A resonance extraction system based on energy regulation

Abstract

The present invention relates to a resonance extraction system based on energy regulation, comprising: a plurality of beam deflection units and a plurality of straight segments, wherein the plurality of beam deflection units are arranged in a ring at intervals and connected end to end in sequence through a vacuum tube, for deflecting the beam; a plurality of straight segments are sequentially formed between the plurality of beam deflection units, for focusing, injecting, accelerating and extracting the beam; wherein an extraction cutting magnet is arranged on the straight segment for beam extraction, an extraction electrostatic deflection plate or a kicking track magnet is arranged on the straight segment adjacent to the upstream of the straight segment for extracting the beam along the beam direction, and a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged downstream of the extraction electrostatic deflection plate or the kicking track magnet. The system has the characteristics of short length of the electrostatic deflection plate, low loading voltage, safe and reliable operation, sufficient space for the thickness of the cutting magnet plate, small number, simple design, and small space occupation, and can greatly shorten the circumference of the synchrotron accelerator.

Description

Technical Field

[0001] The invention relates to a resonance extraction system based on energy regulation, belonging to the technical field of accelerators. Background Art

[0002] The slow extraction beam of synchrotron accelerator is widely used in aerospace, materials, medicine, agriculture, biology and other fields. For example, it can be used to carry out single particle effect irradiation research on aerospace electronic components, especially electronic device complete machines; study the laws of irradiation effects of particles in organisms and semiconductor materials; it can be used in the production of nuclear pore membranes and particle cancer treatment, which is of great significance to promoting the development of relevant social and economic fields in my country.

[0003] At present, the common slow extraction system of synchrotron uses nonlinear magnetic field to excite resonant particles to move along the boundary track. The extraction beam enters the electrostatic deflection plate, and the extraction beam is deflected by loading a high voltage of hundreds of kilovolts, so that a certain separation height is generated at the entrance of the cutting magnet for the extraction beam and the circulating beam. Due to the limitations of the tip discharge sparking and the processing technology level, the effective length of the electrostatic deflection plate is usually ≤1.5m, and the gradient field is ≤100kV / cm. The kick angle that the electrostatic deflection plate can provide within the limited length is certain, so the separation height is very limited. Usually, the separation height needs to be placed: beam envelope under acceptance + closed track volume + extraction beam vacuum pipeline + extraction cutting magnet wire gauge + cutting magnet leakage field shielding layer + cutting magnet wire gauge and shielding laminate, etc. To extract a high-energy beam, the cutting magnet needs a larger wire gauge and a thicker shielding layer, which leads to an increase in the separation height. The length and number of the electrostatic deflection plate can only be increased, which increases the processing difficulty and longitudinal space occupied by the electrostatic deflection plate. At the same time, the electrostatic deflection plate will operate at a higher voltage, and the safety risk is extremely high. Due to the limitation of the pre-separation height, the first cutting magnet generates a low magnetic field due to leakage field and other reasons, and the deflection capacity is limited. The second, third or even more cutting magnets are needed to achieve the complete separation of the extraction beam from the synchrotron, which leads to a large number of cutting irons, a large longitudinal space occupation, and a high difficulty in the design of the extraction system. Therefore, since the electrostatic deflection plate and the cutting magnet, the core extraction components, need to occupy a large longitudinal space, especially for high-energy beam extraction, this limits the shortening of the synchrotron circumference, resulting in a large device footprint and high cost, which is not conducive to the miniaturization and promotion of synchrotron devices. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a resonant extraction system based on energy regulation. After the extracted beam of the resonant extraction system enters the electrostatic deflection plate, it is subjected to the electric field and hits the degrader. The electrostatic deflection plate only needs to generate a separation height of: beam envelope under acceptance + closed track amount at the degrader, without considering the required height of "extracted beam vacuum pipeline + extraction cutting magnet wire gauge + cutting magnet leakage field shielding layer + cutting magnet wire gauge and shielding laminate", which can greatly reduce the length and voltage of the electrostatic deflection plate, and the operation is safe and reliable.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A resonance extraction system based on energy regulation, comprising:

[0007] A plurality of beam deflection units and a plurality of straight line segments, wherein the plurality of beam deflection units are arranged in a ring at intervals and connected end to end in sequence through vacuum tubes, for deflecting the beam;

