Electron gun with controllable electron beam shape

Abstract

The embodiment of the invention discloses an electron gun with a controllable electron beam shape, which can be applied to the technical field of electronics. According to the embodiment of the invention, after the plasma generation module for generating the plasma and the plasma acceleration module comprising the electron beam channels of various shape structures are arranged in the electron gun, the plasma generated by the plasma generation module is accelerated through the plasma acceleration module; and the target electron beam is sent to the target vacuum tube, so that the electron beam with the target shape can be obtained without changing a focusing electrode through a Pearls electron gun, the electron beams with different interface shapes can be provided, and the engineering technical difficulty is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to an electron gun with controllable electron beam shape. Background Technology

[0002] In related technologies, for O-type vacuum tubes, a Pierce electron gun is generally used to provide the electron beam, transferring its kinetic energy to the high-frequency field as it passes through a slow-wave circuit. For centimeter-wave O-type vacuum tubes, the slow-wave circuit characteristics are suitable for electron beams with a circular cross-section; while for millimeter-wave and terahertz-wave O-type vacuum tubes, the slow-wave circuit characteristics require electron beams with a strip-shaped cross-section. The Pierce electron gun is suitable for generating electron beams with a circular cross-section and is widely used in centimeter-wave O-type tubes. However, for millimeter-wave and terahertz-wave O-type vacuum tubes, the conversion efficiency between a circular electron beam and the high-frequency field is low. Existing technologies, such as using a Pierce electron gun to obtain a flat, elliptical electron beam by changing the focusing electrode compression, have extremely high technical requirements, thus increasing the engineering difficulty.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] The main objective of this application is to propose an electron gun with controllable electron beam shape, which can effectively reduce engineering difficulty while providing electron beams with different cross-sectional shapes.

[0005] To achieve the above objectives, embodiments of this application propose an electron gun with controllable electron beam shape, the electron gun comprising: A plasma generation module, the plasma generation module being used to generate plasma; A plasma acceleration module is provided, which includes an electron beam channel with various shapes and structures. The plasma acceleration module is used to accelerate the plasma generated by the plasma generation module to generate a target electron beam with a shape and structure similar to that of the electron beam channel, and then send the target electron beam to a target vacuum tube.

[0006] In some embodiments, the plasma generation module includes a plasma excitation power supply, an internal electrode, a switch, a plasma cavity, and a first capacitor. The internal electrode is connected to the negative terminal of the plasma excitation power supply via the switch; the plasma cavity is connected to the positive terminal of the plasma excitation power supply; the plasma excitation power supply, the switch, the internal electrode, and the plasma cavity form a first excitation closed loop, and the first capacitor, the switch, the internal electrode, and the plasma cavity form a second excitation closed loop; when the switch is closed, the gap between the internal electrode and the plasma cavity discharges to excite the plasma; the first capacitor is used to increase the excitation time of the plasma.

[0007] In some embodiments, the plasma generation module further includes an insulating component embedded between the inner electrode and the plasma cavity.

[0008] In some embodiments, the plasma acceleration module includes a plasma cavity, an electron acceleration power supply, a slow-wave support, a second capacitor, an acceleration electrode module, and an insulating spacer module; the plasma cavity, the electron acceleration power supply, and the slow-wave support form a first acceleration closed loop, and the plasma cavity, the slow-wave support, and the second capacitor form a second acceleration closed loop; the acceleration electrode module and the insulating spacer module are arranged at intervals, and each of the acceleration electrode module and the insulating spacer module has a through hole at its middle position, and a plurality of through holes form an electron beam channel; the plasma in the plasma cavity is accelerated through the electron beam channel to form a target electron beam of the target shape, and the target electron beam is sent to the target vacuum tube through the slow-wave support.

[0009] In some embodiments, the accelerating electrode module includes a plurality of accelerating electrodes, the insulating spacer module includes a plurality of insulating spacers, and the plurality of accelerating electrodes and the plurality of insulating spacers are arranged at intervals.

[0010] In some embodiments, a plurality of insulating spacers are provided with first square holes, and a plurality of accelerating electrodes are provided with second square holes; after the plurality of accelerating electrodes and the plurality of insulating spacers are arranged at intervals, all the first square holes and all the second square holes form a strip-shaped electron beam channel.

