Highly uniform large beam spot ion source device for vacuum proton irradiation test

Abstract

The present invention discloses a high-uniformity large beam spot ion source device for vacuum proton irradiation testing, comprising a gas source, an output end of the gas source connected to an ionization chamber, the ionization chamber connected to an extraction surface, the extraction surface connected to an accelerating electrode, the accelerating electrode connected to a target stage, the target stage connected to a computer, the computer connected to a high-voltage power supply, the high-voltage power supply connected to an electron source, and the high-voltage power supply further connected to the ionization chamber, the extraction surface, and the accelerating electrode. In the present invention, a multi-circle multi-arc hot cathode is used, the temperature of each arc can be controlled separately, and multiple layers of concentric cylindrical electrodes are arranged alternately with the hot cathode, and the extraction electrode is extended to the interior of the ionization chamber, thereby improving the uniformity of the ion beam flow; the number of circles of the hot cathode, the number of layers of the cylindrical electrodes, and the area of the extraction electrode can be increased or decreased, thereby achieving an ion beam flow with a large beam spot area, and having an automatic ion flux adjustment function, thereby improving the beam flux stability at the target stage position.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum-proton irradiation environment testing of spacecraft thermal control coatings, and in particular to a high-uniformity large beam spot ion source device for vacuum proton irradiation testing. Background Art

[0002] The vacuum-proton irradiation environment test for spacecraft thermal control coatings aims to test their adaptability to the vacuum-proton irradiation environment of space. The test involves placing the spacecraft thermal control coating in a ground-based proton irradiation test facility. Based on the principle of equivalent simulation, the coating is irradiated with simulated proton radiation, and the solar absorptivity is measured in situ. The simulated proton radiation is generated by an ion source. Compared to commonly used ion sources, the ion source used for vacuum-proton irradiation testing has unique requirements for beam spot area, beam uniformity, and flux stability. During the test, samples from the same batch are simultaneously irradiated by the proton beam within the beam spot area. A larger beam spot area allows for more samples to be tested in the same batch, which improves test efficiency and reduces the average testing cost. The uniformity of the proton beam spot and the stability of the proton flux determine the spatial and temporal consistency of the proton irradiation dose received by a batch of samples during the test. Improving the beam uniformity and flux stability indicators can reduce the deviation between the irradiation dose received by the same batch of test samples and the test requirements, thereby improving the test quality.

[0003] Currently, there are two main types of ion source devices that produce large-area, uniform beam spots. The first type uses gas discharge to generate a large-area or volume plasma, and uses a large-area grid electrode or electrode array to extract the plasma to meet certain uniformity requirements. Since these devices generate large-area plasma by increasing the cross-sectional area of the ionization chamber and the number of ion beam sources, the resulting plasma / ion beam flux is often large, which does not meet the flux requirements of vacuum-proton irradiation environment testing. The second type uses a focused or linear plasma source. Through electrical scanning of the ion beam or mechanical scanning of the target stage, the beam incident position is rapidly moved within the irradiation area, achieving a uniform beam in the irradiated area in a time-averaged sense. In this case, the proton irradiation intensity experienced by a fixed location on the test sample varies over time, meaning the beam flux fluctuates in the temporal dimension. Due to dose rate effects, the proton irradiation effect is generally not proportional to the irradiation intensity. The test results obtained using this spatially uniform beam, in the time-averaged sense, differ from those obtained using a true spatially and temporally uniform beam. This can lead to deviations in the conclusions of vacuum-proton irradiation tests and compromise test quality. Existing ion sources used for vacuum-proton irradiation tests of spacecraft thermal control coatings have numerous limitations. Therefore, a new ion source is needed that produces a highly uniform ion beam with a large spot area and stable flux. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and to propose a high-uniformity large beam spot ion source device for vacuum proton irradiation test.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-uniformity large-beam-spot ion source device for vacuum proton irradiation testing includes a gas source, an output end of the gas source is connected to an ionization chamber, the ionization chamber is connected to an extraction surface, the extraction surface is connected to an accelerating electrode, the accelerating electrode is connected to a target platform, the target platform is connected to a computer, the computer is connected to a high-voltage power supply, the high-voltage power supply is connected to an electron source, the high-voltage power supply is also connected to the ionization chamber, the extraction surface, and the accelerating electrode, and the electron source is connected to the ionization chamber.

