Miniaturized electron beam gun extraction structure for space manufacturing

Abstract

The present invention provides a miniaturized electron beam gun extraction structure for space manufacturing, comprising: an ECR plasma source, an electron beam extraction module and an electron optical module; the ECR plasma source, the electron beam extraction module and the electron optical module are coaxially arranged in sequence from top to bottom; the ECR plasma source is used to generate plasma; the electron beam extraction module is used to extract electrons from the plasma to form an electron beam, and accelerate and focus the electron beam; the electron optical module is used to adjust and control the beam spot size and position of the electron beam output by the electron beam extraction module. The present invention provides a miniaturized electron beam gun extraction structure for space manufacturing, which can extract electrons stably through the regulation of electrodes and cooperate with the electron optical module to finally focus on a beam spot that meets the processing requirements. The present invention can obtain a stable electron beam flow and a high-precision electron beam spot, and finally meet the needs of on-orbit manufacturing.

Description

Technical Field

[0001] The invention belongs to the technical field of electron beam additive manufacturing, and in particular relates to a miniaturized lead-out structure of an electron beam gun for space manufacturing. Background Art

[0002] Plasma cathode electron beam guns, as high-energy heat sources, can be used in metal smelting, additive manufacturing, etc. At present, plasma cathode electron beam guns have the following problems: the electron beam is drawn out from the plasma, there is no fixed emitting surface, and the electrons are difficult to confine, resulting in insufficient precision of existing plasma electron beam guns. In the field of additive manufacturing, they can only be used for relatively rough parts processing, and it is difficult to meet the needs of high-precision manufacturing. Summary of the invention

[0003] In view of the defects in the prior art, the present invention provides a miniaturized lead-out structure of an electron beam gun for space manufacturing, which can effectively solve the above problems.

[0004] The technical solution adopted by the present invention is as follows:

[0005] The present invention provides a miniaturized electron beam extraction structure for space manufacturing, comprising: an ECR plasma source (1), an electron beam extraction module (2) and an electron optical module (3);

[0006] The ECR plasma source (1), the electron beam extraction module (2) and the electron optical module (3) are coaxially arranged in sequence from top to bottom;

[0007] The ECR plasma source (1) is used to generate plasma;

[0008] The electron beam extraction module (2) is used to extract electrons from the plasma to form an electron beam, and to accelerate and focus the electron beam;

[0009] The electron optical module (3) is used to adjust and control the beam spot size and position of the electron beam output by the electron beam extraction module (2).

[0010] Preferably, the electron beam extraction module (2) comprises a high voltage electrode (21), a second electrode (22) and a ground electrode (23) which are coaxially arranged in sequence;

[0011] in:

[0012] The high voltage electrode (21) is loaded with a negative high voltage voltage;

[0013] The second electrode (22) is loaded with a negative high voltage, and the absolute value of the loaded voltage is between the absolute value of the loaded voltage of the high voltage electrode (21) and the ground electrode (23). Compared with the negative high voltage loaded on the high voltage electrode (21), the second electrode (22) is at a positive potential;

[0014] The potential of the ground electrode (23) is the earth, and compared with the negative high voltage loaded by the high-voltage electrode (21) and the second electrode (22), the ground electrode (23) is at a positive potential;

[0015] Therefore, a first electric field is formed between the high-voltage electrode (21) and the second electrode (22), the direction of the electric field is from the second electrode (22) to the high-voltage electrode (21), and the electric field structure is nearly conical;

[0016] A second electric field is formed between the ground electrode (23) and the second electrode (22), the direction of the electric field is from the ground electrode (23) to the second electrode (22), and the electric field structure is nearly conical;

[0017] The center of the high-voltage electrode (21) is provided with an extraction hole (21A) connected to the ECR plasma source (1); the center of the second electrode (22) is provided with a second electrode through hole (22A); the center of the ground electrode (23) is provided with a ground electrode through hole (23A); the extraction hole (21A), the second electrode through hole (22A) and the ground electrode through hole (23A) are coaxially arranged;

[0018] When the electrons and ions generated by the ECR plasma source (1) move downward and reach above the extraction hole (21A), the first electric field blocks the passage of ions and allows only electrons to pass through the extraction hole (21A), thereby achieving an electron extraction function;

[0019] The electrons passing through the extraction hole (21A) are first accelerated under the action of the first electric field and pass through the second electrode through hole (22A);

[0020] The electrons passing through the second electrode through hole (22A) are first accelerated under the action of the second electric field and pass through the ground electrode through hole (23A);

[0021] The electrons passing through the extraction hole (21A), the second electrode through hole (22A) and the ground electrode through hole (23A) in sequence are subjected to a primary bunching effect under the action of an electrostatic lens composed of the first electric field and the second electric field.

