Device and method for generating long-pulse high-energy Penning ion beam

Abstract

The invention belongs to the technical field of ion beam generation devices, and particularly relates to a long-pulse high-energy Penning ion beam generation device and method, and the device comprises a plasma generation unit, an ion beam extraction unit, an ion beam deflection unit, and an ion beam acceleration focusing unit. The plasma generation unit is used for generating a plasma source with relatively high density under low air pressure, the ion beam extraction unit is used for extracting a low-energy ion beam from the plasma source, and the ion beam deflection unit is used for separating a low-energy electron beam from part of charged particles of the plasma source; the ion beam accelerating and focusing unit is used for accelerating and focusing the low-energy ion beam extracted from the plasma source to form a high-energy ion beam. According to the mode, the device can accelerate and focus the ion beam under higher voltage, is not only suitable for industrial processing and manufacturing and ion beam material surface modification, but also can be used as excitation for interacting with plasma source microwaves to generate a novel radiation source and the like, and is wider in application range.

Description

Technical Field

[0001] The invention belongs to the technical field of ion beam generating devices, and in particular relates to a device and method for generating a long pulse high energy Penning ion beam. Background Art

[0002] Microwave radiation is the product of the interaction between a high-current particle beam and the corresponding microwave medium. Especially in plasma microwave radiation sources, the ion beam current and beam pulse width play an important role in the frequency and radiation time of the electromagnetic waves of microwave radiation.

[0003] Generally, the interaction between conventional electron beams and plasma sources can generate high-power microwave radiation sources, but the mass of electrons in the electron beam is relatively small. If high-power microwave radiation is to be generated, the electron beam energy must be very large, that is, the acceleration field voltage must be very high. The mass of ions in an ion beam is much greater than the mass of electrons in an electron beam. If a certain method is used to make the ion beam and the electron beam acceleration field the same, the ion beam energy will be much greater than the electron beam energy, and the corresponding microwave radiation power will be further increased. Extracting ion beams from plasma sources can generate ion beam currents with large currents and long pulse widths. When studying plasma sources as electron beam sources, Penning discharge is an important way to design high-current, high-energy ion beam sources because of its simple structure and the high density of plasma sources generated under low pressure.

[0004] Generally, the acceleration field and the extraction field of a charged particle beam are combined together. In this case, there is no difference for a hot cathode electron beam, but the hot cathode has a low electron emission capability, which results in a small electron beam current and cannot meet relevant practical requirements. For both field emission and plasma source extraction ion beam sources, the diffusion of charged particles in the plasma source must be considered. After the ions are extracted and accelerated, the extraction field and the acceleration field are usually combined together, so the directions of the two electric fields are the same. Accelerated electrons are easily broken down in the field gap, which results in the acceleration field voltage not being too large. Therefore, the energy obtained by the ion beam is relatively low, which greatly limits the scope of application. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a device and method for generating a long-pulse high-energy Penning ion beam, which can prevent low-speed ions and electrons in a plasma source from diffusing into the acceleration field, thereby increasing the acceleration voltage of the ion beam, allowing the ion beam to obtain greater energy and expanding the scope of application.

[0006] The technical solution of the present invention is:

[0007] A device for generating a long pulse high energy Penning ion beam, comprising:

[0008] A plasma generating unit for generating a high-density plasma source under low pressure;

[0009] An ion beam extraction unit, comprising an extraction field vacuum tube and a low-voltage pulse voltage source, wherein the extraction field vacuum tube is connected to the low-voltage pulse voltage source, and the low-voltage pulse voltage source is equipotentially connected to a plasma generating unit, and the ion beam extraction unit is used to extract a low-energy ion beam from the plasma source;

[0010] An ion beam deflection unit, comprising an electrode plate, a metal tube and a first excitation coil, wherein the metal tube is an arc-shaped structure, and has an inlet and an outlet, and the angle between the axis of the inlet and the axis of the outlet is 80°-130°, the inlet is connected to one end of the extraction field vacuum tube, and the first excitation line is spirally wound clockwise around the outside of the metal tube from one end of the inlet toward the outlet, the electrode plate is an arc-shaped molybdenum mesh structure, and is arranged between the metal tube and the extraction field vacuum tube, the convex portion of the electrode plate faces the extraction field vacuum tube, and the electrode plate is used for focusing a low-energy ion beam;

[0011] The ion beam accelerating and focusing unit is connected to the exit port of the metal tube, and is used for accelerating and focusing the low-energy ion beam extracted from the plasma source to form a high-energy ion beam.

