A method for systematized control and adjustment of full-field dispersion of a core main guide type diamagnetic magnet

Abstract

The application relates to a kind of iron core main guide type di-magnet full field discrete systematized control and regulation method, comprising the following steps: controlling iron core length in the process of iron core splicing respectively, adjusting iron core length after iron core processing;Control the stacking coefficient of the stack and the iron core, reduce the magnetic field discreteness under high field;Air passivation groove is opened in the pole head end after the assembly of the iron core, to realize the regulation of full field discreteness;Control the installation position of the coil, reduce the high field discreteness and optimize the full field consistency;The iron core is grouped and optimized pairing, to reduce the system level magnetic field discreteness.The method can not only actively reduce the magnetic field discreteness in the magnet processing stage, but also can further adjust the existing discrete deviation after processing is completed.Different from the traditional single regulation means, the method considers the discreteness requirement under the reference field condition, and can cover the whole magnetic field working interval, realize the system level optimization and control of the magnetic field discreteness in the whole excitation process.

Description

Technical Field

[0001] This invention relates to a systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet, belonging to the field of accelerator magnet technology. Background Technology

[0002] In synchrotron accelerators, multiple identical dipole magnets are typically assembled into a closed loop to achieve closed-loop beam motion. Differences in core material, stacking factor, and coil spatial positioning among these magnets lead to dispersion in their integral field under different magnetic field excitation states, causing beam trajectory distortion. This trajectory deviation accumulates with increasing acceleration cycles, potentially resulting in beam loss. Furthermore, to reduce overall accelerator costs and simplify beam control, identical magnets are usually supplied in series. This reduces the number of power supplies, improves current-magnetic field synchronization, and lowers control system complexity. However, it also sacrifices the flexibility of compensating for magnet dispersion through independent power supply adjustments. Therefore, accelerator engineering places extremely stringent requirements on the magnetic field consistency of dipole magnets supplied in series, especially those used in synchrotron accelerators.

[0003] Magnetic field dispersion essentially refers to the degree of dispersion of the integrated magnetic field, used to characterize the difference in integrated magnetic fields between different magnets of the same specification. Its mathematical expression is usually defined as the ratio of the difference in integrated magnetic fields between two magnets to the integrated magnetic field of a reference magnet, i.e., ΔBL / BL0, where ΔBL is the difference in integrated fields between the two magnets, and BL0 is the integrated magnetic field value of the reference magnet. As the scale of accelerators increases, the impact of dispersion on beam performance will become increasingly significant.

[0004] In addition, the operation of a synchrotron not only requires a high magnetic field dispersion index under the injected magnetic field, but also requires that the magnetic fields of each magnet remain highly consistent throughout the acceleration process to ensure the synchronization of the magnetic field throughout the acceleration process, thereby ensuring stable acceleration and high-quality transmission of the beam.

[0005] Traditional accelerator magnetic field dispersion control primarily relies on controlling the core length during magnet manufacturing. This method can effectively ensure magnetic field consistency under low to medium field conditions. However, as the excitation level increases, the core material gradually enters the saturation region, and factors such as differences in ferromagnetic material properties, deviations in the stacking coefficient, and mechanical errors during manufacturing and assembly significantly increase the impact on the dispersion of the integrated magnetic field. These influencing factors exhibit strong nonlinearity and coupling, and are difficult to compensate for precisely through subsequent methods. The adjustment process is irreversible, thus severely restricting the effective control of magnetic field dispersion under high field conditions. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet. This method not only actively reduces magnetic field discreteness during the magnet manufacturing stage but also further adjusts existing discrete deviations after manufacturing. Unlike traditional single adjustment methods, this method considers discreteness requirements under reference field conditions and covers the entire magnetic field operating range, achieving system-level optimization and control of magnetic field discreteness throughout the excitation process.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A systematic method for controlling and adjusting the full-field discreteness of a core-dominated dipole magnet includes the following parallel steps: The core length is controlled during the core splicing process and adjusted after the core is processed. Controlling the stacking coefficient of the stacked blocks and iron core reduces the magnetic field dispersion under high fields; An air passivation groove is opened at the end of the pole head after the iron core is assembled to achieve full-field discrete adjustment; Control the installation position of the coil to reduce high-field dispersion and optimize overall field consistency; By optimizing the pairing of iron core groups, the system-level magnetic field dispersion is reduced.