[0007] Preferably, the gas source introduces hydrogen into the ionization chamber at a constant flow rate, and the introduced hydrogen maintains a gas pressure of 0.01 Pa in the ionization chamber.

[0008] Preferably, the electron source includes hot cathode one, hot cathode two, and hot cathode three. The hot cathode one, hot cathode two, and hot cathode three are distributed in multiple circles, each circle is a multiple arc structure, and each arc of the hot cathode is independently powered by a high-voltage power supply, and the temperature can be controlled separately. The electron source generates an electron beam, and the electron beam is introduced into the ionization chamber by the electrode.

[0009] Preferably, the ionization chamber is further provided with cylindrical electrode 1, cylindrical electrode 2, cylindrical electrode 3, and cylindrical electrode 4. The cylindrical electrode 1, cylindrical electrode 2, cylindrical electrode 3, and cylindrical electrode 4 are axially located behind the hot cathode 1, hot cathode 2, and hot cathode 3, and are arranged alternately with the hot cathode in the radial direction.

[0010] Preferably, the lead-out surface includes a lead-out electrode and a grid, the lead-out electrode is connected to the ionization chamber, the lead-out electrode has a cylindrical edge, the edge extends into the ionization chamber, replacing a portion of the inner wall of the ionization chamber close to the lead-out surface, the grid is behind the lead-out electrode, and the voltage of the lead-out electrode is lower than the voltage of the ionization chamber.

[0011] A method for automatically adjusting the ion flux of a high-uniformity, large-beam-spot ion source device used in vacuum proton irradiation testing is provided. A Faraday cup installed on a target platform measures the proton radiation flux in real time. A high-voltage power supply is controlled by a computer to adjust the voltage of the grid on the extraction surface. The computer automatic adjustment process includes the following steps:

[0012] S01. The computer reads the ion beam flux i measured by the Faraday cup mounted on the target stage;

[0013] S02. Compare the measured ion beam flux i with the ion beam flux upper limit i set manually on the computer. up Compare, if i up , then execute step S03, otherwise execute step S07;

[0014] S03. Compare the measured ion beam flux i with the ion beam flux lower limit i set manually on the computer. down Compare. If i>i down , then execute step S04, otherwise execute step S08;

[0015] S04. Waiting time T, so that the ion beam flux generated by the ion source device is stable;

[0016] S05 determines whether the computer receives a manual shutdown command. If a shutdown command is received, step S06 is executed, otherwise step S01 is executed;

[0017] ​S06. Execute the shutdown command to reduce the output voltages of the filament power supply port, ionization chamber power supply port, extraction electrode power supply port, and grid power supply port of the high-voltage power supply to 0V. Then, slowly reduce the output voltage of the accelerating electrode power supply port of the high-voltage power supply to 0V.

[0018] S07. Set the gate voltage V gd Increase ΔV, then execute step S04 to reduce the ion beam flux;

[0019] S08. Set the gate voltage V gd Reduce ΔV, then execute step S04 to increase the ion beam flux.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] 1. In this application, a multi-circle and multi-arc hot cathode with independent temperature control is used, which has multiple layers of concentric cylindrical electrodes arranged alternately with the hot cathode, and the extraction electrode is extended to the interior of the ionization chamber, so that the uniformity of the ion beam is better.

[0022] 2. In the present application, the number of hot cathode turns, the number of cylindrical electrode layers, and the area of the extraction electrode can be increased or decreased, thereby achieving an ion beam with a large beam spot area.

