Accelerator device based on the principle of alternating phase focusing and control method thereof

Abstract

This invention relates to the field of particle accelerator technology, and in particular to an accelerator device and its control method based on the alternating phase focusing principle. The accelerator device includes: an ion source for generating an ion beam; a radio frequency quadrupole accelerator for pre-focusing and pre-accelerating the ion beam; a superconducting acceleration section for rapidly increasing the energy of the ion beam; and a high-energy transmission section connected to the superconducting acceleration section for guiding the ion beam to a terminal. A low-energy transmission line is provided between the ion source and the radio frequency quadrupole accelerator for adjusting the ion beam to match the radio frequency quadrupole accelerator. A medium-energy transmission section is provided between the radio frequency quadrupole accelerator and the superconducting acceleration section for adjusting the ion beam to match the superconducting acceleration section. The superconducting acceleration section includes several acceleration units with radio frequency cavities, wherein the phase and amplitude of the radio frequency cavity in each acceleration unit are independently adjustable, so that the lateral and longitudinal focusing and defocusing of the beam are continuously adjustable.

Description

Technical Field

[0001] This invention relates to the field of particle accelerator technology, and in particular to an accelerator device and its control method based on the principle of alternating phase focusing. Background Technology

[0002] In the field of particle accelerators, reducing accelerator complexity, the number of devices, and costs while ensuring lossless or low-loss beam transmission are core issues for their engineering applications. Superconducting linear accelerators have become a widely used type of accelerator in recent years; however, traditional beam focusing systems typically rely on a large number of lateral focusing elements, and these elements have significant limitations in terms of spatial arrangement and reliability. First, the magnets occupy a large space in the accelerator beamline, which not only reduces acceleration efficiency, but also increases the construction and maintenance costs due to the increased number of devices. Second, too many focusing elements and their supporting equipment will also bring additional reliability risks to the availability of the accelerator.

[0003] Alternating phase focusing (APF) is one of the technical directions to improve the above problems. This scheme has been proposed and applied in both room-temperature accelerators and electron accelerators, but both scenarios have significant limitations: For room-temperature accelerators, their spatial structure is continuous, and although the focusing and defocusing effects remain continuous, the magnetic focusing lattice parameters are coupled with the acceleration structure, resulting in the ability to transport only particles with a specific charge-to-mass ratio, and incompatibility with particles of other charge-to-mass ratios. This leads to problems of limited functionality and poor system flexibility. For electron accelerators, the beam space charge effect is weak, and the lateral defocusing effect is negligible.

[0004] Although superconducting linear accelerators have the advantages of independently adjustable horizontal and vertical components and flexible configuration of functions as needed, the space charge effect of superconducting linear accelerators cannot be ignored, making the experience of APF application unsuitable for superconducting linear accelerators. Summary of the Invention

[0005] This invention provides an accelerator device and its control method based on the principle of alternating phase focusing. By setting the phase and amplitude of the radio frequency cavity to be individually adjustable, and setting the phases of multiple radio frequency cavities to be longitudinal acceleration focusing phase and longitudinal acceleration diverging phase respectively, it can take into account both lateral and longitudinal focusing and longitudinal acceleration, thereby achieving the purpose of efficient lateral and longitudinal focusing of the beam without relying on lateral focusing elements, ensuring beam quality and reducing accelerator energy consumption.

[0006] In a first aspect, the present invention provides an accelerator device based on the principle of alternating phase focusing, comprising: An ion source, used to generate an ion beam; Radio frequency quadrupole accelerators are used for pre-focusing and pre-accelerating ion beams. The superconducting acceleration section is used to rapidly increase the energy of the ion beam. The high-energy transmission section, connected to the superconducting acceleration section, is used to guide the ion beam to the terminal. A low-energy transmission line is provided between the ion source and the radio frequency quadrupole accelerator to adjust the ion beam current to match the radio frequency quadrupole accelerator; a medium-energy transmission line is provided between the radio frequency quadrupole accelerator and the superconducting acceleration section to adjust the ion beam current to match the superconducting acceleration section. The superconducting acceleration section includes several acceleration units with radio frequency cavities. The phase and amplitude of the radio frequency cavity in each acceleration unit are independently adjustable so that the beam's lateral and longitudinal focusing and defocusing are continuously adjustable.

