Multi-charge-state ion source and multi-charge-state ion beam output regulation and control method

Abstract

The invention provides a multi-charge-state ion source and a multi-charge-state ion beam output regulation and control method. The multi-charge-state ion source and the multi-charge-state ion beam output regulation and control method are used for simultaneously or respectively leading out a negative hydrogen ion beam and a proton beam. The multi-charge-state ion source comprises a discharge chamber, the discharge chamber is provided with a negative hydrogen ion extraction assembly and a proton extraction assembly, the negative hydrogen ion extraction assembly is used for extracting a negative hydrogen ion beam, and the proton extraction assembly is used for extracting a proton beam; the device also comprises a regulation and control system, and the regulation and control system is electrically connected with the negative hydrogen ion extraction assembly and the proton extraction assembly, and is used for regulating and controlling the beam intensity of the extracted negative hydrogen ion beam and proton beam on line. The multi-charge-state ion source can independently output the negative hydrogen ion beam or the proton beam or simultaneously output the negative hydrogen ion beam and the proton beam, the beam intensity can be adjusted on line, the intensity of each output charge-state beam can be improved, the operation is simple and convenient, the operation efficiency is greatly improved, the space occupancy is reduced, and the cost is reduced. And the difficulty and the cost of use and maintenance are reduced.

Description

Technical Field

[0001] The present invention relates to the field of ion source generators, and in particular to a multi-charge state ion source and a multi-charge state ion beam output control method. Background Art

[0002] In the field of ion beam applications, negative hydrogen ion beams and proton beams are the most widely used types of ion beams, and can be used in fields such as isotope production, proton therapy, neutron therapy, material analysis, and nuclear physics research. With the development of scientific research, new requirements have been put forward for the electrical properties of beams in some application scenarios. Not only do they need to provide multiple charge state beams at the same time, but the beam intensity of each charge state beam must be able to be flexibly adjusted online. However, the current ion source can only produce proton beams or negative hydrogen ion beams, but not proton beams and negative hydrogen ion beams at the same time.

[0003] Then, in order to solve the problem of providing multi-state charges at the same time, the prior art arranges a beam separation device outside the accelerator exit hole, and arranges different stripping films and stripping targets on the beam trajectory to split the multi-charged ions, so as to obtain a proton beam and a negative hydrogen ion beam at the same time, thereby realizing the mixing requirements of the proton beam and the negative hydrogen ion.

[0004] Although the above technical solution can solve the problem of providing polymorphic charges simultaneously, since the sum of the current intensities of each beam is equal to the beam current intensity of the total ion beam extracted by the ion source, after beam splitting, the beam current intensity of each beam is lower than the beam current intensity of the total ion beam.

[0005] In some application scenarios, when it is necessary to provide multi-charged ion beams at the same time, and reducing the beam intensity of each charge state ion beam cannot meet the application requirements, two or even more ion sources of different charge types and corresponding acceleration structures are often required. However, each ion source has an independent control system. If it is necessary to output multi-charged ion beams at the same time, it is necessary to coordinate and control each ion source. The operation is very complicated, which greatly reduces the operating efficiency and makes it difficult to ensure the synergistic effect of two or even more ion sources. At the same time, it also increases the space requirements, the difficulty and cost of use and maintenance.

[0006] Therefore, it is necessary to further improve the technical means adopted in the prior art so as to achieve the ability to provide multiple charge state beams at the same time, and to maintain or improve the intensity of each charge state beam on the basis of online adjustment of the beam intensity of each charge state beam. Summary of the invention

[0007] The purpose of the present invention is to provide a multi-charged ion source and a multi-charged ion beam output control method to solve the technical problem that when it is necessary to provide multi-charged ion beams at the same time, the technical means of the prior art are difficult to achieve while providing multi-charged beams at the same time, and the beam intensity of each charge state beam can be adjusted online, and the intensity of each charge state beam can be maintained or improved. The multi-charged ion source provided by the present invention can output negative hydrogen ion beams or proton beams separately, or output negative hydrogen ion beams and proton beams at the same time, and the beam intensity of each charge state beam can be adjusted online. In addition, the intensity of each charge state beam output can be improved, the operation is simple, the operating efficiency is greatly improved, and the space requirement is reduced, and the difficulty and cost of use and maintenance are reduced.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a multi-charged ion source for simultaneously or separately extracting a negative hydrogen ion beam and a proton beam; comprising a discharge chamber, wherein the discharge chamber is respectively provided with a negative hydrogen ion extraction component and a proton extraction component, wherein the negative hydrogen ion extraction component is used to extract a negative hydrogen ion beam, and the proton extraction component is used to extract a proton beam; and further comprising a control system, wherein the control system is respectively electrically connected to the negative hydrogen ion extraction component and the proton extraction component, and is used to online control the beam current intensity of the extracted negative hydrogen ion beam and proton beam.

[0010] This solution can solve the technical problem that when it is necessary to provide multiple charged state ion beams at the same time, the technical means of the prior art are difficult to achieve while maintaining or improving the intensity of each charge state beam on the basis that the beam intensity of each charge state beam can be adjusted online. The multi-charged state ion source provided by this solution can output negative hydrogen ion beams or proton beams separately, or output negative hydrogen ion beams and proton beams at the same time, and the beam intensity of each charge state beam can be adjusted online. In addition, it can also maintain or improve the intensity of each charge state beam output, and is easy to operate, greatly improving the operating efficiency, while also reducing the space occupancy, and reducing the difficulty and cost of use and maintenance.

[0011] Preferably, the discharge chamber is a columnar structure; an electron source assembly is installed in the middle of the side wall of the discharge chamber for emitting electrons into the discharge chamber; the negative hydrogen ion extraction assembly is arranged at one end of the discharge chamber, and the proton extraction assembly is arranged at the other end of the discharge chamber. In this scheme, the electron source assembly is arranged on the side wall of the discharge chamber to provide uniform plasma for the negative hydrogen ion extraction assembly and the proton extraction assembly. When the ion source is working, there is a potential difference between the discharge chamber and the electron source assembly, and the discharge chamber is at a high potential. Under the action of the electric field, the electrons generated on the surface of the electron source assembly are emitted to the discharge chamber, so that they can collide with the hydrogen introduced to generate arc discharge and form plasma. The function of the electron source assembly is to provide a large number of electrons that collide with hydrogen molecules.