[0023] 3. In this application, a Faraday cup is used to measure the flux on the target stage, and a computer controls the grid voltage to automatically adjust the ion flux. As a result, the flux stability of the ion beam is higher. This has clear application prospects and development potential in spacecraft reliability engineering fields such as vacuum-proton irradiation environment testing technology for spacecraft thermal control coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic block diagram of a high-uniformity large-beam-spot ion source device for vacuum proton irradiation testing according to an embodiment of the present invention is shown;

[0025] Figure 2 A schematic diagram of a multi-circle and multi-arc hot cathode structure of a high-uniformity large beam spot ion source device for vacuum proton irradiation testing provided by an embodiment of the present invention is shown;

[0026] Figure 3 A schematic diagram of the cylindrical electrode structure of a high-uniformity large beam spot ion source device for vacuum proton irradiation testing provided in an embodiment of the present invention is shown;

[0027] Figure 4 A schematic diagram showing the positional relationship between a multi-circle, multi-arc hot cathode and a cylindrical electrode of a high-uniformity, large-beam-spot ion source device for a vacuum proton irradiation test provided by an embodiment of the present invention is shown;

[0028] Figure 5A schematic diagram showing the positional relationship between the ionization chamber and the extraction surface of a high-uniformity large beam spot ion source device for vacuum proton irradiation testing provided by an embodiment of the present invention is shown;

[0029] Figure 6 A schematic diagram showing the comparison of two equipotential surfaces formed in the ionization chamber of a high-uniformity large-beam-spot ion source device for a vacuum proton irradiation test provided by an embodiment of the present invention is shown;

[0030] Figure 7 A typical graph showing the relationship between the ion flux on the target stage and the grid voltage of a high-uniformity large-beam spot ion source device for vacuum proton irradiation testing provided by an embodiment of the present invention is shown;

[0031] Figure 8 The flowchart of realizing automatic adjustment of ion flux on a target stage of a high-uniformity large-beam-spot ion source device for vacuum proton irradiation test provided by an embodiment of the present invention is shown.

[0032] Legend:

[0033] 1. Gas source; 2. Ionization chamber; 3. Extraction surface; 4. Accelerating electrode; 5. Target stage; 6. Computer; 7. High-voltage power supply; 8. Electron source; 9. Hot cathode 1; 10. Hot cathode 2; 11. Hot cathode 3; 12. Cylindrical electrode 1; 13. Cylindrical electrode 2; 14. Cylindrical electrode 3; 15. Cylindrical electrode 4; 16. Extraction electrode; 17. Grid. DETAILED DESCRIPTION

[0034] 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.

[0035] See also Figure 1-8 , the present invention provides a technical solution:

[0036] The invention relates to a high-uniformity large-beam spot ion source device for vacuum proton irradiation test, comprising a gas source 1, an output end of which is connected to an ionization chamber 2, which is connected to an extraction surface 3. In the ionization chamber 2, an electron beam emitted by an electron source 8 collides with hydrogen molecules in the ionization chamber 2 to ionize them and generate ions. The ions are accelerated by the electric field in the ionization chamber 2 and are extracted from the extraction surface 3. The extraction surface 3 is connected to an accelerating electrode 4, which generates an electrostatic field to accelerate the ions emitted from the extraction surface 3 to the energy required for the vacuum-proton irradiation environment test. The accelerating electrode 4 is connected to a target stage. 5. The target platform 5 is used to place and fix the test sample of the vacuum-proton irradiation environment test. The sample is attached to the irradiation area of the target platform 5 using polyimide tape or double-sided tape. The ion beam accelerated by the accelerating electrode 4 is irradiated on the target platform to irradiate the sample. A Faraday cup is installed on the target platform 5 near the sample position. The ion flux on the target platform 5 is measured by the Faraday cup to achieve automatic adjustment of the ion flux. The target platform 5 is connected to a computer 6, which controls the operation of the ion source device and provides an operation interface. The specific functions include: 1) collecting the ion flux on the target platform 5 1) ion flux measured by the Faraday cup; 2) setting the output voltage of each channel of the high-voltage power supply 7; 3) displaying the operating status of the ion source device and receiving manually input operation instructions. The computer 6 is connected to the high-voltage power supply 7, which is connected to the computer 6 through a serial port. Under the control of the computer 6, the power supply output port of the high-voltage power supply 7 includes: a filament power supply port for powering the multi-circle and multi-arc hot cathodes 9, 10, and 11, a filament power supply port for powering the multi-layer concentric cylindrical electrode 12, the cylindrical electrode 2 13, and the cylindrical electrode 3. 14, a power supply port for the ionization chamber 2 that supplies power to the cylindrical electrode four 15, an extraction electrode power supply port that supplies power to the extraction electrode 16, a grid power supply port that supplies power to the grid 17, and an acceleration electrode power supply port that supplies power to the cylindrical acceleration electrode 4, etc.; wherein, in order to improve the uniformity of the ion beam, there are multiple filament power supply ports, which respectively supply power to each arc segment of the hot cathode one 9, the hot cathode two 10, and the hot cathode three 11, the high-voltage power supply 7 is connected to the electron source 8, and the high-voltage power supply 7 is also connected to the ionization chamber 2, the extraction surface 3, and the acceleration electrode 4, and the electron source 8 is connected to the ionization chamber 2.

