Strip-shaped multi-beam electron gun

Abstract

The application discloses a strip-shaped multi-beam electron gun, and relates to the technical field of electronic devices, which comprises a cathode array assembly, a multi-beam focusing electrode assembly and a multi-beam anode assembly arranged in sequence along an electron transmission direction; the cathode array assembly is composed of a plurality of array-distributed emission cathodes for emitting electron beams; an acceleration electric field is formed between the cathode array assembly and the multi-beam anode assembly; the multi-beam focusing electrode assembly is arranged on the emission side of the cathode array assembly; the grooves and the baffles of the multi-beam focusing electrode assembly are used for compressing and controlling the shape, size and beam waist position of the multi-electron beams, so that the effect of focusing multi-electron beams by a single focusing electrode is achieved; the plurality of anode channels, the plurality of focusing holes and the plurality of emission cathodes are coaxially arranged in one-to-one correspondence; the electrons emitted by the emission cathodes enter the size-gradually-changing anode channels after being accelerated by the electric field and compressed and shaped by the focusing electrode, so that the multi-beam strip-shaped electron beam output with large current and high quality is realized, and the guarantee of the electron source for the high-power output of the terahertz source is provided.

Description

Technical Field

[0001] This application relates to the field of electronic device technology, and in particular to a strip-shaped multi-beam electron gun. Background Technology

[0002] Vacuum electronic devices, due to their significant characteristics such as high power and high efficiency, are widely used in wireless communication, high-precision radar, electronic warfare, and biomedical imaging. The strip-beam traveling wave tube (TWT), as a type of vacuum electronic terahertz amplifier, possesses advantages such as wide bandwidth, high power, miniaturization, and high gain. The electron optical system is the core component of the TWT, used to generate and transmit a high-quality strip electron beam and interact with the input signal to provide energy for signal amplification; the electron gun, as an important part of the electron optical system, is the core of electron beam generation and transmission.

[0003] In related technologies, increasing the electron beam current can significantly improve the power of traveling wave tubes. However, traditional single-beam electron guns are limited by the space charge effect; when the current exceeds a certain threshold, the electron beam divergence angle increases sharply, making it difficult to meet the requirements of terahertz devices for high compression ratios and high-current electron beams. Multi-beam electron guns, through a "multi-beam parallel" approach, overcome the single-beam current bottleneck and have become the mainstream solution for high-current output. Therefore, strip-shaped multi-beam integration technology is currently a highly promising power enhancement technology. However, multi-beam electron guns suffer from limited consistency control effects among multiple cathodes, mutual interference between multiple electron beams, and the need for multi-focusing electrode structures to focus multiple electron beams, resulting in complex and bulky structures. It is difficult to simultaneously achieve compact structure, high stability of multiple beams, and high current, thus hindering its practical application.

[0004] Therefore, how to simultaneously achieve a compact structure, high stability of multiple electron beams, and large current, while realizing the effect of focusing multiple electron beams with a single focusing electrode, has become an urgent problem to be solved in the design of strip-shaped multi-beam electron guns. Summary of the Invention

[0005] The main objective of this application is to propose a strip-shaped multi-beam electron gun, aiming to solve the technical problem of simultaneously achieving compact structure, high stability of multiple beams, and high current in the design of a strip-shaped multi-beam electron gun.

[0006] On the one hand, a strip-shaped multi-beam electron gun is provided, including a cathode array assembly, a multi-beam focusing electrode assembly and a multi-beam anode assembly arranged sequentially along the electron transport direction;

[0007] The multi-injection anode assembly includes an anode plate and a plurality of anode channels disposed on the anode plate;

[0008] The cathode array assembly includes multiple emitting cathodes, each of which is used to emit electrons, and an accelerating electric field region is formed between the cathode array assembly and the multi-beam anode assembly.

[0009] The multi-beam focusing electrode assembly is located on the emission side of the cathode array assembly and has multiple focusing channels. The multiple anode channels, the multiple focusing channels and the multiple emitting cathodes correspond one-to-one and are coaxially arranged.

[0010] The multi-beam focusing electrode assembly includes a focusing body, multiple grooves and multiple baffles disposed on the emission side of the focusing body, multiple focusing channels disposed on the focusing body, and baffles disposed on both sides of each focusing channel, with the baffles disposed in the grooves.

[0011] Electrons emitted from each of the emitting cathodes are compressed into electron beams through the corresponding grooves and baffles. Each electron beam is accelerated by the accelerating electric field region and output through the corresponding anode channels to form multiple ribbon-shaped electron beams.

[0012] In one embodiment, the plurality of emitting cathodes are arranged in an array; the plurality of grooves correspond to the array of emitting cathodes arranged in multiple rows.

[0013] In one embodiment, the length of each groove is 8 mm to 12 mm, and the cross-section of each groove in its length direction is semi-arc.

[0014] In one embodiment, the baffles on both sides of each of the emitting cathodes are distributed in a mirror-symmetric manner about their vertical center lines.

[0015] In one embodiment, the focusing channel is arranged around a corresponding emitting cathode that is coaxially disposed;

[0016] A gap of 0.1 mm to 0.3 mm is formed between the focusing channel and the corresponding coaxially arranged emitting cathode.

[0017] In one embodiment, the emitting surface of the emitting cathode is elliptical, and the cross-section of the focusing channel in the electron transport direction is elliptical.

[0018] The long side of each of the channel sections is greater than the long side of the emission surface of the corresponding emission cathode arranged coaxially, and the short side of each of the channel sections is greater than the short side of the emission surface of the corresponding emission cathode arranged coaxially.

[0019] In one embodiment, the emitting surface of the emitting cathode is a plane or a concave surface.

[0020] In one embodiment, in the electron transport direction, the inner diameter of each of the anode channels gradually decreases from its input side to its output side.

[0021] In one embodiment, the multi-anode assembly further includes multiple drift tubes, and the anode plate has multiple protrusions on the side near the cathode array assembly. The multiple protrusions are arranged in a row corresponding to the multiple emitting cathodes distributed in the array, and the anode channel is arranged through the corresponding protrusions.

[0022] Multiple drift tubes are disposed on the side of the anode plate opposite to the cathode array assembly. Each drift tube is arranged one-to-one with a plurality of protrusions and is connected to the corresponding anode channel.

[0023] In one embodiment, the plurality of emitting cathodes are arranged in an array, wherein the number of rows of the plurality of emitting cathodes arranged in the array is defined as m and the number of columns is n;

[0024] Where: n≥m, n is a positive integer greater than or equal to 2, and m is a positive integer greater than or equal to 1;

[0025] And / or, in a row of multiple emitting cathodes, the center-to-center distance between adjacent emitting cathodes is 1.0 mm to 2.5 mm; in a column of multiple emitting cathodes, the center-to-center distance between adjacent emitting cathodes is 4.5 mm to 6.5 mm.

[0026] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects:

[0027] Setting up multiple emitting cathodes can reduce the magnitude of the single electron beam current; multiple anode channels, multiple focusing channels, and multiple emitting cathodes are one-to-one and coaxially arranged, which can reduce mutual interference between electrons and achieve a compact structural design, while also enabling parallel emission of multiple electron beams; a compact design is achieved by focusing multiple electron beams with a single focusing electrode, and the total output current of multiple parallel electron beams is increased.