[0012] Preferably, the discharge chamber comprises an outer cavity and an inner cavity, both of which are columnar structures and are coaxially arranged, the outer cavity is sleeved on the outer periphery of the inner cavity, there is a gap between the outer cavity and the inner cavity, and the outer periphery of the inner cavity is surrounded by a permanent magnet array; the permanent magnet array comprises a plurality of permanent magnets in a strip shape, and the extension direction of each permanent magnet is the same as the extension direction of the columnar side wall of the discharge chamber; there is a gap between two adjacent permanent magnets, and the electron source assembly is arranged in the gap between any two adjacent permanent magnets. The permanent magnet array is located on the outer wall of the discharge chamber, and forms a closed magnetic field line area of ​​a multi-peak structure through periodic arrangement, which helps to confine plasma, increase plasma density, and reduce the collision of particles with the inner wall of the discharge chamber. Placing the electron source assembly in the gap between any two adjacent permanent magnets will not destroy the closed magnetic field line area of ​​the multi-peak structure formed by the permanent magnet array, and will not weaken the protection of the inner wall of the discharge chamber of the permanent magnet array.

[0013] Preferably, the negative hydrogen ion extraction component includes a first plasma electrode, a first extraction electrode and a first accelerating electrode which are arranged in sequence from the inside to the outside at one end of the discharge chamber; the centers of the first plasma electrode, the first extraction electrode and the first accelerating electrode are coaxially provided with a first extraction hole, a second extraction hole and a third extraction hole respectively; the first plasma electrode, the first extraction electrode and the first accelerating electrode are electrically connected to the positive terminals of the first plasma power supply, the first extraction power supply and the first accelerating power supply respectively, and the negative terminals of the first plasma power supply, the first extraction power supply and the first accelerating power supply are connected to the discharge chamber respectively; according to the order of the discharge chamber, the first plasma electrode, the first extraction electrode and the first accelerating electrode, the corresponding potentials increase in sequence.

[0014] Specifically, the first plasma electrode is used to confine the plasma to remain in the discharge chamber, and at the same time to increase the density of negative hydrogen ions near the extraction hole to a certain extent, thereby promoting the extraction of negative hydrogen ions; the first extraction electrode is used to extract the negative hydrogen ions generated in the discharge chamber; the first acceleration electrode is used to accelerate the negative hydrogen ions extracted by the first extraction electrode so that they obtain the required energy.

[0015] Preferably, the proton extraction assembly comprises a second plasma electrode, a second extraction electrode, and a second accelerating electrode which are sequentially arranged from the inside to the outside at the other end of the discharge chamber; a fourth extraction hole, a fifth extraction hole, and a sixth extraction hole are coaxially arranged at the centers of the second plasma electrode, the second extraction electrode, and the second accelerating electrode, respectively; the second plasma electrode, the second extraction electrode, and the second accelerating electrode are electrically connected to the negative terminals of the second plasma power supply, the second extraction power supply, and the second accelerating power supply, respectively, and the positive terminals of the second plasma power supply, the second extraction power supply, and the second accelerating power supply are respectively connected to the discharge chamber; and the corresponding potentials are sequentially decreased in the order of the discharge chamber, the second plasma electrode, the second extraction electrode, and the second accelerating electrode.

[0016] Specifically, the second plasma electrode is used to confine the plasma to remain in the discharge chamber, and at the same time to increase the density of protons near the extraction hole to a certain extent, thereby promoting the extraction of protons; the second extraction electrode is used to extract the protons generated in the discharge chamber; the second acceleration electrode is used to accelerate the protons extracted by the first extraction electrode so that they obtain the required energy.

[0017] Preferably, the electron source assembly includes a cathode emitter, which is used to generate heat and generate electrons when powered on; there is a potential difference between the cathode emitter and the discharge chamber, and the potential of the discharge chamber is higher than the potential of the cathode emitter; the cathode emitter is located near the inner wall of the inner cavity of the discharge chamber, or the cathode emitter is located at the center of the discharge chamber. When the ion source is working, there is a potential difference between the discharge chamber and the cathode emitter, and the discharge chamber is at a high potential. Under the action of the electric field, the electrons generated on the surface of the cathode emitter are emitted to the discharge chamber, so that they can collide with the hydrogen introduced to generate arc discharge and form plasma. The purpose of limiting the position of the cathode emitter is to enable the emitted electrons to collide with the hydrogen as much as possible to generate more arc discharges and form more plasma.

[0018] Preferably, the permanent magnet array includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet arranged alternately and cyclically in sequence; the N pole of the first permanent magnet is toward the center of the discharge chamber along the radial line of the discharge chamber cross section; the N pole of the second permanent magnet is toward the third permanent magnet along the circumferential direction of the discharge chamber cross section; the N pole of the third permanent magnet is away from the center of the discharge chamber along the radial line of the discharge chamber cross section; the N pole of the fourth permanent magnet is toward the third permanent magnet along the circumferential direction of the discharge chamber cross section. In this way, the cross-sectional form of the first magnetic field formed by the permanent magnet array is that the first magnetic field includes a plurality of magnetic lines of force protruding toward the inside of the discharge chamber, and the two ends of each magnetic line of force are respectively connected to the S pole of the first permanent magnet and the N pole of the third permanent magnet, so that the probability of electrons colliding with the inner wall of the discharge chamber can be reduced, and the structure of the inner wall of the discharge chamber can be protected; in addition, the magnetic pole directions of the second permanent magnet and the fourth permanent magnet are set to increase the strength of the multi-peak field magnetic field formed between the first permanent magnet and the third permanent magnet, thereby improving the confinement ability of the magnetic field on the plasma.

[0019] Preferably, the negative hydrogen ion extraction component also includes a first filter field and a second filter field. The first filter field is arranged at one end of the discharge chamber near the first extraction hole, and is used to retain high-energy electrons in the plasma beam in the discharge chamber and allow low-energy electrons to react with excited hydrogen molecules to generate negative hydrogen ions; the second filter field is arranged on the side around the first extraction electrode, and is used to filter electrons mixed in the extracted negative hydrogen ions.

[0020] Preferably, the output voltages of the first plasma power supply, the first extraction power supply, the first acceleration power supply, the second plasma power supply, the second extraction power supply and the second acceleration power supply are all adjustable; the control system is electrically connected to the first plasma power supply, the first extraction power supply, the first acceleration power supply, the second plasma power supply, the second extraction power supply and the second acceleration power supply, respectively, and is used to control the on and off of each power supply and to adjust the potential of the power supply.