[0012] Preferably, the plasma generating unit comprises:

[0013] A discharge vacuum tube, which is coaxial with the extraction field vacuum tube, one end of which is connected to the extraction field vacuum tube and the other end is sealed;

[0014] A second excitation coil is spirally wound clockwise around the outside of the discharge vacuum tube from one end of the discharge vacuum tube that is closed toward one end of the extraction field vacuum tube;

[0015] Two cathode plates are arranged oppositely at the two ends of the discharge vacuum tube, the cathode plate close to the extraction field vacuum tube is a circular mesh structure, and the cathodes of the ion beam extraction unit are connected at the same potential, and the cathode plate away from one end of the extraction field vacuum tube is a circular solid structure;

[0016] Two anode plates are arranged oppositely between the two cathode plates, and the distance between the two anode plates and the adjacent cathode plates is equal. The two anode plates are both circular ring structures, and a DC voltage source is connected between the adjacent cathode plates and the anode plates.

[0017] Preferably, the ion beam acceleration and focusing unit comprises:

[0018] An accelerating field vacuum tube, one end of which is connected to the metal tube, and the accelerating field vacuum tube is connected to a high-voltage direct current voltage source;

[0019] An ion beam collector connected to an end of the accelerating field vacuum tube away from the metal tube;

[0020] The third excitation coil is spirally wound clockwise around the outer side of the accelerating field vacuum tube from one end close to the metal tube toward the ion beam collecting electrode.

[0021] Preferably, the first excitation coil, the second excitation coil and the third excitation coil are respectively controlled by independent suspended DC current sources, and the current source is 0A-3A.

[0022] Preferably, the voltage of the low-voltage pulse voltage source connected to the extraction field vacuum tube is greater than 300V-1000V, and the single pulse width is 0us-200us.

[0023] Preferably, the voltage of the high-voltage DC voltage source connected to the accelerating field vacuum tube is 0kV-50kV.

[0024] Preferably, the first excitation coil on the metal tube, the second excitation coil on the discharge vacuum tube, and the third excitation coil on the acceleration field vacuum tube are all wound into 4 to 7 layers.

[0025] According to the above-mentioned method of generating a long pulse high energy Penning ion beam generator and an ion beam, the method comprises the following steps:

[0026] S1. Evacuate the plasma generating unit, extraction field vacuum tube, metal tube and ion beam acceleration and focusing unit to make the internal pressure reach 0.008Pa-0.08Pa;

[0027] S2, adjusting the magnetic field of the plasma generating unit to achieve the magnetic field requirement for Penning discharge ignition, and then adjusting the discharge voltage in the plasma generating unit to generate a high-density plasma source;

[0028] S3, turning on the low voltage pulse source connected to the extraction field vacuum tube, and introducing the low energy plasma source in the high density plasma source from the plasma generating unit into the extraction field vacuum tube to form a low energy ion beam;

[0029] S4, energizing the second excitation coil on the metal tube, so that the low-energy ion beam in the initial state is deflected along the direction of the magnetic field generated by the second excitation coil in the metal tube, and utilizing the arc-shaped structural characteristics of the metal tube to eliminate the low-speed ions and electrons in the low-energy ion beam when colliding with the inner wall of the metal tube, and the trimmed low-energy ion beam enters the ion beam acceleration and focusing unit;

[0030] S5. Using an ion beam acceleration and focusing unit, the input low-energy ion beam is accelerated and focused to form a high-energy ion beam.

[0031] Compared with the prior art, the device and method for generating a long pulse high energy Penning ion beam of the present invention has the following beneficial effects:

[0032] 1. The device separates the ion beam extraction unit and the ion beam acceleration and focusing unit, connects a solenoid formed by a metal tube with a 90° arc structure and a first excitation coil between the two, and a low-voltage pulse source connected to the extraction field vacuum tube, introduces the low-energy plasma source in the high-density plasma source in the plasma generation unit into the extraction field vacuum tube to form a low-energy ion beam, and then uses an arc-shaped molybdenum mesh electrode plate to focus the introduced low-energy ion beam and input it into the solenoid, and then the low-energy ion beam drifts into the acceleration field through the magnetic deflection inside the solenoid, and the low-energy plasma source is not affected by the magnetic field inside the solenoid due to the space charge effect, so the low-energy plasma source will not change the drift direction, and the low-speed ions and electrons in the low-energy plasma source will bombard the inner wall of the solenoid and be lost, which can prevent the low-speed ions and electrons in the plasma source from diffusing into the acceleration field, thereby increasing the acceleration voltage of the ion beam, allowing the ion beam to obtain greater energy and expand the scope of application;

[0033] 2. Furthermore, the device surrounds the second excitation coil outside the discharge vacuum tube, and forms horizontal magnetic lines of force inside the discharge space through the second excitation coil. The magnetic lines of force pass through the cathode plate and the anode plate. The introduction of the magnetic field constrains the movement of electrons in the discharge vacuum tube, so that the free electrons in the early stage of discharge oscillate back and forth between the cathode plate and the anode plate along the magnetic lines of force, increasing the collision probability between electrons and neutral atoms, thereby reducing the discharge gas pressure and increasing the plasma source density. It can achieve a gas pressure of 10 -2 A plasma source with higher density is produced under pa. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is an overall structural block diagram of an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of an ion generating unit in an embodiment of the present invention;

[0036] Figure 3 Schematic diagram of the structure of the cathode plate and the anode plate in the ion generating unit in the embodiment of the present invention, a is a circular solid cathode plate structure; b is a circular ring-shaped anode plate structure; c is a circular mesh cathode plate structure;

[0037] Figure 4 Schematic diagram of the structure of an ion beam deflection unit in an embodiment of the present invention;

[0038] Figure 5 Schematic diagram of the structure of an ion beam acceleration and focusing unit in an embodiment of the present invention;

[0039] Figure 6 is a schematic diagram of a sealing structure in an embodiment of the present invention;

[0040] Figure 7 Schematic diagram of the sealing structure in an embodiment of the present invention.