[0028] Each focusing channel of the multi-beam focusing electrode assembly is used to initially constrain the electrons emitted by the corresponding emitting cathode. The grooves and baffles on the exit side of the focusing body are used to compress and control the shape, size, and waist position of the electron beam, thereby constraining electron diffusion, reducing mutual interference between electrons, improving beam stability, and achieving the effect of focusing multiple electron beams with a single focusing electrode. An accelerating electric field region is formed between the cathode array assembly and the multi-beam anode assembly. This accelerating electric field region applies a continuous accelerating force to the electron beams constrained and focused by the multi-beam focusing electrode assembly and restricts divergence, thereby limiting the transmission path of the electron beams and calibrating the transmission paths of the multiple electron beams to be parallel to each other. After the multiple electron beams are accelerated by kinetic energy in the accelerating electric field region, they are output through multiple anode channels to form multiple strip-shaped electron beams, achieving stable high-current output of multiple electron beams. This solves the technical problem of simultaneously achieving compact structure, high stability of multiple beams, and high current in the design of strip-shaped multi-beam electron guns, and further improves the power of the terahertz traveling wave tube used in strip-shaped multi-beam electron guns. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 This is a partial structural schematic diagram of an embodiment of the strip-shaped multi-electron gun of this application;

[0031] Figure 2 This is a structural schematic diagram from another perspective of an embodiment of the strip-shaped multi-electron gun of this application;

[0032] Figure 3 This is a schematic diagram of the structure of an embodiment of the multi-anode assembly of this application;

[0033] Figure 4 This is a partial schematic diagram of an embodiment of the multi-anode assembly of this application;

[0034] Figure 5 This is a schematic diagram of the structure of one embodiment of the multi-beam focusing electrode assembly of this application;

[0035] Figure 6 This is a partial schematic diagram of an embodiment of the multi-beam focusing electrode assembly of this application;

[0036] Figure 7 This is a diagram showing the electric field line distribution between the anode and cathode at the xoz section at y=0.8mm in this application.

[0037] Figure 8 This is a diagram showing the electric field line distribution between the anode and cathode at the yoz cross section at x=2.5mm in this application.

[0038] Figure 9 This is a schematic diagram of the xoz cross-section of the trajectory of four electron beams emitted when multiple emitting cathodes of this application are arranged in a 2×2 configuration;

[0039] Figure 10 This is a schematic diagram of the yoz cross-section of the trajectory of four electron beams emitted when multiple emitting cathodes of this application are arranged in a 2×2 configuration;

[0040] Figure 11 Cross-sectional views of four electron beams at the cathode emission surface and at the beam waist when multiple emitting cathodes of this application are arranged in a 2×2 configuration;

[0041] Figure 12 This is a graph showing the variation of the single-beam electron injection current with transmission distance in this application;

[0042] Figure 13 The graph shows the total current curve of the electron gun in this application after iterative simulation.

[0043] Explanation of icon numbers:

[0044] 110. Emitting cathode;

[0045] 200. Multi-beam focusing electrode assembly; 210. Focusing channel; 220. Focusing body; 230. Groove; 240. Baffle;

[0046] 300. Multi-injection anode assembly; 310. Anode channel; 320. Anode plate; 321. Boss; 330. Drift tube;

[0047] 400, Accelerating electric field region.

[0048] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0050] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0051] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0052] Vacuum electronic devices, due to their significant characteristics such as high power and high efficiency, are widely used in wireless communication, high-precision radar, electronic countermeasures, and biomedical imaging. Strip-beam traveling wave tubes (TBWTs), as a type of vacuum electronic terahertz amplifier, possess advantages such as wide bandwidth, high power, miniaturization, and high gain, making them a highly competitive research hotspot. The electron optical system is the core component of the TWT, used to generate and transmit high-quality strip electron beams and interact with the input signal to provide energy for signal amplification. The electron gun, as an important component of the electron optical system, is the core of electron beam generation and transmission. In the field of high-power terahertz technology, the performance of the electron gun directly determines the output power, operating efficiency, and long-term stability of the terahertz TWT. The terahertz band has wavelengths in the sub-millimeter to micrometer range (corresponding to frequencies of 0.1-10 THz), placing stringent requirements on the current density, divergence, and consistency of multiple electron beams. In related technologies, the commonly used electron gun structures are no longer sufficient to meet the needs of technological upgrades, and electron beam generation and control technology has become the core bottleneck restricting breakthroughs in the performance of terahertz devices. As operating frequencies increase, the size of traveling wave tubes (TWTs) will further shrink. Due to the size co-travel effect, the power levels of commonly used terahertz TWTs are insufficient to meet the output power requirements of advanced terahertz application systems. In related technologies, the electron beam current is increased to significantly improve the power of the TWT. However, because the electron guns commonly used in these technologies are limited by the space charge effect, the electron beam divergence angle increases sharply when the current exceeds a certain threshold, making it difficult to meet the requirements of terahertz devices for high compression ratios and high-current electron beams. Multi-beam electron guns, through the "multi-beam parallel" approach, break through the single-beam current bottleneck and have become the mainstream solution for high-current output. However, most research on strip-shaped multi-beam electron devices focuses on high-frequency systems, and their electron optics systems are still underdeveloped.

[0053] The numerous core technological bottlenecks faced by multi-beam electron guns severely restrict their application in terahertz devices: 1. There is still a lack of effective technical solutions for the uniform control of the space charge field near the multi-cathode structure. The uniform distribution of the space charge field is the core prerequisite for the electron gun to generate electron beams with regular shapes. Differences in the current field distribution can easily cause the initial shape of the electron beam to deviate from the design target, affecting the subsequent focusing and transmission effects; 2. There are significant inter-beam interactions during the generation and transmission of multiple electron beams. The space charge repulsion between adjacent electron beams will directly cause electron beam shape distortion, which in turn leads to a decrease in the matching degree between the electron beam and the channel, ultimately resulting in a decrease in electron beam flux; 3. The device has extremely high requirements for processing and assembly precision. Small errors in processing (such as the flatness of the cathode emitting surface and the channel size tolerance) or assembly (such as the coaxiality of multiple beams and the electrode spacing) may disrupt the uniformity of the electric field distribution or the transmission trajectory of the electron beam, resulting in severe electron beam distortion and significantly weakening the overall performance of the device. The limited consistency control effect of multiple cathodes in multi-beam electron guns, mutual interference between multiple electron beams, and the need to use multiple focusing electrode structures to focus multiple electron beams, which results in complex and large structures, make it difficult to simultaneously achieve compact structure, high stability of multiple beams, and large current, thus restricting their practical application.

[0054] like Figure 1 , Figure 2 , Figure 3 As shown, in order to balance compact structure, high stability of multiple beams, and high current, embodiments of this application propose a strip-shaped multi-beam electron gun. The strip-shaped multi-beam electron gun is used to represent an electron gun that can simultaneously generate multiple flat strip-shaped electron beams, achieve the effect of focusing multiple electron beams with a single focusing electrode, and provide stable high-current output while maintaining a compact structure. By dispersing the single-beam current through multi-beam design and reducing space charge limitations, high total current output can be achieved at a lower accelerating voltage, while ensuring the consistency and stability of multi-beam electron beam emission. This breaks through the power bottleneck of terahertz traveling wave tubes and provides an electron source guarantee for the high-power output of terahertz sources.