[0007] According to an accelerator device based on the alternating phase focusing principle provided by the present invention, the acceleration unit further includes: Radio frequency power source, used to provide radio frequency power; A coupler is used to couple high-frequency power to the radio frequency cavity; A tuner is used to adjust the frequency of the radio frequency cavity; The radio frequency power source is electrically connected to the radio frequency cavity through the coupler.

[0008] An accelerator device based on the alternating phase focusing principle provided by the present invention includes a radio frequency cavity comprising: The radio frequency input port is used to input radio frequency signals into the radio frequency cavity to generate an electromagnetic field; An amplitude and phase adjustment device is provided, one end of which is connected to the radio frequency power source and the other end of which is connected to the radio frequency cavity, for adjusting the phase and amplitude of the electromagnetic field.

[0009] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the low-energy transmission line comprises: A solenoid is used to guide the ion beam generated by the ion source to the radio frequency quadrupole accelerator. A beam transverse chopper is used to intercept an ion beam within a specific time period.

[0010] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the medium-energy transmission section includes: Quadrupole magnets are used to adjust the ion beam to achieve lateral focusing; A focusing cavity is used to adjust the ion beam to achieve longitudinal focusing.

[0011] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the high-energy transmission section includes: Quadrupole magnets are used to adjust the ion beam to achieve lateral focusing; Dipole magnets are used to change the direction of the ion beam to guide it to different terminals.

[0012] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the radio frequency cavity is made of pure niobium to ensure radio frequency performance and mechanical stability.

[0013] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the acceleration unit further includes a low-level control system for improving the response speed of phase adjustment.

[0014] According to the present invention, an accelerator device based on the alternating phase focusing principle is provided, wherein the acceleration unit includes a plurality of radio frequency cavities connected in series; Starting from one end, the phase of the two radio frequency cavities is first set to -40° to achieve longitudinal beam focusing; then the phase of the two radio frequency cavities is set to 15° to achieve lateral beam size constraint; then the phase of the remaining radio frequency cavities is adjusted sequentially according to the above rules. Alternatively, starting from one end, first set the phase of the two radio frequency cavities to -40° to achieve longitudinal beam focusing; then set the phase of the three radio frequency cavities to 15° to achieve lateral beam size constraint; and then adjust the phase of the remaining radio frequency cavities in sequence according to the above rules.

[0015] Secondly, the present invention also provides a control method for an accelerator device, applicable to any of the above-described accelerator devices based on the alternating phase focusing principle, the control method comprising: The phase and amplitude of the electromagnetic field in the radio frequency cavity are dynamically adjusted according to the real-time state of the ion beam.

[0016] The above-described one or more technical solutions of this invention have at least one of the following technical effects: The accelerator device of this invention employs a phase-reversal design for multiple radio frequency cavities and aims to maintain the "unchanged average beam envelope in both the transverse and longitudinal directions." By utilizing an optimization algorithm, it achieves transverse beam envelope oscillation under high-current conditions while simultaneously maintaining longitudinal beam stability. This approach significantly reduces the accelerator device's dependence on transverse focusing elements, directly reducing construction costs and operating power consumption, simplifying the overall structure, and ultimately ensuring long-term reliable operation.

[0017] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted by the present invention, and the advantages brought about by the technical features of these technical solutions as described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings, or will be learned through the practice of the present invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the layout of an accelerator device provided in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the layout of another accelerator device provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of a radio frequency cavity provided in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the radio frequency phase of each radio frequency cavity in the accelerator device provided in the embodiment of the present invention.