[0008] A plurality of straight line segments are sequentially formed between the plurality of beam deflection units and are used for focusing, injecting, accelerating and extracting the beam;

[0009] Wherein, an extraction cutting magnet is arranged on the straight line segment of the extraction beam, an extraction electrostatic deflection plate or a kicking track magnet is arranged on the straight line segment adjacent to the upstream of the extraction beam along the beam direction, and a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged downstream of the extraction electrostatic deflection plate or the kicking track magnet, or;

[0010] The straight line segment for beam extraction is provided with an extraction cutting magnet, and the straight line segment adjacent to the upstream of the straight line segment for extracting the beam along the beam direction is provided with a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam, or;

[0011] An extraction electrostatic deflection plate or a kicker magnet is arranged on the straight line segment upstream of the extraction beam along the beam direction, and a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged downstream of the extraction electrostatic deflection plate or the kicker magnet, or;

[0012] A pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged on the straight line segment upstream of the straight line segment for extracting the beam along the beam direction.

[0013] In the resonance extraction system, preferably, the energy degrader is a wedge-shaped block, and during the beam extraction process, the movement directions of the two wedge-shaped blocks are opposite to each other, so as to realize continuous adjustment of the beam energy.

[0014] In the resonant extraction system, preferably, after the beam is de-energized by the de-energizer, the separation height generated at the outlet is Δx, and the calculation formula is as follows:

[0015] Δx=D x ×ΔP / P1

[0016] Where D x is the dispersion function of the dipole magnet; ΔP is the momentum deviation of the beam before and after passing through the degrader; P1 is the momentum of the beam before passing through the degrader.

[0017] The resonance extraction system, preferably, adjusts Δx in a wide range by adjusting ΔP / P1 to meet the thickness requirement of the cutting plate for extracting the cut iron.

[0018] The resonant extraction system preferably adjusts the position and angle of the extraction beam hitting the energy degrader by adjusting the kick angle of the extraction electrostatic deflection plate, thereby adjusting the position and angle of the extraction beam hitting the inlet of the extraction cutting magnet.

[0019] In the resonance extraction system, preferably, the number of the beam deflection units and the number of the straight line segments are both eight, namely the first to eighth beam deflection units and the first to eighth straight line segments;

[0020] wherein the energy degrader and the lead-out electrostatic deflection plate or kick rail magnet are arranged in the first straight line segment, and the lead-out cutting magnet is arranged in the second straight line segment, or;

[0021] The energy degrader is arranged in the first straight line segment, and the lead-out cutting magnet is arranged in the second straight line segment, or;

[0022] The energy degrader and the lead-out electrostatic deflection plate or the kicker magnet are arranged in the first straight line segment, or;

[0023] The energy degrader is arranged in the first straight line segment.

[0024] In the resonance extraction system, preferably, a high-frequency acceleration cavity is provided on the eighth straight line segment for accelerating the beam.

[0025] In the resonance extraction system, preferably, a DCCT is provided on the fifth straight line segment for detecting direct current intensity.

[0026] In the resonance extraction system, preferably, a sextupole magnet is disposed on each of the fourth straight line segment and the eighth straight line segment.

[0027] The resonance extraction system, preferably, the second straight line segment,

[0028] Two quadrupole magnets are arranged on the fourth straight line segment, the sixth straight line segment and the eighth straight line segment.

[0029] The present invention adopts the above technical solution, which has the following advantages:

[0030] 1. The resonant extraction system involved in the present invention is provided with an energy degrader downstream of the electrostatic deflection plate. After the resonant extraction beam enters the electrostatic deflection plate, it is subjected to the electric field and hits the energy degrader. The electrostatic deflection plate only needs to generate a separation height of: beam envelope under acceptance + closed track amount at the energy degrader, without considering the required height of "extraction beam vacuum pipeline + extraction cutting magnet wire gauge + cutting magnet leakage field shielding layer + cutting magnet wire gauge and shielding laminate", which can greatly reduce the length and voltage of the electrostatic deflection plate, and the operation is safe and reliable. The short length of the electrostatic deflection plate means that the longitudinal space occupied is small, which can significantly reduce the circumference of the synchrotron accelerator.

