Electron beam acceleration tube and electron beam accelerator

Abstract

This application discloses an electron beam accelerating tube and an electron beam accelerator, relating to the field of electron beam accelerator technology. The electron beam accelerating tube includes a first cavity and a suppression cavity. A first electromagnetic field is generated within the first cavity, which is used to accelerate the electron beam emitted from the electron gun through the first electromagnetic field, and the first electromagnetic field forms a leakage field. The suppression cavity is disposed between the first cavity and the electron gun, and the suppression cavity establishes a second electromagnetic field within itself through the leakage field. The intensity of the second electromagnetic field is higher than the intensity of the leakage field, and the second electromagnetic field is used to suppress the movement of electrons in the electron beam toward the electron gun. Using the electron beam accelerating tube disclosed in this application can reduce the back-bombardment phenomenon of electrons on the electron gun, improving the performance and lifespan of the electron gun.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of electron beam accelerator technology, and particularly to an electron beam accelerator tube and an electron beam accelerator. Background Technology

[0002] In a microwave electron gun, the interaction between the electron beam and the microwave field can cause some electrons to be reflected back to the electron gun's cathode, resulting in electron back-bombardment. This back-bombardment phenomenon can damage and evaporate the material of the electron gun's cathode, severely affecting the electron gun's performance and lifespan.

[0003] In the prior art, the beam back-bombing problem is improved by optimizing the structure of the accelerator tube's head cavity. However, the back-bombing electron beam hitting the nose cone of the head cavity for a long time will still change the internal structure of the nose cone, affecting the acceleration field shape established in the head cavity, thus having an adverse effect on the acceleration of the electron beam. Summary of the Invention

[0004] To address the aforementioned issues, the electron beam accelerator tube provided in this application can reduce the back-bombardment phenomenon of electrons on the electron gun, thereby improving the performance and lifespan of the electron gun.

[0005] In a first aspect, this application provides an electron beam accelerating tube, which includes a first cavity and a suppression cavity. A first electromagnetic field can be generated inside the first cavity, which is used to accelerate the electron beam emitted by the electron gun through the first electromagnetic field, and the first electromagnetic field forms a leakage field. The suppression cavity is disposed between the first cavity and the electron gun, and the suppression cavity establishes a second electromagnetic field inside it through the leakage field, and the intensity of the second electromagnetic field is higher than the intensity of the leakage field. The second electromagnetic field is used to suppress the movement of electrons in the electron beam toward the electron gun.

[0006] The electron beam accelerating tube provided in this application can generate a first electromagnetic field inside the first cavity to accelerate the electron beam emitted by the electron gun. Due to the physical structure, material properties, and electric field distribution of the first cavity, leakage of the first electromagnetic field within the first cavity can occur. The first electromagnetic field may "leak" from the inside of the first cavity to the outside, forming a leak field. This causes some electrons in the electron beam to be subjected to a force towards the electron gun, posing a risk of backfiring into the electron gun. Since the suppression cavity is located between the first cavity and the electron gun, the suppression cavity can utilize the leak field to establish a second electromagnetic field within the suppression cavity. The direction of the second electromagnetic field is opposite to the direction of the leak field towards the electron gun, providing a force in the opposite direction to the backfiring electrons in the electron beam. Furthermore, the strength of the second electromagnetic field is higher than the strength of the leak field. Therefore, the second electromagnetic field can cancel out and overcome the force exerted by the leak field on the electrons, thereby suppressing the movement of electrons towards the electron gun and reducing the backfiring phenomenon.

[0007] In one possible implementation of this application, the suppression cavity is made of a high dielectric constant material to suppress thermal deformation of the suppression cavity.

[0008] In one possible implementation of this application, the radial dimension of the suppression cavity is smaller than the radial dimension of the first cavity; the axial dimension of the suppression cavity is smaller than the axial dimension of the first cavity.

[0009] In one possible implementation of this application, the suppression cavity includes a first beam aperture and a second beam aperture. The first beam aperture is connected to the electron gun, and the second beam aperture is connected to the head cavity. The radial dimension of the second beam aperture is larger than that of the first beam aperture.

[0010] In one possible implementation of this application, the first cavity includes a third beam aperture, which is coupled to a second beam aperture, and the third beam aperture and the second beam aperture have the same size.