[0008] The systematic control and adjustment method for the full-field discreteness of the core-dominated diode magnet, preferably, involves controlling the core length during core splicing as follows: During the splicing of the half-core, the machining allowance of the core length is increased to reserve space for subsequent skew fine adjustment. During the skew machining stage, the core length and machining tolerance are precisely controlled by a high-precision CNC machine tool to ensure that the initial machining accuracy meets the design requirements. After the magnet test is completed, the magnet with a large integral field is skewed a second time according to the measured integral field data to further reduce the deviation.

[0009] The systematic control and adjustment method for the full-field discreteness of the core-dominated diode magnet, preferably, involves adjusting the core length after core processing as follows: Depending on whether the magnet has a live pole, different adjustment methods are used: For magnets without a live pole, an end magnetic screw is used for adjustment, and the integral magnetic field is adjusted by controlling the screw's screw-in length; for magnets with a live pole, a lamination method is used, where laminations are added or removed using the live pole and a fixed fixture to achieve fine adjustment of the integral magnetic field; for sector magnets, the effective length is changed by adjusting the position of the central arc of the sector magnet, thereby achieving adjustment of the dispersion of the low and medium fields.

[0010] The systematic control and adjustment method for the full-field discreteness of the core-dominated diode magnet, preferably, involves controlling the stacking coefficient of the stacked blocks and the core to reduce the magnetic field discreteness under high fields as follows: In the stacking and pressing process, the stack length, the number of stamped pieces, and the weight of the stack are strictly controlled by the stacking die to ensure that the stacking coefficient of each stack meets the set tolerance range. Individual stacks with different stacking coefficients are reasonably paired and combined, and the dispersion of stacking coefficients at the semi-core level is further reduced through complementary matching. Based on the completion of the half-core pairing, the upper and lower cores are then optimized for final pairing to further reduce the dispersion deviation caused by the difference in the stacking coefficient between the magnets.

[0011] The systematic control and adjustment method for the full-field discreteness of the core-dominated diode magnet, preferably, involves opening an air passivation groove at the pole end after the core is assembled, as follows: An air passivation groove is created inside the pole head to change the path of the magnetic field lines and the degree of local saturation inside the pole head, thereby adjusting the magnitude of the integrated magnetic field under high field. At the same time, by combining the magnetic field discreteness measurement results and simulation calculations, the relationship between the size of the air passivation groove and the high field integrated magnetic field is established, thereby achieving precise adjustment of discreteness under high field.

[0012] The systematic control and adjustment method for the full-field dispersion of the core-dominated diode magnet, preferably, involves controlling the installation position of the coil to reduce high-field dispersion and optimize full-field consistency as follows: After the core assembly is completed, the integrated magnetic field under high field conditions is adjusted by combining the measured data of magnetic field discreteness and adjusting the position of the coil relative to the pole face in a secondary manner.

[0013] The systematic control and adjustment method for the full-field discreteness of the core-dominated diode magnet, preferably, involves optimizing the pairing of core groups to reduce the system-level magnetic field discreteness as follows: After the magnets are measured, the magnets are optimized and paired based on the measured data of the integrated magnetic field of each magnet. This minimizes the dispersion of the integrated field between magnets driven by the same power supply, thereby further reducing the magnetic field inconsistency of the entire system at the power supply level.

[0014] The present invention has the following advantages due to the adoption of the above technical solutions: 1. Abundant adjustment methods and strong applicability: In response to the magnetic field dispersion under medium and low field conditions, this invention provides a variety of optional adjustment methods, which can be flexibly applied to the control of magnet dispersion under different functional requirements and different processing technology, effectively making up for the shortcomings of the single adjustment path of traditional methods.

[0015] 2. Achieve precise control of discreteness across the entire field: This invention breaks through the limitations of traditional methods that can only adjust the discreteness of low- and medium-field or reference field. Through multi-dimensional and multi-stage collaborative control, it achieves system-level adjustment of the discreteness of the integral magnetic field across the entire working magnetic field range from low field to high field, significantly improving the magnetic field synchronization and consistency of the magnet during the full excitation process.