[0055] In the embodiments of this application, the strip-shaped multi-beam electron gun includes a cathode array assembly, a multi-beam focusing electrode assembly 200, and a multi-beam anode assembly 300 arranged sequentially along the electron transport direction. The multi-beam anode assembly 300 includes an anode plate 320 and multiple anode channels 310 disposed on the anode plate 320. The cathode array assembly includes multiple emitting cathodes 110, each emitting cathode 110 for emitting electrons, and an accelerating electric field region 400 is formed between the cathode array assembly and the multi-beam anode assembly 300. The multi-beam focusing electrode assembly 200 is disposed on the emission side of the cathode array assembly and has multiple focusing channels 210. The multiple anode channels 310, multiple focusing channels 210, and multiple emitting cathodes 110 are one-to-one corresponding and coaxially arranged. The multi-beam focusing electrode assembly 200 includes a focusing body 220, multiple grooves 230 and multiple baffles 240 disposed on the emission side of the focusing body 220, multiple focusing channels 210 disposed on the focusing body 220, and baffles 240 disposed on both sides of each focusing channel 210, with the baffles 240 disposed within the grooves 230. Electrons emitted by each emitting cathode 110 are compressed through the corresponding grooves 230 and baffles 240 to form electron beams. Each electron beam is accelerated by the accelerating electric field region 400 and output through the corresponding anode channel 310 to form multiple strip-shaped electron beams. The grooves 230 and baffles 240 are used to compress and control the shape, size and waist position of the emitted electron beams, so that multiple electron beams are accelerated by the accelerating electric field region 400 and output through the multiple anode channels 310 to form multiple strip-shaped electron beams.

[0056] like Figure 2 , Figure 3 , Figure 4As shown, the cathode array assembly, the multi-beam focusing electrode assembly 200, and the multi-beam anode assembly 300 are arranged sequentially in the electron transport direction, enabling a compact design. Furthermore, only the multi-beam focusing electrode assembly 200 serves as the focusing electrode structure, without other focusing electrode structures, making the overall structure more compact through single-focusing electrode aggregation. The cathode array assembly, as the electron emitting part (i.e., electron source) of the electron gun, is used to emit electrons through thermoemission, field emission, etc. The cathode array assembly has multiple emitting cathodes 110, each emitting electron. After leaving the emitting surface of the emitting cathode 110, the emitted electrons, not being sufficiently constrained and accelerated, diverge due to space charge repulsion. The multi-beam focusing electrode assembly 200 is used to regulate the electric field distribution near the multiple emitting cathodes 110, constraining the electrons emitted by the multiple emitting cathodes 110, suppressing electron divergence, and to a certain extent avoiding distortion of the trajectories of the multiple electron beams. This, to a certain extent, ensures the consistency and stability of the emission of multiple electron beams and improves the electron beam flux. The multi-beam anode assembly 300 and the cathode array assembly are spaced apart, and an accelerating electric field region 400 is formed in the gap between them through the potential difference between them. The accelerating electric field region 400 accelerates the multiple electron beams, enabling the corresponding electron beams to obtain the required energy and form, thereby outputting multiple ribbon-shaped electron beams to guide them into the subsequent transmission channel. The distance between the multi-beam anode assembly 300 and the cathode array assembly is 4.0 mm to 8.0 mm, and can be any distance suitable for practical application, such as, but not limited to, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 7.0 mm, and 8.0 mm. It can also be within the size range of 4.0 mm to 5.5 mm, 5.5 mm to 8.0 mm, or other numerical ranges exceeding 4.0 mm to 8.0 mm, and is not limited here.

[0057] The arrangement of multiple emitting cathodes 110 can reduce the magnitude of the single-beam electron current. Each emitting cathode 110 in the cathode array assembly has an emitting surface. For example, the multiple emitting cathodes 110 can be arranged in an array, that is, the emitting surfaces of the multiple emitting cathodes 110 are arranged in an array. Figures 1 to 3In the diagram, the z-axis represents the direction of electron transport, the x-axis represents the direction of row arrangement, and the y-axis represents the direction of column arrangement. The number of rows (m) and columns (n) of the multiple emitting cathodes 110 arranged in an array are defined. The array of multiple emitting cathodes 110 can be a linear array (m=1 row, n≥2 columns, where n is a positive integer), a rectangular matrix (m≥2 rows, n≥2 columns, where m and n are positive integers), or other array structures set according to actual needs without limitation. Multiple anode channels 310, multiple focusing channels 210, and multiple emitting cathodes 110 are arranged in a one-to-one correspondence along a common central axis. The multiple anode channels 310 and multiple focusing channels 210 are also arranged in arrays, and their array distribution is the same as that of the multiple emitting cathodes 110. This reduces mutual interference between electrons, simplifies the structure, facilitates assembly, and enables a compact design. Simultaneously, it allows for parallel emission of multiple electron beams. Multiple emitting cathodes (110) are arranged in an array, reducing the single-beam current density and achieving a uniform electric field distribution. This reduces space charge repulsion and mitigates the adverse effects of space charge, thereby improving the uniformity and consistency of the multiple strip electron beams to some extent. While achieving a compact structure, it also increases the total output current of the parallel electron beams. With a single beam current of xA, multiple strip electron beams with a total current of m×n×xA can be generated, effectively reducing the space charge effect. This achieves a compact electron gun design, optimizes electron beam quality, and provides a high-quality, high-current electron beam for the terahertz traveling wave tube, thus ensuring the high-power output of the terahertz source.

[0058] Each focusing channel 210 of the multi-beam focusing electrode assembly 200 is used to initially constrain the electrons emitted by the corresponding emitting cathode 110. The groove 230 and baffle 240 provided on the emission side of the focusing body 220 are used to compress and control the shape, size and waist position of the electron beam, thereby constraining electron diffusion, reducing mutual interference between electrons, improving beam stability, and achieving the effect of focusing multiple electron beams with a single focusing electrode. The cathode array assembly can be connected to a low potential or a negative potential, and the multi-beam anode assembly 300 can be connected to a high potential or a positive potential. The potential difference will form a slowly varying electric field from the anode to the cathode between the two, thereby constructing an accelerating electric field region 400 between them. Because electrons are negatively charged, they accelerate in the opposite direction of the electric field. The accelerating electric field region 400 applies a continuous accelerating force to the electron beams constrained and focused by the multi-beam focusing electrode assembly 200 and restricts electron divergence, thereby limiting the transmission path of the multiple electron beams. The transmission paths of the multiple electron beams are calibrated to be parallel to each other, so that the multiple electron beams constrained by the multi-beam focusing electrode assembly 200 are accelerated by kinetic energy in the accelerating electric field region 400 and output through multiple anode channels 310 to form multiple strip-shaped electron beams. This achieves stable high-current output of multiple electron beams, solving the technical problem of simultaneously achieving compact structure, high stability of multiple beams and high current in the design of strip-shaped multi-beam electron guns, thereby further improving the power of the terahertz traveling wave tube used in strip-shaped multi-beam electron guns.