[0023] Figure 5 This is the beam transverse envelope diagram of the accelerator device provided in the embodiment of the present invention when the phase alternation scheme is adopted.

[0024] Figure 6 This is a comparison diagram of the energy of the ion beam propagating in the accelerator according to an embodiment of the present invention.

[0025] Figure label: 1. Ion source; 2. Low-energy transmission line; 3. Radio frequency quadrupole accelerator; 4. Medium-energy transmission section; 5. Superconducting acceleration section; 6. High-energy transmission section; 7. Terminal; 21. Radio frequency cavity; 22. Radio frequency input port; 23. Radio frequency power source; 24. Amplitude and phase adjustment device. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0027] Controlling the transverse quality of the beam is a key factor affecting the stable operation of an accelerator. Compared to a circular accelerator, a linear accelerator has a larger number of beam-related components, and due to its series structure, the failure of any component in the system will directly affect the normal operation of the entire accelerator, resulting in significantly lower fault tolerance.

[0028] In existing accelerators, the type and number of lateral focusing elements must be determined jointly based on beam energy, beam intensity, and beam dynamics simulation results guided by beam loss control. Since the lateral focusing elements are directly related to the lateral dimensions of the beam, failure of these elements will directly cause two major problems: first, the lateral dimensions of the beam will increase significantly; second, the lateral beam distribution will produce corona due to jumps in the focusing period and focusing force, ultimately increasing the probability of beam loss and becoming the core bottleneck restricting the stable operation of the accelerator.

[0029] Therefore, in order to reduce the adverse effects of lateral focusing element failure on the operation of linear accelerators, this invention designs an accelerator device that can laterally focus the ion beam based on the alternating phase focusing principle, thereby reducing the number of lateral focusing elements used. These are described in detail in the following embodiments.

[0030] like Figure 1 As shown, the accelerator device mainly includes an ion source 1, a low-energy transmission line 2, a radio frequency quadrupole accelerator 3, a medium-energy transmission section 4, a superconducting acceleration section 5, and a high-energy transmission section 6.

[0031] Ion source 1 is used to generate an ion beam. The beam current intensity is not less than 10 mA, and the energy is 20-50 keV.

[0032] The radio frequency quadrupole accelerator 3 is used for pre-focusing and pre-accelerating the ion beam. The frequency of the radio frequency quadrupole accelerator 3 is selected from 125 to 200 MHz. The cavity voltage is selected from 50 to 70 kV, the arcing coefficient is selected from 1 to 1.6, and the outlet energy is designed to be 1.5 to 3 MeV / u.

[0033] The superconducting acceleration section 5 is used to rapidly increase the energy of the ion beam. The high-energy transmission section 6 is connected to the superconducting acceleration section 5 and is used to guide the ion beam to the terminal 7.

[0034] A low-energy transmission line 2 is provided between the ion source 1 and the radio frequency quadrupole accelerator 3 to adjust the ion beam current to match the radio frequency quadrupole accelerator 3.

[0035] A medium-energy transmission section 4 is provided between the radio frequency quadrupole accelerator 3 and the superconducting acceleration section 5 to adjust the ion beam to match the superconducting acceleration section 5. Specifically, the medium-energy transmission section 4 can optimize the beam parameters of the ion beam. The main function of the medium-energy transmission section 4 is to meet the matching requirements of the beam extracted from the RFQ linear accelerator to the downstream main acceleration device, achieving high-efficiency transmission of the ion beam.

[0036] Specifically, the ion source 1, the low-energy transmission line 2, the radio frequency quadrupole accelerator 3, the medium-energy transmission section 4, the superconducting acceleration section 5, and the high-energy transmission section 6 are arranged in series sequentially.

[0037] The superconducting acceleration section 5 includes several acceleration units with radio frequency cavities 21. The phase and amplitude of the radio frequency cavity 21 in each acceleration unit are independently adjustable, so that the lateral and longitudinal focusing of the beam can be continuously adjusted. When the radio frequency cavities in the accelerator device are set according to the phase shown in Figure 4, the lateral dimension of the ion beam can be kept within ±2mm, thereby achieving the effect of lateral focusing of the beam without relying on lateral focusing elements.