[0021] In a second aspect, the present invention further provides a method for controlling the output of a multi-charged ion beam, using the multi-charged ion source as described above, comprising the following steps:

[0022] S1. Introduce working gas into the discharge chamber;

[0023] S2. Setting the target ion beam type to be output in the control system, and obtaining the voltage parameter setting values ​​of the corresponding power supplies in the negative hydrogen ion extraction component and the proton extraction component corresponding to the target ion beam type, as well as the working parameter setting values ​​of the electron source component;

[0024] S3, adjusting the voltage of all power supplies to zero, and starting the corresponding power supplies and electron source components in the negative hydrogen ion extraction component and the proton extraction component;

[0025] S4. Through the control system, the voltage parameter values ​​of each power supply and the working parameter values ​​of the electron source assembly are regulated to reach the voltage parameter setting values ​​of each power supply and the working parameter setting values ​​of the electron source assembly in step S2, thereby realizing multi-charge state ion beam current regulation.

[0026] The present invention has the following beneficial effects: the multi-charged state ion source provided by the present invention can output negative hydrogen ion beams or proton beams separately, or output negative hydrogen ion beams and proton beams simultaneously, and the beam intensity of each charge state beam can be adjusted online. In addition, the intensity of each charge state beam output can be improved, the operation is simple, and the operation efficiency is greatly improved. At the same time, the space requirement is reduced, and the difficulty and cost of use and maintenance are reduced. The present invention can solve the technical problem that when it is necessary to provide multiple charge state ion beams simultaneously, the technical means of the prior art are difficult to achieve while maintaining or improving the intensity of each charge state beam on the basis that the beam intensity of each charge state beam can be adjusted online. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to make the purpose, technical solution and advantages of the invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0028] Figure 1 Schematic diagram of the structure of the discharge chamber of the multi-charged ion source according to an embodiment of the present invention.

[0029] Figure 2 It is a longitudinal cross-sectional view of a discharge chamber of a multi-charged state ion source according to an embodiment of the present invention.

[0030] Figure 3 FIG. 4 is a cross-sectional view of a discharge chamber of a multi-charged state ion source according to an embodiment of the present invention.

[0031] Figure 4 Schematic diagram of the position of the electron source assembly according to an embodiment of the present invention.

[0032] Figure 5 Schematic diagram of a permanent magnet array according to an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of the arrangement of permanent magnets in the first filter field according to an embodiment of the present invention.

[0034] Figure 7 4 is a circuit diagram of a multi-charged ion source according to an embodiment of the present invention.

[0035] Description of reference numerals: 100, electron source assembly; 101, cathode emitter; 102, conductive base; 103, insulating member; 104, first interface; 105, second interface; 106, first conductive rod; 107, second conductive rod; 108, cathode emitter power supply; 109, arc discharge power supply; 200, discharge chamber; 201, outer cavity; 202, inner cavity; 203, first filtering field; 204, second filtering field; 205, fifth permanent magnet; 207, sixth permanent magnet; 208, aluminum block; 209, second magnetic field; 300, permanent magnet array; 301, first permanent magnet; 302, second permanent magnet; 303 , third permanent magnet; 304, fourth permanent magnet; 305, first magnetic field; 400, negative hydrogen ion extraction component; 401, first plasma electrode; 402, first extraction electrode; 403, first acceleration electrode; 404, first plasma power supply; 405, first extraction power supply; 406, first acceleration power supply; 500, proton extraction component; 501, second plasma electrode; 502, second extraction electrode; 503, second acceleration electrode; 504, second plasma power supply; 505, second extraction power supply; 506, second acceleration power supply; 600, insulating layer; 700, negative hydrogen ion beam; 800, proton beam. DETAILED DESCRIPTION

[0036] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] To facilitate understanding of the technical solution of the present invention, the technical concept of the present invention is provided as follows:

[0039] The ion source is a key component of the accelerator. Its basic principle is to obtain electrons with a certain energy through certain means, and then use the extraction system to extract the required ions. According to the different charges of the extracted ions, it can be divided into proton sources and negative hydrogen ion sources. When the working gas is hydrogen, the related reactions inside the ion source mainly include excitation, de-excitation, ionization, recombination and elastic collision. The corresponding reaction processes include the interaction between electrons and neutral molecules, electron-ion reaction, ion-neutral molecule reaction, neutral-neutral molecule reaction, wall recombination and other reaction forms. The formed plasma contains H + 、H2 + 、H3 + 、H2、H、H-、e - etc. particles.

[0040] Moreover, H in plasma is usually + The ion concentration is usually higher than H -ions, this is because, the generation of H + The collision cross section of the ion reaction is usually larger than that of the H - The collision cross section of the ion reaction is high, and H - Ions are relatively unstable and easily lose electrons after colliding with other particles. Depending on the plasma density, plasma temperature, hydrogen molecule distribution and other conditions, H - :H + The ratio of H varies from ~1:1 to 1:10 or even higher. - Ion source, except for some of the extracted H - With e - There are still a lot of H + Then, the ion source has the function of providing both H + With H - The ion source provides H + The capacity is usually higher than that of H - High ability.

[0041] Moreover, in the discharge chamber, the total amount of positive and negative charges in the plasma is equal, and the whole is electrically neutral. That is to say, when the cathode emits a electrons into the plasma, at most a negatively charged particles (H-, etc.) can be introduced (some of which will be lost through wall collisions). However, if b positively charged particles (H + etc.), then at most a+b negatively charged particles can be introduced, that is, H + , which has a promoting effect on the amount of H- introduced, that is, it can enhance the beam intensity of the negative hydrogen ion beam;

[0042] Similarly, the cathode emits c electrons into the plasma. In order to extract c positively charged particles (H + etc.), then 2c negative charges need to be led away, but if d negatively charged particles (H - etc.), then we only need to conduct away 2c-d negative charges to realize c positively charged particles (H + In short, the extraction of positive and negative ions at the same time will greatly improve the efficiency compared to the extraction of only monocharged ions.