[0037] Specifically, such as Figure 1 As shown, the gas source 1 introduces hydrogen into the ionization chamber 2 at a constant flow rate. Under the effect of the vacuum system pumping of the vacuum-proton irradiation environment test, the introduced hydrogen maintains a pressure of 0.01 Pa in the ionization chamber 2.

[0038] Specifically, such as Figure 4As shown, the electron source 8 includes a hot cathode 1 9, a hot cathode 2 10, and a hot cathode 3 11. The hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11 are distributed in multiple circles, each circle having multiple arc structures. The hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11 are independently powered by a high-voltage power supply 7, and their temperatures can be controlled separately. When heated to a sufficiently high temperature, thermal electrons are emitted from the surface to form an electron beam. The electron beam generated by the electron source 8 is introduced into the ionization chamber 2 by an electrode.

[0039] Figure 2 The hot cathode one 9, hot cathode two 10, and hot cathode three 11 are explained in the form of three circles: in the figure, from the inside to the outside are the first, second, and third circles of hot cathodes, among which the first circle of hot cathode one 9 is divided into two arcs, the second circle of hot cathode two 10 is divided into three arcs, and the third circle of hot cathode three 11 is divided into six arcs. The heating filaments in each arc are powered by the filament power supply port of the high-voltage power supply 7, heating the arc to a sufficiently high temperature, emitting thermal electrons from the surface to form an electron beam. If the heating of a certain arc is stopped and its temperature is gradually reduced, the thermal electron emission on the surface of the arc will decrease. Therefore, the distribution of electrons emitted by the hot cathode one 9, hot cathode two 10, and hot cathode three 11 can be controlled by controlling the high-voltage power supply 7 to supply energy to each arc for heating, so that the emitted electrons are evenly distributed on the cross section perpendicular to the axis.

[0040] Specifically, such as Figure 4 As shown, a cylindrical electrode 1 12, a cylindrical electrode 2 13, a cylindrical electrode 3 14, and a cylindrical electrode 4 15 are further provided in the ionization chamber 2. The cylindrical electrode 1 12, the cylindrical electrode 2 13, the cylindrical electrode 3 14, and the cylindrical electrode 4 15 are axially located behind the hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11, and are radially staggered with the hot cathodes. The function of the cylindrical electrode 1 12, the cylindrical electrode 2 13, and the cylindrical electrode 3 14 is to adjust the electric field, thereby improving the uniformity of the extracted ion beam.

