Dual-beam accelerator and beam acceleration method based thereon

Abstract

The present invention discloses a dual-beam accelerator and a beam acceleration method based thereon, relating to the technical field of accelerators. The dual-beam accelerator comprises: a positive ion source system and a negative ion source system; an RFQ accelerator connected to the positive ion source system and the negative ion source system, the RFQ accelerator being configured to convert the positive ion beam and the negative ion beam into positive and negative ion bunches with a phase difference of 180 degrees; and a beam acceleration system disposed downstream of the RFQ accelerator and adapted to be injected with the positive and negative ion bunches with a phase difference of 180 degrees, the high-frequency acceleration structure of the beam acceleration system being configured to operate at an odd multiple of the RFQ accelerator frequency. The present invention utilizes dual-source simultaneous injection of positive and negative ions, and the beam acceleration system, based on an odd multiple of the RFQ accelerator operating frequency, enables the positive and negative bunches to continuously sense the accelerating electric field, ensuring subsequent acceleration continues, thereby omitting the phase matching stage.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerators, and in particular to a dual-beam accelerator and a beam acceleration method based thereon. Background Art

[0002] An ion linear accelerator is a device that accelerates ions using a high-frequency electromagnetic field generated by a series of radio frequency cavities. It has a wide range of applications in non-destructive testing, ion implantation, healthcare, cancer treatment, isotope production, and basic scientific research.

[0003] Linear accelerators are essential for implementing these applications. Ion linear accelerators can accelerate various ions, from protons to uranium beams, as needed, providing ion beams of varying energies and intensities at the terminal. However, due to the high cost of accelerators, improving beam efficiency has become a hot topic.

[0004] Thus, the concept of simultaneous acceleration of positive and negative ion beams was proposed. The Los Alamos Neutron Science Center (LANSCE) accelerator, proposed and built by the Los Alamos National Laboratory in the United States, began operation in 1972. This linear accelerator can deliver a 1.25 mA proton beam current and a 70 μA negative hydrogen beam current to multiple terminals, respectively. The accelerator is equipped with two independent proton and negative hydrogen beam injectors. Each injector contains a Cockcroft-Walton-type voltage multiplier and an ion source, capable of producing positively charged protons or negatively charged hydrogen ions with a final energy of 750 keV. The proton and negative hydrogen beams are transported by two independent beamlines and merged at the entrance of a 201.25 MHz drift tube linear accelerator (DTL). Accelerated by the DTL, the beam energy reaches 100 MeV. After the DTL, the transition region beamline directs a 100MeV proton beam to the isotope production facility (IPF), while the negative hydrogen beam is accelerated to a final energy of 800MeV in an 805MHz coupled-cavity linear accelerator (CCL) and transmitted to four terminals. From the perspective of beam intensity, the positive and negative ion currents accelerated by this device are relatively low, resulting in a low space charge effect. From a temporal perspective, due to the large number of terminals, the temporal structure of the beam needs to be modulated at low energies. This accelerator does not simultaneously accelerate and transmit positive and negative ion beams at the microbunch level.

[0005] In 1993, the Institute of Heavy Ion Physics at Peking University proposed the concept of using an RFQ accelerator to simultaneously accelerate positive and negative ion beams of equal charge-mass ratios. Experimental studies were conducted using an existing RFQ. Under weak current conditions, positive and negative oxygen ions of varying intensities were injected into the RFQ for acceleration, both individually and simultaneously. The feasibility of simultaneous acceleration of positive and negative ion beams was verified by comparing the transmission efficiency of the RFQ accelerator under different experimental conditions. Compared to separate injections, the acceleration intensities and transmission efficiencies of the positive and negative ions injected simultaneously were lower. However, the total beam current at the accelerator exit was significantly greater than that obtained with separate accelerations. Therefore, it was confirmed that simultaneous acceleration of positive and negative ions of equal charge-mass ratios using an RFQ accelerator improves RFQ utilization efficiency.

[0006] South Korea's proposed multi-purpose facility, KOMAC, plans to use a dual-beam acceleration scheme. KOMAC will construct a high-intensity proton / negative hydrogen linear accelerator, ultimately capable of delivering a 1 GeV continuous-wave proton beam at a current of 20 mA and extracting negative hydrogen beams at 100 MeV and 260 MeV, respectively.