[0022] Preferably, the shape of the lead-out hole (21A) is: comprising a cylindrical hole (21A-1) and a conical hole (21A-2) connected from top to bottom, wherein the cone tip of the conical hole (21A-2) faces upward, is connected to the bottom surface of the cylindrical hole (21A-1), and has the same aperture as the cylindrical hole (21A-1).

[0023] Preferably, the high voltage electrode (21) is a flat plate electrode;

[0024] The second electrode (22) is a hollow cavity structure with a conical upper portion and a cylindrical lower portion;

[0025] The ground electrode (23) is a hollow cavity structure with a conical upper portion and a cylindrical lower portion, and the cavity diameter of the ground electrode (23) is smaller than the cavity diameter of the second electrode (22).

[0026] Preferably, the cylindrical cavity of the second electrode (22) is extended to the middle position of the cylindrical cavity of the ground electrode (23), so that the cylindrical cavity of the second electrode (22) has the function of blocking charged particles and plasma.

[0027] Preferably, it also includes a high-voltage electrode flange (24), an insulating ring (25) and a ground electrode flange (26);

[0028] The insulating ring (25) is cylindrical, and the upper and lower ends of the insulating ring (25) are respectively equipped with the high-voltage electrode flange (24) and the ground electrode flange (26) to ensure that the high-voltage electrode flange (24) and the ground electrode flange (26) are parallel and coaxially arranged in the upper and lower directions;

[0029] A high-voltage electrode flange tapered hole (24A) is provided at the center of the high-voltage electrode flange (24); the high-voltage electrode (21) is mounted above the center of the high-voltage electrode flange (24), and the lead-out hole (21A) of the high-voltage electrode (21) and the high-voltage electrode flange tapered hole (24A) are coaxially arranged;

[0030] The ground electrode (23) is mounted above the center of the ground electrode flange (26);

[0031] The ground electrode flange (26) is provided with an air extraction hole (27);

[0032] A transition flange (28) for assembly with the electronic optical module (3) is installed below the ground electrode flange (26).

[0033] Preferably, the electronic optical module (3) comprises a primary focusing lens (31), a secondary focusing lens (32) and a deflection coil (33) which are arranged in sequence;

[0034] The electron beam extracted by the electron beam extraction module (2) is projected onto the primary focusing lens (31), and is focused at a focal position after being transmitted through the primary focusing lens (31); it is then projected from the focal position onto the secondary focusing lens (32), and is focused at the center of a deflection coil (33) after being transmitted through the secondary focusing lens (32); and after the deflection coil (33) adjusts the angle of the electron beam, it is projected onto a target position of a workbench.

[0035] Preferably, the electron beam is bunched by the first-level focusing lens (31) and the second-level focusing lens (32).

[0036] The miniaturized electron beam gun lead-out structure for space manufacturing provided by the present invention has the following advantages:

[0037] The present invention provides a miniaturized electron beam gun extraction structure for space manufacturing, which can extract electrons stably through electrode regulation and cooperate with an electron optical module to finally focus on a beam spot that meets the processing requirements. The present invention can obtain a stable electron beam current and a high-precision electron beam spot, ultimately meeting the needs of on-orbit manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A cross-sectional view of a miniaturized lead-out structure of an electron beam gun for space manufacturing provided by the present invention;

[0039] Figure 2 A cutaway perspective view of a miniaturized lead-out structure of an electron beam gun for space manufacturing provided by the present invention;

[0040] Figure 3 A cross-sectional view of the electron beam extraction module provided by the present invention;

[0041] Figure 4 A cutaway perspective view of the electron beam extraction module provided by the present invention;

[0042] Figure 5 An enlarged view of the high-voltage electrode and the high-voltage electrode flange provided by the present invention;