[0011] In some embodiments, a plurality of insulating spacers are provided with a first pentagonal star hole, and a plurality of accelerating electrodes are provided with a second pentagonal star hole; after the plurality of accelerating electrodes and the plurality of insulating spacers are arranged at intervals, all the first pentagonal star holes and all the second pentagonal star holes form a pentagonal electron beam channel.

[0012] In some embodiments, a plurality of first circular holes are provided on a plurality of insulating spacers, and a plurality of second circular holes are provided on a plurality of accelerating electrodes; after the plurality of accelerating electrodes and the plurality of insulating spacers are arranged at intervals, all the first pentagonal holes and all the second pentagonal holes form a multi-beam circular electron beam channel.

[0013] In some embodiments, the operation of the electron gun includes the following steps: After the switch in the plasma generation module is closed, the gap between the inner electrode and the plasma cavity discharges to excite the plasma, and the plasma diffuses to the entrance position of the electron beam channel after passing through the plasma cavity. The plasma acceleration module accelerates the plasma entering the electron beam channel and constrains the shape of the plasma before outputting the target electron beam of the target shape.

[0014] In some embodiments, the operation of the electron gun further includes the following steps: When the electron acceleration duration is less than the plasma supply time, the capacitance in the electron acceleration power supply is increased.

[0015] The embodiments of this application include at least the following beneficial effects: This application provides an electron gun with controllable electron beam shape. This solution, by setting a plasma generation module for generating plasma and a plasma acceleration module with electron beam channels including various shapes and structures inside the electron gun, accelerates the plasma generated by the plasma generation module through the plasma acceleration module to generate a target electron beam with a shape and structure similar to that of the electron beam channel, and sends the target electron beam to the target vacuum tube. Thus, it is possible to obtain an electron beam of the target shape without changing the focusing electrode through the Pierce electron gun, thereby providing electron beams with different interface shapes and effectively reducing engineering and technical difficulties. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the electron gun provided in an embodiment of this application; Figure 2 This is a circuit diagram of the electron gun provided in an embodiment of this application; Figure 3 This is a circuit diagram of an electron gun in the prior art; Figure 4 This is a front view schematic diagram of the strip electron beam electron gun provided in the embodiments of this application; Figure 5 This is provided by the embodiments of this application. Figure 4 A side view of the plasma acceleration module. Figure 6This is a front view schematic diagram of the pentagram electron beam electron gun provided in the embodiments of this application; Figure 7 This is provided by the embodiments of this application. Figure 6 A side view of the plasma acceleration module. Figure 8 This is a front view schematic diagram of the multi-beam circular electron beam electron gun provided in the embodiments of this application; Figure 9 This is provided by the embodiments of this application. Figure 8 A side view of the plasma acceleration module. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application.

[0018] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0019] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit the scope of this application.

[0021] In related technologies, for O-type vacuum tubes, a Pierce electron gun is generally used to provide the electron beam, transferring its kinetic energy to the high-frequency field as it passes through a slow-wave circuit. For centimeter-wave O-type vacuum tubes, the slow-wave circuit characteristics are suitable for electron beams with a circular cross-section; while for millimeter-wave and terahertz-wave O-type vacuum tubes, the slow-wave circuit characteristics require electron beams with a strip-shaped cross-section. The Pierce electron gun is suitable for generating electron beams with a circular cross-section and is widely used in centimeter-wave O-type tubes. However, for millimeter-wave and terahertz-wave O-type vacuum tubes, the conversion efficiency between a circular electron beam and the high-frequency field is low. Existing technologies, such as using a Pierce electron gun to obtain a flat, elliptical electron beam by changing the focusing electrode compression, have extremely high technical requirements, thus increasing the engineering difficulty.

[0022] In view of this, the present application provides an electron gun with controllable electron beam shape, which can effectively reduce engineering difficulty while providing electron beams with different cross-sectional shapes.

[0023] The embodiments of this application will be described in detail below with reference to the accompanying drawings: This application provides an electron gun with controllable electron beam shape. The electron gun includes a plasma generation module and a plasma acceleration module. The plasma generation module generates plasma; the plasma acceleration module has an electron beam channel with various shapes and structures; the plasma acceleration module accelerates the plasma generated by the plasma generation module to generate a target electron beam with a shape and structure similar to the electron beam channel, and sends the target electron beam to a target vacuum tube.