[0043] Therefore, the present invention improves the structure of the ion source body to solve the problem of providing multi-charged ion beams at the source. The present invention provides several application scenarios for reference, but the application scenarios of the multi-charged ion source of the present invention are not limited to the following scenarios. Scenario 1: The negative hydrogen ion beam is extracted and connected to a cyclotron, which is suitable for high-energy and low-intensity applications, such as isotope production, proton therapy, etc.; the proton beam is extracted and connected to a high-voltage accelerator, which is suitable for low-energy and high-intensity applications, such as neutron sources, isotope production, etc.; Scenario 2: The negative hydrogen ion beam is extracted and connected to accelerator A, and the proton beam is extracted and connected to accelerator B. Then, the two beams are extracted at the same time and then deflected by magnets to converge into one beam, which can weaken or even eliminate the influence of space charge effects on individual electrical beams; Scenario 3: The negative hydrogen ion beam is extracted and connected to accelerator A, and the proton beam is extracted and connected to accelerator B. Then, the two beams are extracted at the same time and then deflected by magnets to converge into one beam, and the ratio of the two electrical beams is controlled to form a neutral beam, which is injected into low-temperature plasma to generate high-temperature plasma, such as nuclear fusion.

[0044] The use of the multi-charged ion source and the multi-charged ion beam output control method disclosed in the present invention has the following technical effects: compared with the traditional ion source that can only extract protons or negative hydrogen ions, the multi-charged ion source provided by the present invention can output negative hydrogen ion beams or proton beams alone, or simultaneously output negative hydrogen ion beams and proton beams, or proton / negative hydrogen ion mixed beams, and the beam intensity of each charge state beam can be adjusted online. In addition, the intensity of each charge state beam output can be maintained or improved, the operation is simple, the operating efficiency is greatly improved, and the space occupancy rate is reduced, and the difficulty and cost of use and maintenance are reduced.

[0045] In order to illustrate the multi-charged ion source of the present invention in detail, the present invention provides the following embodiments.

[0046] Example 1, please refer to Figure 1The present invention provides a multi-charged ion source for extracting negative hydrogen ion beams and proton beams simultaneously or separately; comprising a discharge chamber 200, wherein the discharge chamber 200 is provided with a negative hydrogen ion extraction component 400 and a proton extraction component 500, wherein the negative hydrogen ion extraction component 400 is used to extract a negative hydrogen ion beam, and the proton extraction component 500 is used to extract a proton beam; and further comprising a control system, wherein the control system is electrically connected to the negative hydrogen ion extraction component 400 and the proton extraction component 500, respectively, and is used to online control the beam intensity of the extracted negative hydrogen ion beam and proton beam. This embodiment can solve the technical problem that when it is necessary to provide multiple charged ion beams simultaneously, the technical means of the prior art are difficult to achieve while maintaining or improving the intensity of each charge state beam on the basis that the beam intensity of each charge state beam can be adjusted online. The multi-charged ion source provided by the present invention can output negative hydrogen ion beams or proton beams independently, or output negative hydrogen ion beams and proton beams, or proton / negative hydrogen ion mixed beams simultaneously, and the beam intensity of each charge state beam can be adjusted online. In addition, the intensity of each charge state beam output can be maintained or improved. The operation is simple, and the operating efficiency is greatly improved. At the same time, the space occupancy rate is reduced, and the difficulty and cost of use and maintenance are reduced.

[0047] The principle of maintaining or improving the intensity of the output beams of various charge states in this embodiment is as follows: in the discharge chamber, the total amount of positive and negative charges of the plasma is equal, and the whole is electrically neutral, that is, the cathode emits a electrons into the plasma, and can only draw out a (some of which will be lost through wall collision) negatively charged particles (H - etc.), but if b positively charged particles (H + etc.), then at most a+b negatively charged particles can be introduced, that is, H + , for the introduction of H - The amount of has a promoting effect, that is, it can enhance the beam intensity of the negative hydrogen ion beam; similarly, the cathode emits c electrons into the plasma, and in order to extract c positively charged particles (H + etc.), then 2c negative charges need to be led away, but if d negatively charged particles (H - etc.), then we only need to conduct away 2c-d negative charges to realize c positively charged particles (H + In short, the extraction of positive and negative ions at the same time will greatly improve the efficiency compared to the extraction of only monocharged ions.

[0048] Example 2, please refer to Figure 1, on the basis of Example 1, the discharge chamber 200 is a columnar structure; an electron source assembly 100 is installed in the middle of the side wall of the discharge chamber 200, which is used to emit electrons into the discharge chamber 200; the negative hydrogen ion extraction assembly 400 is arranged at one end of the discharge chamber 200, and the proton extraction assembly 500 is arranged at the other end of the discharge chamber 200. In the prior art, the electron source assembly 100 is arranged at one end of the discharge chamber 200, and is arranged opposite to the negative hydrogen ion extraction assembly 400. In this solution, the electron source assembly 100 is arranged on the side wall of the discharge chamber 200 to achieve uniform plasma for the negative hydrogen ion extraction assembly 400 and the proton extraction assembly 500. When the ion source is working, there is a potential difference between the discharge chamber 200 and the electron source assembly 100, and the discharge chamber 200 is at a high potential. Under the action of the electric field, the electrons generated on the surface of the electron source assembly 100 are emitted to the discharge chamber 200, so that they can collide with the hydrogen gas introduced to generate arc discharge and form plasma. The function of the electron source assembly 100 is to provide a large number of electrons to collide with hydrogen molecules. The ways to generate electrons include thermal emission, field emission, secondary electron emission, photoelectron emission, etc.

[0049] Example 3, please refer to Figures 1 to 3 On the basis of Example 2, the discharge chamber 200 includes an outer chamber 201 and an inner chamber 202, the outer chamber 201 and the inner chamber 202 are both columnar structures and are coaxially arranged, the outer chamber is sleeved on the outer periphery of the inner chamber, there is a gap between the outer chamber 201 and the inner chamber 202, and the outer periphery of the inner chamber 202 is surrounded by a permanent magnet array 300; the permanent magnet array 300 includes a plurality of permanent magnets in a strip shape, and the extension direction of each permanent magnet is the same as the extension direction of the columnar side wall of the discharge chamber 200; there is a gap between two adjacent permanent magnets, and the electron source assembly 100 is arranged in the gap between any two adjacent permanent magnets. The permanent magnet array 300 is located on the outer wall of the discharge chamber 200, and forms a closed magnetic field line region with a multi-peak structure through periodic arrangement, which helps to confine plasma, increase plasma density, and reduce the collision of particles with the inner wall of the discharge chamber 200. Placing the electron source assembly 100 in the gap between any two adjacent permanent magnets will not destroy the closed magnetic field line region of the multi-peak structure formed by the permanent magnet array 300, and will not weaken the protection of the inner wall of the discharge chamber 200 of the permanent magnet array 300.