[0038] in addition, Figure 6 The black lines represent the energy of the ion beam after being transmitted at different lengths in an accelerator using a phase-alternating scheme. The red lines represent the energy of the ion beam after being transmitted at different lengths in an accelerator using a conventional scheme. The comparison shows that the accelerator device in this application can achieve high-efficiency energy enhancement at shorter lengths.

[0039] Furthermore, the acceleration unit includes several radio frequency cavities 21 connected in series. By individually adjusting each radio frequency cavity 21, the radio frequency cavities 21 in the acceleration unit can accelerate the ion beam at different phases.

[0040] Specifically, starting from one end, the phase of the two radio frequency cavities 21 is first set to -40° to achieve longitudinal beam focusing; then the phase of the two radio frequency cavities 21 is set to 15° to achieve lateral beam size constraint; then the phase of the remaining radio frequency cavities 21 is adjusted in sequence according to the above rules.

[0041] Alternatively, starting from one end, first set the phase of the two radio frequency cavities 21 to -40° to achieve longitudinal beam focusing; then set the phase of the three radio frequency cavities 21 to 15° to achieve lateral beam size constraint; and then adjust the phase of the remaining radio frequency cavities 21 in sequence according to the above rules.

[0042] Furthermore, such as Figure 3 As shown, the radio frequency cavity 21 includes a radio frequency input port 22 and an amplitude and phase adjustment device 24.

[0043] The radio frequency input port 22 is used to input radio frequency signals into the radio frequency cavity 21 to generate an electromagnetic field.

[0044] One end of the amplitude and phase adjustment device 24 is connected to the radio frequency power source 23, and the other end of the amplitude and phase adjustment device 24 is connected to the radio frequency cavity 21, for adjusting the phase and amplitude of the electromagnetic field.

[0045] Furthermore, to improve acceleration efficiency, the phase of the RF cavity 21 is adjusted to a longitudinal acceleration focusing phase and a longitudinal acceleration diverging phase. This achieves both lateral and longitudinal focusing and longitudinal acceleration while reducing the longitudinal periodic phase shift parameter. Under the condition of satisfying the 90° periodic phase shift limit of beam dynamics, the cavity pressure is further increased, thereby improving acceleration efficiency. In addition, due to the reduction in the number of lateral focusing elements, the space ratio of the longitudinal acceleration elements can be increased, and the longitudinal acceleration efficiency can be further improved.

[0046] Furthermore, the radio frequency cavity 21 is made of pure niobium to ensure radio frequency performance and mechanical stability.

[0047] In this embodiment, by designing multiple radio frequency cavities 21 with phase reversal and aiming to maintain the "unchanged average beam envelope in both the transverse and longitudinal directions," an optimization algorithm is used to achieve transverse beam focusing and longitudinal beam convergence under high-current conditions. This effectively suppresses transverse beam envelope oscillation while maintaining longitudinal beam stability. This approach significantly reduces the accelerator's dependence on transverse focusing elements, directly reducing construction costs and operating power consumption, simplifying the overall structure of the accelerator, and ensuring long-term reliable operation.

[0048] Based on the above embodiments, another embodiment of the present invention introduces an accelerator device based on the principle of alternating phase focusing.

[0049] The acceleration unit mainly includes a radio frequency power source 23, a coupler, and a tuner.

[0050] The radio frequency power source 23 is used to provide radio frequency power. The coupler is used to couple high-frequency power to the radio frequency cavity 21. The tuner is used to adjust the frequency of the radio frequency cavity 21.

[0051] The radio frequency power source 23 is electrically connected to the radio frequency cavity 21 through the coupler.