[0031] 2. The energy degrader of the present invention adopts a double wedge block solution, which can achieve the same thickness of the beam penetrating the wedge block at the same extraction energy, compensate for the thickness deviation of the single wedge block, and the angular divergence of the extracted beam using the double wedge blocks is relatively small, the beam quality is better, and the extraction efficiency is higher. At the same time, the energy of the extracted beam can be continuously adjusted by dynamically adjusting the thickness of the wedge block, and the extracted beams of different energies are extracted according to the same designed track, which reduces the design difficulty of the extraction system and subsequent beam lines.

[0032] 3. The resonance extraction system of the present invention has the characteristics of short electrostatic deflection plate length, low loading voltage, safe and reliable operation, sufficient space for cutting magnet plate thickness, small number, simple design, and small space occupation. It can greatly shorten the circumference of the synchrotron accelerator and is of great significance to ion synchrotron accelerators used in cancer treatment, biological and material irradiation, aerospace and industrial irradiation and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A layout diagram of a resonance extraction system based on energy regulation provided in one embodiment of the present invention;

[0034] Figure 2 is the phase space distribution diagram at the entrance of the electrostatic deflection plate or the kicker magnet;

[0035] Figure 3 This is the relative position diagram of two perpendicular wedge blocks when the lowest energy is induced;

[0036] Figure 4 This is the relative position diagram of two vertical wedge blocks when the highest energy is drawn out;

[0037] The marks in the figure are as follows:

[0038] 1-1~1-8 are dipole magnets; 2-1~2-8 are quadrupole magnets; 3-1~3-2 are sextupole magnets; 4-DCCT; 5-high-frequency acceleration cavity; 6-extraction electrostatic deflection plate; 7-extraction cutting magnet; 8-1~8-2 are wedge blocks; 9-circulation beam center track; 10-extraction beam center track;

[0039] Figure 3 The meanings of the numbers are as follows: 1: the minimum safe distance between the two wedge blocks moving in the vertical direction; 2: 1 / 2 of the total thickness of the wedge blocks to be penetrated when the energy is the lowest; 3: 1 / 2 of the total thickness of the wedge blocks to be penetrated when the energy is the highest; 4: the vertical size of the wedge blocks when the energy is the lowest; 5: the vertical size of the wedge blocks when the energy is the highest; 6: the first wedge block moves vertically upward; 7: the second wedge block moves vertically downward; 8: the position where the extraction beam hits the energy degrader;

[0040] Figure 4 The meanings of the numbers are as follows: 1: the minimum safe distance for the two wedges to move vertically; 2: 1 / 2 of the total thickness of the wedges to be penetrated when the energy is lowest; 3: 1 / 2 of the total thickness of the wedges to be penetrated when the energy is highest; 4: the vertical size of the wedges when the energy is lowest; 5: the vertical size of the wedges when the energy is highest; 6: the first wedge moves vertically downward; 7: the second wedge moves vertically upward; 8: the position where the extraction beam hits the energy degrader. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work are within the scope of protection of the present invention.

[0042] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0043] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outer side", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0044] At present, the slow extraction system of the synchrotron accelerator generates resonant ion jumps to the high-voltage electrostatic deflection plate. Under the deflection of the high electric field, the extraction beam and the circulating beam have a certain separation height at the entrance of the cutting magnet, and are completely extracted from the synchrotron accelerator under the joint deflection of the magnetic field of multiple cutting magnets. However, since the gradient field of the electrostatic deflection plate is usually <100kV / cm, the magnetic field of multiple extraction cutting magnets gradually increases in sequence. To extract high-energy ions, the only way is to continuously increase the length of the electrostatic deflection plate and the extraction cutting magnet, which will lead to a significant increase in the circumference of the synchrotron accelerator.

[0045] In view of the above problems, the present invention proposes to adopt a resonance extraction system based on energy regulation. After the resonance extraction beam enters the electrostatic deflection plate, it is subjected to a small electric field deflection force and hits the energy degrader. The extraction beam and the circulating beam have different deflection radii in the dipole magnet due to different energies. The extraction beam will be deflected inward, and the circulating beam will run along the designed track. A sufficient separation height is generated at the exit of the dipole magnet for placing a cutting plate of the cutting magnet, which can give full play to the deflection effect of the cutting magnet and realize the complete separation of the extraction beam from the synchronization ring.