[0050] Example 4, please refer to Figure 2 and Figure 5On the basis of Example 3, the permanent magnet array 300 includes a first permanent magnet 301, a second permanent magnet 302, a third permanent magnet 303 and a fourth permanent magnet 304 which are arranged alternately in sequence; the N pole of the first permanent magnet 301 is toward the center of the discharge chamber 200 along the radial line of the cross section of the discharge chamber 200; the N pole of the second permanent magnet 302 is toward the third permanent magnet 303 along the circumferential direction of the cross section of the discharge chamber 200; the N pole of the third permanent magnet 303 is away from the center of the discharge chamber 200 along the radial line of the cross section of the discharge chamber 200; the N pole of the fourth permanent magnet 304 is toward the third permanent magnet 303 along the circumferential direction of the cross section of the discharge chamber 200. In this way, the cross-sectional form of the first magnetic field 305 formed by the permanent magnet array 300 is that the first magnetic field 305 includes a plurality of magnetic lines of force protruding toward the inside of the discharge chamber 200, and the two ends of each magnetic line of force are respectively connected to the S pole of the first permanent magnet 301 and the N pole of the third permanent magnet 303, so that the probability of plasma colliding with the inner wall of the discharge chamber 200 can be reduced, and the inner wall structure of the discharge chamber 200 can be protected; in addition, the magnetic pole directions of the second permanent magnet 302 and the fourth permanent magnet 304 are set to increase the multi-peak field magnetic field strength formed between the first permanent magnet 301 and the third permanent magnet 303, thereby improving the magnetic field's ability to confine plasma.

[0051] Example 5, please refer to Figure 2On the basis of Example 3 or Example 4, the negative hydrogen ion extraction component 400 includes a first plasma electrode 401, a first extraction electrode 402 and a first acceleration electrode 403 which are sequentially arranged from the inside to the outside at one end of the discharge chamber 200; the centers of the first plasma electrode 401, the first extraction electrode 402 and the first acceleration electrode 403 are coaxially provided with a first extraction hole, a second extraction hole and a third extraction hole respectively; the first plasma electrode 401, the first extraction electrode 402 and the first acceleration electrode 403 are respectively electrically connected to the positive terminals of the first plasma power supply 404, the first extraction power supply 405 and the first acceleration power supply 406, and the negative terminals 406 of the first plasma power supply 404, the first extraction power supply 405 and the first acceleration power supply are respectively connected to the discharge chamber 200; according to the order of the discharge chamber 200, the first plasma electrode 401, the first extraction electrode 402 and the first acceleration electrode 403, the corresponding potentials are sequentially increased. Specifically, the first plasma electrode 401 is used to directly contact the plasma in the discharge chamber 200, and constrain the plasma to remain in the discharge chamber 200, while increasing the density of negative hydrogen ions near the extraction hole to a certain extent, and promoting the extraction of negative hydrogen ions; the first extraction electrode 402 is used to extract the negative hydrogen ions generated in the discharge chamber 200; the first acceleration electrode 403 is used to accelerate the negative hydrogen ions extracted by the first extraction electrode 402, so that they obtain the required energy. Specifically, the potential of the plasma electrode is close to the potential of the plasma, but there is usually a potential difference of several volts. Under the action of drift motion, the distribution of ions in the plasma is controlled to make the required ions closer to the corresponding extraction system.

[0052] Example 6, please refer to Figure 2 and Figure 6On the basis of Example 5, the negative hydrogen ion extraction component 400 further includes a first filter field 203 and a second filter field 204. The first filter field 203 is arranged at one end of the discharge chamber 200 near the first extraction hole, and is used to retain high-energy electrons in the plasma beam in the discharge chamber 200, and react low-energy electrons with excited hydrogen molecules to generate negative hydrogen ions; the second filter field 204 is arranged around the first extraction electrode 402, and is used to filter electrons mixed in the extracted negative hydrogen ions. On the basis, the technical problem of maintaining or improving the intensity of each charge state beam. The multi-charged ion source provided by this scheme can output negative hydrogen ion beams or proton beams separately, or output negative hydrogen ion beams and proton beams at the same time, and the beam intensity of each charge state beam can be adjusted online. In addition, it can also maintain or improve the intensity of each charge state beam output, which is simple to operate, greatly improves the operating efficiency, and also reduces the space occupancy, and reduces the difficulty and cost of use and maintenance. Because the positive and negative charges are different, different types of electric fields are required to accelerate and extract positive / negative ions respectively. At the same time, H- is mainly obtained by the reaction of excited state H2 with low-energy electrons (<3eV), and high-energy electrons (≥3eV) and H- will collide and ionize, making H - Therefore, a filtering magnetic field is needed to filter the high-energy electrons near the extraction region, thereby promoting H - ions are generated, and the co-extracted electrons need to be filtered out by filtering magnetic fields in the extraction area to obtain H - Ion beam.

[0053] Example 7, please refer to Figure 6 , based on Example 6, as one of the embodiments of the first filtering field 203, the first filtering field 203 includes a plurality of fourth permanent magnets 304 and a corresponding number of fifth permanent magnets 205, each of the fourth permanent magnets 304 and each of the fifth permanent magnets 205 are respectively arranged at the two ends of the radial direction of the cross section of the discharge chamber 200, the N pole of each of the fourth permanent magnets 304 is away from the center of the discharge chamber 200 along the radial line of the cross section of the discharge chamber 200; the N pole of each of the fifth permanent magnets 205 is toward the center of the discharge chamber 200 along the radial line of the cross section of the discharge chamber 200; the first filtering field 203 also includes a plurality of aluminum blocks 208, the sum of the number of each of the fourth permanent magnets 304 and each of the fifth permanent magnets 205 is less than the total number of each permanent magnet in the permanent magnet array 300, and the sum of the number of each aluminum block 208, each of the fourth permanent magnets 304 and each of the fifth permanent magnets 205 is equal to the total number of each permanent magnet in the permanent magnet array 300.