[0041] Description of reference numerals:

[0042] 1. Plasma generating unit; 11. Discharge vacuum tube; 12. Second excitation coil; 13. First cathode plate; 14. Second cathode plate; 15. Anode plate; 2. Ion beam extraction unit; 21. Extraction field vacuum tube; 3. Ion beam deflection unit; 31. Electrode plate; 32. Metal tube; 33. Incident port; 34. Exit port; 35. First excitation coil; 4. Ion beam acceleration and focusing unit; 41. Acceleration field vacuum tube; 42. Third excitation coil; 43. Ion beam collector; 5. First flange; 6. Second flange; 7. Third flange; 8. Fourth flange; 9. Fifth flange; 10. Sealing groove; 101. Rubber ring. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solution and advantages of 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 intended to limit the present invention.

[0044] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0045] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] See also Figures 1 to 5As shown, in order to prevent the low-speed ions and electrons in the plasma source from diffusing into the acceleration field, the acceleration voltage of the ion beam is increased, so that the ion beam obtains greater energy and expands the scope of application. This embodiment provides a device for generating a long-pulse high-energy Penning ion beam, including a plasma generating unit 1, an ion beam extraction unit 2, an ion beam deflection unit 3, and an ion beam acceleration and focusing unit 4. The plasma generating unit 1 is used to generate a higher-density plasma source under low pressure, the ion beam extraction unit 2 is used to extract a low-energy ion beam from the plasma source, the ion beam deflection unit 3 is used to separate and eliminate the low-speed ions and electrons in the low-energy ion beam, and the ion beam acceleration and focusing unit 4 is used to accelerate and focus the low-energy ion beam processed by the ion beam deflection unit 3 to form a high-energy ion beam. The details are as follows:

[0047] During ion acceleration, if the pressure in the acceleration space is too high, that is, when the pressure in the acceleration space is higher than 0.1 Pa, the density of gas molecules in the acceleration space is also relatively high. Ions are extremely likely to collide and ionize with neutral molecules during the acceleration process, which eventually leads to space charge breakdown, making it impossible to increase the voltage in the acceleration space. In order to make the ion beam obtain higher energy, the voltage in the acceleration space needs to be higher. When the voltage in the acceleration space is higher, the kinetic energy of the ions is greater, and the corresponding ion beam energy is also greater, thereby obtaining a high-energy ion beam.

[0048] At present, the working gas pressure of traditional flat-plate glow discharge must be above 1 Pa to ignite. Since the discharge space and the acceleration space in the experiment are in the same gas pressure region, the working gas pressure of traditional flat-plate glow discharge does not meet the conditions for obtaining high-energy ion beams, and its application range is very limited.

[0049] In order to obtain high-energy ion beams, that is, to generate a high-density glow plasma source under lower pressure conditions, the device is designed with a plasma generating unit 1 that can generate a high-density plasma source within a space pressure range of 0.008Pa-0.08Pa.

[0050] See also Figures 1 to 3As shown, the plasma generating unit 1 in the device includes a discharge vacuum tube 11, two cathode plates, two anode plates 15 and a second excitation coil 12. The discharge vacuum tube 11 is horizontally arranged and coaxial with the extraction field vacuum tube 21. One end of the discharge vacuum tube 11 is connected to the extraction field vacuum tube 21, and the other end is sealed. The two cathode plates are arranged at both ends of the discharge vacuum tube 11 opposite to each other. One cathode plate is a circular solid structure and is arranged at an end away from the extraction field vacuum tube 21, which is recorded as the first cathode plate 13; the other cathode plate is a circular mesh structure and is arranged at an end close to the extraction field vacuum tube 21, which is recorded as the second cathode plate 14; the two anode plates 15 are arranged between the first cathode plate 13 and the second cathode plate 14, and the spacing between the first cathode plate 13 and the adjacent anode plate 15 is equal to the spacing between the second cathode plate 14 and the adjacent anode plate 15, and the first cathode plate 13 and the second cathode plate 14, and the two anode plates 15 are symmetrically distributed on the discharge vacuum tube 11. The two anode plates 15 are both circular structures. A DC voltage source is respectively connected between the two anode plates 15 and the adjacent first cathode plate 13 or the second cathode plate 14. The first cathode plate 13 and the second cathode plate 14 are respectively connected to the cathode of the corresponding DC voltage source, and the two anode plates 15 are respectively connected to the anode of the corresponding DC voltage source. A second excitation coil 12 is spirally wound clockwise on the outer wall of the discharge vacuum tube 11 starting from the first cathode plate 13 toward the second cathode plate 14. Horizontal magnetic lines of force are formed inside the discharge space by the second excitation coil 12, and the magnetic lines of force pass through the first cathode plate 13 or the second cathode plate 14 and the anode plate 15. The introduction of the magnetic field constrains the movement of electrons in the discharge vacuum tube 11, so that the free electrons at the initial stage of discharge oscillate back and forth along the magnetic lines of force between the first cathode plate 13 and the corresponding anode plate 15, and between the second cathode plate 14 and the corresponding anode plate 15, thereby increasing the probability of collision between electrons and neutral atoms, thereby reducing the discharge gas pressure and increasing the plasma source density, so that a high-density plasma source can be generated within a gas pressure range of 0.008Pa-0.08Pa.