[0043] Figure 6 A schematic diagram of a miniaturized lead-out structure of an electron beam gun for space manufacturing provided by the present invention;

[0044] Figure 7 A schematic diagram of the electronic optical module provided by the present invention;

[0045] in:

[0046] 1-ECR plasma source;

[0047] 2-Electron beam extraction module;

[0048] 21-high voltage electrode; 21A-lead-out hole; 21A-1-cylindrical hole; 21A-2-conical hole;

[0049] 22-second electrode; 22A-second electrode through hole;

[0050] 23-ground electrode; 23A-ground electrode through hole;

[0051] 24-high voltage electrode flange; 24A-conical hole of high voltage electrode flange;

[0052] 25-insulating ring; 26-ground electrode flange; 27-exhaust hole; 28-adapter flange;

[0053] 3-electronic optical module; 31-primary focusing lens; 32-secondary focusing lens; 33-deflection coil; 34-lens barrel. DETAILED DESCRIPTION

[0054] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] The purpose of the present invention is to provide a miniaturized electron beam gun extraction structure for space manufacturing. By regulating the electrodes to stably extract electrons and cooperating with the electron optical module, the electrons are finally focused into a beam spot that meets the processing requirements. The present invention can obtain a stable electron beam current and a high-precision electron beam spot, ultimately meeting the needs of on-orbit manufacturing.

[0056] The present invention provides a miniaturized electron beam gun lead-out structure for space manufacturing, referring to Figure 1 and Figure 2 , comprising: an ECR plasma source 1, an electron beam extraction module 2 and an electron optical module 3;

[0057] From top to bottom, an ECR plasma source 1, an electron beam extraction module 2 and an electron optical module 3 are coaxially arranged in sequence;

[0058] An ECR plasma source 1, for generating plasma;

[0059] The electron beam extraction module 2 is used to extract electrons from the plasma to form an electron beam, and to accelerate and focus the electron beam;

[0060] The electron optical module 3 is used to adjust and control the beam spot size and position of the electron beam output by the electron beam extraction module 2 .

[0061] The ECR plasma source 1, the electron beam extraction module 2 and the electron optical module 3 are described in detail below:

[0062] (I) ECR plasma source:

[0063] The ECR plasma source 1 is used for providing plasma, and is characterized in that a plasma with a sufficiently high electron density is generated by using an extremely small gas flow rate.

[0064] In specific implementation, the ECR plasma source 1 uses a solid-state microwave source to generate microwaves, which are transmitted via coaxial cables and introduced into a microwave ECR resonant cavity through a coaxial waveguide converter to generate plasma. The microwave ECR resonant cavity is characterized in that it can generate plasma with a sufficiently high electron density using a very small gas flow rate. By using coaxial cable transmission, dielectric waveguides, etc., a compact structure design can be achieved.

[0065] (II) Electron beam extraction module:

[0066] The electron beam extraction module is the design focus of the present invention. The core components mainly include a high-voltage electrode 21, a second electrode 22 and a ground electrode 23. The function of the module is to extract and regulate electrons from the plasma.

[0067] refer to Figure 3 and Figure 4 , an electron beam extraction module 2, comprising a high voltage electrode 21, a second electrode 22 and a ground electrode 23 which are coaxially arranged in sequence;

[0068] in:

[0069] The high voltage electrode 21 is loaded with a negative high voltage;

[0070] The second electrode 22 is loaded with a negative high voltage, and the absolute value of the loaded voltage is between the absolute value of the loaded voltage of the high voltage electrode 21 and the ground electrode 23. Compared with the negative high voltage loaded by the high voltage electrode 21, the second electrode 22 is at a positive potential;

[0071] The potential of the ground electrode 23 is the earth. Compared with the negative high voltage loaded by the high voltage electrode 21 and the second electrode 22, the ground electrode 23 is at a positive potential;

[0072] Therefore, a first electric field is formed between the high-voltage electrode 21 and the second electrode 22, and the direction of the electric field is from the second electrode 22 to the high-voltage electrode 21, and the electric field structure is nearly conical;

[0073] A second electric field is formed between the ground electrode 23 and the second electrode 22. The direction of the electric field is from the ground electrode 23 to the second electrode 22. The electric field structure is nearly conical.