[0011] In one possible implementation of this application, the suppression cavity includes a first nasal cone and a second nasal cone; the first nasal cone is circumferentially arranged around the first beam aperture, and the second nasal cone is circumferentially arranged around the second beam aperture; both the first and second nasal cones are recessed toward the interior of the suppression cavity so that the inner surfaces of the first and second nasal cones are close to each other.

[0012] In one possible implementation of this application, the first nose cone has a first bottom surface along the radial direction of the first beam aperture, and the second nose cone has a second bottom surface along the radial direction of the second beam aperture, wherein the area of ​​the first bottom surface is larger than the area of ​​the second bottom surface.

[0013] In one possible implementation of this application, the edges of the first nasal cone, the second nasal cone, and the inhibition cavity are all rounded.

[0014] In one possible implementation of this application, the electron beam accelerating tube further includes a coupling cavity and an accelerating cavity, with the first cavity, the coupling cavity, and the accelerating cavity connected by a coupling hole; the coupling hole is eccentrically positioned relative to the central axis of the first cavity; and the accelerating cavity is used to accelerate the electron beam.

[0015] Secondly, this application provides an electron beam accelerator, which includes an electron gun and an electron beam accelerating tube of any one of the above, wherein the suppression cavity of the electron beam accelerating tube is connected to the electron gun.

[0016] The electron beam accelerator provided in this application, since it includes any of the electron beam accelerating tubes mentioned above, has the same technical effect as the electron beam accelerating tubes mentioned above, that is, it can reduce the phenomenon of electrons returning to the electron gun and improve the performance and lifespan of the electron gun. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an electron beam accelerator provided in an embodiment of this application;

[0018] Figure 2 A partial structural schematic diagram of an electron beam accelerator tube provided in an embodiment of this application;

[0019] Figure 3 A front view of the suppression cavity of an electron beam accelerator tube provided in an embodiment of this application;

[0020] Figure 4 A rear view of the suppression cavity of an electron beam accelerator tube provided in an embodiment of this application;

[0021] Figure 5 Provided for the embodiments of this application Figure 4 A cross-sectional view from the perspective of the Chinese Academy of Sciences (AA).

[0022] Figure 6 This is a schematic diagram of the internal structure of the first cavity of the electron beam accelerator tube provided in an embodiment of this application.

[0023] Figure label:

[0024] 1-Electron beam accelerating tube; 11-First cavity; 111-Third beam aperture; 112-Fourth beam aperture; 12-Suppression cavity; 121-First beam aperture; 122-Second beam aperture; 123-First nose cone; 1231-First bottom surface; 124-Second nose cone; 1241-Second bottom surface; 13-Coupled cavity; 14-Accelerating cavity; 15-Coupled aperture; 2-Electron gun; 21-Cathode; 3-Waveguide. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the specific technical solutions of this application will be further described in detail below with reference to the accompanying drawings of the embodiments of this application. The following embodiments are used to illustrate this application, but are not intended to limit the scope of this application.

[0026] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0027] Furthermore, in the embodiments of this application, directional terms such as "upper," "lower," "left," and "right" are defined relative to the positions in which the components are schematically placed in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the position of the components in the accompanying drawings.

[0028] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0029] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0030] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0031] The working principle of a microwave electron beam accelerator is based on the interaction between microwaves and electrons. A microwave power source generates microwave energy, which is transmitted to the electron beam accelerating tube through a waveguide system. Inside the electron beam accelerating tube, the microwave electromagnetic field accelerates the electrons, giving them high energy, and also confines and focuses the electron beam, enabling the electrons to move along a predetermined trajectory.

[0032] A microwave electron beam accelerator generally consists of a microwave power source, a waveguide system, an accelerating cavity, a magnet system, and an electron gun. The microwave power source generates microwave energy; the waveguide system transfers this energy from the power source to the accelerating cavity, facilitating efficient energy transfer; the electron beam accelerating tube is the main region for electron acceleration; and the electron gun emits electrons and is the starting part of the microwave electron beam accelerator.

[0033] Reference Figure 1 This application provides an electron beam accelerator, which includes an electron gun 2 and an electron beam accelerating tube 1, wherein the suppression cavity 12 of the electron beam accelerating tube 1 is connected to the electron gun 2.

[0034] In this embodiment of the application, the cathode 21 of the electron gun 2 is used to generate a high energy density electron beam. The cathode 21 of the electron gun 2 is usually made of a high melting point metal (such as tungsten) and emits electrons by heating.