[0051] The ion beam extraction unit 2 includes an extraction field vacuum tube 21 and a low-voltage pulse voltage source. The extraction field vacuum tube 21 is connected to the low-voltage pulse voltage source, and the low-voltage pulse voltage source connected to the extraction field vacuum tube 21 is a low-voltage pulse voltage source with a re-frequency, adjustable pulse width, and a voltage of 300V-1000V, and the single pulse width is set to 100us-200us. The low-voltage pulse voltage source has a cathode and an anode. The cathode of the low-voltage pulse voltage source is connected to the low potential of the extraction field vacuum tube 21, and the anode is connected to the high potential of the extraction field vacuum tube 21. The cathode of the low-voltage pulse voltage source is connected to the cathode of the plasma generating unit 1 at the same potential, that is, the cathode of the low-voltage pulse voltage source is connected to the second cathode plate 14 of the plasma generating unit 1, so that the low-energy ion beam can be extracted from the plasma source generated in the plasma generating unit 1 through the ion beam extraction unit 2.

[0052] The ion beam deflection unit 3 includes an electrode plate 31, a metal tube 32 and a first excitation coil 35. The metal tube 32 is an arc-shaped structure, having an inlet 33 and an outlet 34. The angle between the axis of the inlet 33 and the axis of the outlet 34 is 80°-130°. The optimal angle generally used in the experiment is 90°. The first excitation coil 35 is spirally wound clockwise around the outside of the metal tube 32 from one end close to the extraction field vacuum tube 21 toward the direction of the acceleration field vacuum tube 41, so that the first excitation coil 35 and the metal tube 32 form a solenoid, the cathode of the solenoid is connected to the anode of the ion beam extraction unit 2, and the anode of the solenoid is connected to the cathode of the ion beam acceleration and focusing unit 4. The electrode plate 31 is an arc-shaped molybdenum mesh structure, which is arranged between the extraction field vacuum tube 21 and the metal tube 32, and the convex part of the electrode plate 31 faces the extraction field vacuum tube 21, and is used for focusing low-energy ion beams;

[0053] See also Figure 1 and Figure 5 As shown, the ion beam acceleration and focusing unit 4 includes an accelerating field vacuum tube 41, a third excitation coil 42 and an ion beam collector 43. The angle between the central axis of the accelerating field vacuum tube 41 and the central axis of the extraction field vacuum tube 21 is equal to the angle between the axis of the entrance port 33 of the metal tube 32 and the axis of the exit port 34. The third excitation coil 42 is spirally wound clockwise from the entrance port 33 to the exit port 34 on the outside of the accelerating field vacuum tube 41. The accelerating field vacuum tube 41 is connected to a high-voltage DC voltage source. The voltage of the high-voltage DC voltage source connected to the accelerating field vacuum tube 41 is 0kV-50kV. The cathode of the high-voltage DC voltage source is connected to the anode of the solenoid. The cathode of the high-voltage DC voltage source is connected to the ion beam collector 43. The ion beam collector 43 is installed at the end of the accelerating field vacuum tube 41 away from the metal tube 32. The ion beam collector 43 is made of copper material and is connected to the end of the accelerating field vacuum tube 41 away from the metal tube 32. When connecting with the application equipment, the ion beam collector 43 can be connected to the application equipment at the connecting end; or the ion beam collector 43 can be omitted, and the end of the accelerating field vacuum tube 41 away from the metal tube 32 can be directly connected to the application equipment.

[0054] Furthermore, the first excitation coil 35, the second excitation coil 12 and the third excitation coil 42 are respectively controlled by independent suspended DC current sources, and the current source range is 0A-3A. One end of the first excitation coil 35 close to the extraction field vacuum tube 21 is connected to the negative pole of the corresponding suspended DC current source, and the other end is connected to the positive pole of the corresponding suspended DC current source; one end of the second excitation coil 12 close to the extraction field vacuum tube 21 is connected to the positive pole of the corresponding suspended DC current source, and the other end is connected to the negative pole of the corresponding suspended DC current source; one end of the third excitation coil 42 close to the metal tube 32 is connected to the positive pole of the corresponding suspended DC current source, and the other end is connected to the negative pole of the corresponding suspended DC current source.