[0007] The aforementioned accelerator primarily uses even-multiple RF frequency selection. To achieve simultaneous acceleration of the two beams, a transmission line consisting of a dipole magnet and a quadrupole magnet is used when the frequency is increased. The difference in their transmission paths is exploited to create a 180-degree phase difference between the positive and negative beams, enabling joint acceleration in the acceleration structure at the next frequency. The presence of the phase-matching segment increases the complexity of the system. Furthermore, this method achieves phase control through distance, placing high demands on hardware processing accuracy. Furthermore, the presence of a long deflection and weak focusing segment in the phase-matching segment significantly degrades the beam quality. This technical approach cannot meet the application requirements of high-power accelerators with continuous beams in the milliampere range. Summary of the Invention

[0008] In response to the above problems, the purpose of the present invention is to provide a dual-beam accelerator and a beam acceleration method based thereon, which aims to achieve that the positive and negative ion bunches can continuously feel the accelerating electric field by adopting a dual-source injection of positive and negative ions. The beam acceleration system is based on an odd multiple of the RFQ accelerator frequency, thereby ensuring that subsequent acceleration continues, thereby omitting the phase matching section.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A dual-beam accelerator comprises: a positive ion source system and a negative ion source system, wherein the positive ion source system and the negative ion source system are configured to generate a positive ion beam and a negative ion beam, respectively; an RFQ accelerator connected to the positive ion source system and the negative ion source system, wherein the RFQ accelerator is configured to convert the positive ion beam and the negative ion beam into positive and negative ion bunches with a phase difference of 180 degrees; and a beam acceleration system, arranged downstream of the RFQ accelerator and suitable for being injected with the positive and negative ion bunches with a phase difference of 180 degrees, wherein the operating frequency of the high-frequency acceleration structure of the beam acceleration system is configured to be an odd multiple of the operating frequency of the RFQ accelerator.

[0011] According to some embodiments of the present invention, the dual-beam accelerator also includes a low-energy transmission line arranged between the positive ion source system and the negative ion source system and the RFQ accelerator, and the low-energy transmission line includes a bidirectional dipole magnet arranged near the positive ion source system and the negative ion source system, and a plurality of solenoids or a plurality of quadrupole magnets arranged at subsequent positions of the bidirectional dipole magnet; the positive ion source system and the negative ion source system respectively include a solenoid arranged at their respective outlets.

[0012] According to some embodiments of the present invention, the solenoid at the outlet of the positive ion source system is configured to match the positive ion beam to the bidirectional dipole magnet of the low-energy transmission line, and the solenoid at the outlet of the negative ion source system is configured to match the negative ion beam to the bidirectional dipole magnet of the low-energy transmission line; the low-energy transmission line is configured to merge the positive and negative ion beams into the same beam orbit; multiple solenoids and multiple quadrupole magnets are configured to simultaneously match the positive and negative ion beams into the RFQ accelerator.

[0013] According to some embodiments of the present invention, the operating frequency of the RFQ accelerator is 50 to 1000 MHz, and the positive ion beam and the negative ion beam have the same exit energy, which is designed to be 1-5 MeV; the RFQ accelerator is configured to utilize a radio frequency acceleration field to achieve simultaneous acceleration of positive and negative ion beams, and to separate them in the longitudinal space to form positive and negative ion beam clusters with a phase difference of 180 degrees.

[0014] According to some embodiments of the present invention, the dual-beam accelerator further includes a medium-energy transmission section arranged between the RFQ and the beam acceleration system, the medium-energy transmission section includes at least two bunching cavities, the operating frequency of the bunching cavities is the same as the operating frequency of the RFQ accelerator, and the positive and negative ion beams are longitudinally manipulated to match them into a downstream beam acceleration system; the medium-energy transmission section is provided with a plurality of quadrupole magnets to transversely match the positive and negative ion bunches injected from the RFQ accelerator into symmetric beams or antisymmetric beams and inject them into the downstream beam acceleration system.