[0041] Figure 3 According to the form of 4 layers, the concentric cylindrical electrode 12, cylindrical electrode 2 13, cylindrical electrode 3 14, and cylindrical electrode 4 15 are explained: in the figure, from the inside to the outside, they are the 1st, 2nd, 3rd, and 4th layers of cylindrical electrodes, and the voltages of the cylindrical electrodes 12, 13, 14, and 15 are equal, and the voltage is provided by the ionization chamber power supply port of the high-voltage power supply 7;

[0042] Figure 4The positional relationship between the hot cathode 1 9, the hot cathode 2 10, the hot cathode 3 11 and the cylindrical electrode 1 12, the cylindrical electrode 2 13, the cylindrical electrode 3 14, and the cylindrical electrode 4 15 is explained as follows: Electrons and ions are transported along the axial direction of the device. The ionization chamber 2 is located below the electron source 8. Therefore, in the axial direction, the cylindrical electrode 1 12, the cylindrical electrode 2 13, and the cylindrical electrode 3 14 are located behind the hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11, as shown in FIG. Figure 4 In the right figure, in the radial direction, cylindrical electrode 1 12, cylindrical electrode 2 13, cylindrical electrode 3 14, cylindrical electrode 4 15 and hot cathode 1 9, hot cathode 2 10, hot cathode 3 11 are arranged alternately. Each circle of arc-shaped hot cathode 1 9, hot cathode 2 10, hot cathode 3 11 is adjacent to a pair of cylindrical electrode 1 12, cylindrical electrode 2 13, cylindrical electrode 3 14, cylindrical electrode 4 15, as shown in FIG. Figure 4 In the left figure, the voltage of cylindrical electrode 1 12, cylindrical electrode 2 13, cylindrical electrode 3 14, and cylindrical electrode 4 15 is higher than that of hot cathode 1 9, hot cathode 2 10, and hot cathode 3 11. Under this staggered arrangement, the electric field between the electron source 8 and the ionization chamber 2 is approximately along the axial direction. The electrons emitted from the surface of hot cathode 1 9, hot cathode 2 10, and hot cathode 3 11 will be drawn out along the axial direction by cylindrical electrode 1 12, cylindrical electrode 2 13, cylindrical electrode 3 14, and cylindrical electrode 4 15 and enter the ionization chamber 2. The speed of electron diffusion along the radial direction is very small, which makes the electrons in the ionization chamber 2 perpendicular to the axis. The electron distribution on the cross section is consistent with the distribution of electrons emitted by the hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11. Therefore, the electron distribution in the ionization chamber 2 can be controlled and adjusted by the distribution of the emitted electrons, so that the electron distribution in the ionization chamber 2 is uniform; the number of circles of the multi-circle and multi-arc hot cathode 1 9, the hot cathode 2 10, and the hot cathode 3 11 and the number of layers of the multi-layer concentric cylindrical electrode 1 12, the cylindrical electrode 2 13, the cylindrical electrode 3 14, and the cylindrical electrode 4 15 can be increased or decreased according to the beam spot area, and the ion extraction electrode and the grid are in the form of a grid, and the pass area of the electrode can be adjusted.

[0043] Specifically, such as Figure 5 As shown, the extraction surface 3 includes an extraction electrode 16 and a grid 17. The extraction electrode 16 is connected to the ionization chamber 2. The extraction electrode 16 has a cylindrical edge that extends into the ionization chamber 2, replacing a portion of the inner wall of the ionization chamber 2 close to the extraction surface 3. The grid 17 is behind the extraction electrode 16. The voltage of the extraction electrode 16 is lower than the voltage of the ionization chamber 2. Ions in the ionization chamber 2 are extracted through the extraction electrode 16 under the action of the electric field. In order to make the extracted ion beam more uniform, the extraction electrode 16 has an edge that extends into the ionization chamber 2. The voltage of the grid 17 is adjustable. Setting the voltage of the grid 17 can control the flux of the extracted ion beam.