[0016] 3. The method of this invention can not only actively reduce magnetic field dispersion during the magnet processing stage, but also further adjust the existing dispersion deviation after processing. Unlike traditional single adjustment methods, this method takes into account the dispersion requirements under reference field conditions and can cover the entire magnetic field working range, realizing system-level optimization and control of magnetic field dispersion throughout the excitation process. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a magnet core provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the stacking of blocks provided in this embodiment of the present invention; Figure 3 This is a schematic diagram of the pairing of semi-core stacks provided in this embodiment of the present invention; Figure 4 This is a diagram showing the air passivation groove formed at the end of the electrode head in this embodiment of the invention; Figure 5 This is a coil position control diagram provided in this embodiment of the present invention; The attached figures are labeled as follows: 1-Upper core; 2-Lower core; 3-End beveling; 4-Adjusting screw; 5-Live pole; 6-Adding plate; 7-Stacked block; 8-Stacked block length; 9-Stacking mold; 10-Half core; 11-Matched stacked block; 12-Pole head; 13-Air passivation groove; 14-Coil. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," "third," "fourth," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0020] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "above," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure.

[0021] Traditional accelerator magnetic field dispersion control primarily relies on controlling the core length during magnet manufacturing. This method can effectively ensure magnetic field consistency under low to medium field conditions. However, as the excitation level increases, the core material gradually enters the saturation region, and factors such as differences in ferromagnetic material properties, deviations in the stacking coefficient, and mechanical errors during manufacturing and assembly significantly increase the impact on the dispersion of the integrated magnetic field. These influencing factors exhibit strong nonlinearity and coupling, and are difficult to compensate for precisely through subsequent methods. The adjustment process is irreversible, thus severely restricting the effective control of magnetic field dispersion under high field conditions.

[0022] Based on the aforementioned technical problems, this invention provides a systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet. This method addresses the practical need for more stringent magnetic field discreteness targets by proposing a systematic approach to adjusting the magnetic field discreteness of magnets, with the core as the dominant factor. This method aims to be applied throughout the entire magnet manufacturing process, providing guidance for the manufacturing process and, after manufacturing, incorporating magnetic field measurement results to specifically adjust and optimize the magnetic field discreteness. Ultimately, it achieves the goal of systematically reducing magnetic field discreteness and meeting the requirements of high-precision beam operation.

[0023] like Figure 1-5 As shown, to systematically reduce the integral magnetic field dispersion of a dipole magnet across its entire operating magnetic field range, this invention proposes a systematic control and adjustment method for the full-field dispersion of a core-dominated dipole magnet, based on five dimensions: core length, stacking coefficient, pole head structure, coil installation, and optimized pairing of magnet groups. The method includes the following steps: Step 1: Precisely control the core length to reduce magnetic field dispersion under medium and low field conditions. The effective length of the magnet is positively correlated with the core length, while the air gap of the magnet is negatively correlated with the magnetic field strength. Both factors jointly determine the integrated magnetic field characteristics under medium- and low-field conditions. With continuous advancements in manufacturing processes, the machining accuracy of the magnet air gap has been significantly improved, and its dispersion has nearly reached the limit of current manufacturing capabilities in influencing the integrated field deviation. Therefore, the effective length of the magnet is the primary factor affecting the integrated magnetic field characteristics under medium- and low-field conditions. This invention uses core length control as the core means to reduce dispersion under medium- and low-field conditions.

[0024] Core length control is divided into two categories: machining control and post-machining adjustment. Machining control: During the splicing of the half-cores (e.g., upper core 1 or lower core 2), the machining allowance of the half-core length is appropriately increased to reserve space for subsequent fine-tuning by skewing. During the skewing stage, the core length and machining tolerance are precisely controlled by a high-precision CNC machine tool to ensure that the initial machining accuracy meets the design requirements. After the magnet test is completed, based on the measured integral field data, magnets with excessive integral fields are subject to secondary skewing to further reduce the deviation.