[0015] According to some embodiments of the present invention, the beam acceleration system includes a low-energy acceleration section, which adopts a room temperature or superconducting acceleration structure, and the operating frequency of the high-frequency acceleration structure of the low-energy acceleration section is the same as the operating frequency of the RFQ accelerator.

[0016] According to some embodiments of the present invention, the high-frequency acceleration structure of the low-energy acceleration section is configured as a half-wavelength cavity or a room-temperature DTL cavity.

[0017] According to some embodiments of the present invention, the beam energy at the exit of the low-energy acceleration section is 10-50 MeV.

[0018] According to some embodiments of the present invention, the low-energy acceleration section is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position.

[0019] According to some embodiments of the present invention, the beam acceleration system further comprises a medium-energy acceleration section disposed downstream of the low-energy acceleration section, and the operating frequency of the high-frequency acceleration structure of the medium-energy acceleration section is three times the operating frequency of the RFQ accelerator.

[0020] According to some embodiments of the present invention, the medium-energy acceleration section adopts a room-temperature or superconducting acceleration structure.

[0021] According to some embodiments of the present invention, the high-frequency acceleration structure of the medium-energy acceleration section is configured as a spoke-type cavity or a room-temperature SCDTL or CH cavity.

[0022] According to some embodiments of the present invention, the medium energy acceleration section enables positive and negative ion bunches to be accelerated simultaneously through a phase scanning technique.

[0023] According to some embodiments of the present invention, the beam energy at the exit of the medium-energy acceleration section is 50-500 MeV.

[0024] According to some embodiments of the present invention, the beam acceleration system further includes a high-energy acceleration section disposed downstream of the medium-energy acceleration section, and the operating frequency of the high-frequency acceleration structure of the high-energy acceleration section is five times the operating frequency of the RFQ accelerator.

[0025] According to some embodiments of the present invention, the high-energy acceleration section adopts a room-temperature or superconducting acceleration structure, and the high-frequency acceleration structure of the high-energy acceleration section is configured as an ellipsoidal cavity or a room-temperature CCL or BTW cavity.

[0026] According to some embodiments of the present invention, the high-energy acceleration section enables positive and negative ion bunches to be accelerated simultaneously through a phase scanning technique.

[0027] According to some embodiments of the present invention, the beam energy at the exit of the high-energy acceleration section is 500-2000 MeV.

[0028] According to some embodiments of the present invention, the high-energy acceleration section is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position.

[0029] According to some embodiments of the present invention, the beam acceleration system also includes a high-energy transmission terminal arranged downstream of the beam acceleration system, and the high-energy transmission terminal includes a series of quadrupole lenses and a bidirectional dipole magnet to simultaneously send positive and negative beam groups to different terminals.

[0030] According to some embodiments of the present invention, when the dual-beam accelerator completes acceleration to provide a beam for a high-power terminal, it uses stripping technology to strip negative ions into positive ions to double the beam intensity, thereby meeting the high-power application requirements of the terminal.

[0031] A beam acceleration method based on any of the above-mentioned dual-beam accelerators, the beam acceleration method comprising: when the radio frequency operating frequency increases, using an odd multiple of the radio frequency operating frequency to enable positive and negative ion beams to operate simultaneously in the acceleration and focusing phase, thereby achieving simultaneous acceleration transmission of the dual beams.

[0032] The present invention has at least the following advantages due to the adoption of the above technical solution:

[0033] 1. This invention proposes, for the first time, the simultaneous acceleration of positive and negative beams using odd-numbered frequencies, omitting the phase-matching section and shortening the overall length of the accelerator. Combined with negative ion stripping technology, the terminal beam intensity can be tripled. Different ion sources can also be used to generate positive and negative ion beams of varying intensities, which can then be accelerated simultaneously, meeting the terminal's requirements for simultaneous high-power and low-power beam applications.

[0034] 2. The use of bidirectional dipole magnets in the high-energy acceleration section can easily realize the automatic separation of positive and negative ion beams, meeting the independent application of positive and negative ion beams at the terminal;

[0035] 3. In the application of high-power devices such as accelerator-driven transmutation research, the use of superconducting acceleration structures to accelerate continuous wave positive and negative ion beams can double the beam power. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of a dual-beam accelerator according to some embodiments of the present invention.