[0059] It should be noted that, in addition to setting baffles 240 on both sides of each focusing channel 210 on the emission side of the focusing body 220 and placing these baffles 240 in the groove 230 to further constrain electron diffusion and improve beam stability by compressing and controlling the shape, size and waist position of the electron beam; the embodiments of this application can be optimized in any one or more of the following ways: improving the emission uniformity of the emission surface of the emission cathode 110, stabilizing the emission of electrons by the emission cathode 110, and further improving the stability of the multi-beam electron beam; Multiple emitting cathodes 110 are arranged at equal intervals, so that the electric field distribution of the multiple electron beams is consistent with the emission trajectory, thereby improving the stability of the multiple electron beams. The structural precision and flatness of the emitting surface, focusing channel 210, anode channel 310, etc. of the emitting cathode 110 are optimized, thereby further limiting the emission electron path and reducing electron collision loss, thereby further improving the throughput of the multiple electron beams. The dimensions of the multiple anode channels 310, the multiple focusing channels 210, and the multiple emitting cathodes 110 are set to be equal, so as to further improve the consistency of the multiple beams.

[0060] like Figure 5 , Figure 6 As shown, in one embodiment, the focusing channel 210 is disposed around the corresponding coaxially disposed emitting cathode 110. A gap of 0.1 mm to 0.3 mm is formed between the focusing channel 210 and the coaxially disposed corresponding emitting cathode 110.

[0061] For example, to achieve a compact design, the multi-beam focusing electrode assembly 200 can be integrated into the emission side of the cathode array assembly, but not limited to this. Since electrons tend to diverge immediately after leaving the emission surface of the emitting cathode 110, integrating the multi-beam focusing electrode assembly 200 into the emission side of the cathode array assembly, with each focusing channel 210 surrounding the corresponding emitting cathode 110, can constrain electrons before initial divergence. This minimizes the distance between the cathode array assembly and the multi-beam focusing electrode assembly 200, shortens the electron transport path, and accelerates the constraint of electrons emitted from the coaxially positioned corresponding emitting cathode 110 by the focusing channels 210. This reduces energy loss and beam distortion, optimizes the constraint effect on emitted electrons, and facilitates the acceleration of most electrons in the accelerating electric field region 400, thereby significantly improving electron flux and achieving a stronger effective beam without changing the cathode emission capability. This not only makes the electron gun operation more reliable and stable but also effectively improves focusing accuracy and electron beam quality.

[0062] like Figure 5 As shown, an annular vacuum gap is formed between the focusing channel 210 and the corresponding coaxially arranged emitting cathode 110. The size of the gap is determined by the difference between the inner diameter of the focusing channel 210 and the outer diameter of the coaxially arranged emitting cathode 110. The gap is 0.1 mm to 0.3 mm, which can be, but is not limited to, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm or other sizes. It can also be any size range such as 0.1 mm to 0.2 mm, 0.2 mm to 0.3 mm or other sizes exceeding 0.1 mm to 0.3 mm without limitation.

[0063] like Figure 5 , Figure 6 As shown, exemplarily, the side of the emitting cathode 110 closest to the multi-beam focusing electrode assembly 200 is defined as the emitting surface of the emitting cathode 110. The emitting surface of the emitting cathode 110 can be, but is not limited to, any one of elliptical, circular, rectangular, or other shapes. When the emitting surface of the emitting cathode 110 is elliptical, the uneven current density caused by edge effects can be reduced; when the emitting surface of the emitting cathode 110 is circular, it is easier to process and reduces the possibility of electric field concentration; when the emitting surface of the emitting cathode 110 is rectangular, it simplifies the structure, facilitates the processing of the matrix structure formed by multiple emitting cathodes 110, and facilitates the determination of the spacing between multiple emitting cathodes 110, thereby flexibly adjusting the distribution position of multiple emitting cathodes 110; specifically, the position of multiple emitting cathodes 110 and the shape of the emitting surface of multiple emitting cathodes 110 can be set according to actual conditions, and are not limited here.

[0064] In the embodiments of this application, the cross-section of the focusing channel 210 in the electron transmission direction is adapted to the shape of the emitting surface of the emitting cathode 110. That is, when the emitting surface of the emitting cathode 110 is elliptical, the cross-section of the focusing channel 210 is elliptical; when the emitting surface of the emitting cathode 110 is circular, the cross-section of the focusing channel 210 is circular; when the emitting surface of the emitting cathode 110 is rectangular, the cross-section of the focusing channel 210 is rectangular; when the emitting surface of the emitting cathode 110 is other shapes, the focusing channel 210 is configured accordingly, which is not limited here.

[0065] like Figure 5 , Figure 6 As shown, in one embodiment, taking the emitting surface of the emitting cathode 110 as elliptical and the cross-section of the focusing channel 210 in the electron transport direction as elliptical as an example, the long side of each channel cross-section is greater than the long side of the emitting surface of the corresponding coaxially arranged emitting cathode 110, and the short side of each channel cross-section is greater than the short side of the emitting surface of the corresponding coaxially arranged emitting cathode 110. A gap of 0.1 mm to 0.3 mm is formed between the focusing channel 210 and the emitting surface of the emitting cathode 110, that is, the difference between the long side of the focusing channel 210 and the long side of the emitting surface of the corresponding emitting cathode 110 is 0.2 mm to 0.6 mm, and the difference between the short side of the focusing channel 210 and the short side of the emitting surface of the corresponding emitting cathode 110 is 0.2 mm to 0.6 mm. This ensures the consistency and stability of the emission of multiple electron beams and improves the electron beam flux. While meeting the requirements of strip electron beam forming, it also facilitates the acceleration processing of a majority of electrons in the accelerating electric field region 400. When the emitting surface of the emitting cathode 110 has other shapes, the relevant implementation methods of the focusing channel 210 can be referred to accordingly, and will not be described in detail here.

[0066] like Figure 1 As shown, in one embodiment, the emitting surface of the emitting cathode 110 is a plane or a concave surface.

[0067] Understandably, each emitting cathode 110 can be configured with an elliptical (or circular, etc.) cross-section in the electron transport direction, and the emitting cathode 110 as a whole can be elliptical cylindrical (or cylindrical, etc.). The emitting surface of each emitting cathode 110 can be constructed as a plane or a concave surface. When the emitting surface of the emitting cathode 110 is constructed as a plane, a uniform electron emission reference surface can be provided, thereby optimizing the uniformity of electron emission and reducing the processing difficulty and facilitating processing. When the emitting surface of the emitting cathode 110 is constructed as a concave surface, the emitting surface is set in a recessed manner away from the cathode array assembly, thereby realizing automatic focusing of the emitted electrons, reducing the initial divergence of the emitted electrons, thereby improving the transmission stability of the emitted electrons, and reducing the focusing difficulty of the subsequent multi-beam focusing electrode assembly 200.

[0068] like Figure 5 , Figure 6 As shown, in one embodiment, the number of rows of the multiple emitting cathodes 110 arranged in an array is defined as m, and the number of columns is n; where n ≥ m, n is a positive integer greater than or equal to 2, and m is a positive integer greater than or equal to 1. In the embodiments of this application, the number of rows and columns of the emitting cathodes 110 can be determined according to the imaging field size. Setting the number of columns n to be greater than the number of rows m can improve the lateral resolution, thereby reducing the longitudinal electric field crosstalk problem.

