frame is arranged perpendicular to the winding plane of the racetrack-shaped coil and is located between the two deflection segments of the racetrack-shaped coil. The lifting mechanism includes: The driving component is fixed to the upper bottom side frame located on the inner side of the main frame; The lifting arm consists of two parallel and symmetrically arranged V-shaped links. One end of the V-shaped link is rotatably connected to the output end of the drive component, and the other end is hinged to the acute angle end of the main frame. The moving device also includes a support clamp and a spreading device. The support clamp includes two clamping units, which are respectively hinged to the bottom ends of the two V-shaped connecting rods, for fixing the deflection section of the racetrack-shaped coil. The spreading device is disposed between the two supporting clamps and is used to spread or retract the supporting clamps in the horizontal direction to adjust the length-to-width ratio of the deflection section and the bending section of the racetrack-shaped coil.

6. The diode magnet according to claim 5, characterized in that, The clamping unit is U-shaped, and the inner surface of the clamping unit is provided with a rolling mechanism, which includes a roller. The rolling direction of the roller is consistent with the winding direction of the racetrack-shaped coil.

7. The diode magnet according to claim 5, characterized in that, The other end of the two V-shaped connecting rods is hinged to the acute angle end of the main frame via a rotating shaft; The V-shaped connecting rod is provided with a limiting rod on the side near the central particle beam path, and the limiting rod is fixedly connected to the main frame. The limiting rod contacts the side wall of the V-shaped connecting rod to limit the maximum unfolding angle of the V-shaped connecting rod, thereby limiting the minimum distance between the supporting clamp and the central particle beam path. The minimum spacing is the critical threshold for adjusting the aspect ratio of the deflection and bending sections of the runway-shaped coil.

8. The diode magnet according to any one of claims 1 to 7, characterized in that, At least one of the saddle-shaped coils or racetrack-shaped coils is a superconducting material.

9. A composite magnet, characterized in that, include: The polar magnet as described in any one of claims 1 to 8; A quadrupole coil is disposed inside the diode magnet and is coaxial with the racetrack-shaped coil and saddle-shaped coil of the diode magnet. The magnetic field component of the quadrupole coil is superimposed with the deflection magnetic field of the diode magnet to form a composite magnetic field. The gradient component of the composite magnetic field is used for beam focusing, and the uniformity component is used for particle path deflection.

10. A particle accelerator, characterized in that, include: The diode magnet as described in any one of claims 1 to 8, or The combined magnet as described in claim 9; The diode magnet or combined magnet is arranged along the particle beam path to deflect and / or focus the particle beam.

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