Electrode assembly, electron gun and electron gun equipment

Abstract

The present invention discloses an electrode assembly, an electron gun and an electron gun device, relating to the field of microwave and millimeter wave technology. The electron gun comprises an anode for receiving a first acceleration voltage signal, the electrode assembly is arranged in the anode, and the electrode assembly comprises a cathode, a first control electrode and a second control electrode; the cathode has an emission surface for emitting an electron beam; the cathode is arranged in the first control electrode; the second control electrode is arranged in the first control electrode, the second edge of the second control electrode is arranged toward the first edge of the first control electrode, and an electron penetration gap for the electron beam to pass through is formed between the first edge, the electron penetration gap faces the emission surface and is connected to the anode; the first control electrode and the second control electrode are used to receive a second acceleration voltage signal that is smaller than the first acceleration voltage signal; the present invention can solve the problems of the electron gun requiring a complex and expensive high-power pulse modulation circuit and the influence of high-voltage fast switching noise in high-frequency, high-power and short-pulse operation.

Description

Technical Field

[0001] The present invention relates to the field of microwave and millimeter wave technology, and in particular to an electrode assembly, an electron gun and electron gun equipment. Background Art

[0002] Currently, microwave vacuum electron devices are operating at increasingly higher frequencies and powers, with shorter operating pulses and higher voltages. For example, electron guns are often switched on and off during operation, particularly in applications requiring high repetition rates. The most common approach involves applying a pulsed voltage between the cathode and anode. However, this approach typically requires complex and expensive high-power pulse modulation circuits, making it difficult to achieve the short rise times of high-voltage pulses. Furthermore, the noise generated by the rapid switching of high voltage is proportional to the rate of voltage change, which can affect not only the proper operation of the device itself but also the operation of surrounding electronic equipment. Summary of the Invention

[0003] The primary objective of this invention is to provide an electrode assembly, electron gun, and electron gun apparatus designed to address the issues of high-frequency, high-power, and short-pulse operation requiring complex and expensive high-power pulse modulation circuits, as well as the impact of high-voltage, rapid switching noise. Furthermore, this invention addresses issues such as insufficient and uneven emission from the emitting surface caused by a small emission slope, as well as difficulties in focusing and susceptibility to electron beam fluctuations.

[0004] To achieve the above-mentioned object, the present invention provides an electrode assembly for an electron gun, wherein the electron gun includes an anode for receiving a first accelerating voltage signal, and the electrode assembly is disposed within the anode. The electrode assembly includes:

[0005] a cathode having an emitting surface for emitting an electron beam;

[0006] a first control electrode having a first edge, wherein the cathode is disposed within the first control electrode;

[0007] A second control electrode is arranged in the first control electrode, the second control electrode has a second edge, the second edge is arranged toward the first edge and an electron penetration gap is formed between the second edge and the first edge for the electron beam to pass through, the electron penetration gap is arranged toward the emission surface and is connected to the anode; the first control electrode and the second control electrode are used to receive a second acceleration voltage signal, and the second acceleration voltage signal is less than the first acceleration voltage signal.

[0008] In one embodiment, the first control electrode has a receiving cavity and an opening communicating with the receiving cavity, and the opening has the first edge;

[0009] The second control electrode has a first end and a second end opposite to each other along its length, the first end is arranged toward the opening and has the second edge protruding outwards;

[0010] The cathode has a third end and a fourth end that are oppositely arranged. The third end is provided with the emission surface. The fourth end is ring-shaped and is arranged on the outer periphery of the second end.

[0011] In one embodiment, the cathode is provided with a receiving groove for accommodating the first end at a position corresponding to the third end, the emission surface is arranged on the inner wall surface of the receiving groove, and the emission surface is an annular conical concave surface; the electron penetration gap is an annular gap.

[0012] In one embodiment, the length of the electron penetration slit is not less than 1.5 times the length of the emitting surface and not more than 2 times the length of the emitting surface.

[0013] In one embodiment, the portion of the first control electrode close to the emitting surface is arranged parallel to the cathode;

[0014] And / or, a portion of the second control electrode close to the emitting surface is arranged parallel to the cathode.

[0015] In one embodiment, a first electric field compensation portion is provided on a portion of the first control electrode close to the emitting surface, the first electric field compensation portion being provided close to the first edge, and a second electric field compensation portion is provided on the cathode spaced apart from and parallel to the first electric field compensation portion, the shape of the second electric field compensation portion matching the shape of the first electric field compensation portion;

[0016] And / or, a first oscillation suppression portion is recessed in a portion of the second control electrode close to the emitting surface, the first oscillation suppression portion is arranged close to the second edge, a second oscillation suppression portion is provided at a position of the cathode corresponding to and parallel to the position of the first oscillation suppression portion, and a shape of the second oscillation suppression portion matches the shape of the first oscillation suppression portion.

[0017] In one embodiment, the first electric field compensation portion has a first electric field compensation surface and a second electric field compensation surface, the second electric field compensation portion has a third electric field compensation surface and a fourth electric field compensation surface, the third electric field compensation surface and the first electric field compensation surface are spaced apart and arranged parallel to each other along the width direction of the cathode, and the fourth electric field compensation surface is arranged obliquely in a direction away from the second control electrode from an end close to the third electric field compensation surface to an end away from the third electric field compensation surface, and is spaced apart and arranged parallel to the second electric field compensation surface;

[0018] And / or, the first oscillation suppression portion has a first oscillation suppression surface and a second oscillation suppression surface, the second oscillation suppression portion has a third oscillation suppression surface and a fourth oscillation suppression surface, the third oscillation suppression surface and the first oscillation suppression surface are spaced apart and parallel to each other along the length direction of the cathode, and the fourth oscillation suppression surface is inclined from one end close to the third oscillation suppression surface to one end away from the third oscillation suppression surface in a direction away from the second control electrode, and is spaced apart and parallel to the second oscillation suppression surface.

[0019] The present invention further provides an electron gun, comprising:

[0020] an anode, configured to receive a first accelerating voltage signal; and

[0021] As described above, the electrode assembly is disposed in the anode, and the electrode assembly is used to receive a second acceleration voltage signal, wherein the second acceleration voltage signal is smaller than the first acceleration voltage signal.

[0022] In one embodiment, a portion of the first control electrode of the electrode assembly close to the anode is arranged parallel to the anode;

[0023] And / or, the inner wall surface of the anode is provided with a field intensity concentrating smooth protrusion facing the electron penetration gap of the electrode assembly, and the field intensity concentrating smooth protrusion is used to concentrate the electron beam of the electrode assembly passing through the electron penetration gap and prevent the electron beam from penetrating the anode.