[0069] For example, multiple anode channels 310, multiple focusing channels 210, and multiple emitting cathodes 110 are coaxially arranged in a one-to-one correspondence. The focusing channels 210 are arranged around the corresponding coaxially arranged emitting cathodes 110. There is a potential difference between the multi-beam anode assembly 300 and the cathode array assembly, thereby forming an accelerating electric field region 400 between them. Each emitting cathode 110 is used to emit electrons. The shape, size, and beam waist position of the electron beam are controlled by the groove and baffle provided on the emission side of the focusing body to constrain electron diffusion, reduce mutual interference between electrons, and improve beam stability, thereby reducing energy loss and beam distortion. The constrained and focused multi-beam electron beams are accelerated by the accelerating electric field region 400 to output multiple ribbon-shaped electron beams through the multiple anode channels 310. When the number of rows of multiple emitting cathodes 110 is m and the number of columns is n, and the number of columns n is equal to the number of rows m (i.e., m=n), each focusing channel 210, groove 230, and baffle 240 is used to constrain and focus the electrons, thereby forming an initial shape of n² independent ribbon-shaped electron beams. After acceleration by the accelerating electric field, the final output is a multi-beam ribbon-shaped electron beam with a total current of n²×xA. Other implementation methods of arrays formed by multiple emitting cathodes 110 can be referred to accordingly, and will not be described in detail here.

[0070] like Figure 5 , Figure 6As shown, in another embodiment, the center-to-center distance between adjacent emitting cathodes 110 arranged in a row is 1.0 mm to 2.5 mm; the center-to-center distance between adjacent emitting cathodes 110 arranged in a column is 4.5 mm to 6.5 mm. The row spacing is determined by the center-to-center distance between adjacent emitting cathodes 110 arranged in a row, and the column spacing is determined by the center-to-center distance between adjacent emitting cathodes 110 arranged in a column. To adapt the row and column spacing to the interaction structure layout of the terahertz traveling wave tube, the column spacing can be set to be greater than the row spacing to reduce electric field crosstalk and space charge interference, thereby improving the electric field isolation effect. The row spacing can be, but is not limited to, 1.0mm, 1.5mm, 1.6mm, 2.0mm, 2.5mm or other values, or any value range from 1.0mm to 1.6mm, 1.6mm to 2.5mm or other values ​​exceeding 1.0mm to 2.5mm; the column spacing can be, but is not limited to, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm or other values, or any value range from 4.5mm to 5.0mm, 5.0mm to 6.5mm or other values ​​exceeding 4.5mm to 6.5mm.

[0071] For example, each groove 230 may have one or more focusing channels 210. The groove 230 may be constructed as an arc-shaped groove 230 (i.e., the cross-section of the groove 230 in its length direction is semi-circular, semi-elliptical, or other arbitrary shapes). The groove design can further suppress electron divergence, constrain electron diffusion, and reduce mutual interference between electrons, thereby improving beam stability. When multiple emitting cathodes 110 are arranged in an array, the multiple grooves 230 are arranged in multiple rows corresponding to the arrayed multiple emitting cathodes 110, which can further reduce mutual interference between electron beams in adjacent rows, thereby reducing collision losses that may occur when electron beams enter the corresponding anode channel 310, and improving throughput. The number of grooves 230 is equal to the number of rows formed by the arrayed multiple emitting cathodes 110. The multiple grooves 230 are arranged in parallel to each other, which facilitates the processing of multiple focusing channels 210. The multiple focusing channels 210 are integrated on the same focusing body 220, which can further realize the compact design of the strip-shaped multi-beam electron gun.

[0072] For example, multiple emitting cathodes 110 are arranged in an m×n array with m rows and n columns, thus forming an m×n array channel along the electron transport direction. m grooves 230 can be set one-to-one with each of the m rows. For instance, when the number of rows m and columns n of the multiple emitting cathodes 110 is 2, i.e., when the multiple emitting cathodes 110 are arranged in a 2×2 array, grooves 230 can be set in the upper and lower rows of the 2×2 array channel. The grooves 230 adopt a curved transition design, which can eliminate electric field distortion at abrupt changes in the channel, making the space charge field distribution in each beam channel uniform. This is used to further focus and compress the electron beam, thereby solving the problem of space charge asymmetry near the multiple emitting cathodes 110 and, to a certain extent, avoiding the phenomenon of excessive focusing at the corners of the electron beam.

[0073] like Figure 1 , Figure 2 As shown, in one embodiment, the length of each groove 230 is 8mm to 12mm, and the cross-section of each groove 230 in its length direction is semi-arc-shaped. The shape and size of the cross-sections of multiple grooves 230 in the length direction can be the same or different. Besides having a semi-circular, semi-elliptical, or other semi-arc-shaped cross-section in its length direction, each groove 230 can also be configured as a triangle, rectangle, trapezoid, frustum, or any other practically applicable structure, which is not limited here.

[0074] The length of each groove 230 can be, but is not limited to, 8mm, 8.5mm, 9mm, 9.5mm, 9.8mm, 10mm, 11mm, 12mm, or any size suitable for practical application, or a size range of 8mm to 10mm, 10mm to 12mm, or other sizes exceeding the range of 8mm to 12mm. The cross-section of the groove 230 along its length can be any semi-circular, semi-elliptical, or other semi-arc shape. When the cross-section of the groove 230 along its length is semi-elliptical, it can be set with a long side of 0.8mm to 2.5mm, a short side of 0.5mm to 2.0mm, and a curved transition length (arc length) of 2mm to 7mm. The long side can be, but is not limited to, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 2.0mm, 2.5mm, or any size suitable for practical application. The dimensions can be in the range of 0.8mm to 1.2mm, 1.2mm to 2.0mm, or other dimensions exceeding the range of 0.8mm to 2.5mm. The short side can be any size suitable for practical application, such as 0.5mm, 0.8mm, 1.0mm, 1.5mm, or 2.0mm. The curved surface transition length can be any size suitable for practical application, such as 2mm, 3mm, 3.46mm, 4mm, 5mm, 6mm, or 7mm. The specific dimensions can be in the range of 2mm to 3.46mm, 3.46mm to 7mm, or other dimensions exceeding the range of 2mm to 7mm. The specific dimensions can be set according to actual needs and are not limited here.

[0075] In one embodiment, to further optimize the confinement effect of the focusing channel 210 on the electron beam, the focusing body 220 is provided with baffles 240 on both sides of each emitting cathode 110. The baffles 240 are disposed within the grooves 230 and can be embedded in the grooves 230 for easy processing and assembly. They are used to confine the lateral diffusion of electrons and reduce mutual interference between adjacent electron beams, thereby improving beam stability. To ensure uniform and symmetrical focusing of electrons, the baffles 240 on both sides of each emitting cathode are mirror-symmetrically distributed about their vertical center lines. By coordinating the focusing channel 210, the grooves 230, and the baffles 240 to compress and control the shape, size, and waist position of the electron beam, the beam stability is significantly improved. The baffle 240 is a metal baffle 240. The number of rows of multiple emitting cathodes 110 is m and the number of columns is n. The number of columns n is equal to the number of rows m. That is, when m=n, n×(n+1) baffles 240 can be set to adapt to the lateral constraint requirements of the electron beam. Through the synergistic effect of physical structure and electric field, the lateral diffusion of the electron beam is suppressed, and the space charge repulsion between adjacent beams is weakened, so as to reduce the morphological distortion rate caused by the interaction between beams.