[0035] In the microwave electron gun 2, the interaction between the electron beam and the microwave electromagnetic field may cause some electrons to be reflected back to the cathode 21 of the electron gun 2, resulting in electron back-bombardment. This back-bombardment phenomenon can damage and evaporate the material of the cathode 21 of the electron gun 2, seriously affecting the performance and lifespan of the electron gun 2.

[0036] In existing technology, the first cavity 11 of the accelerating tube is optimized in some ways. The lower side of the first cavity beam has no nose cone, and the interior of the downstream side is a smooth surface. The downstream beam channel of the first cavity is connected to the center of the downstream side of the first cavity, and the other end of the downstream beam channel is connected to the upstream side of the second cavity. This structure allows the reverse electron beam to disperse as it moves through the upstream beam channel of the first cavity, hitting the nose cone and the transition section of the beam aperture, thus effectively improving the problem of beam back-bombardment. However, the prolonged impact of the back-bombarded electron beam on the nose cone of the first cavity 11 alters the internal structure of the nose cone, thereby affecting the acceleration field shape established by the first cavity 11 and impacting the acceleration of the electron beam.

[0037] Reference Figure 1 and Figure 2 This application provides an electron beam accelerator tube 1, which includes a first cavity 11 and a suppression cavity 12. A first electromagnetic field can be generated inside the first cavity 11. The first cavity 11 is used to accelerate the electron beam emitted by the electron gun 2 through the first electromagnetic field, and the first electromagnetic field forms a leakage field. The suppression cavity 12 is disposed between the first cavity 11 and the electron gun 2. The suppression cavity 12 establishes a second electromagnetic field inside it through the leakage field, and the intensity of the second electromagnetic field is higher than the intensity of the leakage field. The second electromagnetic field is used to suppress the movement of electrons in the electron beam toward the electron gun 2.

[0038] In this embodiment, microwave power is fed into the electron beam accelerating tube 1 via the input waveguide 3, and is continuously reflected within the electron beam accelerating tube 1, ultimately forming a first electromagnetic field within the first cavity 11.

[0039] In the embodiments of this application, the shape, size, and material of the first cavity 11 can be adjusted according to requirements, and this application does not limit them. For example, in the embodiments provided by this application, the shape of the first cavity 11 is a cylindrical cavity with a short axial dimension and a circumferentially rounded surface. The material of the first cavity 11 is generally copper.

[0040] In this embodiment, the suppression cavity 12 is made of a high dielectric constant material. The high dielectric constant material may include perovskite-structured ceramic materials such as barium titanate (BaTiO3) and lead titanate (PbTiO3), as well as complex oxide ceramics such as potassium sodium niobate (KNN). This application does not limit the specific materials used.

[0041] In the embodiment of this application, the electron beam accelerating tube 1 can generate a first electromagnetic field inside the first cavity 11 to accelerate the electron beam emitted by the electron gun 2. Due to the physical structure, material properties and electric field distribution of the first cavity 11, the first electromagnetic field inside the first cavity 11 may "leak". The first electromagnetic field may "leak" from the inside of the first cavity 11 to the outside of the first cavity 11, thus forming a leakage field. This causes some electrons in the electron beam to be subjected to a force in the direction of the electron gun 2, which may result in a back-bombardment of the electron gun 2.

[0042] Since the suppression cavity 12 is positioned between the first cavity 11 and the electron gun 2, the suppression cavity 12 can utilize the leakage field to establish a second electromagnetic field within it. The direction of the second electromagnetic field is opposite to the direction of the leakage field towards the electron gun 2, providing a force in the opposite direction to the electrons returning to the electron beam. Furthermore, because the intensity of the second electromagnetic field is higher than that of the leakage field, it can cancel out and overcome the force exerted by the leakage field on the electrons, thereby suppressing the movement of electrons towards the electron gun 2 and reducing the phenomenon of electrons returning to the electron gun 2.

[0043] In some possible embodiments of this application, the suppression cavity is made of a high dielectric constant material to suppress thermal deformation of the suppression cavity.

[0044] Materials with high dielectric constants have lower quality factors (Q), meaning they have lower Q values ​​and higher attenuation coefficients. This helps improve the heat resistance and stability of the suppression cavity 12, making it more heat-resistant than a copper cavity. It can effectively suppress the thermal deformation caused by electrons back-bombarding the cavity wall, thereby better maintaining the field shape of the second electromagnetic field within the suppression cavity 12 and enhancing the stability of the electron beam transmission process.