[0037] Markings in the accompanying drawings:

[0038] 1. Positive ion source system;

[0039] 2. Negative ion source system;

[0040] 3. Low energy transmission line;

[0041] 4. RFQ accelerator;

[0042] 5. Medium energy transmission section;

[0043] 6. Low-energy acceleration section;

[0044] 7. Medium energy acceleration section;

[0045] 8. High-energy acceleration section;

[0046] 9. High-energy transmission terminal. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the system or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0049] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "assembly," "disposition," and "connection" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0050] The first aspect of the present invention provides a dual-beam accelerator, including a positive ion source system, a negative ion source system, an RFQ accelerator and a beam acceleration system. The purpose is to use a dual-source of positive and negative ions for simultaneous injection. The beam acceleration system is based on an odd multiple of the RFQ accelerator frequency, so that the positive and negative beams can continuously feel the accelerating electric field, ensuring that subsequent acceleration continues, thereby omitting the phase matching section.

[0051] The liquid medicine transfer and preparation device provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] A dual-beam accelerator according to an embodiment of the present invention includes: a positive ion source system 1, a negative ion source system 2, an RFQ accelerator 4, and a beam acceleration system. The positive ion source system 1 and the negative ion source system 2 are configured to generate a positive ion beam and a negative ion beam, respectively, and simultaneously input the positive ion beam and the negative ion beam, respectively, into the RFQ accelerator 4. The RFQ accelerator 4 is configured to generate positive and negative ion bunches with a phase difference of 180 degrees. A high-frequency structure of the beam acceleration system is configured to have a high-frequency frequency that is an odd multiple of the operating frequency of the RFQ accelerator 4, and is disposed downstream of the RFQ accelerator 4 and is adapted to be injected with the positive and negative ion bunches with a phase difference of 180 degrees.

[0053] The dual-beam accelerator in the above embodiment can achieve at least the following beneficial effects:

[0054] 1. This invention proposes, for the first time, the simultaneous acceleration of positive and negative beams using odd-numbered frequencies, omitting the phase-matching section and shortening the overall length of the accelerator. Combined with negative ion stripping technology, the terminal beam intensity can be tripled. Different ion sources can also be used to generate positive and negative ion beams of varying intensities, which can then be accelerated simultaneously, meeting the terminal's requirements for simultaneous high-power and low-power beam applications.

[0055] 2. The use of bidirectional dipole magnets in the high-energy acceleration section 8 can easily realize the automatic separation of positive and negative ion beams, meeting the independent application of positive and negative ion beams by the terminal;

[0056] 3. In the application of high-power devices such as accelerator-driven transmutation research, the use of superconducting acceleration structures to accelerate continuous wave positive and negative ion beams can double the beam power.

[0057] It should be noted that the positive ion source system 1 and the negative ion source system 2 can be used to generate positive and negative ion beams of the same energy (approximately 10-150 keV), or they can be used to generate positive and negative ion beams of different energies. It is understood that when the positive ion source system 1 and the negative ion source system 2 generate positive and negative ion beams of different intensities and then accelerate them simultaneously, the terminal can meet the simultaneous application of high-power and low-power beams.

[0058] In some embodiments, the dual-beam accelerator further includes a low-energy transmission line 3 disposed between the positive ion source system 1 and the negative ion source system 2 and the RFQ accelerator 4. The low-energy transmission line 3 includes a bidirectional dipole magnet disposed near the positive ion source system 1 and the negative ion source system 2, and a plurality of solenoids or a plurality of quadrupole magnets disposed at positions subsequent to the bidirectional dipole magnets. The positive ion source system 1 and the negative ion source system 2 each include a solenoid disposed at their respective exits. Figure 1 In the illustrated embodiment, a plurality of solenoids or a plurality of quadrupole magnets are sequentially arranged in series at subsequent positions of the bidirectional two-pole magnet.

[0059] Optionally, the low-energy transmission line 3 includes four or five solenoids.