[0074] The center of the high voltage electrode 21 is provided with an extraction hole 21A connected to the ECR plasma source 1; the center of the second electrode 22 is provided with a second electrode through hole 22A; the center of the ground electrode 23 is provided with a ground electrode through hole 23A; the extraction hole 21A, the second electrode through hole 22A and the ground electrode through hole 23A are coaxially arranged;

[0075] When the electrons and ions generated by the ECR plasma source 1 move downward and reach the top of the extraction hole 21A, the first electric field blocks the passage of the ions and only allows the electrons to pass through the extraction hole 21A, thereby realizing the electron extraction function;

[0076] The electrons passing through the extraction hole 21A are first accelerated by the first electric field and pass through the second electrode through hole 22A;

[0077] The electrons passing through the second electrode through hole 22A are first accelerated by the second electric field and pass through the ground electrode through hole 23A;

[0078] The electrons passing through the extraction hole 21A, the second electrode through hole 22A and the ground electrode through hole 23A in sequence are subjected to a primary focusing effect under the action of the electrostatic lens composed of the first electric field and the second electric field.

[0079] As a specific implementation method, refer to Figure 5 The shape of the lead-out hole 21A is: including a cylindrical hole 21A-1 and a conical hole 21A-2 connected from top to bottom, wherein the cone tip of the conical hole 21A-2 faces upward, is connected to the bottom surface of the cylindrical hole 21A-1, and has the same aperture as the cylindrical hole 21A-1.

[0080] As a specific implementation, the high voltage electrode 21 is a flat plate electrode;

[0081] The second electrode 22 is a hollow cavity structure with a conical upper portion and a cylindrical lower portion; for example, the cone angle is between 70° and 120°, which has the advantage of offsetting the defocusing of the magnetic field in the lead-out area through the focusing force of the lateral electric field, thereby improving the initial emission of the electron beam.

[0082] The ground electrode 23 is a hollow cavity structure with a conical upper portion and a cylindrical lower portion, and the cavity diameter of the ground electrode 23 is smaller than the cavity diameter of the second electrode 22. For example, the cone angle is between 70° and 120°, which has the advantage of cooperating with the second electrode 22 to offset the defocusing of the magnetic field in the extraction area through the effect of the transverse electric field focusing force, thereby improving the initial emission degree of the electron beam.

[0083] As a specific implementation, the cylindrical cavity of the second electrode 22 is extended to the middle position of the cylindrical cavity of the ground electrode 23, so that the cylindrical cavity of the second electrode 22 has the function of blocking charged particles and plasma, thereby enhancing the stability of the electron beam operation.

[0084] As a specific implementation method, combined with Figure 3 , further comprising a high voltage electrode flange 24, an insulating ring 25 and a ground electrode flange 26;

[0085] The insulating ring 25 is cylindrical, and the upper and lower ends of the insulating ring 25 are respectively equipped with a high-voltage electrode flange 24 and a ground electrode flange 26 to ensure that the high-voltage electrode flange 24 and the ground electrode flange 26 are parallel and coaxially arranged up and down;

[0086] A high-voltage electrode flange tapered hole 24A is provided at the center of the high-voltage electrode flange 24; a high-voltage electrode 21 is mounted above the center of the high-voltage electrode flange 24, and the lead-out hole 21A of the high-voltage electrode 21 and the high-voltage electrode flange tapered hole 24A are coaxially arranged;

[0087] The ground electrode 23 is mounted above the center of the ground electrode flange 26;

[0088] The ground electrode flange 26 is provided with an exhaust hole 27, which has the advantage of increasing the exhaust efficiency and enabling the electrode position to quickly reach the optimal vacuum required for operation.

[0089] An adapter flange 28 for assembly with the electronic optical module 3 is installed below the ground electrode flange 26 .

[0090] In the present invention, the high-voltage electrode flange 24, the insulating ring 25 and the ground electrode flange 26 provide the position accuracy and insulation requirements required for the installation of the three electrodes through precise assembly. The assembly accuracy and convenience are improved through high-precision design and assembly scheme optimization. The electron beam extraction module 2 forms a specific electric field distribution and working pressure distribution through structure and potential, extracts electrons from the plasma and regulates the spatial morphology of the electron beam.