[0024] The present invention further provides an electron gun device, comprising:

[0025] At least two magnetic cutting die sets; and,

[0026] In the electron gun as described above, at least two magnetic resonant cutting modules are axially symmetrically arranged on both sides of the electron gun, and the magnetic resonant cutting modules are used to convert the electron beam emitted by the electron gun into a large cyclotron electron beam.

[0027] The technical effects that the technical solution of the present invention can produce are:

[0028] On the one hand, the present invention arranges the electrode assembly in the anode, and the cathode in the first control electrode, which has an emission surface for emitting an electron beam, the first control electrode has a first edge, the second control electrode is arranged in the first control electrode, the second control electrode has a second edge, the second edge is arranged toward the first edge and an electron penetration gap is formed between the second edge and the first edge, the electron penetration gap is arranged toward the emission surface and is connected to the anode, thereby ensuring that the electron beam is efficiently transmitted to the anode along a preset path, suppressing beam fluctuations while reducing speed dispersion caused by the uneven electric field in the path space, thereby maintaining good consistency of the electron beam and greatly improving the quality of the electron beam.

[0029] Furthermore, after emission, the electron beam first passes through the lower accelerating voltage regions of the first and second control electrodes for initial acceleration before entering the higher accelerating voltage region of the anode for final acceleration. This phased acceleration method avoids the situation where the small electric field near the emission surface, caused by the small emission slope of the emission surface, is unable to effectively extract electrons. This allows for a smaller emission slope on the emission surface. The smaller the emission slope, the thinner the electron beam, and the higher the beam quality.

[0030] In other words, the present invention not only addresses the problems of requiring complex and expensive high-power pulse modulation circuits and the impact of high-voltage rapid switching noise when operating an electron gun at high frequencies, high powers, and short pulses, but also addresses the issues of insufficient and uneven emission from a shallow-slope emission surface, as well as the difficulty in focusing and susceptibility of the electron beam to fluctuations. Furthermore, the present invention can improve electron beam quality by adjusting the accelerating voltage signals of the first control electrode and the second electrode using an external device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0032] Figure 1 A schematic structural diagram of an embodiment of an electrode assembly provided by the present invention;

[0033] Figure 2 for Figure 1 Structural diagram from another angle;

[0034] Figure 3 for Figure 2 Exploded view of

[0035] Figure 4 A schematic structural diagram of an electron gun according to an embodiment of the present invention;

[0036] Figure 5 for Figure 4 sectional view of

[0037] Figure 6 for Figure 5 A partial enlarged view of point A in the middle;

[0038] Figure 7 for Figure 5 A simple plan view of

[0039] Figure 8This is a structural schematic diagram of an embodiment of the electron gun device provided by the present invention.

[0040] Description of Figure Numbers:

[0041] 100. Electron Gun; 1. Electrode Assembly; 101. Electron Penetration Slit; 11. Cathode; 1101. Receiving Slot; 111. Emitting Surface; 112. Third End; 113. Fourth End; 114. Second Electric Field Compensation Unit; 1141. Third Electric Field Compensation Surface; 1142. Fourth Electric Field Compensation Surface; 115. Second Oscillation Suppression Unit; 1151. Third Oscillation Suppression Surface; 1152. Fourth Oscillation Suppression Surface; 12. First Control Electrode; 1201. Receiving Cavity; 1202. Opening; 121. First Side Edge; 122, first electric field compensation portion; 1221, first electric field compensation surface; 1222, second electric field compensation surface; 13, second control electrode; 131, second edge; 132, first end; 133, second end; 134, first oscillation suppression portion; 1341, first oscillation suppression surface; 1342, second oscillation suppression surface; 2, anode; 201, first cavity; 202, second cavity; 3, smooth protrusion with field intensity concentration; a, first angle; b, second angle; c, third angle; d, fourth angle;

[0042] 200. Magnetic cutting module; 4. Auxiliary coil; 5. Cathode coil; 6. Main coil.

[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0045] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0046] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] Microwave vacuum electronic devices are evolving toward ever-higher frequencies and powers, driven primarily by the pursuit of higher performance in modern applications such as radar, communications, and electronic countermeasures. Higher frequencies not only support wider bandwidths but also enable longer detection ranges or higher resolution. For example, high-frequency radar can significantly improve target detection accuracy, while high-power devices such as high-power microwave tubes can meet the high energy output requirements of applications such as long-distance signal transmission and particle accelerators. At the same time, the operating pulses of these devices are becoming shorter and shorter, and the operating voltage is gradually increasing. This shift responds to the demand for fast switching capabilities in applications such as radar systems, enabling multi-target tracking or rapid response to jamming signals in electronic countermeasures. Using short pulses improves temporal resolution and reduces unnecessary energy consumption.

[0048] Taking the electron gun as an example, the electron gun is usually turned on and off during operation, especially in applications that require high repetition rate operation. The most common method is to apply a pulse voltage between the cathode and the anode to control the on / off of the electron beam. However, there are the following problems: switching high voltages (such as kilovolts) requires high-power pulse modulation circuits (such as IGBTs). These devices are expensive, large in size, and have difficulty achieving nanosecond rise times. In addition, the noise generated by the high-power pulse modulation circuit is proportional to the voltage change rate, which will not only affect the normal operation of the device itself, but also the normal operation of surrounding electronic equipment.

[0049] To improve the above problems, the present invention provides an electrode assembly 1 .

[0050] See also Figures 1 to 7 In one embodiment of the present invention, the electrode assembly 1 is used in an electron gun 100. The electron gun 100 includes an anode 2 for receiving a first acceleration voltage signal. The electrode assembly 1 is disposed in the anode 2. The electrode assembly 1 includes:

[0051] a cathode 11 having an emitting surface 111 for emitting electron beams;

[0052] The first control electrode 12 has a first edge 121 , and the cathode 11 is disposed within the first control electrode 12 ;

[0053] The second control electrode 13 is arranged in the first control electrode 12. The second control electrode 13 has a second edge 131. The second edge 131 is arranged toward the first edge 121 and forms an electron penetration gap 101 for the electron beam to pass through between the second edge 131 and the first edge 121. The electron penetration gap 101 is arranged toward the emission surface 111 and is connected to the anode 2. The first control electrode 12 and the second control electrode 13 are used to receive a second acceleration voltage signal, and the second acceleration voltage signal is smaller than the first acceleration voltage signal.

[0054] In this embodiment, the electron gun 100 may include an anode 2 and an electrode assembly 1, and the electrode assembly 1 may include a cathode 11. A relatively high first accelerating voltage signal, such as several thousand volts to several tens of kilovolts, is applied to the anode 2, thereby forming a first accelerating electric field with a relatively high accelerating voltage with the cathode 11. The anode 2 primarily serves as the final acceleration region of the electron beam, ensuring that the electron beam has sufficient power to meet high-frequency and high-power requirements.