[0055] Furthermore, the first excitation coil 35 on the metal tube 32, the second excitation coil 12 on the discharge vacuum tube 11, and the third excitation coil 42 on the acceleration field vacuum tube 41 are all wound in the range of 4 to 7 layers, and are generally wound in 5 layers in experiments.

[0056] See also Figures 1 to 5 As shown, the discharge vacuum tube 11, the extraction field vacuum tube 21, the metal tube 32, the acceleration field vacuum tube 41 and the ion beam collector 43 are all connected by flanges and provided with a sealing structure. Further, the flange at the left end of the discharge vacuum tube 11 is marked as the first flange 5, and the flange at the right end is marked as the second flange 6. The discharge vacuum tube 11 is connected to one end of the extraction field vacuum tube 21 through the second flange 6, and the other end of the extraction field vacuum tube 21 is connected to one end of the metal tube 32 through the third flange 7. The other end of the metal tube 32 is connected to one end of the acceleration field vacuum tube 41 through the fourth flange 8, and the other end of the acceleration field vacuum tube 41 is connected to the ion beam collector 43 through the fifth flange 9.

[0057] See also Figures 1 to 5 As shown, according to the above-mentioned device for generating a long pulse high energy Penning ion beam, the method for generating an ion beam comprises the following steps:

[0058] S1, evacuate the discharge vacuum tube 11, the extraction field vacuum tube 21, the metal tube 32 and the acceleration field vacuum tube 41 to make the internal pressure reach 0.008Pa-0.08Pa;

[0059] S2, energize the first excitation coil 35 outside the discharge vacuum tube 11 to achieve the magnetic field requirement for Penning discharge ignition;

[0060] S4, adjusting the discharge voltage of the DC voltage source connected between the first cathode plate 13 and the adjacent anode plate 15, and between the second cathode plate 14 and the adjacent anode plate 15 on the discharge vacuum tube 11, so that a high-density plasma source is generated in the discharge vacuum tube 11;

[0061] S5, turning on the low voltage pulse source connected to the extraction field vacuum tube 21, and introducing the low energy plasma source in the high density plasma source from the discharge vacuum tube 11 into the extraction field vacuum tube 21 to form a low energy ion beam;

[0062] S6. The second excitation coil 12 on the metal tube 32 is energized, so that the low-energy ion beam in the initial state is deflected along the direction of the magnetic field generated by the second excitation coil 12 in the metal tube 32, and the low-speed ions and electrons in the low-energy ion beam are separated by using the 90° arc structure feature of the metal tube. The low-speed ions and electrons will bombard the inner wall of the metal tube 32 and be lost, which can prevent the low-speed ions and electrons in the plasma source from diffusing into the acceleration field vacuum tube 41, and then the low-energy ion beam after being trimmed by the metal tube enters the acceleration field vacuum tube 41 after passing through the metal tube 32;

[0063] S7. Energize the third excitation coil 42 on the accelerating field vacuum tube 41, and turn on the high-voltage DC voltage source connected to the accelerating field vacuum tube 41, so that the low-energy ion beam is accelerated and focused to obtain a high-energy ion beam, which is convenient for application in different devices.

[0064] Working principle of this device:

[0065] Specifically, the second excitation coil 12 is wound around the outside of the discharge vacuum tube 11 from the first cathode plate 13 to the second cathode plate 14, and horizontal magnetic lines of force are formed inside the discharge space through the second excitation coil 12. The magnetic lines of force pass through the cathode plate and the anode plate 15. The introduction of the magnetic field constrains the movement of electrons in the discharge vacuum tube 11, so that the free electrons in the early stage of discharge oscillate back and forth between the cathode plate and the anode plate 15 along the magnetic lines of force, thereby increasing the probability of collision between electrons and neutral atoms, thereby reducing the discharge gas pressure and increasing the plasma source density, so that a high-density plasma source can be generated at a gas pressure of 0.008-0.08 Pa.

[0066] A solenoid formed by a metal tube 32 with a 90° arc structure and a first excitation coil 35 is connected between the ion beam extraction unit 2 and the ion beam acceleration and focusing unit 4, and the winding direction of the first excitation coil 35 is specified to be wound from the entrance port 33 of the metal tube 32 to the exit port 34, and then a low-voltage pulse source is introduced into the extraction field vacuum tube 21, and the low-energy plasma source in the high-density plasma source in the plasma generation unit 1 is introduced into the extraction field vacuum tube 21 to form a low-energy ion beam, and then the introduced low-energy ion beam is focused and input into the solenoid by using the arc-shaped molybdenum mesh structure electrode plate 31, and then the low-energy ion beam is drifted by the magnetic deflection inside the solenoid. The low-energy plasma source will move into the acceleration field, while the low-energy plasma source will not be affected by the magnetic field inside the solenoid due to the space charge effect, so the low-energy plasma source will not change the drift direction, and the low-speed ions and electrons in the low-energy plasma source will bombard the inner wall of the solenoid and be lost. The low-speed ions and electrons in the low-energy plasma source are separated by the 90° arc structure, thereby preventing the low-speed ions and electrons in the low-energy ion beam from diffusing into the ion beam acceleration and focusing unit 4, thereby utilizing the effect of the high-voltage DC voltage source provided by the acceleration field vacuum tube 41 to effectively increase the acceleration voltage of the low-energy ion beam, so that the low-energy ion beam obtains greater energy and expands the scope of application.