[0045] Reference Figure 1 and Figure 2 In some possible embodiments of this application, the radial dimension of the suppression cavity 12 is smaller than the radial dimension of the first cavity 11.

[0046] In this embodiment, because the suppression cavity 12 is made of a high dielectric constant material, reducing the size of the suppression cavity 12 can make the intrinsic frequency of the suppression cavity 12 consistent with that of the first cavity 11, thereby improving the working stability.

[0047] In this embodiment, the radial dimension of the suppression cavity 12 is smaller than the radial dimension of the first cavity 11. Specifically, this application does not limit the difference in radial dimensions between the suppression cavity 12 and the first cavity 11, and it can be adjusted according to different needs.

[0048] In this embodiment, since the suppression cavity 12 is located between the electron gun 2 and the first cavity 11, after the electron beam is emitted from the electron gun 2, it first enters the suppression cavity 12 and then enters the first cavity 11. That is, the electron beam line passes through the second electromagnetic field and then is transmitted to the first electromagnetic field. In this way, the second electromagnetic field can optimize the transmission of the electron beam and reduce the phenomenon of electron back-bombardment.

[0049] Furthermore, the electrons that bounce back from the first cavity 11 (i.e., the first electromagnetic field) to the electron gun 2 will move in the direction from the first cavity 11 to the electron gun 2. When the electrons move into the suppression cavity 12, under the action of the axial and radial forces of the second electromagnetic field in the suppression cavity 12, the electrons that are accelerated along the axial direction of the suppression cavity 12 will be laterally (i.e., along the axial direction of the suppression cavity 12) and thus hit the cavity wall of the suppression cavity 12 on the side closer to the electron gun 2, thereby reducing the number of back-bombing electrons (i.e., electrons moving in the direction of the electron gun 2). The electrons that are decelerated along the radial direction of the suppression cavity 12 will have less energy, thereby weakening the energy of the back-bombing particles. In this way, the suppression cavity 12 will suppress the back-bombing of electrons in both the axial and radial directions.

[0050] In the electron beam accelerating tube 1 of this application embodiment, the radial dimension of the suppression cavity 12 is smaller than that of the first cavity 11. This makes the distribution of the second electromagnetic field (i.e., the electromagnetic field within the suppression cavity 12) more compact than that of the first electromagnetic field (i.e., the electromagnetic field within the first cavity 11). Consequently, the phase velocity of the electromagnetic wave propagating in the suppression cavity 12 is closer to the velocity of the electrons emitted by the electron gun 2. This closeness between the phase velocity and the electron velocity helps optimize the performance of the electron beam, reducing scattering and energy loss of the electron beam in the suppression cavity 12, and improving the stability and focusing of the electron beam.

[0051] Reference Figure 1 and Figure 2 In some possible embodiments of this application, the axial dimension of the suppression cavity 12 is smaller than the axial dimension of the first cavity 11.

[0052] In this embodiment, the axial dimension of the suppression cavity 12 depends on the energy of the electrons emitted by the electron gun 2. The greater the energy of the electrons emitted by the electron gun 2, the longer the axial dimension of the suppression cavity 12.

[0053] In the electron beam accelerating tube 1 of this application embodiment, the axial dimension of the suppression cavity 12 is smaller than that of the first cavity 11. This can be understood as the transmission path of the electron beam in the suppression cavity 12 being shorter than that in the first cavity 11. This helps to reduce the diffusion and energy loss of the electron beam during transmission, thereby improving the focusing performance of the electron beam.

[0054] Reference Figure 3 , Figure 4 and Figure 5In some possible embodiments of this application, the suppression cavity 12 includes a first beam aperture 121 and a second beam aperture 122. The first beam aperture 121 is connected to the electron gun 2, and the second beam aperture 122 is connected to the head cavity 11. The radial dimension of the second beam aperture 122 is larger than the radial dimension of the first beam aperture 121.

[0055] In this embodiment, the first beam aperture 121 and the second beam aperture 122 are coaxially arranged with the suppression cavity 12 and are located on opposite sides of the suppression cavity 12 in the axial direction. This application does not limit the specific size of the first beam aperture 121 and the second beam aperture 122, and they can be adjusted according to the requirements.