[0025] Post-processing adjustment: Depending on whether the magnet has a live pole head 5, different adjustment methods are used. For magnets without a live pole head 5, the end magnetic screw (adjusting screw 4) is used for adjustment, and the integral magnetic field is adjusted by precisely controlling the screw's screw-in length. For magnets with a live pole head 5, a lamination method is used. By using the movable pole head and fixed fixture, laminations are added or removed to achieve fine adjustment of the integral magnetic field. In addition, for sector magnets, since the arc length of the iron core varies at different radii, the effective length can be changed by adjusting the position of the magnet's central arc, thereby achieving adjustment of the dispersion of the low and medium fields.

[0026] Step 2: Control the superposition factor to reduce the magnetic field dispersion under high field conditions. Due to the saturation effect of ferromagnetic materials, the superposition factor significantly alters the magnetic permeability of the core material under high-field conditions, thereby increasing the dispersion of the integrated magnetic field. To address this, this invention establishes a quantitative relationship between the superposition factor and the high-field integrated magnetic field (through simulation calculations using Opera or ANSYS software), and implements a hierarchical control strategy during magnet manufacturing to effectively manage the superposition factor tolerance and achieve system-level adjustment of dispersion under high-field conditions. The first step is to control the stacking coefficient of a single stack 7: In the stacking stage of stack 7, the stack length 8, the number of stampings and the weight of stack 7 are strictly controlled by the stacking die to ensure that the stacking coefficient of each stack 7 meets the set tolerance range, thereby reducing the discrete basis from the source. The second step is to optimize the pairing of stacked blocks 7: individual stacked blocks 7 with different stacking coefficients are reasonably paired and combined, and the degree of dispersion of stacking coefficients at the half-core (e.g., upper core 1 or lower core 2) level is further reduced through complementary matching. The third step is to pair the upper iron core 1 and the lower iron core 2: Based on the completion of the half iron core pairing, the upper iron core 1 and the lower iron core 2 are finally paired and optimized to further reduce the dispersion deviation caused by the difference in the stacking coefficient between the magnets.

[0027] Through the above-mentioned step-by-step control and pairing process, the dispersion of the superposition coefficient between magnets can be effectively reduced during the processing stage, thus providing a key guarantee for improving the consistency of the integrated magnetic field under high field conditions.

[0028] Step 3: An air passivation groove 13 is opened at the end of the electrode head to achieve discrete adjustment across the entire field. An air passivation groove 13 is created inside the pole head, which alters the path of the magnetic field lines and the degree of local saturation, thereby adjusting the magnitude of the integrated magnetic field under high field conditions. Simultaneously, by combining magnetic field discreteness measurement results with simulation calculations, the relationship between the size of the air passivation groove 13 and the high-field integrated magnetic field is established (the relationship is simulated using Opera or ANSYS software), thus achieving precise adjustment of discreteness under high field conditions. This method not only helps improve the overall discreteness index but can also be used in conjunction with a snap-fit ​​joint to reduce the difficulty and cost of secondary magnet trimming.

[0029] Step 4: Control the installation position of coil 14 to reduce high-field dispersion and optimize overall field consistency. The installation position of coil 14, especially the distance from its surface to the pole face, significantly affects the magnetic circuit saturation characteristics under high field conditions, and thus directly relates to the dispersion of the integrated magnetic field in the high field range. To reduce the dispersion deviation caused by installation position errors, the manufacturing precision and assembly positioning precision of coil 14 should be strictly controlled during the processing stage. Simultaneously, after the magnet assembly is completed, the relationship between the distance from the surface of coil 14 to the pole face and the high-field integrated magnetic field can be established by combining measured data of magnetic field dispersion with simulation calculations (the relationship can be simulated using Opera or ANSYS software). By adjusting the position of coil 14 relative to the pole face, the integrated magnetic field under high field conditions can be specifically adjusted. This method not only effectively improves the magnetic field dispersion under high field conditions but also helps to improve the consistency of the integrated magnetic field across the entire working magnetic field range.

[0030] Step 5: Optimize magnet grouping and pairing to reduce system-level magnetic field dispersion. Synchrotrons typically use multiple power supplies, each driving several dipole magnets simultaneously. After the magnets are measured, the magnets are optimized and paired based on the measured integrated magnetic field data of each magnet. This minimizes the dispersion of the integrated field between magnets driven by the same power supply, thereby further reducing the magnetic field inconsistency of the entire system at the power supply level.