[0076] It should be noted that the thickness of the baffle 240 can be from 0.5mm to 2.0mm (e.g., 0.5mm, 1.0mm, 1.5mm, 2.0mm, etc. without limitation). The thickness of the baffle 240 can be set according to the lateral constraint requirements of the electron beam to reduce mutual interference between adjacent electron beams. For multiple focusing channels 210 located in the same groove 230 (i.e., in the same row), adjacent channels can share the same baffle 240, or an independent baffle 240 can be set for each channel. In addition, an annular baffle set coaxially with the focusing channel 210 can be used as an alternative; the specific setting can be determined according to actual conditions and is not limited here.

[0077] like Figure 2 , Figure 3 , Figure 4 As shown, in one embodiment, the inner diameter of each anode channel 310 gradually decreases from its input side to its output side in the electron transport direction. This makes the projection of each anode channel 310 on its longitudinal section trapezoidal. The tapered aperture of the anode channel 310 strengthens the radial constraint force on the electron beam, achieving final focusing and transmission of the electron beam, while further suppressing inter-beam interference and optimizing the focusing effect. The initial electron beam constrained by the multi-beam focusing electrode assembly 200 is continuously accelerated in the accelerating electric field between the cathode array assembly and the multi-beam anode assembly 300, and outputs through the aforementioned anode channels with gradually decreasing inner diameters, ultimately forming multiple stable ribbon-shaped electron beams. In this way, while maintaining compactness, the stability and flux of the multi-beam electron beam are effectively improved, and the output power of the applied terahertz traveling wave tube is enhanced.

[0078] For example, the output side dimensions of each anode channel 310 can be set to a lateral length (x-direction corresponding to the row arrangement direction of the matrix) of 0.7 mm to 2.0 mm and a longitudinal length (y-direction corresponding to the column arrangement direction of the matrix) of 0.6 mm to 1.5 mm. The transverse length can be any size suitable for practical application, such as 0.7mm, 0.8mm, 0.9mm, 0.94mm, 1.0mm, 1.5mm, or 2.0mm, or a size range of 0.7mm to 0.94mm, 0.94mm to 2.0mm, or other sizes exceeding 0.7mm to 2.0mm; the longitudinal length can be any size suitable for practical application, such as 0.6mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 1.0mm, or 1.5mm, or a size range of 0.6mm to 0.8mm, 0.8mm to 1.5mm, or other sizes exceeding 0.6mm to 1.5mm; no limitation is imposed here.

[0079] It should be noted that the inner diameter of the input side of each anode channel 310 is adapted to the inner diameter of the output side of the focusing channel 210 to achieve seamless connection of the electron beam, thereby reducing trajectory disturbance caused by abrupt changes in the channel cross-section and adapting to the focusing requirements of the electron beam. The projection of each anode channel 310 on its longitudinal section is trapezoidal, and the single-sided contraction angle can be set according to the focusing requirements of the electron beam to reduce the electron divergence angle, which is not specifically limited here.

[0080] like Figure 2 , Figure 3 , Figure 4 As shown, in one embodiment, the multi-anode assembly 300 includes an anode plate 320 and a plurality of drift tubes 330. The anode plate 320 has a plurality of protrusions 321 on the side near the cathode array assembly. These protrusions 321 are arranged in a row corresponding to a plurality of array-distributed emitting cathodes 110. An anode channel 310 passes through the corresponding protrusion 321 and the anode plate 320. The plurality of drift tubes 330 are located on the side of the anode plate 320 opposite to the cathode array assembly. Each drift tube 330 corresponds one-to-one with one of the protrusions 321 and is connected to its corresponding anode channel 310.

[0081] Understandably, multiple protrusions 321 are arranged in a row on the side of the anode plate 320 near the cathode array assembly, corresponding to the arrayed multiple emitting cathodes 110. This arrangement of the multiple emitting cathodes 110 can be matched to reduce inter-beam electric field crosstalk and electron beam diffusion. Drift tubes 330 are located on the side of the anode plate 320 away from the cathode array assembly. The tube bodies of multiple drift tubes 330 are arranged one-to-one with the multiple protrusions 321 and are respectively connected to the corresponding anode channels 310, which can further optimize the stability of multi-electron beam transmission.

[0082] For example, the cross-section of each anode channel 310 can be rectangular, and the body of the drift tube 330 can be constructed as a suitable rectangular tube. The specific dimensions of the drift tube 330 can be adjusted according to the corresponding slow-wave structure and other electron transmission requirements and actual applications, and are not limited here. The anode plate 320 can be a circular plate or other types of plates. When using a circular plate, the radius can be 10mm to 25mm, such as 10mm, 12mm, 15mm, 18mm, 20mm, 25mm, etc., any value suitable for actual applications, or a value range of 10mm to 15mm, 15mm to 25mm, or other values ​​exceeding 10mm to 25mm, and are not limited here.

[0083] like Figure 1 , Figure 2 , Figure 3 As shown, in a specific embodiment, the number of rows of the plurality of emitting cathodes 110 is m, the number of columns is n, and the number of columns n is equal to the number of rows m and is 2, that is, m=n=2, for the following explanation:

[0084] The strip-shaped multi-beam electron gun includes a cathode array assembly, a multi-beam focusing electrode assembly 200, and a multi-beam anode assembly 300 arranged sequentially along the electron transport direction. The multi-beam anode assembly 300 includes multiple anode channels 310. The cathode array assembly is the electron generation source and includes four independent emitting cathodes 110 arranged in a 2×2 array. Each emitting cathode 110 has a length of 0.8 mm to 2.0 mm (e.g., 0.8 mm, 1.0 mm, 1.5 mm, 2.0 mm, etc.). Each emitting cathode 110 is configured as an elliptical cylinder with an elliptical plane or an elliptical concave surface. The emitting surface area of ​​each emitting cathode 110 is 0.3 mm² to 1.5 mm² (e.g., 0.3 mm², 0.5 mm², 0.55 mm², 0.6 mm², 1.0 mm², 1.5 mm², etc.). The ratio of the long side to the short side of each emitting cathode 110 is 10:7 or any other ratio suitable for practical application. The row spacing of multiple emitting cathodes 110 can be any value between 1.0 mm and 2.5 mm, and the column spacing can be any value between 4.5 mm and 6.5 mm, thereby ensuring a certain degree of structural compactness. Each emitting cathode 110 is used to emit electrons and form an initial electron cloud. An accelerating electric field region 400 is formed between the cathode array assembly and the multi-beam anode assembly 300. The multi-beam anode assembly 300 includes multiple anode channels 310. The multi-beam focusing electrode assembly 200 is located on the emission side of the cathode array assembly and has multiple focusing channels 210. The multiple anode channels 310, multiple focusing channels 210, and multiple emitting cathodes 110 correspond one-to-one and are coaxially arranged. The multi-beam focusing electrode assembly 200 includes a focusing body 220, multiple grooves 230 and multiple baffles 240 disposed on the emission side of the focusing body 220, and multiple focusing channels 210 disposed on the focusing body 220. Each focusing channel 210 is provided with baffles 240 on both sides, and the baffles 240 are disposed in the grooves 230. Each focusing channel 210 of the multi-beam focusing electrode assembly 200 is used to initially constrain the electrons emitted by the corresponding emitting cathode 110. The grooves 230 and baffles 240 disposed on the emission side of the focusing body 220 are used to compress and control the shape, size and waist position of the electron beam, so as to constrain electron diffusion, reduce mutual interference between electrons, and thus improve beam stability. This allows multiple electron beams to be accelerated by the accelerating electric field region 400, so as to output multiple strip-shaped electron beams through multiple anode channels 310.