[0091] A specific embodiment is described below:

[0092] In this embodiment, the electron beam extraction module 2 includes three electrodes, namely: a high voltage electrode 21, a second electrode 22 and a ground electrode 23;

[0093] The high voltage electrode 21 is made of tungsten or copper-tungsten alloy, and the material has the advantage of being resistant to high temperatures and electrical ablation, so as to withstand the high temperature environment and charged particle bombardment at this location and ensure the life of the component.

[0094] The voltage applied to the high voltage electrode 21 is a negative high voltage, with an absolute value of 30 kV-90 kV, which provides the energy required for electron beam acceleration.

[0095] The second electrode 22 is made of non-magnetic stainless steel. The material has the advantage of allowing magnetic lines of force to pass through it and having good strength and processability, thus meeting the requirements of providing an electron beam control electric field.

[0096] The second electrode 22 is loaded with a negative high voltage, and its absolute value is between the high voltage electrode 21 and the ground electrode 23. It serves as an extraction electrode and a control electrode to control the size and quality of the electron beam emission. The second electrode 22 is provided with a second electrode through hole 22A, which controls the conductivity through the aperture, adjusts the upstream and downstream working pressures, and further adjusts the space charge compensation and the vacuum state, thereby improving the quality and stability of the electron beam emission.

[0097] The ground electrode 23 is made of non-magnetic stainless steel. The material has the advantage of allowing magnetic lines of force to pass through it and having good strength and processability, thus meeting the requirements of providing an electron beam control electric field.

[0098] The ground electrode 23 has a potential equal to the earth, which is at a positive potential compared to the negative high voltage, and forms an accelerating electric field between the ground electrode 23 and the high voltage electrode 21 to accelerate electrons.

[0099] The ECR plasma source has the advantages of long service life, stable operation, large beam current, etc., but it also has the disadvantages of large initial divergence angle of cathode electrons, large beam spot, low power density, etc. In order to solve the above problems, the present invention designs an electron beam extraction module, the main features of which are as follows:

[0100] (1) The electron beam extraction module is designed as a three-electrode structure, and the second electrode serves as both the extraction electrode and the control electrode, which facilitates the control of the electron beam emission size and quality.

[0101] (2) The maximum flux that can be extracted theoretically mainly depends on the ECR plasma density or space charge limit density in the extraction position area, while the actual flux extracted mainly depends on the shape and structure of the extraction electrode. By adjusting the aspect ratio (the ratio of the extraction hole radius to the acceleration gap), the extraction efficiency of the extraction system can be changed and the flux can be controlled.

[0102] (3) The difference in magnetic field at the lead-out position will also cause the difference in the lead-out flow intensity. The purpose of adjusting the flow intensity can also be achieved by selecting the lead-out hole position.

[0103] (4) The excitation magnetic ring of the ECR plasma source will inevitably form a certain magnetic field tail in the extraction area. This magnetic field has two main effects on the extracted electrons. One of them is that the transverse component of the magnetic field will produce a transverse defocusing force on the electrons, making the angle of the extracted beam larger and the emittance increase accordingly. The design of the conical electrode can offset the defocusing of the magnetic field in the extraction area through the effect of the transverse electric field focusing force, thereby improving the initial emittance of the electron beam.

[0104] (5) For ECR plasma sources, the emitted electrons are affected by the space charge effect starting from the extraction hole, especially in the acceleration region, where the electron energy is low and the beam divergence caused by the space charge force is more obvious. In order to reduce the opening angle of the extracted electrons and improve the beam emittance, in addition to optimizing the electrode shape to focus the electron beam, the influence of the space charge force must be further weakened by space charge compensation. This goal is achieved by controlling the argon density in the extraction area, adjusting the space charge compensation, and improving the beam quality.

[0105] (6) Another effect of the exciting magnetic field is that when its longitudinal component is too large, it is easy to cause Penning discharge in the acceleration zone, affecting the stability of the electron beam. The sparking phenomenon is extremely sensitive to the vacuum state at this position. By opening holes in the side wall of the electrode, the gas conduction is increased and the stability of the electron beam is improved.

[0106] (III) Electronic optical module:

[0107] The electron optical module mainly comprises the first and second focusing lenses and a deflection coil, and its function is to control the beam spot size and position of the electron beam.