[0046] like Figure 1 As shown, the resonance extraction system based on energy regulation involved in the present invention includes: first to eighth beam deflection units (i.e., dipole magnets 1-1 to 1-8, the number of beam deflection units is only taken as an example and is not limited thereto), which are arranged in a ring at intervals and connected end to end in sequence through vacuum tubes for deflecting the beam; first to eighth straight line segments are formed between the first to eighth beam deflection units in sequence for focusing, injecting, accelerating and extracting the beam.

[0047] In a preferred embodiment of the present invention, an extraction electrostatic deflection plate 6 and an energy degrader (i.e., wedge blocks 8-1~8-2) are provided in the first straight segment. The extraction electrostatic deflection plate 6 utilizes the generated electric field to extract the beam and generates a pre-separation height at the energy degrader. The extraction electrostatic deflection plate 6 can also be a kicker magnet, which utilizes the generated magnetic field to act on the extraction beam and generates a pre-separation height at the energy degrader to cut and separate the extracted ions from the circulating beam. The second straight segment is provided with an extraction cutting magnet 7 for extracting the ions cut and separated by the extraction electrostatic deflection plate 6 from the accelerator. The fifth straight segment is provided with a DCCT (direct current intensity detector) for direct current intensity detection. The eighth straight segment is provided with a high-frequency acceleration cavity 5 for accelerating the beam.

[0048] The present invention can significantly reduce the length and voltage of the electrostatic deflection plate 6 by adding an energy reducer in the resonance extraction system, and the operation is safe and reliable. Figure 2 As shown, the nonlinear sextupole magnets 3-1~3-2 are used to excite the third-order resonance, so that the resonant particles jump to the extraction electrostatic deflection plate 6. The pre-separation height of the electric field generated by the extraction electrostatic deflection plate 6 at the energy degrader is: the beam envelope under the acceptance degree + the closed track amount (the separation height of the conventional device is "extraction beam vacuum pipeline + extraction cutting magnet wire gauge + cutting magnet leakage field shielding layer + cutting magnet wire gauge and shielding laminate", etc.), so that the extraction beam entering the extraction electrostatic deflection plate 6 can hit the energy degrader. Due to the small pre-separation height, the required kick angle of the extraction electrostatic deflection plate 6 is small, which can greatly reduce the length and voltage of the extraction electrostatic deflection plate 6.

[0049] In some specific examples, the resonant extraction system of the present invention can also remove the extraction electrostatic deflection plate 6, and use the nonlinear sextupole magnets 3-1~3-2 to excite the third-order resonance, so that the resonant particles directly hit the resonant extraction beam on the energy degrader (removing the extraction electrostatic deflection plate 6, only the resonant extraction system of the energy degrader), and the subsequent track design scheme is similar to the above situation (including the extraction electrostatic deflection plate 6+resonant extraction system of the energy degrader). However, compared with situation 2 (removing the extraction electrostatic deflection plate 6, only the resonant extraction system of the energy degrader), situation 1 (including the extraction electrostatic deflection plate 6+resonant extraction system of the energy degrader) can change the position and angle of the extraction beam hitting the energy degrader by appropriately adjusting the kick angle of the extraction electrostatic deflection plate 6, thereby adjusting the position and angle of the beam hitting the entrance of the extraction cutting magnet 7, making it easier to achieve efficient beam extraction, and the extraction system is more flexible to adjust, and the redundancy is higher.

[0050] Further, for ease of understanding, the present invention takes the energy of the circulating beam as E k1 For example, the corresponding momentum is P1, and the energy of the extracted beam after passing through the degrader is E k2, the corresponding momentum is P2, and the resulting momentum deviation is ΔP / P1=(P2-P1) / P1<0, E k2 <E k1 When the circulating beam passes through the downstream dipole magnets 1-1 to 1-8, it will move along the equilibrium orbit. The outgoing beam will be biased by the negative momentum and the dispersion function D in the dipole magnets 1-1 to 1-8. x , the extraction beam will move inwards in the ring in the dipole magnets 1-1~1-8 (such as Figure 1 As shown in the figure), the separation height generated inward at the outlet is Δx. Among them, Δx is approximately equal to Δx=D x ×ΔP / P1. After the lattice structure of the ring is designed (Chinese patent 202211331886.9, a compact multi-ion synchrotron), the dispersion function D in the dipole magnets 1-1~1-8 x Yes, Δx can be adjusted in a wide range by adjusting ΔP / P1 to meet the cutting plate thickness requirement of the cutting magnet 7.