[0085] Four emitting cathodes 110 are nested within corresponding focusing channels 210. The focusing channels 210 have an elliptical cross-section and are arranged around the coaxially arranged emitting cathodes 110 to initially constrain the electron beam morphology. Multiple grooves 230 of the multi-beam focusing electrode assembly 200 are arranged in multiple rows corresponding to the arrayed emitting cathodes 110. A gap of 0.1 mm to 0.3 mm is formed between the focusing channel 210 and the emitting surface of the coaxially arranged emitting cathode 110 (e.g., the difference between the long side of the focusing channel 210 and the long side of the emitting surface of the coaxially arranged emitting cathode 110 is 0.2 mm, and the difference between the short side of the focusing channel 210 and the short side of the emitting surface of the coaxially arranged emitting cathode 110 is 0.2 mm). The multi-beam focusing electrode assembly 200 has grooves 230 arranged in the upper and lower rows corresponding to the 2×2 array channel. The grooves 230 employ a curved transition design, with each groove 230 having a length of 8mm to 12mm (e.g., 10mm) and a semi-arc cross-section along its length. Each groove 230 can be formed by cutting an elliptical cylinder, with a long side of 0.8mm to 2.5mm (e.g., 1.2mm), a short side of 0.5mm to 2.0mm (e.g., 1.0mm), and a curved transition length (arc length) of 2mm to 7mm (e.g., 3.46mm). The grooves 230 are used to eliminate abrupt changes in the electric field. Each focusing channel 210 has baffles 240 on both sides, located within the grooves 230. The thickness of the baffles 240 can be 0.5mm to 2.0mm (e.g., 1.0mm), which can be set according to the lateral constraint requirements of the electron beam to prevent interference between adjacent electrons to a certain extent.

[0086] By optimizing the position and size of the groove 230 and the baffle 240, the charge field on the xoz plane near each row of dual cathodes and on the yoz plane near each column of dual cathodes can be adjusted. This ensures, to a certain extent, the consistency and symmetry of the space charge field distribution. The space charge field distribution between the cathode and anode is as follows: Figure 7 , Figure 8 As shown, regardless of whether it is the xoz plane or the yoz plane, the space charge field near the dual cathodes is consistent and symmetrical about the central axis of the cathode array assembly. From Figures 7 to 10 It can also be seen that the electric field equipotential lines near the cathode array component are concave inward, indicating that it has a focusing effect on electrons; while the equipotential lines near the anode channel 310 are relatively flat, indicating that the anode channel 310 effect is weak, which provides favorable conditions for the stable transmission of electron beams.

[0087] An accelerating electric field region 400 is formed between the cathode array assembly and the multi-beam anode assembly 300. The distance between the multi-beam anode assembly 300 and the cathode array assembly is 4.0 mm to 8.0 mm (e.g., 5.5 mm). The multi-beam anode assembly 300 includes an anode plate 320 and multiple drift tubes 330. Two protrusions 321 are provided on the side of the anode plate 320 closest to the cathode array assembly. The multiple drift tubes 330 are located on the side of the anode plate 320 away from the cathode array assembly, and are arranged one-to-one with the multiple protrusions 321, and are respectively connected to the corresponding anode channels 310. The anode plate 320 can be a circular plate with a radius of 10 mm to 25 mm (e.g., 15 mm). In this way, the electric field between the multi-beam anode assembly 300 and the cathode array assembly can be effectively shielded, preventing interference with the subsequent electron beam transmission to a certain extent. Two protrusions 321 correspond to multiple emitting cathodes 110 arranged in a row. Each protrusion 321 is frustoconical. In the electron transmission direction, the cross-section of each anode channel 310 can be rectangular, so that each protrusion 321 has two rectangular anode holes arranged in parallel. The output side dimensions of each anode channel 310 are set to a lateral length (x-direction corresponding to the row arrangement direction of the matrix) of 0.7mm to 2.0mm (e.g., 0.94mm or other dimensions) and a longitudinal length (y-direction corresponding to the row arrangement direction of the matrix) of 0.6mm to 1.5mm (e.g., 0.8mm or other dimensions). The anode channel 310 is disposed through the anode plate 320 and the corresponding boss 321. In the electron transport direction, the inner diameter of each anode channel 310 gradually decreases from its input side to its output side, so that the projection of each anode channel 310 on its longitudinal section is trapezoidal. The single-sided contraction angle can be set to 18° or other angles suitable for practical applications according to the electron beam focusing requirements, so that the electron beam is further compressed after entering the anode channel 310 and forms a beam waist in the electron beam channel. The body of the drift tube 330 is constructed as a rectangular tube. The specific dimensions of the drift tube 330 can be adjusted according to the corresponding slow wave structure and other electron transport requirements and practical applications, and are not limited here.

[0088] The following embodiment primarily uses an emitting cathode 110 with a length of 1.0 mm, each emitting cathode 110 configured as an elliptical cylinder with an elliptical plane emitting surface, an emitting surface area of ​​0.55 mm², and a ratio of the long side to the short side of each emitting cathode 110 of 10:7; the row spacing of the multiple emitting cathodes 110 is 1.6 mm, and the column spacing is 5.0 mm. A 0.2 mm gap is formed between the focusing channel 210 and the emitting surface of the corresponding coaxially arranged emitting cathode 110. Each groove 230 has a length of 10 mm and is cut from an elliptical cylinder with a cross-section of a long side of 1.2 mm, a short side of 1.0 mm, a curved transition length of 3.46 mm, and a baffle 240 thickness of 1.0 mm as an example. The aforementioned structure can be modeled and simulated using the Particle Tracking solver in Computer Simulation Technology (CST), and the settings can be adjusted according to actual needs. The voltage of the cathode array assembly and the multi-beam focusing electrode assembly 200 can be set from -35kV to -10kV (e.g., -35kV, -27.8kV, -25kV, -20kV, -15kV, -10kV, or other values), while the voltage of the multi-beam anode assembly 300 can be set to 0V. Taking a voltage setting of -27.8kV for both the multi-beam anode assembly 300 and the multi-beam focusing electrode assembly 200 as an example... Figure 9 , Figure 10 These are schematic diagrams of the electron beam trajectory xoz and yoz sections of the 2×2 array-type high-current strip-shaped four-beam electron gun of this application (wherein, Figure 9 A schematic diagram of the cross-section of the corresponding electron beam trajectory xoz. Figure 9 The cross-section corresponding to the center of the cathode; Figure 10 A schematic diagram of the yoz cross section corresponding to the electron beam trajectory. Figure 10 (Corresponding to the cross-section at the center of the cathode), as shown in the figure, the ribbon-shaped electron beam is emitted from the emitting cathode 110, compressed by the multi-beam focusing electrode assembly 200, and enters the electron beam channel through the anode channel 310; from Figure 9 , Figure 10 As can be seen from the data, the multi-beam focusing electrode assembly 200 of this application features bilateral compression, but the compression of the wide side of the electron beam is relatively small. The main compression occurs at the narrow side of the electron beam. During the emission process, none of the four electron beams were intercepted, and they all reached the beam waist position simultaneously with 100% throughput. The beam waist position is z=7.28mm. The results may vary depending on the actual parameter settings, which are not limited here.