[0067] Specifically, the application and installation method of the device and the size coordination of each component can refer to the following methods:

[0068] like Figure 3 As shown, the first cathode plate 13 is denoted by a, which is a circular solid structure; the second cathode plate 14 is denoted by c. It is a circular mesh structure; the anode plate 15 is denoted by b, which is a circular ring structure. a, b, and c are all aluminum electrodes, 2mm thick, the outer radius of a, c and b is 25mm, and the inner radius of b is 20mm; the mesh of c is 1mm*1mm, and the first cathode plate 13, the second cathode plate 14 and the anode plate 15 are all provided with wiring holes, and the size of the wiring holes is φ6;

[0069] like Figure 2As shown, both ends of the discharge vacuum tube 11 are connected by a first flange 5 and a second flange 6. A total of four electrodes are arranged on the discharge vacuum tube 11, namely two cathodes and two anodes, namely a first cathode plate 13, a second cathode plate 14 and two anode plates 15. The discharge vacuum tube 11 is made of organic glass material, 100 mm long and 20 mm thick, with an inner diameter of 100 mm. The outer edges of the first cathode plate 13 and the second cathode plate 14 are 70 mm apart, and the inner edges of the two anode plates 15 are 46 mm apart. The first cathode plate 13, the second cathode plate 14 and the two anode plates 15 are installed symmetrically on the discharge vacuum tube 11; the second cathode plate 14 is installed near the second flange 6. Through holes are drilled at the corresponding positions of the discharge vacuum tube 11 (two through holes are drilled on the left and right sides of the center line of the first cathode plate 13 and the second cathode plate 14), and the first cathode plate 13, the second cathode plate 14 and the two anode plates 15 are placed in the discharge vacuum tube 11. The corresponding through holes are passed through by wires to connect with the DC voltage source on the outside, and the holes drilled inside and outside the discharge vacuum tube 11 are sealed with insulating resin to ensure the airtightness of the vacuum tank. The first flange 5 is made of organic material with a diameter of 150mm, a diameter of 50mm in the middle of the bottom opening, and a thickness of 15mm. It is used for bottom vacuuming and is sealed after vacuuming; the second flange 6 is an aluminum plate with a thickness of 5mm, a diameter of 150mm, and a diameter of 70mm in the middle opening. The diameter of the coil wrapped around the outside of the discharge vacuum tube 11 is 4mm 2 Insulated wire, 5 layers in total.

[0070] like Figure 6 and 7 As shown, a sealing groove 10 is provided at the end of the discharge vacuum tube 11, the sealing groove 10 is 3 mm deep, the difference between the outer radius and the inner radius of the sealing groove 10 is 5 mm, and a 5 mm thick rubber ring 101 is installed in the sealing groove 10 at the end of the discharge vacuum tube 11. When evacuating, a metal flat plate or a flat plate of organic material can be directly pressed on the top to make the connection with the first flange 5 or the second flange 6 more sealed. Preferably, the sealing method of the extraction field vacuum tube 21, the metal tube 32 and the acceleration field vacuum tube 41 connected to the corresponding flange is the same as described above.