[0054] A second magnetic field 209 is formed between each of the fourth permanent magnets 304 and each of the fifth permanent magnets 205. The second magnetic field 209 is located in the inner region of the discharge chamber 200 corresponding to the first extraction hole. The coverage of the second magnetic field 209 can cover the first extraction hole to effectively intercept high-energy electrons. When electrons pass through the second magnetic field 209, faster electrons have a larger movement radius and will deflect to all sides, while slower electrons have a smaller movement radius and will move in a spiral trajectory toward the first extraction hole under the action of the electric field and the magnetic field.

[0055] Example 8, please refer to Figure 2 On the basis of any one of the above embodiments, the proton extraction assembly 500 includes a second plasma electrode 501, a second extraction electrode 502, and a second accelerating electrode 503 which are sequentially arranged from the other end of the discharge chamber 200 from the inside to the outside; the second plasma electrode 501, the second extraction electrode 502, and the second accelerating electrode 503 are coaxially arranged with a fourth extraction hole, a fifth extraction hole, and a sixth extraction hole at their centers; the second plasma electrode 501, the second extraction electrode 502, and the second accelerating electrode 503 are electrically connected to the negative terminals of the second plasma power supply 504, the second extraction power supply 505, and the second accelerating power supply 506, respectively, and the positive terminals of the second plasma power supply 504, the second extraction power supply 505, and the second accelerating power supply 506 are respectively connected to the discharge chamber; according to the order of the discharge chamber 200, the second plasma electrode 501, the second extraction electrode 502, and the second accelerating electrode 503, the corresponding potentials decrease in sequence. Specifically, the second plasma electrode 501 is used to directly contact the plasma in the discharge chamber 200, and constrain the plasma to remain in the discharge chamber 200, while increasing the density of protons near the extraction hole to a certain extent, and promoting the extraction of protons; the second extraction electrode 502 is used to extract the protons generated in the discharge chamber 200; the second acceleration electrode 503 is used to accelerate the protons extracted by the first extraction electrode 402, so that they obtain the required energy. The working principle of this embodiment is: according to the different properties of the ion charge, there is a potential difference of several hundred to several thousand volts between the required extraction electrode and the plasma electrode, thereby generating an electric field for accelerating protons / negative hydrogen ions, and extracting the corresponding ions from the plasma; in addition, when extracting negative hydrogen ions, a filtering magnetic field is set on the extraction electrode, so that the electrons significantly affected by the magnetic field are deflected and collected by the extraction electrode, and will not be accelerated; the role of the acceleration electrode is to accelerate the extracted ions to the required energy.

[0056] Example 9, please refer to Figure 3 and Figure 4On the basis of any of the above embodiments, the electron source assembly 100 includes a cathode emitter 101, which is used to generate heat and generate electrons when powered on; there is a potential difference between the cathode emitter 101 and the discharge chamber 200, and the potential of the discharge chamber 200 is higher than the potential of the cathode emitter 101; the cathode emitter 101 is located near the inner wall of the inner cavity 202 of the discharge chamber 200, or the cathode emitter 101 is located at the center of the discharge chamber 200. When the ion source is working, there is a potential difference between the discharge chamber 200 and the cathode emitter 101, and the discharge chamber 200 is at a high potential. Under the action of the electric field, the electrons generated on the surface of the cathode emitter 101 are emitted to the discharge chamber 200, so that they can collide with the hydrogen gas introduced to generate arc discharge and form plasma. The purpose of limiting the position of the cathode emitter 101 is to enable the emitted electrons to collide with the hydrogen gas as much as possible to generate more arc discharges and form more plasma.

[0057] Specifically, there is a potential difference between the cathode emitter 101 and the discharge chamber 200, which is achieved by connecting an arc discharge power supply 109 between the electron source assembly 100 and the discharge chamber 200. In addition, the arc discharge power supply 109 can also provide an energy source for the cathode emitter 101 to generate arc discharge. The arc discharge power supply 109 accelerates the electrons generated by the cathode emitter 101. The electrons gain a certain amount of energy and collide with the working gas to ionize neutral particles, forming an arc discharge and generating plasma. The thermal emission electron source has mature technology, simple structure, high beam intensity, and is most widely used. The electron source assembly 100 in this embodiment makes the cathode emitter 101 reach the operating temperature by ohmic heating. The arc discharge power supply 109 in this embodiment is a DC power supply.

[0058] Example 10, please refer to Figure 3On the basis of Example 9, the two ends of the cathode emitter 101 are respectively fixed with a first conductive rod 106 and a second conductive rod 107; correspondingly, the inner side wall of the inner cavity 202 of the discharge chamber 200 is fixed with a conductive base 102, and the conductive base 102 includes an insulating member 103, a first interface 104 and a second interface 105; the first interface 104 and the second interface 105 are used to respectively connect the positive and negative electrodes of the cathode emitter 101 power supply; the insulating member 103 is fixed to the inner side wall of the inner cavity 202 of the discharge chamber 200, and through holes are respectively opened at both ends of the insulating member 103, and the first interface 104 and the second interface 105 respectively extend through the corresponding through holes to the inside of the discharge chamber 200; the first conductive rod 106 is fixed to the first interface 104, and the second conductive rod 107 is fixed to the second interface 105. In this way, the first interface 104 and the second interface 105 are connected respectively through an external power supply, and then a circuit path is formed through the first conductive rod 106, the second conductive rod 107 and the cathode emitter 101. Specifically, the cathode emitter 101 itself has resistance. When powered on, the cathode emitter 101 directly heats itself through ohmic heating, and forms an electric field with the discharge chamber 200 to accelerate electrons. The power supply of the cathode emitter 101 in this embodiment is a DC power supply. Specifically, the insulating member 103 is an insulating ceramic. The insulating ceramic is fixed and vacuum-isolated to the side wall of the inner cavity 202 of the discharge chamber by brazing, and at the same time plays an insulating role between the cathode emitter 101 and the discharge chamber 200.

[0059] Further, in Example 10, please refer to Figure 3 , an external terminal is provided at a position corresponding to the conductive base 102 on the outer periphery of the outer cavity 201 of the discharge chamber 200, for connecting the cathode emitter 101 power supply, the external terminal extends into the gap between the outer cavity 201 and the inner cavity 202, and is electrically connected to the conductive base 102, for providing current to the conductive base 102, specifically, corresponding to the first interface 104 and the second interface 105, the external terminal is provided with a first terminal and a second terminal, the first interface 104 and the second interface 105 are electrically connected to the first terminal and the second terminal, respectively.