[0056] In this embodiment, the first beam aperture 121 is connected to the electron gun 2 through a drift section, which reduces the radial dimension of the first beam aperture 121 and effectively reduces the electromagnetic field propagating from the suppression cavity 12 toward the electron gun 2, thereby reducing the interference experienced by the electrons after they are drawn from the anode and enhancing the stability of the beam transmission.

[0057] In this embodiment, the second beam aperture 122 is used to connect with the first cavity 11. The acceleration cavities 14 are usually coupled together through the coupling aperture 15. However, since the radial dimension of the suppression cavity 12 is small, the opening position of the coupling aperture 15 of the first cavity 11 connected to the suppression cavity 12 is restricted. Therefore, the coupling method is changed from magnetic coupling using the edge coupling aperture 15 to electrical coupling using the beam aperture. As a result, the size of the second beam aperture 122 is larger than that of the first beam aperture 121, which can reduce the power loss of coupling when the second beam aperture 122 and the first cavity 11 are connected.

[0058] The electron beam accelerating tube 1 of this application embodiment can reduce the introduction of the second electromagnetic field into the electron gun 2 from the first beam aperture 121, thereby reducing interference to the electrons inside the electron gun 2, reducing the fluctuation and deflection of the electron beam, and helping to maintain the stability of the electron beam during transmission.

[0059] Reference Figure 3 , Figure 4 , Figure 5 and Figure 6 In some possible embodiments of this application, the first cavity 11 includes a third beam aperture 111, which is coupled to a second beam aperture 122, and the third beam aperture 111 and the second beam aperture 122 have the same size.

[0060] In this embodiment, the third beam aperture 111 of the first cavity 11 is connected to the second beam aperture 122 of the suppression cavity 12. The electron beam is transmitted from the second beam aperture 122 of the suppression cavity 12 to the third beam aperture 111 of the first cavity 11. After being accelerated by the first electromagnetic field in the first cavity 11, it passes through the fourth beam aperture 112 of the first cavity 11 and reaches the next cavity.

[0061] In this embodiment of the application, the first cavity 11 further includes a fourth beam aperture 112 disposed opposite to the third beam aperture 111. The radial dimension of the fourth beam aperture 112 is smaller than the radial dimension of the third beam aperture 111. The fourth beam aperture 112 is used to connect to the next cavity.

[0062] In the electron beam accelerator tube 1 of this application embodiment, since the third beam aperture 111 and the second beam aperture 122 have the same size, the electron beam can maintain a relatively consistent beam diameter when transmitted from the suppression cavity 12 to the first cavity 11, reducing electron beam diffusion and energy loss caused by changes in beam aperture size. Simultaneously, the consistent size of the third beam aperture 111 and the second beam aperture 122 allows for better matching and coupling between the suppression cavity 12 and the first cavity 11, enhancing the stability between them.

[0063] Reference Figure 3 , Figure 4 and Figure 5 In some possible embodiments of this application, the suppression cavity 12 includes a first nasal cone 123 and a second nasal cone 124; the first nasal cone 123 is circumferentially arranged around the first beam aperture 121, and the second nasal cone 124 is circumferentially arranged around the second beam aperture 122; both the first nasal cone 123 and the second nasal cone 124 are recessed toward the interior of the suppression cavity 12, so that the inner surfaces of the first nasal cone 123 and the second nasal cone 124 are close to each other.

[0064] In this embodiment, the first nose cone 123 is arranged around the first beam aperture 121. The first nose cone 123 can focus the electron beam, enabling the electron beam to pass stably through the first beam aperture 121 and reducing energy loss during transmission. The first nose cone 123 can also withstand electrons accelerated in the opposite direction, reducing the outflow of electrons from the first beam aperture 121. The inner surfaces of the first nose cone 123 and the second nose cone 124 are close to each other, which can optimize the shape of the accelerating electric field established in the suppression cavity 12.

[0065] In this embodiment, both the first nose cone 123 and the second nose cone 124 are recessed towards the interior of the suppression cavity 12. The shape of the recess can be conical or similar. The recessed structure can optimize the field shape of the second point magnetic field within the suppression cavity 12, focusing the forward-accelerated electrons (i.e., electrons accelerated from the electron gun 2 towards the first cavity 11) and defocusing the reverse-accelerated electrons (i.e., electrons returning from the first cavity 11 towards the electron gun 2). The reverse-accelerated electrons will eventually hit the first nose cone 123 and be intercepted by it, thus achieving the effect of suppressing electron back-bombardment.