[0031] The systematic control and adjustment method for the full-field dispersion of core-dominated dipole magnets provided in this invention addresses the practical need for more stringent magnetic field dispersion targets. It proposes a comprehensive method for adjusting magnetic field dispersion with the core as the dominant factor. This method aims to be applied throughout the entire magnet manufacturing process. It can guide the manufacturing process during manufacturing and, after manufacturing, combine magnetic field measurement results to perform targeted adjustment and optimization of magnetic field dispersion, ultimately achieving the goal of systematically reducing magnetic field dispersion and meeting the requirements of high-precision beam operation. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet, characterized in that, Includes the following parallel steps: The core length is controlled during the core splicing process and adjusted after the core is processed. Control the stacking coefficient of the stack (7) and the iron core to reduce the magnetic field dispersion under high field; An air passivation groove (13) is opened at the end of the pole head after the iron core is assembled in order to achieve full-field discrete adjustment; Control the installation position of the coil (14) to reduce high-field dispersion and optimize overall field consistency; By optimizing the pairing of iron core groups, the system-level magnetic field dispersion is reduced.

2. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of controlling the length of the iron core during the splicing of the iron core is as follows: During the splicing of the half-core, the machining allowance of the core length is increased to reserve space for subsequent skew fine adjustment. During the skew machining stage, the core length and machining tolerance are precisely controlled by a high-precision CNC machine tool to ensure that the initial machining accuracy meets the design requirements. After the magnet test is completed, the magnet with a large integral field is skewed a second time according to the measured integral field data to further reduce the deviation.

3. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of adjusting the length of the iron core after machining is as follows: Depending on whether the magnet has a live pole (5), different adjustment methods are used: for magnets without the live pole (5), the end magnetic screw is used for adjustment, and the integral magnetic field is adjusted by controlling the screw screw insertion length; for magnets with the live pole (5), the method of adding or subtracting laminations is used, and the laminations are added or removed by means of the live pole and the fixed fixture, so as to achieve fine adjustment of the integral magnetic field; for sector magnets, the effective length is changed by adjusting the position of the central arc of the sector magnet, so as to achieve adjustment of the dispersion of the medium and low field.

4. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of controlling the stacking coefficient of the stack (7) and the iron core to reduce the magnetic field dispersion under high field is as follows: In the pressing stage of the stack (7), the stack length (8), the number of punches and the weight of the stack (7) are strictly controlled by the stacking die to ensure that the stacking coefficient of each stack (7) meets the set tolerance range. Individual stacks (7) with different stacking coefficients are reasonably paired and combined to further reduce the dispersion of stacking coefficients at the semi-core level through complementary matching; Based on the completion of the half-core pairing, the upper core (1) and lower core (2) are finally paired and optimized to further reduce the discrete deviation caused by the difference in the stacking coefficient between the magnets.

5. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of opening an air passivation groove (13) at the end of the pole head after the iron core is assembled to achieve full-field discreteness adjustment is as follows: An air passivation groove (13) is opened inside the pole head to change the magnetic field line path and local saturation degree inside the pole head, thereby adjusting the magnitude of the integrated magnetic field under high field. At the same time, the relationship between the size of the air passivation groove (13) and the integrated magnetic field under high field is established by combining the magnetic field discreteness measurement results and simulation calculations, thereby realizing the precise adjustment of discreteness under high field.

6. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of controlling the installation position of the control coil (14), reducing high-field dispersion, and optimizing overall field consistency is as follows: After the iron core is assembled, the position of the coil (14) relative to the pole face is adjusted twice by combining the measured data of magnetic field discreteness to make targeted adjustments to the integral magnetic field under high field.

7. The systematic control and adjustment method for the full-field discreteness of a core-dominated dipole magnet according to claim 1, characterized in that, The process of optimizing the pairing of iron core groups to reduce system-level magnetic field dispersion is as follows: After the magnets are measured, the magnets are optimized and paired based on the measured data of the integrated magnetic field of each magnet. This minimizes the dispersion of the integrated field between magnets driven by the same power supply, thereby further reducing the magnetic field inconsistency of the entire system at the power supply level.

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