[0060] In some embodiments, the solenoid at the outlet of the positive ion source system 1 is configured to match the positive ion beam to the bidirectional dipole magnet of the low-energy transmission line 3, and the solenoid at the outlet of the negative ion source system 2 is configured to match the negative ion beam to the bidirectional dipole magnet of the low-energy transmission line 3; the low-energy transmission line 3 is configured to merge the positive and negative ion beams into the same beam orbit; multiple solenoids and multiple quadrupole magnets are configured to simultaneously match the positive and negative ion beams to the downstream RFQ accelerator 4.

[0061] In some embodiments, the operating frequency of the RFQ accelerator 4 is 50-1000 MHz, and the positive ion beam and the negative ion beam have the same outlet energy, which is designed to be 1-5 MeV.

[0062] Furthermore, the RFQ accelerator 4 is configured to achieve simultaneous acceleration of positive and negative ion beams using a radio frequency acceleration field, and to separate the positive and negative ion beams in the longitudinal space to form positive and negative ion clusters with a phase difference of 180 degrees.

[0063] In some embodiments, the dual-beam accelerator further includes a medium energy transmission section 5 disposed between the RFQ and the beam acceleration system. The medium energy transmission section 5 includes at least two bunching cavities. The operating frequency of the bunching cavity is the same as the operating frequency of the RFQ accelerator 4. The positive and negative ion beams are longitudinally manipulated and matched to the downstream beam acceleration system (for example, in Figure 1 In the embodiment shown, it is matched to the acceleration cavity of the downstream low-energy acceleration section 6).

[0064] Optionally, the medium energy transmission section 5 includes two or three bunching cavities.

[0065] In some embodiments, the medium energy transmission section 5 is provided with a plurality of quadrupole magnets to laterally match the positive and negative ion bunches injected from the RFQ accelerator 4 into symmetric beams or antisymmetric beams for injection into the downstream beam acceleration system.

[0066] In some embodiments, the beam acceleration system includes a low-energy acceleration section 6 , which adopts a room temperature or superconducting acceleration structure. The operating frequency of the high-frequency acceleration structure of the low-energy acceleration section 6 is the same as the operating frequency of the RFQ accelerator 4 .

[0067] In some embodiments, the high-frequency acceleration structure of the low-energy acceleration section 6 is configured as a half-wavelength cavity or a room-temperature DTL cavity. It should be noted that in other embodiments, the high-frequency of the low-energy acceleration section 6 can also be configured as other types of devices or structures.

[0068] In some embodiments, the beam energy at the exit of the low-energy acceleration section 6 is 10-50 MeV.

[0069] In some embodiments, the low energy acceleration section 6 is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position, for example, Figure 1 In the embodiment shown, the beam is transported into a medium-energy acceleration section 7 located subsequent to the low-energy acceleration section 6 .

[0070] In some embodiments, the beam acceleration system further includes a medium-energy acceleration section 7 disposed downstream of the low-energy acceleration section 6 , and the operating frequency of the high-frequency acceleration structure of the medium-energy acceleration section 7 is three times the operating frequency of the RFQ accelerator 4 .

[0071] In some embodiments, the medium energy acceleration section 7 adopts a room temperature or superconducting acceleration structure.

[0072] In some embodiments, the high-frequency acceleration structure of the intermediate energy acceleration section 7 is configured as a spoke-type cavity or a room-temperature SCDTL or CH cavity. It should be noted that in other embodiments, the high-frequency acceleration structure of the intermediate energy acceleration section 7 can also be configured as other types of devices or structures.

[0073] In some embodiments, the medium energy acceleration section 7 uses a phase scanning technique to simultaneously accelerate positive and negative ion bunches in the frequency tripling cavity.

[0074] In some embodiments, the beam energy at the exit of the medium energy acceleration section 7 is 50-500 MeV.

[0075] In some embodiments, the beam acceleration system further includes a high-energy acceleration section 8 disposed downstream of the medium-energy acceleration section 7 , and the high-frequency frequency of the high-frequency structure of the high-energy acceleration section 8 is five times the operating frequency of the RFQ accelerator 4 .