[0089] Simulations were performed using the aforementioned values. Figure 11The image shows a cross-sectional view of the electron beam at the emitting surface and waist of the emitting cathode 110 (red indicates the emitting surface, green indicates the waist). By comparison, it is clear that the elliptical electron beam is compressed into a band shape. The cross-sectional dimensions of a single electron beam at the waist are 0.614 mm × 0.069 mm, the current density is 295.4 A / cm², the narrow-side compression ratio is 11.4, the wide-side compression ratio is 1.63, and the area compression ratio is 13.1. The z-axis is used to indicate the electron transport direction. Figure 12 The single-beam electron beam current diagram of this application shows that after being emitted from the emitting surface of the emitting cathode 110, the electron beam current rapidly increases to 0.125A and is transmitted stably for 8.3mm. Then the current gradually decreases to zero. This is because after the electron beam reaches the beam waist position, the electrons lose the focusing force of the electrostatic field and begin to diverge under the action of space charge force, and are finally intercepted by the drift tube 330. Figure 13 The total current diagram of the electron gun in this embodiment is shown. From the iterative emission current curve, it can be seen that the current of the four electron guns corresponding to the four emitting cathodes 110 remains constant after 16 iterations, and the total current finally stabilizes at 0.5A. Based on the aforementioned parameter example, a 2×2 array high-current strip-shaped four-beam electron gun is provided, with an operating voltage of 27.8kV, a single-beam current of 0.125A, a total current of 0.5A, a cross-sectional dimension of 0.614mm × 0.069mm at the waist of each electron beam, an area compression ratio of 13.1 between the emitting surface and the waist of the emitting cathode 110, and a current density of 295.4A / cm² at the waist.

[0090] In the embodiments of this application, by employing multiple emitting cathodes 110 arranged in an array, the emission current is effectively increased compared to a single emitting cathode 110 (for example, when the number of rows of the multiple emitting cathodes 110 is m and the number of columns is n, and the number of columns n is equal to the number of rows m, i.e., m=n, the emission current can be increased by n). 2This improves the output efficiency of vacuum electronic devices by several times, thus meeting the high current requirements of high-power devices. The multi-beam focusing electrode assembly 200 has multiple grooves 230 arranged in multiple rows on the emission side of the focusing body 220 corresponding to the arrayed multiple emitting cathodes 110. The grooves 230 adopt a curved transition design, which can eliminate electric field distortion on the cathode emission side, making the space charge field distribution in each beam channel uniform. This eliminates electric field distortion caused by abrupt changes in the channel and further focuses and compresses the electron beam, thus solving the problem of space charge asymmetry near the multiple emitting cathodes 110 and, to a certain extent, avoiding the phenomenon of excessive focusing at the edges of the electron beam. The physical constraint and electric field guidance of the baffles 240 in the grooves 230 between the emitting cathodes 110 weaken the space charge repulsion of the electron beam, significantly reducing the electron beam deformation rate caused by inter-beam interactions and effectively improving the electron beam flux. Multiple anode channels 310 output form multiple ribbon-shaped electron beams, thereby achieving stable and efficient output of multiple electron beams, achieving high stability and high current for multiple beams while maintaining a compact structure.

[0091] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A strip-shaped multi-beam electron gun, characterized in that, It includes a cathode array assembly, a multi-beam focusing electrode assembly, and a multi-beam anode assembly arranged sequentially along the electron transport direction; The multi-injection anode assembly includes an anode plate and a plurality of anode channels disposed on the anode plate; The cathode array assembly includes multiple emitting cathodes, each of which is used to emit electrons, and an accelerating electric field region is formed between the cathode array assembly and the multi-beam anode assembly. The multi-beam focusing electrode assembly is located on the emission side of the cathode array assembly and has multiple focusing channels. The multiple anode channels, the multiple focusing channels and the multiple emitting cathodes correspond one-to-one and are coaxially arranged. The multi-beam focusing electrode assembly includes a focusing body, multiple grooves and multiple baffles disposed on the emission side of the focusing body, multiple focusing channels disposed on the focusing body, and baffles disposed on both sides of each focusing channel, with the baffles disposed in the grooves. Electrons emitted by each of the emitting cathodes are compressed into electron beams through the corresponding grooves and baffles. Each electron beam is accelerated by the accelerating electric field region and output through the corresponding anode channels to form multiple ribbon-shaped electron beams.

2. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The multiple emitting cathodes are arranged in an array; the multiple grooves correspond to the multiple emitting cathodes arranged in multiple rows.

3. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The length of each groove is 8mm to 12mm, and the cross-section of each groove in its length direction is semi-arc.

4. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The baffles on both sides of each of the emitting cathodes are distributed in a mirror-symmetric manner about their vertical center lines.

5. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The focusing channel is arranged around the corresponding emission cathode, which is coaxially arranged. A gap of 0.1 mm to 0.3 mm is formed between the focusing channel and the corresponding coaxially arranged emitting cathode.

6. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The emitting cathode has an elliptical emitting surface, and the focusing channel has an elliptical cross-section in the electron transmission direction. The long side of each of the channel sections is greater than the long side of the emission surface of the corresponding emission cathode arranged coaxially, and the short side of each of the channel sections is greater than the short side of the emission surface of the corresponding emission cathode arranged coaxially.

7. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, The emitting surface of the emitting cathode is either a plane or a concave surface.

8. The strip-shaped multi-beam electron gun as described in claim 1, characterized in that, In the electron transport direction, the inner diameter of each anode channel gradually decreases from its input side to its output side.

9. The strip-shaped multi-beam electron gun as described in any one of claims 1 to 8, characterized in that, The multi-anode assembly also includes multiple drift tubes. The anode plate has multiple protrusions on the side near the cathode array assembly. The multiple protrusions are arranged in a row corresponding to the multiple emitting cathodes distributed in the array. The anode channel passes through the corresponding protrusions. Multiple drift tubes are disposed on the side of the anode plate opposite to the cathode array assembly. Each drift tube is arranged one-to-one with a plurality of protrusions and is connected to the corresponding anode channel.

10. The strip-shaped multi-beam electron gun as described in any one of claims 1 to 8, characterized in that, The multiple emitting cathodes are arranged in an array, and the number of rows and columns of the multiple emitting cathodes arranged in the array is defined as m; Where: n≥m, n is a positive integer greater than or equal to 2, and m is a positive integer greater than or equal to 1; And / or, in a row of multiple emitting cathodes, the center-to-center distance between adjacent emitting cathodes is 1.0 mm to 2.5 mm; in a column of multiple emitting cathodes, the center-to-center distance between adjacent emitting cathodes is 4.5 mm to 6.5 mm.

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