[0055] In this embodiment, the anode 2 can be a cylindrical or conical conductive structure, and the surface can be coated with an insulating coating to improve the pressure resistance. The anode 2 can form a first cavity 201 and a second cavity 202, and the first cavity 201 is connected to the second cavity 202 and arranged along the length direction of the anode 2. The inner diameter of the first cavity 201 gradually decreases from the end away from the second cavity 202 to the end close to the second cavity 202. The lateral space of the electron beam is compressed, forcing the electron beam to concentrate and accelerate in the axial direction, increasing its kinetic energy, reducing energy loss due to scattering, and ensuring that the electron beam energy is more concentratedly transmitted along the axial direction. The inner diameter of the second cavity 202 gradually decreases from the end close to the first cavity 201 to the end away from the first cavity 201. The inner diameter of the second cavity 202 continues to shrink relative to the first cavity 201, forming a continuous acceleration path, further compressing the electron beam, forming a thinner beam, reducing the divergence angle, so that the electron beam reaches the highest speed and minimum divergence angle at the end of the anode 2, forming a stable, extremely thin hollow electron beam.

[0056] The cathode 11 can be a hot cathode or a cold cathode. The cathode 11 of this embodiment is a hot cathode, which can avoid significant changes in the emission current density of the cold cathode due to slight changes in the electric field strength, thereby making the emission stability of the electron gun 100 relatively poor, and requiring high stability of the power supply and electric field control accuracy. The electron emission current density of the hot cathode is mainly determined by temperature and follows the "Richardson-Dushman equation". At this time, as long as the temperature of the hot cathode does not change significantly, the emission current density will be relatively stable. In addition, the energy distribution of the electrons emitted by the hot cathode exhibits certain Maxwell-Boltzmann distribution characteristics. Since electrons are generated by thermal excitation, the electrons emitted from the hot cathode have a certain initial transverse energy, thereby enhancing the compression and focusing performance of the electron gun 100 in the magnetic field. In other words, the use of a hot cathode in this application can produce a more stable and more concentrated electron beam.

[0057] To address the issues of complex and expensive high-power pulse modulation circuits required for high-frequency, high-power, and short-pulse operation of the electron gun 100, as well as the impact of high-voltage, fast-switching noise, the electrode assembly 1 of this embodiment further includes a first control electrode 12 and a second control electrode 13. The first control electrode 12 can be an annular or cylindrical conductive structure (such as stainless steel or molybdenum), with its inner wall maintaining a certain distance from the cathode 11. This structure can limit the lateral diffusion of the electron beam and ensure its transmission along the axial direction of the electron gun 100. The second control electrode 13 can be a more slender cylindrical structure than the first control electrode 12 and is embedded in the first control electrode 12.

[0058] The first control electrode 12 and the second control electrode 13 are core electrodes in the electron gun 100 for controlling the emission and shape of the electron beam. Their function is to switch the electron beam or adjust the electron beam shape by applying a second accelerating voltage signal, while allowing the electron beam to pass through. The second accelerating voltage signal can be no less than -1500V and no more than 1500V. When the second accelerating voltage signal applied by the first control electrode 12 and the second control electrode 13 is a positive voltage signal relative to the cathode 11, a second accelerating electric field is formed between the first control electrode 12 and the second control electrode 13 and the cathode 11, which is consistent with the emission direction of the cathode 11. This helps electrons overcome surface barriers and accelerate through the first control electrode 12 and the second control electrode 13 to enter the anode 2. If the second accelerating voltage signal applied by the first control electrode 12 and the second control electrode 13 is a negative voltage signal relative to the cathode 11, a second accelerating electric field is formed between the first control electrode 12 and the second control electrode 13 and the cathode 11, which is opposite to the emission direction of the cathode 11, hindering electron emission and even completely preventing electrons from passing through. What is special is that the intensity of the second accelerating electric field is equal to that of the first accelerating electric field, in order to ensure uniform electric field distribution, reduce velocity dispersion caused by non-uniform electric field, and improve electron beam quality.

[0059] Furthermore, the emission time, emission current density, and velocity dispersion of the electron beam can be flexibly adjusted by independently controlling the second accelerating voltage signals of the first control electrode 12 and the second control electrode 13. For example, in short-pulse applications, electron emission can be quickly turned on / off by simply controlling the smaller second accelerating voltage signals of the first control electrode 12 and the second control electrode 13, without directly performing high-frequency modulation on the first accelerating voltage signal of the anode 2. This significantly reduces the need for high-voltage pulse modulation circuits, such as reducing dependence on high-power switches and avoiding the noise and energy consumption problems caused by traditional high-power switches.

[0060] It should be noted that the first control electrode 12 has a first edge 121, and the second control electrode 13 has a second edge 131, and the second edge 131 is arranged opposite to the first edge 121, and an electron penetration gap 101 is formed between the second edge 131 and the first edge 121. The electron penetration gap 101 is arranged toward the emission surface 111 and is connected to the first cavity 201 of the anode 2, forming a linear acceleration path, that is, the emission surface 111-electron penetration gap 101-first cavity 201. In actual applications, after the cathode 11 is heated, the surface electrons obtain enough energy to overcome the work function and are emitted through the emission surface 111. Since the thermal velocity of electron emission presents a divergent distribution due to temperature differences, an electron beam with a certain divergence angle is formed. The electron beam first passes through the second accelerating electric field with a smaller acceleration voltage signal formed by the first control electrode 12 and the second control electrode 13 for preliminary acceleration, and then enters the first accelerating electric field with a larger acceleration voltage signal of the first cavity 201 through the electron penetration gap 101 to complete the final acceleration. This staged acceleration method also reduces the distance energy variation of the electron beam in the initial stage, reducing transient noise caused by rapid high-voltage switching, thereby suppressing electromagnetic interference to surrounding equipment. Furthermore, by using a second accelerating electric field with a lower voltage to assist in the initial acceleration of the electron beam, and then using the first accelerating electric field with a higher voltage provided by the anode 2 to complete the final acceleration, the need for complex and expensive high-power pulse modulation circuits can be simplified, as the entire voltage difference between the cathode 11 and the anode 2 need not be rapidly switched. This achieves the desired short-pulse operation while avoiding electromagnetic interference caused by rapid high-voltage switching, ensuring the operational stability of the device itself and surrounding electronic equipment.

[0061] The technical solution of the present invention decomposes the high-voltage acceleration process into controllable multiple stages through the structural design of a graded accelerating electric field, which not only reduces the dependence on complex high-voltage modulation circuits, but also reduces the speed dispersion of the electron beam through precise electron beam path control, thereby improving device performance while solving the core technical challenges in high-frequency and high-power scenarios.