[0051] By adjusting the momentum deviation ΔP / P1, the cutting plate thickness requirement of the first extraction cutting magnet 7 with a high magnetic field can be met, reducing the design difficulty of the extraction cutting magnet 7 and its power supply. At the same time, the deflection capacity of the extraction cutting magnet 7 can be fully utilized, the number of extraction cutting magnets 7 can be reduced, and the longitudinal space occupied by the extraction cutting magnets 7 can be reduced. If the extraction energy is low, the beam extraction can be achieved without the extraction cutting magnet 7.

[0052] Since the separation height Δx can be flexibly adjusted, the shielding space requirement for the high magnetic field of the first extraction cutting magnet 7 can be met, making the structural design of the extraction cutting magnet 7 simple, and at the same time, the deflection ability of the extraction cutting magnet 7 can be fully utilized, thereby reducing the number of extraction cutting magnets 7 and reducing the longitudinal space occupied by the extraction cutting magnets 7. If the extraction energy is low, the deflection effect of the extraction cutting magnet 7 is not required, and the extraction beam is completely separated from the accelerator under the direct action of the magnetic field of the extraction channel of the dipole magnets 1-1 to 1-8.

[0053] When Δx is determined, ΔP / P1 is also determined, that is, the extraction trajectory of the extraction beam in the dipole magnets 1-1 to 1-8 is determined. At this time, the kinetic energy change of the extraction beam is ΔE k =(γ+1) / γ×E k1 ×ΔP / P1, where γ is the Lorentz factor, γ=1+E k1 / E k0 , E k0 is the static energy of the particle. k0 The beam current produces a kinetic energy change ΔE kThis means that the thickness of the energy degrader corresponding to beams of different extraction energies is different. Therefore, in order to achieve the same extraction trajectory for different energies after passing through the energy degrader, the thickness of the energy degrader needs to be dynamically adjusted.

[0054] In order to achieve continuous adjustment of the extracted beam, the present invention designs a pair of wedge blocks 8-1~8-2 of the same size and thickness, which are installed on a surface perpendicular to the beam direction. The pair of wedge blocks 8-1~8-2 are distributed in a mirror image along the vertical axis (the vertical axis of the circulating beam center track 9), are parallel to each other, and move in opposite directions. When the extracted beam energy is the lowest, the thickness of the energy degrader required to penetrate is the smallest. Since the emittance in the vertical axis direction is the largest, the required vertical dimension is large, such as Figure 3 As shown. As the energy increases, the two wedge blocks 8-1 ~ 8-2 move toward each other. When the energy of the extracted beam is the highest, the thickness of the energy degrader required to penetrate is the largest, and because the emittance in the vertical axis direction is the smallest at this time, the required vertical dimension is the smallest, as shown in FIG. Figure 4 The thickness of the energy degrader required for the kinetic energy change ΔEk of the extracted beam with different energies is the sum of the longitudinal thicknesses of the two wedge-shaped blocks 8-1 to 8-2. Since the thickness combination of the two wedge-shaped blocks 8-1 to 8-2 can cover the kinetic energy change ΔE corresponding to all the extracted energies, k range, so the extracted beam current can be continuously adjusted.

[0055] The present invention uses two wedge blocks, which has the following advantages: first, if one wedge block is used, the thickness of the wedge block penetrated by the beam of the same energy will deviate, resulting in an increase in the angular divergence of the extracted beam, poor beam quality, and easy beam loss. However, the use of two wedge blocks 8-1 to 8-2 can achieve the same thickness of the wedge block penetrated by the beam at the same extraction energy, compensating for the thickness deviation of one wedge block, and the angular divergence of the extracted beam is relatively small, the beam quality is better, and the extraction efficiency is higher.