[0071] like Figure 4 and Figure 5As shown, the cathode and anode of the low voltage pulse source connected to the extraction field vacuum tube 21 are fixed on the second flange 6 and the third flange 7, respectively. The second flange 6 is connected to the discharge vacuum tube 11 on the left side and the extraction field vacuum tube 21 on the right side; the connection between the discharge vacuum tube 11 and the extraction field vacuum tube 21 and the second flange 6 is sealed by a rubber ring 101; the cathode of the low voltage pulse source connected to the extraction field vacuum tube 21 is connected to the second cathode plate 14 on the discharge vacuum tube 11 at the same potential, and the extraction field vacuum tube 21 is provided with an electrode plate 31 made of a semi-arc molybdenum mesh (grid 2mm*2mm or 1mm*1mm) electrode near the metal tube 32. The electrode plate 31 is connected to the third flange 7 at the same potential. The third flange 7 is an aluminum plate with a thickness of 5mm, an outer diameter of 150mm, and a middle opening diameter of 50mm. The extraction field vacuum tube 21 is connected to the arc-shaped metal tube 32 through the third flange 7. The connection end of the metal tube 32 and the extraction field vacuum tube 21 is set as the inlet 33, and the other end is the outlet 34. The angle between the axis of the inlet 33 of the metal tube 32 and the axis of the outlet 34 is preferably set to 90°. The outer side of the metal tube 32 is wound with a coil diameter of 4 mm from the inlet 33 to the outlet 34. 2 The insulated wire has 5 layers in total, and an arc-shaped solenoid is formed by the cooperation of the metal tube 32 and the first excitation coil 35. The arc-shaped metal tube 32 is made of stainless steel pipe with a wall thickness of 3mm and an inner diameter of 50mm. It can be seamlessly and airtightly welded with the third flange 7 on the extraction field vacuum tube 21. This connection method will not have too much impact on the electric field distribution of the extraction field and the magnetic field distribution in the solenoid. However, on the basis of ensuring the vacuum pumping strength, the wall thickness of the metal tube 32 is reduced as much as possible, in order to ensure that the metal tube 32 is more compact when it is wrapped around the first excitation coil 35. At the other end of the metal tube 32, that is, the outlet 34 of the metal tube 32 is seamlessly and airtightly welded with the fourth flange 8. The fourth flange 8 is an aluminum plate with a thickness of 5mm, an outer diameter of 150mm, and a middle opening diameter of 50mm.

[0072] like Figure 5 As shown, in the ion beam acceleration and focusing unit 4, the exit port of the metal tube 32 is connected to the acceleration field vacuum tube 41 through the fourth flange 8. The acceleration field vacuum tube 41 is also made of organic glass. The inner diameter of the acceleration field vacuum tube 41 is 60mm and the outer diameter is 80mm. The acceleration field vacuum tube 41 is tightly connected to the ion beam collector 43 through the fifth flange 9. The two sides of the acceleration field vacuum tube 41 are also sealed with the fourth flange 8 and the fifth flange 9 by rubber rings 101. The fifth flange 9 is an aluminum plate with a thickness of 5mm, an outer diameter of 150mm, and a middle opening diameter of 50mm. The third excitation coil 42 is wound around the outside of the acceleration field vacuum tube 41 along the direction of the metal tube 32 toward the ion beam collector 43. The third excitation coil 42 is 4mm 2Insulated wire, 5 layers in total; ions pass through the cathode of the accelerating field vacuum tube 41, and after being focused, they are incident on the ion beam collector 43. In practical applications, such as as a microwave radiation source, the ion beam collector 43 shown above is not required, and the high-energy ion beam should directly enter the corresponding microwave medium for interaction after passing through the accelerating field vacuum tube 41.

[0073] This device also has the following advantages:

[0074] 1) The device provides a long-pulse high-energy Penning ion beam generating device and method. The structure is small in size and occupies little space. At the same time, compared with the prior art method of generating microwave radiation by utilizing the interaction between an electron beam and a plasma source, the interaction between a high-energy ion beam and a plasma source can be applied to the field of higher-power wide-bandwidth microwave radiation. The high-energy ion beam of this design can withstand the reverse ion bombardment of the plasma source filling device in the beam microwave medium.

[0075] 2) The device provides a long pulse high energy Penning ion beam generating device and method. Compared with the traditional glow discharge generating device, the plasma generating unit 1 can generate a plasma source at a lower gas pressure. In the plasma generating unit 1, the introduction of the magnetic field greatly increases the density of the plasma source at the local center of the discharge, thereby improving the extraction efficiency of the low energy ion beam. In addition, by introducing the ion beam deflection unit 3 between the ion beam extraction unit 2 and the ion beam acceleration and focusing unit 4, the voltage in the ion beam acceleration and focusing unit 4 can be higher, so that the low energy ion beam can be accelerated and focused to form a high energy ion beam after passing through the shaping of the ion beam deflection unit 3 and entering the ion beam acceleration and focusing unit 4, thereby obtaining greater energy and expanding the scope of application.

[0076] 3) The long pulse high energy Penning ion beam generating device and method provided by the present device, compared with the traditional plasma source ion beam generating device, on the basis of the single pulse width of the ion beam reaching 50us-100us, the voltage of the ion beam acceleration and focusing unit 4 can theoretically reach 50kV. In addition, by taking advantage of the ease of realization of the low voltage pulse source, the high repetition rate of the ion beam pulse can be achieved.