[0060] Embodiment 11, based on any of the above embodiments, the material of the cathode emitter 101 is one of tungsten, tantalum, an alloy of tungsten or tantalum, and lanthanum hexaboride. All materials are non-magnetic materials, and the spatial volume of the cathode emitter 101 is small, so when the position of the cathode emitter 101 changes, it will not significantly affect the magnetic field distribution inside the ion source.

[0061] Example 12, please refer to Figure 2On the basis of any of the above embodiments, the outer peripheries of the first plasma electrode 401, the first extraction electrode 402, and the first acceleration electrode 403, as well as the outer peripheries of the second plasma electrode 501, the second extraction electrode 502, and the second acceleration electrode 503 are respectively provided with an insulating layer 600 for insulating and fixing each electrode so that each electrode can work normally. The material of the insulating layer 600 includes but is not limited to alumina ceramics, zirconia ceramics, quartz, boron nitride, polytetrafluoroethylene, etc.

[0062] Example 13, please refer to Figure 7 On the basis of Example 1, Example 5 and Example 8, the output voltages of the first plasma power supply 404, the first extraction power supply 405, the first acceleration power supply 406, the second plasma power supply 504, the second extraction power supply 505 and the second acceleration power supply 506 are all adjustable; the control system is electrically connected to the first plasma power supply 404, the first extraction power supply 405, the first acceleration power supply 406, the second plasma power supply 504, the second extraction power supply 505 and the second acceleration power supply 506, respectively, for controlling the on and off of each power supply and adjusting the potential of the power supply. The working process of this embodiment is: when the provided multi-charged ion source needs to output positive / negative hydrogen ion beam 700 separately, first pass a certain flow of working gas; adjust all power supply voltages to zero, and start each power supply; set the positive / negative hydrogen ion plasma power supply parameters; set the arc discharge power supply 109 parameters, and the voltages of the negative / positive plasma power supply, extraction power supply, and acceleration power supply that do not need to be output are all the same as the arc discharge power supply 109 voltage; set the positive / negative extraction power supply parameters; slowly increase the cathode emitter 101 power supply current until it reaches the set value; slowly increase the positive / negative hydrogen ion acceleration power supply voltage until it reaches the set value. When the provided multi-charged ion source needs to output proton beam 800 and negative hydrogen ion beam 700 at the same time, first pass the working gas; adjust all power supplies to zero, and start each power supply; set the positive and negative hydrogen ion plasma power supply parameters; set the arc discharge power supply 109 parameters; set the positive and negative extraction power supply parameters; slowly increase the cathode emitter 101 power supply current until it reaches the set value; slowly increase the positive and negative hydrogen ion acceleration power supply voltages respectively until they reach the set value.

[0063] Embodiment 14, based on embodiment 13, provides a method for controlling the output of a multi-charged ion beam, comprising the following steps:

[0064] S1. Introduce working gas into the discharge chamber;

[0065] S2. Setting the target ion beam type to be output in the control system, and obtaining the voltage parameter setting values ​​of the corresponding power supplies in the negative hydrogen ion extraction component and the proton extraction component corresponding to the target ion beam type, as well as the working parameter setting values ​​of the electron source component;

[0066] S3, adjusting the voltage of all power supplies to zero, and starting the corresponding power supplies and electron source components in the negative hydrogen ion extraction component and the proton extraction component;

[0067] S4. Through the control system, the voltage parameter values ​​of each power supply and the working parameter values ​​of the electron source assembly are regulated to reach the voltage parameter setting values ​​of each power supply and the working parameter setting values ​​of the electron source assembly in step S2, thereby realizing multi-charge state ion beam current regulation.

[0068] In Example 14, in step S1, the working gas is hydrogen.

[0069] In Example 14, in step S2, the target ion beam type refers to a proton beam, a negative hydrogen ion beam, or a proton / negative hydrogen ion mixed beam. Then, for different target ion beam types, corresponding embodiments are given below.

[0070] In Example 14, when the provided multi-charged ion source needs to output positive / negative hydrogen ion beams separately, first, a certain flow rate of working gas is passed; all power supplies are adjusted to zero and each power supply is started; the positive / negative hydrogen ion plasma power supply parameters are set; the arc discharge power supply parameters are set, and the voltages of the negative / positive plasma power supply, extraction power supply, and acceleration power supply that do not need to be output are all the same as the arc discharge power supply voltage; the positive / negative extraction power supply parameters are set; the cathode emitter power supply current is slowly increased until it reaches the set value; the positive / negative hydrogen ion acceleration power supply voltage is slowly increased until it reaches the set value.

[0071] In Example 14, when the provided multi-charged ion source needs to output positive and negative hydrogen ion beams separately, first pass the working gas; adjust all power supplies to zero, and start each power supply; set the positive and negative hydrogen ion plasma power supply parameters; set the arc discharge power supply parameters; set the positive and negative extraction power supply parameters; slowly increase the cathode emitter power supply current until it reaches the set value; and slowly increase the positive and negative hydrogen ion acceleration power supply voltages until they reach the set value.

[0072] In Example 14, the beam intensity is affected by factors such as gas flow rate, cathode emitter operating temperature, arc discharge voltage, plasma electrode voltage, extraction electrode voltage, etc. Then, in actual operation, the beam intensity of the multi-charged ion beam is adjusted by the following method: first, the gas flow rate is adjusted to make the gas flow rate reach the set minimum gas flow rate value; then, the first / second extraction electrode voltage, the first / second plasma electrode voltage, the cathode emitter operating current, and the arc discharge voltage are respectively adjusted by the control system until the beam intensity reaches the set target value, thereby achieving the adjustment of the beam intensity, and this adjustment process is all online adjustment.

[0073] In Example 14, the voltage parameter setting values ​​of each power supply in the negative hydrogen ion extraction component and the proton extraction component corresponding to the specific target ion beam type, as well as the working parameter setting values ​​of the electron source component are given. Please refer to Table 1 for the potential conditions of each electrode modulated by the control system.

[0074] Table 1 Potential of each electrode

[0075] The first accelerating electrode 0V The first extraction electrode -23kV First plasma electrode -24.99kV Discharge chamber -25kV Second plasma electrode -25.01kV The second extraction electrode -27kV The second accelerating electrode -50kV Cathode emitter anode -25.04kV Cathode emitter negative electrode -25.05kV

[0076] Under the premise of the above parameter settings, it is possible to provide multiple charged ion beams simultaneously, and by adjusting the potential of each electrode online, the beam intensity of each charge state beam can be adjusted online, and the intensity of each charge state beam can be maintained or improved.