[0108] refer to Figure 6 and Figure 7 , the electronic optical module 3 includes a primary focusing lens 31, a secondary focusing lens 32 and a deflection coil 33 which are arranged in sequence;

[0109] The electron beam extracted by the electron beam extraction module 2 is projected onto the primary focusing lens 31, and after being transmitted through the primary focusing lens 31, it is focused at the focal position; then it is projected from the focal position to the secondary focusing lens 32, and after being transmitted through the secondary focusing lens 32, it is focused at the center of the deflection coil 33, and after the deflection coil 33 adjusts the angle of the electron beam, it is projected to the target position of the workbench.

[0110] As a specific implementation method, the electron beam is focused by the primary focusing lens 31 and the secondary focusing lens 32 .

[0111] The primary focusing lens 31, the secondary focusing lens 32 and the deflection coil 33 form an electron optical module. The primary focusing lens 31 focuses the electron beam of the electron gun to form a minimum cross spot, and converges the electron beam on the workbench through the secondary focusing lens 32. In order to meet the requirements of molded part size and molding speed, a large-range high-precision scanning system of the electron gun is required. The ECR electron gun and its electron optical module require high-precision parts processing and assembly, and the lens barrel 34 is used for the installation of the electron optical module.

[0112] In the present invention, the electron optical module is composed of two magnetic lenses to form a dual focusing mode, which has the advantage that as the electron beam current size changes, the dual focusing system can flexibly control the electron beam to meet the beam spot and power size required for processing. The ECR electron gun and its electron optical module require high-precision parts processing and assembly. Therefore, the necessary high-precision design and assembly solution optimization are also carried out for the tripole electrostatic lens and the dual focusing system, which improves the assembly accuracy and convenience.

[0113] In the present invention, the deflection coil determines the processing range and the forming speed. From the analysis of electron optics theory, the larger the deflection angle, the larger the beam spot distortion, so the electron optics angle optimization design is carried out to eliminate the distortion and improve the precision.

[0114] The present invention provides a miniaturized electron beam gun lead-out structure for space manufacturing, the main advantages of which are:

[0115] The problem of insufficient control accuracy of existing plasma cathode electron beam guns is solved through a specially designed electron beam extraction structure. The plasma cathode electron beam source uses an electric field to extract electrons from the plasma, and accelerates them through the electric field formed by the accelerating electrode to form an electron beam. The electron beam emission is affected by the combined effects of the plasma and the extraction electric field. Electrons move under the combined effects of the electrode electrostatic field, the space free charge electric field, the focusing coil and the deflection coil magnetic field. By studying the coupling effect between multiple fields and combining the characteristics of the ECR electron beam, a high-precision plasma cathode electron beam of 40μm can be achieved and effectively controlled.

[0116] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the scope of protection of the present invention.