[0052] Furthermore, the acceleration unit also includes a low-level control system. The low-level control system is used to improve the response speed of the radio frequency cavity 21 to phase adjustment, so as to achieve rapid phase adjustment of the radio frequency cavity 21 within milliseconds. Figure 5 The trajectory of the ion beam through the radio frequency cavity 21 is shown.

[0053] Furthermore, the low-energy transmission line 2 includes a solenoid and a beam lateral chopper.

[0054] A solenoid is used to guide the ion beam generated by the ion source 1 to the radio frequency quadrupole accelerator 3. A beam transverse chopper is used to intercept the ion beam within a specific time period. Specifically, the rise time of the beam transverse chopper does not exceed 20 ns, and the beam loss in the downstream accelerator is reduced by cutting off the leading and trailing "tails" of the ion beam.

[0055] Furthermore, the medium-energy transmission section 4 mainly includes a quadrupole magnet and a focusing cavity.

[0056] Quadrupole magnets are used to adjust the ion beam for lateral focusing. A focusing cavity is used to adjust the ion beam for longitudinal focusing.

[0057] Furthermore, the high-energy transmission segment 6 mainly includes a quadrupole magnet and a dipole magnet.

[0058] Quadrupole magnets are used to adjust the ion beam for lateral focusing. Dipole magnets are used to change the transmission direction of the ion beam to guide it to different terminals.

[0059] Preferably, the high-energy transmission section 6 includes multiple diode magnets and multiple quadrupole magnets. For example... Figure 2 As shown, a diode magnet is used to deflect the ion beam to multiple terminals 7. A quadrupole magnet enables the ion beam to be matched with multiple terminals 7, achieving high-efficiency beam transmission.

[0060] Furthermore, the present invention also provides a control method for an accelerator device, applicable to the accelerator device based on the alternating phase focusing principle described in any one of the above claims, the control method comprising: The phase and amplitude of the electromagnetic field in the radio frequency cavity 21 are dynamically adjusted according to the real-time state of the ion beam.

[0061] Specifically, feedforward prediction compensation technology is used for the RF cavity 21 to control the adjustment accuracy of the RF phase to the millisecond level, so as to meet the requirements for rapid adjustment of the operating parameters of the RF cavity 21 in the time-division acceleration scenario.

[0062] Furthermore, the accelerator device also includes a time synchronization system and a fast pulse magnet system. The fast pulse magnet system enables rapid changes in the magnetic field, and combined with rapid radio frequency phase adjustment technology, they work together to achieve longitudinal beam focusing acceleration and lateral focusing compensation for different types of particles, thereby ensuring stable beam transmission during time-division acceleration.

[0063] like Figure 2As shown, the accelerator device has multiple terminals 7 connected in parallel after the high-energy transmission section 6. Terminals 7 can be configured as target stations for isotope production. Here, the accelerator device uses the ion source 1 to generate an ion beam, which is then accelerated to increase its energy. Finally, relying on precise beam control and rapid switching technology at the experimental terminals 7, the valuable ion beam is divided into precise time units to achieve time-sharing beam supply to different target stations.

[0064] The accelerator device employs fast-pulse magnets and accelerator radio frequency phase adjustment, which can switch the focusing structure parameters of the accelerator within milliseconds to change the beam type, enabling a single accelerator device to provide different beams to meet the production needs of multiple isotopes and achieve multiple uses of one device; it can also switch the transmission path within milliseconds to introduce different ion beams into different experimental terminals 7 in a time-division manner, achieving time-division acceleration and transmission, expanding the application scenarios of the accelerator, realizing the multi-purpose of the accelerator, avoiding the construction of multiple accelerator devices, and reducing scientific research costs.