[0062] See also Figures 1 to 7In one embodiment of the present invention, the first control electrode 12 has a accommodating cavity 1201 and an opening 1202 communicating with the accommodating cavity 1201, and the opening 1202 has a first edge 121; the second control electrode 13 has a first end 132 and a second end 133 arranged opposite to each other along its length direction, and the first end 132 is arranged toward the opening 1202 and has a second edge 131 protruding outward; the cathode 11 has a third end 112 and a fourth end 113 arranged opposite to each other, the third end 112 has an emitting surface 111, and the fourth end 113 is arranged in a ring-like manner around the outer periphery of the second end 133.

[0063] In this embodiment, the first control electrode 12 is a cylindrical conductive structure, the inner wall of which maintains a certain distance from the cathode 11, forming a housing cavity 1201. The housing cavity 1201 provides an independent working space for the second control electrode 13 and the cathode 11, avoiding direct exposure to the high-voltage electric field of the anode 2 and reducing electric field distortion. The first control electrode 12 is also provided with an opening 1202 connected to the housing cavity 1201. The edge of the opening 1202 is a first edge 121, and the first edge 121 can be an annular flange or a sharp edge. The second control electrode 13 can be a solid cylindrical conductive structure, whose diameter is smaller than the inner diameter of the cylinder of the first control electrode 12 to ensure concentric nesting with the first control electrode 12. The second control electrode 13 is divided into a first end 132 and a second end 133 along the length direction. The first end 132 faces the opening 1202 of the first control electrode 12 and protrudes outward at this end to form a second edge 131, which can be an annular flange or a sharp edge. The cathode 11 is a cylindrical conductive structure that can ensure uniform electron emission and reduce spatial charge inhomogeneity. The cathode 11 is divided into a third end 112 and a fourth end 113 along the length direction. The third end 112 is provided with an emission surface 111 responsible for releasing the electron beam, and the fourth end 113 surrounds the outer periphery of the second end 133 of the second control electrode 13 to form physical support and electric field isolation. Through the above arrangement, after the electron beam is emitted from the emission surface 111 of the cathode 11, it first moves toward the first end 132 of the second control electrode 13, and is accelerated by the second accelerating electric field with a smaller voltage formed by the first control electrode 12 and the second control electrode 13 relative to the cathode 11, and then passes through the electron penetration gap 101 formed between the second edge 131 of the second control electrode 13 and the first edge 121 of the first control electrode 12. Since the first edge 121 and the second edge 131 are precisely aligned, the electron penetration gap 101 formed can ensure that the electron beam is accurately transmitted along the axial direction and reduce lateral divergence. After the electrons penetrate the gap 101 , the electron beam enters the space between the outer wall of the second control electrode 13 and the edge of the opening 1202 of the first control electrode 12 , and then enters the anode 2 through the opening 1202 , and is finally accelerated by the first accelerating electric field with a larger voltage.

[0064] Furthermore, it's important to emphasize that the second control electrode 13 is embedded within the cavity 1201 of the first control electrode 12, with the cathode 11 positioned between them. The first and second control electrodes 12, 13 can independently apply positive / negative voltage signals (within a range of ±1500V), enabling precise switching of the electron beam or adjusting its shape. Furthermore, a gradient electric field provides staged acceleration, reducing high-voltage noise. For example, in the first stage, a low voltage (e.g., +500V) applied to the second control electrode 13 can provide initial acceleration, while a rapid switch to a negative voltage (e.g., -1000V) can completely shut down the electron beam. This requires only the low voltage of the second control electrode 13, eliminating the need to directly modulate the high voltage of the anode 2. This allows for microsecond-level pulse control, meeting high-frequency requirements. In the second stage, a medium voltage (e.g., +1200V) applied to the first control electrode 12 can further constrain the electron beam path and provide a transition to anode 2 acceleration.

[0065] It is not difficult to find that the second control electrode 13 is adjacent to the cathode 11, which can provide initial emission control and fast switching capabilities. Its low-voltage design can achieve nanosecond switching and adapt to short pulse requirements. The first control electrode 12 forms an outer confinement layer, which maintains the stability of the electron beam path through a medium voltage and provides a transition for the acceleration of the anode 2, avoiding the noise caused by the high voltage directly acting on the cathode 11.

[0066] See also Figures 1 to 7 In one embodiment of the present invention, a receiving groove 1101 for accommodating the first end 132 is provided at a position corresponding to the third end 112 of the cathode 11, and the emitting surface 111 is arranged on the inner wall surface of the receiving groove 1101, and the emitting surface 111 is an annular conical concave surface; the electron penetration gap 101 is an annular gap.

[0067] In this embodiment, the third end 112 of the cathode 11 is provided with a receiving groove 1101, and the inner wall surface of the receiving groove 1101 is annularly conical along the axial direction, which can provide a physical nesting space for the first end 132 of the second control electrode 13, ensuring its precise alignment with the emission surface 111, reducing the alignment deviation caused by assembly errors, and at the same time making the geometric center of the electron penetration gap 101 completely coincide with the geometric center of the emission surface 111, reducing the deviation of the electron beam path. The emission surface 111 is arranged on the inner wall surface of the receiving groove 1101, which is an annular conical concave surface, that is, the cross section gradually shrinks from the outer wall of the cathode 11 inward. The curvature of the annular conical concave surface can be very small, close to a plane. In this way, compared with the annular conical plane, the annular concave surface can not only increase the emission area and emit more electrons at the same emission density, thereby providing a higher electron beam current, but also make the electron beam naturally form an annular distribution without the need for additional magnetic field constraints, reducing dependence on high voltage. Moreover, the annular conical concave surface coincides with the equipotential surface of the second accelerating voltage signal, that is, the electric field intensity of the second accelerating voltage signal on the annular conical concave surface is equal, which is conducive to the same emission density at all locations on the emitting surface 111 and the focusing of the electron beam, thereby reducing the velocity dispersion of the electron beam and improving the quality of the electron beam.

[0068] By adjusting the voltage difference between the first control electrode 12 and the second control electrode 13, the electric field gradient is changed, thereby adjusting the optimization of the electron beam morphology. For example, applying a voltage slightly higher than that of the second control electrode 13 (such as +500V or +300V) to the first control electrode 12 can enhance the axial acceleration of the annular electron beam, change the electron beam trajectory, and reduce electron beam fluctuations.