[0066] Reference Figure 3 , Figure 4 and Figure 5In some possible embodiments of this application, the first nose cone 123 has a first bottom surface 1231 along the radial direction of the first beam aperture 121, and the second nose cone 124 has a second bottom surface 1241 along the radial direction of the second beam aperture 122, wherein the area of ​​the first bottom surface 1231 is larger than the area of ​​the second bottom surface 1241.

[0067] In this embodiment, since both the first nose cone 123 and the second nose cone 124 are recessed towards the interior of the suppression cavity 12, the first nose cone 123 and the second nose cone 124 have two opposing surfaces inside the suppression cavity 12. The first bottom surface 1231 can be understood as the inner surface of the first nose cone 123 facing the second nose cone 124, and the second bottom surface 1241 can be understood as the inner surface of the second nose cone 124 facing the first nose cone 123. The first bottom surface 1231 and the second bottom surface 1241 can form a focusing electric field, reducing electron scattering and enabling the electron beam to be stably transmitted from the second beam aperture to the next accelerating cavity.

[0068] In this embodiment, since the first nose cone 123 is arranged circumferentially around the first beam hole 121, and the first beam hole 121 is connected to the electron gun 2, when the area of ​​the first bottom surface 1231 of the first nose cone 123 is large, it can withstand more reverse-accelerated electrons (that is, electrons that are bombarded back from the first cavity 11 to the electron gun 2), reducing the amount of electrons flowing out of the first beam hole 121.

[0069] In this embodiment, since the second nose cone 124 is arranged circumferentially around the second beam aperture 122, and the second beam aperture 122 is connected to the first cavity 11, when the area of ​​the second bottom surface 1241 of the second nose cone 124 is small, the scattering of electrons can be reduced, so that the electron beam can be stably transmitted from the second beam aperture 122 to the next acceleration cavity 14.

[0070] Reference Figure 3 , Figure 4 and Figure 5 In some possible embodiments of this application, the edges of the first nasal cone 123, the second nasal cone 124, and the suppression cavity 12 are all rounded.

[0071] In this embodiment, the size and shape of the rounded corners can be determined according to the specific needs of the equipment and the working environment. The design of the rounded corner transition is coordinated with the shape and size of other components to improve the overall performance and stability of the electron beam accelerator tube 1.

[0072] In this embodiment, the edges of the first nose cone 123, the second nose cone 124, and the suppression cavity 12 refer to the transition edges between the first nose cone 123, the second nose cone 124, and the gas inner wall of the suppression cavity 12 inside the suppression cavity 12. These edges are rounded transitions, which can optimize the streamline of the inner wall of the suppression cavity 12 and suppress electrical breakdown caused by the tip effect.

[0073] In this embodiment, when the edges between the first nose cone 123, the second nose cone 124, and the suppression cavity 12 are sharp, the electron beam may be affected by non-uniform electric or magnetic fields, causing the electron beam trajectory to deviate. Compared to the previous method, a rounded transition provides a smooth transition region, allowing the electron beam to pass through more stably and reducing scattering.

[0074] In the electron beam accelerator tube 1 of this application embodiment, the edges of the first nose cone 123, the second nose cone 124 and the suppression cavity 12 are all rounded to suppress electrical breakdown caused by the tip effect, thereby providing a more stable acceleration environment and contributing to the stable transmission of the electron beam.

[0075] Reference Figure 5 and Figure 6 In some possible embodiments of this application, the electron beam accelerating tube 1 further includes a coupling cavity 13 and an accelerating cavity 14. The first cavity 11, the coupling cavity 13 and the accelerating cavity 14 are connected through a coupling hole 15. The coupling hole 15 is eccentrically arranged relative to the central axis of the first cavity 11. The accelerating cavity 14 is used to accelerate the electron beam.

[0076] In this embodiment, the first cavity 11 and the coupling cavity 13 form a whole. Since the standing wave accelerator primarily operates in π / 2 mode, the electric field distribution within the accelerating tube exhibits a specific periodicity in π / 2 mode. The electric fields in two adjacent accelerating cavities 14 differ in phase by π / 2, or half a period. This electric field distribution allows electrons to achieve stable acceleration as they pass through the accelerating cavity 14. Therefore, the electric field is excited within the first cavity 11. In π / 2 mode, the electric field is mainly distributed within the first cavity 11, providing the energy required for beam acceleration. The magnetic field, on the other hand, is mainly distributed near the coupling aperture 15, used to achieve power coupling between the first cavity 11, the coupling cavity 13, and the accelerating cavity 14. This distribution pattern facilitates efficient beam acceleration and power transmission.