[0056] The present invention adopts the scheme of double wedge blocks 8-1~8-2, so that the beam penetrating the same thickness of the wedge blocks 8-1~8-2 under the same extraction energy can be achieved, and the thickness deviation existing in the use of one wedge block can be compensated. The angular divergence of the extracted beam using the double wedge blocks 8-1~8-2 is relatively small, the beam quality is better, and the extraction efficiency is higher. At the same time, by dynamically adjusting the thickness of the wedge blocks 8-1~8-2 (the two wedge blocks 8-1~8-2 move toward each other), the energy of the extracted beam can be continuously adjusted, and the extracted beams of different energies are extracted according to the same designed track, which reduces the design difficulty of the extraction system and subsequent beam lines.

[0057] For ease of understanding, the present invention provides a specific example to extract C with an energy of 80-400 MeV / u. 6+For example, when the required momentum deviation is -3.7% and the energy degrader is a carbon wedge block, the total thickness of the required penetrating wedge block ranges from about 300 to 5000 microns, the required length of the lead-out electrostatic deflection plate 6 can be reduced to 1 / 3-1 / 4 of the original, the number of lead-out cutting magnets 7 is reduced from 3 to 4 to 1, and the required longitudinal length can be reduced to 1 / 3 of the original.

[0058] In some specific examples, further, the first to eighth beam deflection units 1-1~1-8 are two-pole magnets, which are used to change the direction of the beam so that the beam's motion trajectory in the accelerator forms a closed circle. Two quadrupole magnets 2-1~2-8 are arranged on the second straight line segment, the fourth straight line segment, the sixth straight line segment and the eighth straight line segment. A sextupole magnet 3-1~3-2 is arranged on the fourth straight line segment and the eighth straight line segment.

[0059] Sextuple magnets 3-1~3-2 are the core components of the third-order resonant slow extraction. During the slow extraction process, the horizontal operating point of the accelerator is adjusted to the vicinity of the 1 / 3 resonance line. Under the action of the resonant sextuple magnets 3-1 and 3-2, the phase space is divided into a stable region and an unstable region. The beam is stored in the stable region in the initial stage. Under the action of RF-KO (Radio Frequency Knockout), the beam amplitude gradually increases and enters the unstable region. Due to the nonlinear action of the resonant sextuple magnets 3-1 and 3-2, the ions entering the unstable region rapidly increase in amplitude along the boundary orbit direction, and then enter the extraction electrostatic deflection plate 6 to be extracted. The nonlinear sextuple magnet excitation third-order resonant slow extraction method not only improves the extracted beam quality, but also the larger pitch makes the extraction efficiency higher.

[0060] The position and strength of the magnet elements in the accelerator determine the optical structure of the synchronization ring. The movement of ions in the synchronization ring is similar to that of light, with characteristics such as rectilinear propagation, focusing, and defocusing. The effect of the quadrupole magnets 2-1 to 2-8 on the beam is similar to that of a convex lens and a concave lens, so the movement of the beam in the synchrotron is also called beam optics. The main magnet elements that determine the optics in the accelerator are the dipole magnets 1-1~1-8 and the quadrupole magnets 2-1~2-8. The role of the dipole magnets 1-1~1-8 is to change the direction of the beam so that the beam's trajectory in the accelerator forms a closed circle. The role of the quadrupole magnets 2-1~2-8 is to focus and defocus the beam. The difference from the optical lens is that the quadrupole magnets 2-1~2-8 focus the beam in the horizontal direction while defocusing it in the vertical direction, and focus the vertical direction while defocusing it in the horizontal direction. An important part of the optical design is to reasonably set the position and strength of the quadrupole magnets 2-1~2-8 so that both the horizontal and vertical directions can be stably periodically focused and defocused without uncontrollable divergence. There is a complete theoretical system for designing beam optics, which can theoretically obtain the focusing and defocusing conditions for stable beam transmission to guide the optical design. In the actual design process, software such as MADX and Winagile are usually used to calculate and optimize the optical parameters.