[0069] The electron penetration gap 101 is formed by aligning the first edge 121 of the first control electrode 12 with the second edge 131 of the second control electrode 13, and is an annular gap. The annular conical concave surface near the annular gap will generate an electric field that matches the shape of the cone surface, so that the electric field intensity in the entire annular conical concave surface is consistent, ensuring the consistency of the emission density and reducing the emission noise and beam instability caused by local electric field unevenness. It is precisely because of the uniform electric field that the emission surface 111 can emit electrons uniformly, reducing the energy loss and emission efficiency reduction caused by local hot spots. Through the synergistic effect of the annular gap and the annular conical concave surface, it can be ensured that the electron beam maintains an annular shape during transmission, reducing lateral divergence and improving energy utilization.

[0070] See also Figures 1 to 7 In one embodiment of the present invention, the length of the electron penetration gap 101 is not less than 1.5 times the length of the emission surface 111 and not more than 2 times the length of the emission surface 111 .

[0071] In this embodiment, the length of the electron transmission gap 101 is the circumferential dimension of the annular gap along the notch of the receiving groove 1101, that is, the circumferentially expanded length of the annular gap formed by the first edge 121 of the first control electrode 12 and the second edge 131 of the second control electrode 13. The length of the emitting surface 111 is the circumferential dimension of the annular concave surface along the notch of the receiving groove 1101, that is, the circumferentially expanded length of the annular concave surface. The ratio of the two must meet the following condition: 1.5 × circumferential dimension of the emitting surface 111 ≤ circumferential dimension of the annular gap ≤ 2 × circumferential dimension of the emitting surface 111. This is because:

[0072] If the circumferential size of the annular gap is insufficient, for example, the circumferential size of the annular gap is less than 1.5× the circumferential length of the emitting surface 111, it is easy to cause the electric field intensity of the first edge 121 and / or the second edge 131 to be significantly higher than that in the central area, for example, the edge intensity is twice that of the center, resulting in uneven acceleration of the electron beam in the edge area of the annular gap, causing beam scattering. In addition, the annular gap with insufficient circumferential size may directly intercept some electrons due to a sudden change in field intensity, thereby reducing the emission efficiency. When the circumferential size of the annular gap meets the above conditions, the electric field gradient can be "flattened" by the annular gap, the difference between the edge intensity and the central field intensity can be effectively controlled, and the electron beam is less affected by the circumferential force when passing through the annular gap, so that the uniformity of the electric field distribution can be maintained.

[0073] If the circumferential size of the annular gap is too large, for example, the circumferential size of the annular gap is greater than 2× the circumferential size of the emitting surface 111, the voltage change of the first control electrode 12 and the second control electrode 13 will weaken the effect on the electric field in the central area of the gap, resulting in a decrease in the switching response speed. For example, the switching time is extended from nanoseconds to microseconds, which cannot meet the high-frequency requirements. When the circumferential size of the annular gap meets the above conditions, the voltage change of the first control electrode 12 and the second control electrode 13 can effectively cover the entire annular gap area. For example, when -200V is applied, the entire gap area can form an electric field opposite to the emission direction of the cathode 11, and the electron beam is completely blocked, realizing nanosecond switching, and all emitted electrons experience similar acceleration paths and electric field strengths to form a uniform annular beam, thereby improving energy utilization.

[0074] See also Figures 1 to 7 In one embodiment of the present invention, a portion of the first control electrode 12 close to the emission surface 111 is arranged parallel to the cathode 11; and / or a portion of the second control electrode 13 close to the emission surface 111 is arranged parallel to the cathode 11.

[0075] In this embodiment, the inner sidewall of the first control electrode 12 is disposed away from the outer sidewall of the cathode 11, and the top wall of the first control electrode 12 is disposed close to and parallel to the top wall of the cathode 11. The outer sidewall of the second control electrode 13 is disposed close to and parallel to the inner sidewall of the cathode 11, and the top wall of the second control electrode 13 is disposed away from the top wall of the cathode 11. By limiting the relative profile of the first control electrode 12 and / or the second control electrode 13 to be consistent with the cathode 11 near the emission surface 111, a uniform electric field distribution is ensured between the first control electrode 12 and / or the second control electrode 13 and the cathode 11, thereby suppressing uneven electron emission, causing all emitted electrons to experience similar electric field acceleration, reducing beam density differences, and simultaneously suppressing the uneven distribution of Coulomb repulsion between electrons, thereby reducing electron beam dispersion caused by the first control electrode 12 and / or the second control electrode 13.

[0076] It is understandable that the structure of the first control electrode 12 in the area close to the emission surface 111 may lead to uneven electric field distribution due to edge effects or curvature differences. For example, the sharp structure of the top edge of the first control electrode 12 may generate a local high field, resulting in uneven electron emission or secondary electron emission, or the curvature difference between the first control electrode 12 and the emission surface 111 may cause the electromagnetic wire to be distorted.

[0077] See also Figures 1 to 7 In one embodiment of the present invention, a first electric field compensation portion 122 is provided at a portion of the first control electrode 12 close to the emitting surface 111. The first electric field compensation portion 122 is arranged close to the first edge 121. The cathode 11 is provided with a second electric field compensation portion 114 spaced apart and parallel to the position of the first electric field compensation portion 122. The shape of the second electric field compensation portion 114 matches the shape of the first electric field compensation portion 122.

[0078] In this embodiment, the electric field distribution can be precisely adjusted by the shape-matched first electric field compensation portion 122 and the second electric field compensation portion 114. The first electric field compensation portion 122 and the second electric field compensation portion 114 can be a first protrusion or a first groove. In this embodiment, the first electric field compensation portion 122 is a first groove, and the second electric field compensation portion 114 is a corresponding first protrusion. The combination of the first protrusion and the first groove can offset the difference in curvature between the first control electrode 12 and the emission surface 111, making the electric field line distribution more uniform, while reducing the field strength at the top edge of the first control electrode 12, making the electron emission more uniform, and reducing the probability of secondary electron emission.

[0079] See also Figures 1 to 7In one embodiment of the present invention, the first electric field compensation portion 122 has a first electric field compensation surface 1221 and a second electric field compensation surface 1222, the second electric field compensation portion 114 has a third electric field compensation surface 1141 and a fourth electric field compensation surface 1142, the third electric field compensation surface 1141 and the first electric field compensation surface 1221 are spaced apart and parallel to each other along the width direction of the cathode 11, and the fourth electric field compensation surface 1142 is inclined from an end close to the third electric field compensation surface 1141 to an end away from the third electric field compensation surface 1141 in a direction away from the second control electrode 13, and is spaced apart and parallel to the second electric field compensation surface 1222.