[0076] In some embodiments, the high-energy acceleration section 8 employs a room-temperature or superconducting acceleration structure, and the high-frequency structure of the high-energy acceleration section 8 is configured as an ellipsoidal q-cavity, a room-temperature CCL, or a BTW cavity. It should be noted that in other embodiments, the high-frequency structure of the high-energy acceleration section 8 may also be configured as other types of devices or structures.

[0077] In some embodiments, the high energy acceleration section 8 uses a phase scanning technique to simultaneously accelerate positive and negative ion bunches in the quintupled frequency cavity.

[0078] In some embodiments, the beam energy at the exit of the high-energy acceleration section 8 is 500-2000 MeV.

[0079] In some embodiments, the high energy acceleration section 8 is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position, for example, Figure 1 In the embodiment shown, the beam is delivered into a high energy delivery terminal 9 located downstream of the beam acceleration system.

[0080] In certain embodiments, the beam acceleration system further includes a high-energy transmission terminal 9, located downstream of the beam acceleration system. The high-energy transmission terminal 9 comprises a series of quadrupole lenses and a bipolar magnet, which simultaneously delivers positive and negative beams to different terminals. Specifically, the bipolar magnet achieves spatial separation of the positive and negative ion beams, satisfying the needs of different terminals for their application.

[0081] In some embodiments, when the dual-beam accelerator completes acceleration to provide a beam for a high-power terminal, it uses stripping technology to strip negative ions into positive ions to double the beam intensity, thereby meeting the high-power application requirements of the terminal.

[0082] It is worth noting that the dual-beam accelerator provided in the embodiment of the present invention can be used in cancer treatment devices, doubling the beam efficiency of the terminal to meet the needs of different treatment terminals; it can also transmit high-power ion beams to meet the needs of high neutron flux, greatly reducing the equipment construction cost compared to single-beam accelerators.

[0083] The second aspect of the present invention also provides a beam acceleration method based on any of the above-mentioned dual-beam accelerators. The beam acceleration method includes using an odd multiple of the radio frequency operating frequency to enable positive and negative ion beams to operate simultaneously in the acceleration and focusing phase when the radio frequency operating frequency increases, thereby realizing simultaneous acceleration transmission of the dual beams.

[0084] 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 various embodiments of the present invention.

Claims

1. A dual-beam accelerator, characterized in that: include: A positive ion source system and a negative ion source system, wherein the positive ion source system and the negative ion source system are configured to generate a positive ion beam and a negative ion beam, respectively; an RFQ accelerator connected to the positive ion source system and the negative ion source system, wherein the RFQ accelerator is configured to generate positive and negative ion bunches with a phase difference of 180 degrees from the positive ion beam and the negative ion beam; as well as a beam acceleration system, disposed downstream of the RFQ accelerator and adapted to be injected with the positive and negative ion bunches having a phase difference of 180 degrees, wherein the operating frequency of the high-frequency acceleration structure of the beam acceleration system is configured to be an odd multiple of the operating frequency of the RFQ accelerator; The beam acceleration system includes a low-energy acceleration section, wherein the low-energy acceleration section adopts a room temperature or superconducting acceleration structure, and the operating frequency of the high-frequency acceleration structure of the low-energy acceleration section is the same as the operating frequency of the RFQ accelerator; The beam acceleration system further includes a medium-energy acceleration section disposed downstream of the low-energy acceleration section, wherein the operating frequency of the high-frequency acceleration structure of the medium-energy acceleration section is three times the operating frequency of the RFQ accelerator; The beam acceleration system further includes a high-energy acceleration section disposed downstream of the medium-energy acceleration section, wherein the operating frequency of the high-frequency acceleration structure of the high-energy acceleration section is five times the operating frequency of the RFQ accelerator; The beam acceleration system is based on an odd-number multiple frequency of the RFQ accelerator frequency, so that the positive and negative bunches can continuously feel the accelerating electric field, ensuring that subsequent acceleration continues, thereby omitting the phase matching section.

2. The dual-beam accelerator according to claim 1, characterized in that: The dual-beam accelerator further includes a low-energy transmission line disposed between the positive ion source system, the negative ion source system, and the RFQ accelerator, wherein the low-energy transmission line includes a bidirectional dipole magnet disposed near the positive ion source system and the negative ion source system, and a plurality of solenoids or a plurality of quadrupole magnets disposed at positions subsequent to the bidirectional dipole magnets; The positive ion source system and the negative ion source system respectively include solenoids arranged at their respective outlets.