[0077] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. The embodiments described in the present invention are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all other embodiments obtained by ordinary technicians in the art without creative work based on the embodiments in the present invention belong to the scope of protection of the present invention.

Claims

1. A multi-charged ion source for simultaneously or separately extracting a negative hydrogen ion beam and a proton beam, characterized in that: The invention comprises a discharge chamber, wherein the discharge chamber is provided with a negative hydrogen ion extraction component and a proton extraction component, wherein the negative hydrogen ion extraction component is used to extract a negative hydrogen ion beam, and the proton extraction component is used to extract a proton beam; and further comprises a control system, wherein the control system is electrically connected to the negative hydrogen ion extraction component and the proton extraction component, respectively, and is used to online control the beam current intensity of the extracted negative hydrogen ion beam and proton beam.

2. The multi-charged ion source according to claim 1, characterized in that: The discharge chamber is a columnar structure; an electron source assembly is installed in the middle of the side wall of the discharge chamber for emitting electrons into the discharge chamber; the negative hydrogen ion extraction assembly is arranged at one end of the discharge chamber, and the proton extraction assembly is arranged at the other end of the discharge chamber.

3. The multi-charged ion source according to claim 2, characterized in that: The discharge chamber comprises an outer cavity and an inner cavity, both of which are columnar structures and are coaxially arranged, the outer cavity is sleeved on the outer periphery of the inner cavity, a gap is provided between the outer cavity and the inner cavity, and a permanent magnet array surrounds the outer periphery of the inner cavity; the permanent magnet array comprises a plurality of strip-shaped permanent magnets, and the extension direction of each permanent magnet is the same as the extension direction of the columnar side wall of the discharge chamber; there is a gap between two adjacent permanent magnets, and the electron source assembly is arranged in the gap between any two adjacent permanent magnets.

4. The multi-charged ion source according to claim 1, characterized in that: The negative hydrogen ion extraction component includes a first plasma electrode, a first extraction electrode and a first acceleration electrode which are sequentially arranged from the inside to the outside at one end of the discharge chamber; the centers of the first plasma electrode, the first extraction electrode and the first acceleration electrode are coaxially arranged with a first extraction hole, a second extraction hole and a third extraction hole respectively; the first plasma electrode, the first extraction electrode and the first acceleration electrode are respectively electrically connected to the positive terminals of the first plasma power supply, the first extraction power supply and the first acceleration power supply, and the negative terminals of the first plasma power supply, the first extraction power supply and the first acceleration power supply are respectively connected to the discharge chamber; according to the order of the discharge chamber, the first plasma electrode, the first extraction electrode and the first acceleration electrode, the corresponding potentials are sequentially increased.

5. The multi-charged ion source according to claim 1 or 4, characterized in that: The proton extraction assembly comprises a second plasma electrode, a second extraction electrode, and a second accelerating electrode which are sequentially arranged from the inside to the outside at the other end of the discharge chamber; a fourth extraction hole, a fifth extraction hole, and a sixth extraction hole are coaxially arranged at the centers of the second plasma electrode, the second extraction electrode, and the second accelerating electrode, respectively; the second plasma electrode, the second extraction electrode, and the second accelerating electrode are respectively electrically connected to the negative terminals of the second plasma power supply, the second extraction power supply, and the second accelerating power supply, and the positive terminals of the second plasma power supply, the second extraction power supply, and the second accelerating power supply are respectively connected to the discharge chamber; and the corresponding potentials are sequentially decreased in the order of the discharge chamber, the second plasma electrode, the second extraction electrode, and the second accelerating electrode.

6. The multi-charged ion source according to claim 2 or 3, characterized in that: The electron source assembly includes a cathode emitter, which is used to generate heat and electrons when powered; there is a potential difference between the cathode emitter and the discharge chamber, and the potential of the discharge chamber is higher than the potential of the cathode emitter; the cathode emitter is located near the inner wall of the inner cavity of the discharge chamber, or the cathode emitter is located at the center of the discharge chamber.

7. The multi-charged ion source according to claim 3, characterized in that: The permanent magnet array comprises a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet which are arranged alternately and cyclically in sequence; the N pole of the first permanent magnet is directed toward the center of the discharge chamber along the radial line of the cross section of the discharge chamber; The N pole of the second permanent magnet faces the third permanent magnet along the circumferential direction of the discharge chamber cross section; the N pole of the third permanent magnet faces away from the center of the discharge chamber along the radial line of the discharge chamber cross section; the N pole of the fourth permanent magnet faces the third permanent magnet along the circumferential direction of the discharge chamber cross section.

8. The multi-charged ion source according to claim 4, characterized in that: The negative hydrogen ion extraction assembly further comprises a first filter field and a second filter field, wherein the first filter field is arranged at one end of the discharge chamber near the first extraction hole, and is used to retain high-energy electrons in the plasma beam in the discharge chamber; The second filtering field is arranged around the first extraction electrode and is used for filtering electrons mixed in the extracted negative hydrogen ions.

9. The multi-charged ion source according to claims 4 and 5, characterized in that: The output voltages of the first plasma power supply, the first extraction power supply, the first acceleration power supply, the second plasma power supply, the second extraction power supply and the second acceleration power supply are all adjustable; the control system is electrically connected to the first plasma power supply, the first extraction power supply, the first acceleration power supply, the second plasma power supply, the second extraction power supply and the second acceleration power supply, respectively, and is used to control the on and off of each power supply and adjust the output voltage of each power supply.

10. A method for controlling the output of a multi-charged ion beam, using the multi-charged ion source as claimed in claim 9, characterized in that: The following steps are involved: S1. Introduce working gas into the discharge chamber; S2. Setting the target ion beam type to be output in the control system, and obtaining the voltage parameter setting values ​​of the corresponding power supplies in the negative hydrogen ion extraction component and the proton extraction component corresponding to the target ion beam type, as well as the working parameter setting values ​​of the electron source component; S3, adjusting the voltage of all power supplies to zero, and starting the corresponding power supplies and electron source components in the negative hydrogen ion extraction component and the proton extraction component; S4. Through the control system, the voltage parameter values ​​of each power supply and the working parameter values ​​of the electron source assembly are regulated to reach the voltage parameter setting values ​​of each power supply and the working parameter setting values ​​of the electron source assembly in step S2, thereby realizing multi-charge state ion beam current regulation.

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