[0080] In this embodiment, the third electric field compensation surface 1141 and the first electric field compensation surface 1221 are spaced apart and parallel in the width direction of the cathode 11, forming a first main electric field distribution region. This ensures that the electron beam is uniformly stressed during the initial acceleration phase and reduces beam current density variations. The fourth electric field compensation surface 1142 extends from an end proximal to the third electric field compensation surface 1141 to an end distal to the third electric field compensation surface 1141 and is inclined away from the second control electrode 13. While remaining parallel to and spaced apart from the second electric field compensation surface 1222, it forms a first gradient transition electric field distribution region. This gradually redirects the electric field lines toward the axial direction, reducing the transverse kinetic energy of the electron beam and ensuring more uniform electric field coverage across the cathode 11 region, particularly in the area proximal to the first control electrode 12, thereby preventing electric field distortion due to the presence of the first control electrode 12.

[0081] That is, if the angle formed by the extension direction of the second electric field compensation surface 1222 and the extension direction of the first electric field compensation surface 1221 is defined as the first angle a, and the angle formed by the extension direction of the fourth electric field compensation surface 1142 and the extension direction of the third electric field compensation surface 1141 is defined as the second angle b, then the second angle b is equal to the first angle a. The first control electrode 12 and the cathode 11 form the same angle through the parallel and spaced compensation surfaces, thereby forming a symmetrical electric field distribution path and reducing local electric field intensity non-uniformity.

[0082] It is understandable that in the prior art, when the emitting surface 111 has a large radius, it is prone to causing lateral oscillation or instability of the electron beam. This is because the large radius of the emitting surface makes it difficult for the second control electrode 13 to effectively control the trajectory of the electron beam that obtains a large radial velocity in the second accelerating voltage region. In this region, the electron beam begins to oscillate and experience different electric field conditions, resulting in further divergence and oscillation of the electron beam.

[0083] See also Figures 1 to 7In one embodiment of the present invention, the first oscillation suppression portion 134 has a first oscillation suppression surface 1341 and a second oscillation suppression surface 1342, the second oscillation suppression portion 115 has a third oscillation suppression surface 1151 and a fourth oscillation suppression surface 1152, the third oscillation suppression surface 1151 and the first oscillation suppression surface 1341 are spaced apart and parallel to each other along the length direction of the cathode 11, the fourth oscillation suppression surface 1152 is inclined from one end close to the third oscillation suppression surface 1151 to one end away from the third oscillation suppression surface 1151 in a direction away from the second control electrode 13, and is spaced apart and parallel to the second oscillation suppression surface 1342.

[0084] In this embodiment, the first oscillation suppression portion 134 and the second oscillation suppression portion 115 can be a second protrusion or a second groove. In this embodiment, the first oscillation suppression portion 134 is a second groove, and the second oscillation suppression portion 115 is a corresponding second protrusion. The combination of the second groove and the second protrusion can effectively improve the electric field distribution, ensuring more uniform coverage of the entire emission area. This allows electrons to undergo a similar acceleration process regardless of where they are emitted from the emission surface 111, thereby ensuring the consistency and stability of the electron beam. Furthermore, it can guide the electron beam to accelerate axially, reducing unnecessary lateral kinetic energy. Furthermore, the second groove provides a more uniform and controlled electric field environment that better matches the large radius of the emission surface 111. This allows electrons exiting the emission surface 111 to receive more uniform electric field acceleration and guidance upon entering the second groove, thereby reducing electron beam oscillations caused by geometric changes. Furthermore, the use of the second groove allows the emission surface 111 to have a larger radius without increasing the thickness of the electron beam. This means that even if the emission area increases, the electron beam cross-sectional dimensions can be maintained relatively small, helping to improve the focus and consistency of the electron beam, thereby enhancing the quality of the electron beam.

[0085] See also Figures 1 to 7 In one embodiment of the present invention, the first oscillation suppression portion 134 has a first oscillation suppression surface 1341 and a second oscillation suppression surface 1342, the second oscillation suppression portion 115 has a third oscillation suppression surface 1151 and a fourth oscillation suppression surface 1152, the third oscillation suppression surface 1151 and the first oscillation suppression surface 1341 are spaced apart and parallel to each other along the length direction of the cathode 11, the fourth oscillation suppression surface 1152 is inclined from one end close to the third oscillation suppression surface 1151 to one end away from the third oscillation suppression surface 1151 in a direction away from the second control electrode 13, and is spaced apart and parallel to the second oscillation suppression surface 1342.

[0086] In this embodiment, the third oscillation suppression surface 1151 and the first oscillation suppression surface 1341 are spaced apart and parallel in the longitudinal direction of the cathode 11, forming a second main electric field distribution region, ensuring that the electron beam is uniformly stressed during the initial acceleration phase and reducing beam current density differences. The fourth oscillation suppression surface 1152 is inclined from one end proximal to the third oscillation suppression surface 1151 to the end distal to the third oscillation suppression surface 1151, in a direction away from the second control electrode 13, while remaining parallel to and spaced apart from the second oscillation suppression surface 1342, forming a second gradient transition electric field distribution region. This gradually turns the electric field lines toward the axial direction, reducing the transverse kinetic energy of the electron beam and ensuring more uniform electric field coverage of the cathode 11, particularly in the region proximal to the second control electrode 13, thereby preventing electric field distortion due to the presence of the second control electrode 13. The second gradient transition electric field distribution region is connected to the first gradient transition electric field distribution region and lies on the same straight line, thereby alleviating electric field distortion caused by geometric shape mutations in the transition region between the first control electrode 12 and the second control electrode 13.

[0087] That is, if the angle formed by the extension direction of the second oscillation suppression surface 1342 and the extension direction of the first oscillation suppression surface 1341 is defined as the third angle c, and the angle formed by the extension direction of the fourth oscillation suppression surface 1152 and the extension direction of the third oscillation suppression surface 1151 is defined as the fourth angle d, then the fourth angle d is equal to the third angle c. The second control electrode 13 and the cathode 11 form the same angle through the parallel and spaced oscillation suppression surfaces, which can effectively improve the distribution of the electric field lines and make them more uniform. The uniform electric field distribution is conducive to improving the emission stability of the electron beam, allowing electrons to be accelerated and pass through the electron penetration gap 101 under relatively ideal conditions, reducing lateral divergence and ensuring the consistency of the beam current density.

[0088] The present invention further provides an electron gun 100, which includes an anode 2 and an electrode assembly 1. The specific structure of the electrode assembly 1 refers to the above embodiments. Since the electron gun 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0089] Among them, the anode 2 is located in the outermost layer of the entire electron gun 100 structure and is arranged around the electrode assembly 1. It not only provides the final first acceleration voltage signal for the electron beam, but also collects and focuses the electron beam to ensure that the electron beam can be effectively transmitted to the target position or enter the subsequent amplifier cavity. The electrode assembly 1 includes a cathode 11, a first control electrode 12 and a second control electrode 13, which work together to generate a second acceleration voltage signal. Compared with the first acceleration voltage signal, the second acceleration voltage signal mainly performs preliminary acceleration and fine control of the electron beam to ensure the quality and consistency of the electron beam.