[0024] like Figure 1 and Figure 2 As shown, the plasma generation module includes a plasma excitation power supply, an inner electrode 110, a switch, a plasma cavity 120, and a first capacitor. The inner electrode 110 is connected to the negative terminal of the plasma excitation power supply via the switch; the plasma cavity 120 is connected to the positive terminal of the plasma excitation power supply; the plasma excitation power supply, the switch, the inner electrode, and the plasma cavity form a first excitation closed loop, and the first capacitor, the switch, the inner electrode, and the plasma cavity form a second excitation closed loop; when the switch is closed, the gap between the inner electrode and the plasma cavity discharges to excite the plasma; the first capacitor is used to increase the excitation time of the plasma.

[0025] Specifically, such as Figure 1 and Figure 2 As shown, the plasma generation module of this embodiment also includes an insulating component 130, which is embedded between the inner electrode 110 and the plasma cavity 120. Both the inner electrode and the plasma cavity are made of conductive material, and the insulating component is made of insulating material.

[0026] like Figure 1 and Figure 2 As shown, the plasma acceleration module includes a plasma cavity 120, an electron acceleration power supply, a slow-wave support 140, a second capacitor, an acceleration electrode module 160, and an insulating spacer module 150. The plasma cavity, the electron acceleration power supply, and the slow-wave support form a first acceleration closed loop, and the plasma cavity, the slow-wave support, and the second capacitor form a second acceleration closed loop. The acceleration electrode module and the insulating spacer module are arranged at intervals, and each of the acceleration electrode module and the insulating spacer module has a through hole in the middle position. Several through holes form an electron beam channel 170. The plasma in the plasma cavity 120 is accelerated through the electron beam channel 170 to form a target electron beam of the target shape, and the target electron beam is sent to the target vacuum tube through the slow-wave support 140.

[0027] Specifically, the accelerating electrode module includes several accelerating electrodes, and the insulating spacer module includes several insulating spacers, with the accelerating electrodes and insulating spacers arranged alternately. The plasma cavity, accelerating electrodes, and slow-wave support are all made of conductive materials, while the insulating spacers are made of insulating materials.

[0028] It is understandable that, such as Figure 3 As shown, in the prior art, when the electron gun is in operation, after the internal electrode directly ignites and excites plasma from the plasma cavity, the circuit is turned on, the external circuit of the plasma excitation power supply is short-circuited, and it enters a power-off protection state. However, the capacitive devices in the plasma excitation power supply have limited energy storage and cannot provide sufficient plasma. Furthermore, the presence of internal resistance in the plasma excitation power supply causes repeated on-off switching of plasma excitation, resulting in a discontinuous plasma that cannot provide a stable and continuous plasma for the electron acceleration system. In addition, during plasma acceleration, the plasma is discontinuous. Although the presence of resistance may increase the total duration of the electron beam, the discontinuous electron beam formed by the prior art means that the duration of a single electron beam does not reach the minimum oscillation time (10 ns) of the slow-wave circuit, thus insufficient to excite electromagnetic waves. Moreover, the fixed shape of the electron beam channel in the prior art results in a fixed shape of the formed electron beam, making it impossible to produce electron beams with different cross-sectional shapes.

[0029] It is understood that, in this embodiment of the application, a second excitation closed loop can be added by adding a first capacitor to the plasma generation module. Figure 2In the circuit shown, when the switch is closed, the gap between the inner electrode and the plasma cavity discharges continuously, forming a continuous plasma within the plasma cavity, thereby providing the corresponding electron beam for the O-type vacuum tube. Specifically, during discharge between the inner electrode and the plasma cavity, the inner electrode and the plasma cavity are connected, the voltage is divided across the internal resistor of the power supply, and the discharge stops; after the discharge stops, the voltage is divided back across the gap between the inner electrode and the plasma cavity, and the gap between the inner electrode and the plasma cavity re-discharges; that is, an oscillating gap discharge is formed between the inner electrode and the plasma cavity, which will result in the formation of an oscillating electron beam. Simultaneously, this embodiment eliminates the resistor on the second acceleration closed loop in the plasma acceleration module. When plasma is excited out of the plasma cavity, the electron beam is drawn into the electron beam channel and accelerated sequentially between the accelerating electrodes until it enters the slow-wave support cavity, thereby obtaining the desired electron beam.