[0044] There is a voltage difference between the extraction electrode 16 and the inner wall of the ionization chamber, thereby generating an electric field gradient in the ionization chamber 2. The cylindrical edge of the extraction electrode 16 extends into the interior of the ionization chamber 2. The cylindrical edge of the extraction electrode 16 is equivalent to a cylindrical electrode with the same diameter as the inner wall of the ionization chamber 2. The electric field equipotential surface formed by the two in the ionization chamber 2 is the same as the Figure 6 In the left figure, the electric field gradient is relatively uniform. If the conventional method is used and a planar extraction electrode 16 is used, the electric field equipotential surface formed by the extraction electrode 16 and the inner wall of the ionization chamber 2 is relatively different in shape. Figure 6 In the right figure, the uniformity of the electric field gradient is poor, especially the electric field gradient far away from the symmetry axis is large. Compared with the electric field shown in the equipotential surface 1, using the electric field shown in the equipotential surface 1 to extract ions in the ionization chamber 2 can better maintain the uniformity of the ion distribution, thereby improving the uniformity of the ion beam.

[0045] A method for automatically adjusting the ion flux of a high-uniformity, large-beam-spot ion source device for vacuum proton irradiation testing is provided. A Faraday cup installed on a target stage 5 measures the proton radiation flux in real time. A computer 6 controls a high-voltage power supply 7 to adjust the voltage of a grid 17 in an extraction surface 3. The computer automatically adjusts the flow, including the following steps:

[0046] S01. The computer 6 reads the ion beam flux i measured by the Faraday cup mounted on the target stage 5;

[0047] S02. The measured ion beam flux i is compared with the ion beam flux upper limit i set manually on the computer 6. up Compare, if i up , then execute step S03, otherwise execute step S07;

[0048] S03. The measured ion beam flux i is compared with the ion beam flux lower limit i set manually on the computer 6. down Compare. If i>i down , then execute step S04, otherwise execute step S08;

[0049] S04. Waiting time T, so that the ion beam flux generated by the ion source device is stable;

[0050] S05 determines whether the computer 6 receives a shutdown command manually issued, if a shutdown command is received, step S06 is executed, otherwise step S01 is executed;

[0051] S06. Execute the shutdown command to reduce the output voltage of the filament power supply port of the high-voltage power supply 7, the ionization chamber 2 power supply port, the extraction electrode 16 power supply port, the grid 17 power supply port, etc. to 0V, and then slowly reduce the output voltage of the acceleration electrode 4 power supply port of the high-voltage power supply 7 to 0V; ​

[0052] S07. Set the gate voltage V gd Increase ΔV, then execute step S04 to reduce the ion beam flux;

[0053] S08. Set the gate voltage V gd Reduce ΔV, then execute step S04 to increase the ion beam flux;

[0054] The automatic adjustment of the ion beam flux is based on the relationship between the ion flux on the target 5 and the voltage of the grid 17. A typical curve of this relationship is shown in FIG. Figure 7 As shown, for Figure 7 As shown in the curve, when the gate voltage V gd <-20V, the ion flux on the target 5 has almost no effect on the gate 17 voltage V gd changes, and remains at a higher value when the gate 17 voltage is -20V <V gd When the voltage V gd When the gate voltage V gd When the voltage of the gate 17 is -20V, the ion flux on the target 5 is 0. <V gd In the range of <+140V, the ion flux on the target stage 5 can be controlled by changing the voltage of the gate 17.

[0055] In summary, the highly uniform large beam spot ion source device for vacuum proton irradiation testing provided in this embodiment uses multiple turns of multi-arc hot cathode 1 9, hot cathode 2 10, and hot cathode 3 11 to emit electrons. Within the ionization chamber 2, there are multiple layers of concentric cylindrical electrode 1 12, cylindrical electrode 2 13, and cylindrical electrode 3 14 arranged alternately with the hot cathode 1 9, hot cathode 2 10, and hot cathode 3 11. The ion extraction electrode is extended into the interior of the ionization chamber 2, thereby improving the uniformity of the ion beam generated by the ion source. Moreover, the number of turns of the hot cathode, the number of layers of the cylindrical electrodes, and the area of the extraction electrode of the device can all be increased or decreased, thereby generating an ion beam with a large beam spot area. In addition, the device uses a Faraday cup to measure the flux on the target stage 5, and a computer controls the grid voltage, thereby having an automatic ion flux adjustment function, thereby improving the flux stability of the ion beam.