[0090] It is understandable that in a high-voltage environment, if the electric field strength between the electrodes is too high, it is easy to cause voltage breakdown, which will not only damage the equipment but also affect the quality and stability of the electron beam.

[0091] See also Figures 1 to 7 In one embodiment of the present invention, the portion of the first control electrode 12 of the electrode assembly 1 close to the anode 2 is arranged parallel to the anode 2 .

[0092] In this embodiment, the anode 2 has a first cavity 201 and a second cavity 202, and the electrode assembly 1 is disposed in the first cavity 201, that is, the electrode assembly 1 is disposed near the first cavity 201 of the anode 2. This can be extended to mean that the first control electrode 12 of the electrode assembly 1 is disposed adjacent to the first cavity 201 and is parallel to the portion of the anode 2 corresponding to the first cavity 201. This arrangement can effectively reduce the situation where the local electric field intensity is too high, helps to evenly distribute the electric field lines, avoids electric field concentration areas caused by sudden changes in geometric shape, and thus reduces the risk of voltage breakdown.

[0093] See also Figures 1 to 7 In one embodiment of the present invention, the inner wall surface of the anode 2 is provided with a field intensity concentrating smooth protrusion 3 facing the electron penetration gap 101 of the electrode assembly 1. The field intensity concentrating smooth protrusion 3 is used to concentrate the electron beam passing through the electron penetration gap 101 of the electrode assembly 1 and prevent the electron beam from breaking through the anode 2.

[0094] In this embodiment, the field-concentrating smooth protrusion 3 is located on the inner wall surface of the anode 2, directly opposite the electron penetration gap 101 of the electrode assembly 1. The field-concentrating smooth protrusion 3 can further concentrate the electric field lines near the electron penetration gap 101, helping the electron beam to gather more tightly together and reducing lateral diffusion. At the same time, the increased electric field strength helps to further accelerate the electrons, allowing them to reach the required energy level more quickly, thereby improving the operating efficiency of the electron gun 100. In addition, the field-concentrating smooth protrusion 3 can also prevent the electric field from being overly concentrated in a certain area, thereby reducing the possibility of voltage breakdown. In other words, the field-concentrating smooth protrusion 3 can both prevent voltage breakdown and increase the electric field strength of the guided electron beam, which is beneficial for enhancing the compression and focusing performance of the electron gun 100.

[0095] The present invention further provides an electron gun device, comprising an electron gun 100 and at least two magnetic reversing modules 200. The specific structure of the electron gun 100 is similar to that of the aforementioned embodiments. Since the present electron gun device utilizes all of the technical solutions of all of the aforementioned embodiments, it at least possesses all of the beneficial effects provided by the technical solutions of the aforementioned embodiments, and therefore will not be further detailed here. The magnetic reversing modules 200 are used to convert the electron beam emitted by the electron gun 100 into a large cyclotron electron beam, and are capable of reducing ripple in the large cyclotron electron beam, thereby improving the stability of the large cyclotron electron beam emitted by the electron gun 100.

[0096] In the prior art, the magnetic tangent module includes two magnetic fields in opposite directions. When the electron beam moves from one magnetic field to the other, that is, through a reversal (tangent) magnetic field, a hollow large cyclotron electron beam is generated, and most of the energy of the electron beam is concentrated in the rotational motion. According to the law of conservation of energy, the electron beam continuously converts the energy of longitudinal motion into the energy of transverse motion in the reversal magnetic field. Ideally, an electron beam that initially moves in a straight line with a radius of R0 will be transformed into a large cyclotron electron beam with the same spiral radius R0 after passing through an ideal step reversal magnetic field. However, due to technical limitations, the pole shoes between the two coils form a gap, and the magnetic field reversal often requires a transition section to achieve, which makes it difficult to achieve the ideal step reversal effect. In the transition section, the electron beam easily deviates from the ideal rotational symmetry axis, forming a ripple phenomenon, which has an adverse effect on the quality and stability of the large cyclotron electron beam.

[0097] In this embodiment, the magnetic cusp module 200 includes a main coil 6 and a cathode coil 5 with opposite magnetic field directions. When the electron beam moves from the area corresponding to the cathode coil 5 to the area corresponding to the main coil 6, it will become a large cyclotron electron beam. The main coil 6 is set corresponding to the anode 2 of the electron gun 100 and is used to generate a first magnetic field; the cathode coil 5 is set corresponding to the cathode 11 of the electron gun 100 and is used to generate a third magnetic field with a direction opposite to the direction of the first magnetic field. When the electron beam moves from the area where the main coil 6 is located to the area where the cathode coil 5 is located, it will experience a cusp magnetic field composed of these two opposite magnetic fields. This process causes the electron beam, which was originally moving in a straight line, to be deflected when passing through the cusp magnetic field, forming a large cyclotron electron beam.

[0098] Based on the aforementioned cusp magnetic field, an auxiliary coil 4 is also provided. This auxiliary coil 4 is positioned at the junction of the anode 2 and cathode 11 of the electron gun 100 and is used to generate a second magnetic field. Since the auxiliary coil 4 is positioned between the main coil 6 and the cathode coil 5, and the direction of the second magnetic field generated by the auxiliary coil 4 is the same as the direction of the first magnetic field generated by the main coil 6, and the direction of the second magnetic field generated by the auxiliary coil 4 is opposite to the direction of the third magnetic field generated by the cathode coil 5, the auxiliary coil 4 and the main coil 6 can be considered integral. Therefore, the cusp magnetic field in this embodiment is formed between the auxiliary coil 4 and the cathode coil 5. In other words, when the electron beam moves from the region corresponding to the cathode coil 5 to the region corresponding to the auxiliary coil 4, it becomes a large cyclotron electron beam. It is important to note that the magnetic fields of the auxiliary coil 4 and the main coil 6 have the same direction, but the intensity of the second magnetic field generated by the auxiliary coil 4 is greater than that of the first magnetic field, effectively reducing ripple in the large cyclotron electron beam. Due to the greater intensity of the second magnetic field, there is a region of significantly increased magnetic field strength during the magnetic field reversal process (i.e., the transition from the third magnetic field of the cathode coil 5 to the second magnetic field of the auxiliary coil 4). This enhanced magnetic field provides a greater radial force to the electron beam. Based on the principle that the integral of the radial force over the transition length equals the radial force provided by the ideal cusped magnetic field, this enhanced magnetic field (the second magnetic field) can compensate for the uneven energy distribution caused by non-ideal factors during the magnetic field reversal process. In practical applications, magnetic field reversal typically requires a transition period, which causes the electron beam to deviate from its ideal rotational symmetry axis, thus generating ripples. However, by increasing the strength of the second magnetic field generated by the auxiliary coil 4 and ensuring that it reaches a higher value shortly after the reversal, additional radial force can be effectively provided, helping the electron beam stabilize more quickly on its ideal trajectory and reducing or even eliminating the ripples.