[0030] It is understandable that, such as Figure 4 and Figure 5 As shown, each of the plurality of insulating spacers has a first square hole, and each of the plurality of accelerating electrodes has a second square hole; after the plurality of accelerating electrodes and the plurality of insulating spacers are arranged at intervals, all the first square holes and all the second square holes form a strip-shaped electron beam channel 171. In this embodiment of the application, by setting the intermediate channel between the accelerating electrode and the insulating spacer as a strip, the electron beam channel is also strip-shaped, thereby allowing a strip-shaped electron beam to be emitted from the end of the insulating spacer.

[0031] It is understandable that, such as Figure 6 and Figure 7 As shown, several insulating spacers are provided with first pentagonal holes, and several accelerating electrodes are provided with second pentagonal holes. After the several accelerating electrodes and several insulating spacers are arranged at intervals, all the first pentagonal holes and all the second pentagonal holes form a pentagonal electron beam channel 172. In this embodiment, by setting the middle channel between the accelerating electrodes and the insulating spacers to a pentagonal shape, the electron beam channel is also pentagonal in shape, thereby allowing a pentagonal-shaped electron beam to be emitted from the end of the insulating spacers.

[0032] It is understandable that, such as Figure 8 and Figure 9 As shown, several insulating spacers each have multiple first circular holes, and several accelerating electrodes each have multiple second circular holes. When the accelerating electrodes and insulating spacers are arranged at intervals, all the first pentagonal holes and all the second pentagonal holes form a multi-beam circular electron beam channel 173. In this embodiment, by setting a multi-beam circular hole in the middle channel between the accelerating electrode and the insulating spacer, the electron beam channel becomes a multi-beam circular channel, thereby allowing multiple circular electron beams to be emitted from the ends of the insulating spacers.

[0033] Understandably, when the electron gun is needed, the plasma generation module and plasma acceleration module of the electron gun are placed in a low-pressure environment, and the circuits of the electron acceleration power supply and plasma excitation power supply are connected. Specifically, when the switch in the plasma generation module is closed, the gap between the inner electrode and the plasma cavity discharges to excite the plasma. The plasma diffuses through the plasma cavity to the entrance of the electron beam channel. The plasma acceleration module accelerates the plasma entering the electron beam channel and constrains its shape, then outputs the target electron beam with the target shape. When the electron acceleration duration is less than the plasma supply time, the electron beam duration can be increased by increasing the capacitance in the electron acceleration power supply.

[0034] Specifically, the electron gun operation in this embodiment is divided into a plasma acquisition process and an electron beam acquisition process. During the plasma acquisition process, when the switch of the plasma generation module is closed, the gap between the inner electrode and the plasma cavity (outer electrode) discharges to excite the plasma, and the plasma continues to diffuse until it reaches the entrance of the electron beam channel, and may even fill the internal space of the plasma cavity.

[0035] During electron beam acquisition, the plasma near the electron beam channel entrance is accelerated by the plasma acceleration module, drawing electrons into the electron beam channel. Plasma from other locations within the plasma cavity and plasma generated by the plasma generation module replenish the area near the electron beam channel entrance. Meanwhile, positively charged ions bombard the plasma cavity and inner electrodes. Electrons continuously bombard the first accelerating electrode, causing it to become negatively charged and its potential to gradually decrease until it reaches a level where it can no longer bombard the first accelerating electrode. This generates a dynamic induced electrostatic field within the electron channel, achieving dynamic electrostatic focusing and confining the electrons to fill the electron beam channel, thus obtaining an electron beam with a shape approximately similar to the electron beam channel. Subsequently, electrons bombard the second, third, ..., nth accelerating electrodes sequentially, further increasing the electron velocity aspect ratio (longitudinal velocity / lateral velocity). Furthermore, the greater the voltage between the plasma cavity and the slow-wave support, the greater the distance between them, and the smaller the electron beam channel, the greater the electron velocity aspect ratio (longitudinal velocity / lateral velocity).

[0036] During the operation of the electron gun, when the electron acceleration duration is less than the plasma supply time, increasing the capacitance in the electron acceleration power supply can effectively increase the electron beam duration. However, when the electron acceleration duration is greater than the plasma supply time, increasing the capacitance in the electron acceleration power supply cannot effectively increase the electron beam duration. In this embodiment, after the electron beam is accelerated by the accelerating electrode, it is injected into the slow-wave support in the shape of the electron beam channel (ribbon, pentagram, multi-beam). The greater the electron velocity and the greater the aspect ratio of the electron velocity, the longer the effective range of the electron beam that can be applied by the O-type vacuum tube slow-wave circuit. Simultaneously, this embodiment... Figure 2 The circuit diagram of the electron gun shown is used to assist in the operation, so that the duration of the electron beam generated by the electron gun in this embodiment of the application (>10ns) is greater than the threshold time for the slow wave circuit to start oscillation, thereby providing the vacuum tube with a compliant electron beam.