[0077] In this embodiment, the coupling aperture 15 is offset from the central axis of the first cavity 11, meaning the coupling aperture 15 and the first cavity 11 are not coaxial. The coupling aperture 15 is located in a region far from the axis of the first cavity 11. The coupling aperture 15 can couple inter-cavity power through a magnetic field. The coupling aperture 15 couples power from one first cavity 11 to the accelerating cavity 14 through a magnetic field, which helps maintain the stability and efficiency of the electron beam accelerating tube 1. Through the coupling aperture 15, energy can be efficiently transferred between the first cavity 11 and the accelerating cavity 14, thereby achieving continuous acceleration of the electron beam.

[0078] In this embodiment, the strength and efficiency of the coupling between the first cavity 11 and the acceleration cavity 14 depend on a variety of factors, including the size, shape, and position of the coupling hole 15, as well as the relative position and distance between the cavities.

[0079] The electron beam accelerating tube 1 of this application embodiment achieves efficient coupling of power between cavities, which not only improves the stable acceleration of electrons when passing through the accelerating cavity 14, but also optimizes the power transfer efficiency between the first cavity 11 and the accelerating cavity 14 through the eccentrically set coupling hole 15.

[0080] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made based on the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An electron beam accelerator tube, characterized in that, include: The first cavity can generate a first electromagnetic field inside, and the first cavity is used to accelerate the electron beam emitted by the electron gun through the first electromagnetic field, and the first electromagnetic field has a leakage field. A suppression cavity is disposed between the first cavity and the electron gun. The suppression cavity establishes a second electromagnetic field within itself through the leakage field, and the intensity of the second electromagnetic field is higher than the intensity of the leakage field. The second electromagnetic field is used to suppress the movement of electrons in the electron beam toward the electron gun. The suppression cavity includes a first beam aperture and a second beam aperture. The first beam aperture is connected to the electron gun, and the second beam aperture is connected to the first cavity. The radial dimension of the second beam aperture is larger than that of the first beam aperture, and the first beam aperture and the second beam aperture are coaxially arranged.

2. The electron beam accelerating tube according to claim 1, characterized in that, The suppression cavity is made of a high dielectric constant material to suppress thermal deformation of the suppression cavity.

3. The electron beam accelerating tube according to claim 2, characterized in that, The radial dimension of the suppression cavity is smaller than the radial dimension of the first cavity; the axial dimension of the suppression cavity is smaller than the axial dimension of the first cavity.

4. The electron beam accelerating tube according to claim 1, characterized in that, The first cavity includes a third beam aperture, which is coupled to the second beam aperture, and the third beam aperture has the same size as the second beam aperture.

5. The electron beam accelerator tube according to claim 1, characterized in that, The suppression cavity includes a first nose cone and a second nose cone; the first nose cone is circumferentially arranged around the first beam aperture, and the second nose cone is circumferentially arranged around the second beam aperture; both the first nose cone and the second nose cone are recessed towards the interior of the suppression cavity so that the inner surfaces of the first nose cone and the second nose cone are close to each other.

6. The electron beam accelerator tube according to claim 5, characterized in that, The first nose cone has a first bottom surface along the radial direction of the first beam aperture, and the second nose cone has a second bottom surface along the radial direction of the second beam aperture, wherein the area of ​​the first bottom surface is larger than the area of ​​the second bottom surface.

7. The electron beam accelerator tube according to claim 6, characterized in that, The edges of the first nasal cone, the second nasal cone, and the inhibition cavity are all rounded.

8. The electron beam accelerating tube according to claim 1, characterized in that, It also includes a coupling cavity and an accelerating cavity, wherein the first cavity, the coupling cavity and the accelerating cavity are connected by a coupling hole; the coupling hole is eccentrically positioned relative to the central axis of the first cavity; the accelerating cavity is used to accelerate the electron beam.

9. An electron beam accelerator, characterized in that, An electron gun is used to generate an electron beam; The electron beam accelerator tube according to any one of claims 1 to 8, wherein the suppression cavity of the electron beam accelerator tube is connected to the electron gun.

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