[0065] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0067] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0068] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms are not limited to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0069] 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. An accelerator device based on the principle of alternating phase focusing, characterized in that, include: Ion source (1), used to generate ion beam; A radio frequency quadrupole accelerator (3) is used to pre-focus and pre-accelerate the ion beam; The superconducting acceleration section (5) is used to rapidly increase the energy of the ion beam. The high-energy transmission section (6) is connected to the superconducting acceleration section (5) and is used to guide the ion beam to the terminal (7). A low-energy transmission line (2) is provided between the ion source (1) and the radio frequency quadrupole accelerator (3) to adjust the ion beam to match the radio frequency quadrupole accelerator (3); a medium-energy transmission section (4) is provided between the radio frequency quadrupole accelerator (3) and the superconducting acceleration section (5) to adjust the ion beam to match the superconducting acceleration section (5). The superconducting acceleration section (5) includes several acceleration units with radio frequency cavities (21). The phase and amplitude of the radio frequency cavity (21) in each acceleration unit are independently adjustable so that the beam's lateral and longitudinal focusing and defocusing are continuously adjustable.

2. The accelerator device based on the alternating phase focusing principle according to claim 1, characterized in that, The acceleration unit further includes: Radio frequency power source (23) is used to provide radio frequency power; Coupler for coupling high-frequency power to the radio frequency cavity (21). A tuner for adjusting the frequency of the radio frequency cavity (21); The radio frequency power source (23) is electrically connected to the radio frequency cavity (21) through the coupler.

3. The accelerator device based on the alternating phase focusing principle according to claim 2, characterized in that, The radio frequency cavity (21) includes: The radio frequency input port (22) is used to input radio frequency signals into the radio frequency cavity (21) to generate an electromagnetic field; Amplitude and phase adjustment device (24) is provided, one end of which is connected to the radio frequency power source (23) and the other end of which is connected to the radio frequency cavity (21), for adjusting the phase and amplitude of the electromagnetic field.

4. The accelerator device based on the alternating phase focusing principle according to any one of claims 1 to 3, characterized in that, The low-energy transmission line (2) includes: A solenoid is used to guide the ion beam generated by the ion source (1) to the radio frequency quadrupole accelerator (3). A beam transverse chopper is used to intercept an ion beam within a specific time period.

5. The accelerator device based on the alternating phase focusing principle according to claim 4, characterized in that, The medium-energy transmission segment (4) includes: Quadrupole magnets are used to adjust the ion beam to achieve lateral focusing; A focusing cavity is used to adjust the ion beam to achieve longitudinal focusing.

6. The accelerator device based on the alternating phase focusing principle according to claim 5, characterized in that, The high-energy transmission segment (6) includes: Quadrupole magnets are used to adjust the ion beam to achieve lateral focusing; Dipole magnets are used to change the transmission direction of the ion beam to guide it to different terminals (7).

7. The accelerator device based on the alternating phase focusing principle according to claim 6, characterized in that, The radio frequency cavity (21) is made of pure niobium to ensure radio frequency performance and mechanical stability.

8. The accelerator device based on the alternating phase focusing principle according to claim 7, characterized in that, The acceleration unit also includes a low-level control system for improving the response speed of phase adjustment.

9. The accelerator device based on the alternating phase focusing principle according to claim 8, characterized in that, The acceleration unit includes several radio frequency cavities (21) connected in series. Starting from one end, the phase of the two radio frequency cavities (21) is first set to -40° to achieve longitudinal beam focusing; then the phase of the two radio frequency cavities (21) is set to 15° to achieve lateral beam size constraint; then the phase of the remaining radio frequency cavities (21) is adjusted in sequence according to the above rules. Alternatively, starting from one end, first set the phase of the two radio frequency cavities (21) to -40° to achieve longitudinal beam focusing; then set the phase of the three radio frequency cavities (21) to 15° to achieve lateral beam size constraint; then adjust the phase of the remaining radio frequency cavities (21) in sequence according to the above rules.

10. A control method for an accelerator device, characterized in that, The control method, applied to the accelerator device based on the alternating phase focusing principle as described in any one of claims 1 to 9, includes: The phase and amplitude of the electromagnetic field in the radio frequency cavity (21) are dynamically adjusted according to the real-time state of the ion beam.

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