[0077] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A device for generating a long pulse high energy Penning ion beam, characterized in that: include: A plasma generating unit (1) for generating a high-density plasma source under low pressure; An ion beam extraction unit (2) comprises an extraction field vacuum tube (21) and a low-voltage pulse voltage source, wherein the extraction field vacuum tube (21) is connected to the low-voltage pulse voltage source, and the low-voltage pulse voltage source is connected to the plasma generating unit (1) at the same potential, and the ion beam extraction unit (2) is used to extract a low-energy ion beam from the plasma source; An ion beam deflection unit (3) comprises an electrode plate (31), a metal tube (32) and a first excitation coil (35); the metal tube (32) is an arc-shaped structure; the metal tube (32) has an incident port (33) and an exit port (34); the angle between the axis of the incident port (33) and the axis of the exit port (34) is 80°-130°; the incident port (33) is connected to one end of the extraction field vacuum tube (21); the first excitation coil (35) is spirally wound clockwise from the incident port (33) toward the exit port (34) on the outside of the metal tube (32); the electrode plate (31) is an arc-shaped molybdenum mesh structure, and is arranged between the metal tube (32) and the extraction field vacuum tube (21); the convex portion of the electrode plate (31) faces the extraction field vacuum tube (21); and the electrode plate (31) is used for focusing a low-energy ion beam; An ion beam accelerating and focusing unit (4) is connected to the exit port (34) of the metal tube (32), and the ion beam accelerating and focusing unit (4) is used to accelerate and focus a low-energy ion beam extracted from a plasma source to form a high-energy ion beam.

2. The device for generating a long pulse high energy Penning ion beam according to claim 1, characterized in that: The plasma generating unit comprises: A discharge vacuum tube (11) is coaxial with the extraction field vacuum tube (21), one end of the discharge vacuum tube (11) is connected to the extraction field vacuum tube (21), and the other end is sealed; A second excitation coil (12) is spirally wound clockwise around the outside of the discharge vacuum tube (11) from one end of the discharge vacuum tube (11) which is closed toward one end of the extraction field vacuum tube (21); Two cathode plates are arranged oppositely at two ends of the discharge vacuum tube (11), the cathode plate close to the extraction field vacuum tube (21) is a circular mesh structure, and the cathodes of the ion beam extraction unit (2) are connected at the same potential, and the cathode plate at one end away from the extraction field vacuum tube (21) is a circular solid structure; Two anode plates (15) are arranged oppositely between the two cathode plates, and the spacing between the two anode plates (15) and the adjacent cathode plates is equal. The two anode plates (15) are both annular structures, and a DC voltage source is connected between the adjacent cathode plates and the anode plates (15).

3. The device for generating a long pulse high energy Penning ion beam according to claim 2, characterized in that: The ion beam accelerating and focusing unit (4) comprises: An accelerating field vacuum tube (41), one end of which is connected to the metal tube (32), and the accelerating field vacuum tube (41) is connected to a high-voltage direct current voltage source; An ion beam collector (43) connected to an end of the accelerating field vacuum tube (41) away from the metal tube (32); The third excitation coil (42) is spirally wound clockwise around the outside of the accelerating field vacuum tube (41) from one end close to the metal tube (32) toward the ion beam collector (43).

4. The device for generating a long pulse high energy Penning ion beam according to claim 3, characterized in that: The first excitation coil (35), the second excitation coil (12) and the third excitation coil (42) are respectively controlled by mutually independent suspended direct current sources, and the current source is 0A-3A.

5. The device for generating a long pulse high energy Penning ion beam according to claim 1, characterized in that: The voltage of the low-voltage pulse voltage source connected to the extraction field vacuum tube (21) is greater than 300V-1000V, and the single pulse width is 0us-200us.

6. The device for generating a long pulse high energy Penning ion beam according to claim 3, characterized in that: The voltage of the high-voltage direct current voltage source connected to the accelerating field vacuum tube (41) is 0 kV-50 kV.

7. The device for generating a long pulse high energy Penning ion beam according to claim 3, characterized in that: The first excitation coil (35) on the metal tube (32), the second excitation coil (12) on the discharge vacuum tube (11), and the third excitation coil (42) on the acceleration field vacuum tube (41) are all wound into 4 to 7 layers.

8. A method for generating an ion beam using a long pulse high energy Penning ion beam generator according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, evacuating the plasma generating unit (1), the extraction field vacuum tube (21), the metal tube (32) and the ion beam acceleration and focusing unit (4) to a vacuum condition such that the internal gas pressure reaches 0.008 Pa-0.08 Pa; S2, adjusting the magnetic field of the plasma generating unit (1) to achieve the magnetic field requirement for Penning discharge ignition, and then adjusting the discharge voltage in the plasma generating unit (1) to generate a high-density plasma source; S3, turning on the low voltage pulse source connected to the extraction field vacuum tube (21), and introducing the low energy plasma source in the high density plasma source from the plasma generating unit (1) into the extraction field vacuum tube (21) to form a low energy ion beam; S4, energizing the second excitation coil (12) on the metal tube (32), so that the low-energy ion beam in the initial state is deflected along the direction of the magnetic field generated by the second excitation coil (12) in the metal tube (32), and utilizing the arc-shaped structural characteristics of the metal tube (32) to eliminate low-speed ions and electrons in the low-energy ion beam when colliding with the inner wall of the metal tube, and the trimmed low-energy ion beam enters the ion beam acceleration and focusing unit (4); S5. Using the ion beam acceleration and focusing unit (4), the input low-energy ion beam is accelerated and focused to form a high-energy ion beam.

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