[0037] As can be seen from the above, the electron gun in this application embodiment can generate electron beams of multiple shapes, thereby adapting to millimeter-wave and terahertz O-type vacuum tubes to improve interaction efficiency and power.

[0038] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0039] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0040] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0041] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0042] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. An electron gun with controllable electron beam shape, characterized in that, The electron gun comprises: a plasma generating module for generating plasma; a plasma accelerating module, wherein an electron beam channel is arranged in the plasma accelerating module, and the electron beam channel comprises a plurality of shape structures; the plasma accelerating module is used for accelerating the plasma generated by the plasma generating module to generate a target electron beam with a shape similar to that of the electron beam channel, and sending the target electron beam to a target vacuum tube.

2. The electron gun of claim 1, wherein The plasma generating module comprises a plasma excitation power supply, an inner electrode, a switch, a plasma cavity and a first capacitor; the inner electrode is connected to a negative electrode of the plasma excitation power supply through the switch; the plasma cavity is connected to a positive electrode of the plasma excitation power supply; the plasma excitation power supply, the switch, the inner electrode and the plasma cavity form a first excitation closed loop, and the first capacitor, the switch, the inner electrode and the plasma cavity form a second excitation closed loop; when the switch is closed, a gap between the inner electrode and the plasma cavity discharges to excite plasma; and the first capacitor is used for increasing the excitation time of the plasma.

3. The electron gun of claim 2, wherein, The plasma generating module further comprises an insulating component inlaid between the inner electrode and the plasma cavity.

4. The electron gun of claim 2, wherein, The plasma accelerating module comprises the plasma cavity, an electron accelerating power supply, a slow wave support, a second capacitor, an accelerating electrode module and an insulating spacer module; the plasma cavity, the electron accelerating power supply and the slow wave support form a first accelerating closed loop, and the plasma cavity, the slow wave support and the second capacitor form a second accelerating closed loop; the accelerating electrode module and the insulating spacer module are arranged in intervals, and a through hole is arranged in the middle position of the accelerating electrode module and the insulating spacer module; a plurality of through holes form an electron beam channel; the plasma in the plasma cavity is accelerated through the electron beam channel to form a target electron beam with a target shape, and the target electron beam is sent to the target vacuum tube through the slow wave support.

5. The electron gun of claim 4, wherein, The accelerating electrode module comprises a plurality of accelerating poles, and the insulating spacer module comprises a plurality of insulating spacers.

6. The electron gun of claim 5, wherein, A first square hole is arranged on each of the plurality of insulating spacers, and a second square hole is arranged on each of the plurality of accelerating poles; after the plurality of accelerating poles and the plurality of insulating spacers are arranged in intervals, all the first square holes and all the second square holes form a strip-shaped electron beam channel.

7. The electron gun of claim 5, wherein, A first pentagonal hole is arranged on each of the plurality of insulating spacers, and a second pentagonal hole is arranged on each of the plurality of accelerating poles; after the plurality of accelerating poles and the plurality of insulating spacers are arranged in intervals, all the first pentagonal holes and all the second pentagonal holes form a pentagonal electron beam channel.

8. The electron gun of claim 5, wherein, A plurality of first circular holes are arranged on each of the insulating spacers, and a plurality of second circular holes are arranged on each of the accelerating electrodes; after the accelerating electrodes and the insulating spacers are arranged at intervals, all the first pentagonal holes and all the second pentagonal holes form a plurality of injection circular electron beam channels.

9. The electron gun of claim 4, wherein, The working process of the electron gun comprises the following steps: After the switch in the plasma generation module is closed, the gap between the inner electrode and the plasma cavity discharges to excite the plasma, and the plasma diffuses to the entrance position of the electron beam channel after passing through the plasma cavity; The plasma acceleration module accelerates the plasma entering the electron beam channel and constrains the shape of the plasma, and then outputs the target electron beam with a target shape.

10. The electron gun of claim 9, wherein, The working process of the electron gun further comprises the following steps: When the electron acceleration survival time is less than the plasma supply time, the capacitance capacity in the electron acceleration power supply is increased.

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