Linear plasma device

Abstract

The invention relates to the technical field of material irradiation damage, in particular to a linear plasma device which comprises a plasma source, a sample chamber, a sample table assembly, a first position adjusting assembly and a detection assembly. The sample chamber is provided with a sealed vacuum cavity; the sample table assembly comprises a sample table and a connecting pipe, the sample table is used for bearing and fixing a sample material, the sample table can extend into the vacuum cavity, the first end of the connecting pipe is hermetically connected with the vacuum cavity, and the second end of the connecting pipe is hermetically arranged; the plasma source can generate a plasma beam; the detection assembly comprises a temperature sensor, and the temperature sensor is arranged in the vacuum cavity and can detect the temperature distribution of the sample material; the first position adjusting assembly is connected with the sample table assembly and can drive the sample table so that the physical center of the sample material can coincide with the temperature center. Therefore, the problem that a plasma beam spot deviates from the geometric center of a sample material is solved.

Description

Technical Field

[0001] This invention relates to the field of material irradiation damage technology, and more specifically, to a linear plasma device. Background Technology

[0002] Nuclear fusion energy is a promising and sustainable long-term solution to humanity's energy needs. Tokamak devices with magnetically confined fusion plasma are among the most feasible devices for achieving controlled thermonuclear fusion. The interaction between plasma and wall materials in fusion reactors is a critical issue affecting the performance, safety, and availability of ITER and future fusion reactors. Linear plasma devices have emerged due to their advantages of lower cost, simpler geometry, steady-state operation, and ease of diagnostics. They can generate stable plasma that lasts for tens of hours, enabling equivalent simulation and verification of the boundary environment in a tokamak under relatively simple laboratory conditions.

[0003] Linear plasma facilities offer the feasibility of studying plasma-material interactions at a moderate cost and with similar boundary plasma state parameters. The multifunctional linear plasma testing platform can generate steady-state plasmas of different ion species (H, D, He, Ar, D+He, etc.). Material samples are placed within the linear plasma facility and exposed to plasma with pre-set discharge parameters to simulate the interaction between boundary plasma and materials in the ITER environment.

[0004] In existing linear plasma devices, multiple components are fixedly arranged on the same straight line. However, due to factors such as installation precision and deformation of the support structure over time, the plasma beam spot may shift from the geometric center of the sample, or the plasma beam may shift from the central axis of the vacuum chamber, affecting experimental results. Furthermore, existing linear plasma devices suffer from low repeatability of plasma parameters and sample temperature under the same plasma source input parameters. This lack of stability and repeatability reduces the efficiency, increases cost, and lengthens the time required for radiation effect studies using linear plasma devices. Summary of the Invention

[0005] To address the problem of plasma beam misalignment with the geometric center of the sample material, this invention provides a linear plasma device, comprising: a plasma source, a sample chamber, a sample stage assembly, a first position adjustment assembly, and a detection assembly; the sample chamber has a sealed vacuum chamber; the sample stage assembly includes a sample stage and a connecting tube, the sample stage being used to support and fix the sample material and extending into the vacuum chamber, the connecting tube being coaxially sleeved on the outside of the sample stage, with a gap between the sample stage and the connecting tube, the first end of the connecting tube being sealed to the vacuum chamber, and the second end of the connecting tube being sealed; the plasma source is capable of generating a plasma beam, and the plasma source is sealed to the vacuum chamber, allowing the plasma beam to enter the vacuum chamber and irradiate the sample material; the detection assembly includes a temperature sensor, which is disposed within the vacuum chamber and capable of detecting the temperature distribution of the sample material; the first position adjustment assembly is connected to the sample stage assembly and is capable of driving the sample stage so that the physical center of the sample material coincides with the temperature center.

[0006] In some embodiments, the sample stage assembly further includes a first sealing plate, the sample stage assembly is fixedly connected to the first sealing plate, and the first sealing plate is sealed to the side of the connecting tube opposite to the vacuum chamber; the connecting tube includes a first flexible segment disposed in the middle of the connecting tube, and the first flexible segment is also capable of extending and retracting along the extension direction of the connecting tube.

[0007] In some embodiments, the plasma source includes an outer casing tube, an anode tube, and a cathode. The anode tube is fitted inside the outer casing tube, and the cathode end face is fitted inside one end of the anode tube, with a gap between it and the inner wall of the anode tube. The linear plasma device also includes a second position adjustment component, which is connected to the cathode and can drive the central axis of the cathode to coincide with the central axis of the vacuum chamber.