[0056] The above description of the embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-uniformity large-beam-spot ion source device for vacuum proton irradiation testing, characterized by: The invention comprises a gas source (1), wherein the output end of the gas source (1) is connected to an ionization chamber (2), the ionization chamber (2) is connected to an extraction surface (3), the extraction surface (3) is connected to an acceleration electrode (4), the acceleration electrode (4) is connected to a target table (5), the target table (5) is connected to a computer (6), the computer (6) is connected to a high-voltage power supply (7), the high-voltage power supply (7) is connected to an electron source (8), the high-voltage power supply (7) is further connected to the ionization chamber (2), the extraction surface (3), and the acceleration electrode (4), and the electron source (8) is connected to the ionization chamber (2); The electron source (8) includes a hot cathode 1 (9), a hot cathode 2 (10), and a hot cathode 3 (11), wherein the hot cathode 1 (9), the hot cathode 2 (10), and the hot cathode 3 (11) are distributed in multiple circles, each circle being a plurality of arc structures. The electron source (8) generates an electron beam, and the electron beam is introduced into the ionization chamber (2) by an electrode; The ionization chamber (2) is further provided with a cylindrical electrode 1 (12), a cylindrical electrode 2 (13), a cylindrical electrode 3 (14), and a cylindrical electrode 4 (15). The cylindrical electrode 1 (12), the cylindrical electrode 2 (13), the cylindrical electrode 3 (14), and the cylindrical electrode 4 (15) are axially located behind the hot cathode 1 (9), the hot cathode 2 (10), and the hot cathode 3 (11), and are radially staggered with the hot cathodes. The extraction surface (3) includes an extraction electrode (16) and a grid (17), wherein the extraction electrode (16) is connected to the ionization chamber (2), and the extraction electrode (16) has a cylindrical edge, which extends into the ionization chamber (2) and replaces a portion of the inner wall of the ionization chamber (2) close to the extraction surface (3). The grid (17) is behind the extraction electrode (16), and the voltage of the extraction electrode (16) is lower than the voltage of the ionization chamber (2).

2. The high uniformity large beam spot ion source device for vacuum proton irradiation test according to claim 1, characterized in that: The gas source (1) introduces hydrogen into the ionization chamber (2) at a constant flow rate, and the introduced hydrogen maintains a gas pressure of 0.01 Pa in the ionization chamber (2).

3. An automatic ion flux adjustment method for the high uniformity large beam spot ion source device for vacuum proton irradiation test according to claim 1, characterized in that: The Faraday cup installed on the target platform (5) measures the proton radiation flux in real time, and the computer (6) controls the high voltage power supply (7) to adjust the voltage of the grid (17) in the lead-out surface (3). The computer automatically adjusts the process, including the following steps: S01. The computer (6) reads the ion beam flux i measured by the Faraday cup mounted on the target stage (5); S02. Compare the measured ion beam flux i with the ion beam flux upper limit i set manually on the computer (6). up Compare, if i up , then execute step S03, otherwise execute step S07;​ S03. Compare the measured ion beam flux i with the ion beam flux lower limit i set manually on the computer (6). down Compare; if i>i down , then execute step S04, otherwise execute step S08; S04. Waiting time T, so that the ion beam flux generated by the ion source device is stable; S05. Determine whether the computer (6) receives a shutdown command manually issued. If a shutdown command is received, execute step S06; otherwise, execute step S01; S06. Execute the shutdown command to reduce the output voltages of the filament power supply port of the high-voltage power supply (7), the ionization chamber (2) power supply port, the extraction electrode (16) power supply port, and the grid (17) power supply port to 0V, and then slowly reduce the output voltage of the acceleration electrode (4) power supply port of the high-voltage power supply (7) to 0V; S07. Set the gate (17) voltage V gd Increase ΔV, then execute step S04 to reduce the ion beam flux; S08. Set the gate (17) voltage V gd Reduce ΔV, then execute step S04 to increase the ion beam flux.

Images