3. The dual-beam accelerator according to claim 2, characterized in that: The solenoid at the exit of the positive ion source system is configured to match the positive ion beam to the bidirectional dipole magnet of the low-energy transmission line, and the solenoid at the exit of the negative ion source system is configured to match the negative ion beam to the bidirectional dipole magnet of the low-energy transmission line; The low energy transmission line is configured to merge the positive and negative ion beams into a same beam trajectory; The plurality of solenoids and the plurality of quadrupole magnets are configured to simultaneously match positive and negative ion beams into the RFQ accelerator.

4. The dual-beam accelerator according to claim 1, characterized in that: The operating frequency of the RFQ accelerator is 50-1000 MHz, and the positive ion beam and the negative ion beam have the same outlet energy, which is designed to be 1-5 MeV; The RFQ accelerator is configured to achieve simultaneous acceleration of positive and negative ion beams using a radio frequency acceleration field, and to separate the positive and negative ion beams in a longitudinal space to form positive and negative ion clusters with a phase difference of 180 degrees.

5. The dual-beam accelerator according to claim 1, characterized in that: The dual-beam accelerator further includes a medium-energy transmission section disposed between the RFQ and the beam acceleration system, the medium-energy transmission section including at least two bunching cavities, the operating frequency of the bunching cavities being the same as the operating frequency of the RFQ accelerator, and longitudinally manipulating the positive and negative ion beams to match them to the downstream beam acceleration system; The medium energy transmission section is provided with a plurality of quadrupole magnets to laterally match the positive and negative ion bunches injected from the RFQ accelerator into symmetric beams or antisymmetric beams for injection into a downstream beam acceleration system.

6. The dual-beam accelerator according to claim 1, characterized in that: The high-frequency acceleration structure of the low-energy acceleration section is configured as a half-wavelength cavity or a room-temperature DTL cavity; The beam energy at the exit of the low-energy acceleration section is 10-50 MeV; The low-energy acceleration section is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position.

7. The dual-beam accelerator according to claim 6, characterized in that The medium energy acceleration section adopts a room temperature or superconducting acceleration structure; The high-frequency acceleration structure of the medium-energy acceleration section is configured as a spoke-type cavity or a room-temperature SCDTL or CH cavity; The medium energy acceleration section accelerates positive and negative ion bunches simultaneously through phase scanning technology; The beam energy at the exit of the medium-energy acceleration section is 50-500 MeV.

8. The dual-beam accelerator according to claim 7, characterized in that: The high-energy acceleration section adopts a room-temperature or superconducting acceleration structure, and the high-frequency acceleration structure of the high-energy acceleration section is configured as an ellipsoidal cavity or a room-temperature CCL or BTW cavity; The high-energy acceleration section accelerates positive and negative ion bunches simultaneously through phase scanning technology; The beam energy at the exit of the high-energy acceleration section is 500-2000 MeV; The high-energy acceleration section is provided with a three-way dipole magnet for beam deflection, or a device for straight-tube transmission of the beam to a subsequent position.

9. The dual-beam accelerator according to any one of claims 1 to 8, characterized in that: The beam acceleration system further includes a high-energy transmission terminal disposed downstream of the beam acceleration system, wherein the high-energy transmission terminal includes a series of quadrupole lenses and a bidirectional dipole magnet to simultaneously deliver positive and negative beam groups to different terminals; When the dual-beam accelerator completes acceleration and provides a beam current for a high-power terminal, it uses a stripping technology to strip negative ions into positive ions to double the beam current intensity, thereby meeting the application requirements of the terminal's high power.

10. A beam acceleration method based on the dual-beam accelerator according to any one of claims 1 to 9, characterized in that: This includes using odd multiples of the RF operating frequency to enable positive and negative ion beams to operate simultaneously in the acceleration and focusing phase when the RF operating frequency increases, thereby achieving simultaneous acceleration transmission of the dual beams.

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