[0099] See also Figures 1 to 8 In one embodiment of the present invention, at least two magnetic switching modules 200 are axially symmetrically disposed on both sides of the electron gun 100 .

[0100] When the magnetic reciprocating modules 200 are arranged axially symmetrically, it means that they form a mirror symmetry in space relative to the electron gun 100. This layout helps to ensure that the forces acting on the electron beam emitted from the electron gun 100 when passing through the magnetic fields on both sides are symmetrical. This can avoid the electron beam path deviation caused by the asymmetric magnetic field, so that the electron beam can complete the transition from linear motion to large cyclotron motion more stably and accurately. And because the auxiliary coil 4 is designed to increase the magnetic field strength and provide additional radial force, it helps the electron beam stabilize to the ideal orbit more quickly and reduces the ripple phenomenon. If the two magnetic reciprocating modules 200 are axially symmetrically arranged on both sides of the electron gun 100, this will further enhance this effect, because the magnetic field forces from both sides will be more balanced, which will help guide the electron beam to move along the ideal path with less deviation, further reduce the ripple phenomenon, and improve the stability of the large cyclotron electron beam.

[0101] The above are merely exemplary embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's description and drawings under the technical concept of the present invention, or direct / indirect application in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An electron gun device, characterized in that: include: An electron gun includes an anode and an electrode assembly, wherein the anode is used to receive a first acceleration voltage signal, the electrode assembly is arranged in the anode, the electrode assembly includes a cathode, a first control electrode and a second control electrode, the cathode has an emission surface for emitting an electron beam; the first control electrode has a first edge, and the cathode is arranged in the first control electrode; the second control electrode is arranged in the first control electrode, the second control electrode has a second edge, the second edge is arranged toward the first edge and an electron penetration gap is formed between the second edge and the first edge for the electron beam to pass through, the electron penetration gap is arranged toward the emission surface and is connected to the anode; the first control electrode and the second control electrode are used to receive a second acceleration voltage signal, the second acceleration voltage signal is smaller than the first acceleration voltage signal; and, At least two magnetic resonant cutting module groups are axially symmetrically arranged on both sides of the electron gun, and the magnetic resonant cutting module groups are used to convert the electron beam emitted by the electron gun into a large cyclotron electron beam; the magnetic resonant cutting module group includes a main coil, a cathode coil and an auxiliary coil, the main coil is arranged corresponding to the anode, the main coil is used to generate a first magnetic field, the cathode coil is arranged corresponding to the cathode, the anode of the cathode coil is connected to the anode of the auxiliary coil through the second pole shoe, the cathode coil is used to generate a third magnetic field whose direction is opposite to the direction of the first magnetic field, the auxiliary coil is arranged corresponding to the junction of the anode and the cathode, and is used to generate a second magnetic field, the cathode of the auxiliary coil is connected to the anode of the main coil through the first pole shoe, the auxiliary coil is arranged between the main coil and the cathode coil, the direction of the second magnetic field generated by the auxiliary coil is the same as the direction of the first magnetic field generated by the main coil, the direction of the second magnetic field generated by the auxiliary coil is opposite to the direction of the third magnetic field generated by the cathode coil, and the intensity of the second magnetic field is greater than the intensity of the first magnetic field.

2. The electron gun device according to claim 1, wherein The first control electrode has a receiving cavity and an opening communicating with the receiving cavity, and the opening has the first edge; The second control electrode has a first end and a second end opposite to each other along its length, the first end is arranged toward the opening and has the second edge protruding outwards; The cathode has a third end and a fourth end that are oppositely arranged. The third end is provided with the emission surface. The fourth end is ring-shaped and is arranged on the outer periphery of the second end.

3. The electron gun device according to claim 2, wherein The cathode is provided with a receiving groove for receiving the first end at a position corresponding to the third end. The emission surface is arranged on the inner wall of the receiving groove and is an annular conical concave surface. The electron penetration gap is an annular gap.

4. The electron gun device according to claim 3, wherein The length of the electron penetration gap is not less than 1.5 times the length of the emission surface and not more than 2 times the length of the emission surface.

5. The electron gun device according to claim 1, wherein The portion of the first control electrode close to the emitting surface is arranged parallel to the cathode; And / or, a portion of the second control electrode close to the emitting surface is arranged parallel to the cathode.

6. The electron gun device according to claim 5, wherein A first electric field compensation portion is provided on a portion of the first control electrode close to the emitting surface, the first electric field compensation portion being provided close to the first edge, and a second electric field compensation portion is provided on the cathode spaced apart from and parallel to the first electric field compensation portion, the shape of the second electric field compensation portion matching the shape of the first electric field compensation portion; And / or, a first oscillation suppression portion is recessed in a portion of the second control electrode close to the emitting surface, the first oscillation suppression portion is arranged close to the second edge, a second oscillation suppression portion is provided at a position of the cathode corresponding to and parallel to the position of the first oscillation suppression portion, and a shape of the second oscillation suppression portion matches the shape of the first oscillation suppression portion.

7. The electron gun device according to claim 6, wherein The first electric field compensation portion has a first electric field compensation surface and a second electric field compensation surface, the second electric field compensation portion has a third electric field compensation surface and a fourth electric field compensation surface, the third electric field compensation surface and the first electric field compensation surface are spaced apart and arranged parallel to each other along the width direction of the cathode, and the fourth electric field compensation surface is inclined from an end close to the third electric field compensation surface to an end away from the third electric field compensation surface in a direction away from the second control electrode, and is spaced apart and arranged parallel to the second electric field compensation surface; And / or, the first oscillation suppression portion has a first oscillation suppression surface and a second oscillation suppression surface, the second oscillation suppression portion has a third oscillation suppression surface and a fourth oscillation suppression surface, the third oscillation suppression surface and the first oscillation suppression surface are spaced apart and parallel to each other along the length direction of the cathode, and the fourth oscillation suppression surface is inclined from one end close to the third oscillation suppression surface to one end away from the third oscillation suppression surface in a direction away from the second control electrode, and is spaced apart and parallel to the second oscillation suppression surface.

8. The electron gun device according to claim 1, wherein The portion of the first control electrode of the electrode assembly close to the anode is arranged parallel to the anode; And / or, the inner wall surface of the anode is provided with a field intensity concentrating smooth protrusion facing the electron penetration gap of the electrode assembly, and the field intensity concentrating smooth protrusion is used to concentrate the electron beam of the electrode assembly passing through the electron penetration gap and prevent the electron beam from penetrating the anode.

Images