Claims

1. A miniaturized electron beam gun lead-out structure for space manufacturing, characterized in that: include: ECR plasma source (1), electron beam extraction module (2) and electron optical module (3); The ECR plasma source (1), the electron beam extraction module (2) and the electron optical module (3) are coaxially arranged in sequence from top to bottom; The ECR plasma source (1) is used to generate plasma; The electron beam extraction module (2) is used to extract electrons from the plasma to form an electron beam, and to accelerate and focus the electron beam; The electron optical module (3) is used to adjust and control the beam spot size and position of the electron beam output by the electron beam extraction module (2); The electron beam extraction module (2) comprises a high voltage electrode (21), a second electrode (22) and a ground electrode (23) which are coaxially arranged in sequence; in: The high voltage electrode (21) is loaded with a negative high voltage voltage; The second electrode (22) is loaded with a negative high voltage, and the absolute value of the loaded voltage is between the absolute value of the loaded voltage of the high voltage electrode (21) and the ground electrode (23). Compared with the negative high voltage loaded on the high voltage electrode (21), the second electrode (22) is at a positive potential; The potential of the ground electrode (23) is the earth, and compared with the negative high voltage loaded on the high voltage electrode (21) and the second electrode (22), the ground electrode (23) is at a positive potential; Therefore, a first electric field is formed between the high-voltage electrode (21) and the second electrode (22), the direction of the electric field is from the second electrode (22) to the high-voltage electrode (21), and the electric field structure is nearly conical; A second electric field is formed between the ground electrode (23) and the second electrode (22), the direction of the electric field is from the ground electrode (23) to the second electrode (22), and the electric field structure is nearly conical; The center of the high-voltage electrode (21) is provided with an extraction hole (21A) which is connected to the ECR plasma source (1); the center of the second electrode (22) is provided with a second electrode through hole (22A); the center of the ground electrode (23) is provided with a ground electrode through hole (23A); the extraction hole (21A), the second electrode through hole (22A) and the ground electrode through hole (23A) are coaxially arranged; When the electrons and ions generated by the ECR plasma source (1) move downward and reach above the extraction hole (21A), the first electric field blocks the passage of the ions and allows only the electrons to pass through the extraction hole (21A), thereby achieving an electron extraction function; The electrons passing through the extraction hole (21A) are first accelerated under the action of the first electric field and pass through the second electrode through hole (22A); The electrons passing through the second electrode through hole (22A) are first accelerated under the action of the second electric field and pass through the ground electrode through hole (23A); The electrons passing through the extraction hole (21A), the second electrode through hole (22A) and the ground electrode through hole (23A) in sequence are subjected to a primary bunching effect under the action of an electrostatic lens composed of the first electric field and the second electric field; Wherein: the electronic optical module (3) comprises a primary focusing lens (31), a secondary focusing lens (32) and a deflection coil (33) which are arranged in sequence; The electron beam extracted by the electron beam extraction module (2) is projected onto the primary focusing lens (31), and after being transmitted through the primary focusing lens (31), is focused at a focal position; it is then projected from the focal position onto the secondary focusing lens (32), and after being transmitted through the secondary focusing lens (32), is focused at the center of a deflection coil (33); after the deflection coil (33) adjusts the electron beam angle, it is projected onto a target position of a workbench.

2. The miniaturized electron beam gun lead-out structure for space manufacturing according to claim 1, characterized in that: The shape of the lead-out hole (21A) is: comprising a cylindrical hole (21A-1) and a conical hole (21A-2) connected from top to bottom, wherein the conical tip of the conical hole (21A-2) faces upward, is connected to the bottom surface of the cylindrical hole (21A-1), and has the same aperture as the cylindrical hole (21A-1).

3. The miniaturized electron beam gun lead-out structure for space manufacturing according to claim 1, characterized in that: The high voltage electrode (21) is a flat plate electrode; The second electrode (22) is a hollow cavity structure with a conical upper portion and a cylindrical lower portion; The ground electrode (23) is a hollow cavity structure with a conical upper portion and a cylindrical lower portion, and the cavity diameter of the ground electrode (23) is smaller than the cavity diameter of the second electrode (22).

4. The miniaturized electron beam gun lead-out structure for space manufacturing according to claim 1, characterized in that: The cylindrical cavity of the second electrode (22) is extended to the middle of the cylindrical cavity of the ground electrode (23), so that the cylindrical cavity of the second electrode (22) has the function of blocking charged particles and plasma.

5. The miniaturized electron beam gun lead-out structure for space manufacturing according to claim 1, characterized in that: It also includes a high-voltage electrode flange (24), an insulating ring (25) and a ground electrode flange (26); The insulating ring (25) is cylindrical, and the high-voltage electrode flange (24) and the ground electrode flange (26) are respectively mounted on the upper and lower ends of the insulating ring (25) to ensure that the high-voltage electrode flange (24) and the ground electrode flange (26) are vertically parallel and coaxially arranged; A high-voltage electrode flange tapered hole (24A) is provided at the center of the high-voltage electrode flange (24); the high-voltage electrode (21) is mounted above the center of the high-voltage electrode flange (24), and the lead-out hole (21A) of the high-voltage electrode (21) and the high-voltage electrode flange tapered hole (24A) are coaxially arranged; The ground electrode (23) is mounted above the center of the ground electrode flange (26); The ground electrode flange (26) is provided with an air extraction hole (27); A transition flange (28) for assembly with the electronic optical module (3) is installed below the ground electrode flange (26).

6. The miniaturized electron beam gun lead-out structure for space manufacturing according to claim 1, characterized in that: The electron beam is bunched by the first-level focusing lens (31) and the second-level focusing lens (32).

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