[0061] By adopting the resonant extraction system based on energy regulation proposed by the present invention, after the resonant extraction beam enters the extraction electrostatic deflection plate 6, it is subjected to a small electric field deflection force and hits the energy degrader. Due to the different energies, the extraction beam and the circulating beam have different deflection radii in the dipole magnets 1-1 to 1-8. The extraction beam will be deflected inwardly of the ring, while the circulating beam will run along the designed track. A sufficient separation height is generated at the exit of the dipole magnet 1-1 for placing the cutting plate of the extraction cutting magnet 7, which can give full play to the deflection effect of the extraction cutting magnet 7 and realize the complete separation of the extraction beam from the synchronization ring. The separation height generated at the entrance of the extraction cutting magnet 7 is determined by the required energy reduction, that is, the thickness of the energy degrader. The designed resonant extraction system of the present invention has the characteristics of short extraction electrostatic deflection plate 6, low loading voltage, safe and reliable operation, sufficient space for the thickness of the cutting plate of the extraction cutting magnet 7, small number, simple design, and small space occupation, which can greatly shorten the circumference of the accelerator and has important significance for accelerators used in the fields of cancer treatment, biological and material irradiation, aerospace and industrial irradiation.

[0062] The accelerator in the present invention can be a synchrotron, or a FFAG or any other type of accelerator. The accelerator can adopt a room temperature or superconducting solution, and can be extracted horizontally or vertically. The separation can be achieved by one dipole magnet or multiple dipole magnets, and the resonance extraction system of the present invention can be used.

[0063] 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 resonance extraction system based on energy regulation, characterized in that: include: A plurality of beam deflection units and a plurality of straight line segments, wherein the plurality of beam deflection units are arranged in a ring at intervals and connected end to end in sequence through vacuum tubes, for deflecting the beam; A plurality of straight line segments are sequentially formed between the plurality of beam deflection units and are used for focusing, injecting, accelerating and extracting the beam; Wherein, an extraction cutting magnet is arranged on the straight line segment of the extraction beam, an extraction electrostatic deflection plate or a kicking track magnet is arranged on the straight line segment adjacent to the upstream of the extraction beam along the beam direction, and a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged downstream of the extraction electrostatic deflection plate or the kicking track magnet, or; The straight line segment for beam extraction is provided with an extraction cutting magnet, and the straight line segment adjacent to the upstream of the straight line segment for extracting the beam along the beam direction is provided with a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam, or; An extraction electrostatic deflection plate or a kicker magnet is arranged on the straight line segment upstream of the extraction beam along the beam direction, and a pair of energy degraders distributed in a mirror image along the vertical axis of the central track of the circulating beam are arranged downstream of the extraction electrostatic deflection plate or the kicker magnet, or; A pair of energy degraders are arranged on the straight line segment upstream of the straight line segment for extracting the beam along the beam direction and are distributed in a mirror image along the vertical axis of the central track of the circulating beam; The energy degrader is a wedge-shaped block. During the beam extraction process, the movement directions of the two wedge-shaped blocks are opposite to each other, so as to realize continuous adjustment of the beam energy.

2. The resonance extraction system according to claim 1, characterized in that: After the beam is degraded by the degrader, the separation height generated at the exit is Δx, which is calculated as follows: Δx=D x ×ΔP / P1 Where D x is the dispersion function of the dipole magnet; ΔP is the momentum deviation of the beam before and after passing through the degrader; P1 is the momentum of the beam before passing through the degrader.

3. The resonance extraction system according to claim 2, characterized in that: By adjusting ΔP / P1, Δx can be adjusted in a wide range to meet the cutting plate thickness requirements of the lead-out cutting iron.

4. The resonance extraction system according to claim 1, characterized in that: By adjusting the kick angle of the extraction electrostatic deflection plate, the position and angle of the extraction beam hitting the energy degrader are changed, thereby adjusting the position and angle of the extraction beam hitting the inlet of the extraction cutting magnet.

5. The resonance extraction system according to claim 1, characterized in that: The number of the beam deflection units and the number of the straight line segments are both eight, namely the first to eighth beam deflection units and the first to eighth straight line segments.

6. The resonance extraction system according to claim 5, characterized in that: A high-frequency accelerating cavity is arranged on the eighth straight line segment for accelerating the beam.

7. The resonance extraction system according to claim 5, characterized in that: A DC current intensity detector is arranged on the fifth straight line segment for detecting the DC current intensity.

8. The resonance extraction system according to claim 5, characterized in that: A six-pole magnet is disposed on each of the fourth straight line segment and the eighth straight line segment.

9. The resonance extraction system according to claim 5, characterized in that: Two quadrupole magnets are arranged on the second straight line segment, the fourth straight line segment, the sixth straight line segment and the eighth straight line segment.

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