[0008] In some embodiments, the plasma source further includes a second sealing plate for connecting the side of the outer casing tube away from the vacuum chamber and the side of the cathode away from the vacuum chamber; the outer casing tube includes a flexible second flexible segment disposed in the middle of the outer casing tube, the flexible second flexible segment being capable of extending and retracting along the extension direction of the vacuum chamber.

[0009] In some embodiments, a first magnet coil and a second magnet coil are disposed on the outer side of the outer casing tube. The first magnet coil and the second magnet coil are coaxially disposed and spaced apart along the extension direction of the outer casing tube. The second magnet coil is disposed on the side of the first magnet coil near the vacuum cavity. The magnetic flux of the second magnet coil is less than that of the first magnet coil.

[0010] In some embodiments, the linear plasma device further includes a molecular pump assembly connected to a vacuum chamber. The molecular pump assembly includes a main line, a branch line, a first molecular pump, and a second molecular pump. One end of the main line is connected to the vacuum chamber, and the other end is connected to the first molecular pump. The second molecular pump is connected to the main line through the branch line. The branch line includes a telescopic section that can extend and retract along the extension direction of the branch line, so that the length of the branch line can be changed.

[0011] In some embodiments, the plasma source further includes a third molecular pump connected to the outer casing tube, the power of which is set to be the same as that of the second molecular pump.

[0012] In some embodiments, the sample stage assembly includes a sample stage and a cover plate. The sample stage is provided with a bearing surface for bearing a material sample. The cover plate is capable of applying a force toward the bearing surface to the material sample and fixing the material sample to the bearing surface. The center of the cover plate is provided with a through hole for plasma to pass through. The bearing surface is an arc surface, and the convex direction of the bearing surface is toward the cover plate.

[0013] In some embodiments, the radius of the arc of the bearing surface is 470mm-490mm.

[0014] In some embodiments, the linear plasma apparatus further includes a gate valve disposed between the plasma source and the sample chamber.

[0015] To address the problem of plasma beam spot misalignment with the geometric center of the sample material, this invention offers the following advantages: The plasma source is connected to and sealed within the sample chamber, providing a relatively stable vacuum environment for the experiment. The plasma source generates plasma from the introduced gas, which, under the confinement of a magnetic field, forms a plasma beam that irradiates the sample material fixed on the sample stage assembly. A temperature sensor detects the temperature distribution of the sample material to determine its temperature center position. The first adjustment component supports the sample stage assembly and drives its movement, thereby adjusting the position of the sample stage and, consequently, the position of the sample material. Typically, the temperature center position is the location where the plasma beam irradiates the sample material. By aligning the physical center of the sample material with its temperature center position, the plasma beam can be aligned with the geometric center of the sample material. Attached Figure Description

[0016] Figure 1 A schematic diagram of one embodiment of a linear plasma device is shown. Figure 2 A front view structural schematic diagram of one embodiment of a linear plasma device is shown; Figure 3A schematic diagram of one embodiment of the connection between the sample stage assembly and the sample chamber is shown. Figure 4 A schematic diagram of one embodiment of the connection between the connecting tube and the sample chamber is shown. Figure 5 It shows Figure 4 A magnified view of the local structure of section A in the middle; Figure 6 A cross-sectional view is shown of one embodiment in which the connecting tube is connected to the sample chamber; Figure 7 A schematic diagram of one embodiment of the first position adjustment component is shown; Figure 8 An exploded structural schematic diagram of one embodiment of the first position adjustment assembly is shown; Figure 9 An exploded structural schematic diagram of one embodiment of the first level adjustment mechanism is shown; Figure 10 A structural schematic diagram of one embodiment of the base plate and the first fixed rail is shown; Figure 11 An exploded structural schematic diagram of one embodiment of the second level adjustment mechanism is shown; Figure 12 An exploded structural schematic diagram of one embodiment of the vertical adjustment mechanism is shown; Figure 13 A partial structural schematic diagram of one embodiment of the vertical adjustment mechanism is shown; Figure 14 A partial structural cross-sectional view of one embodiment of a plasma source is shown; Figure 15 A cross-sectional view of one embodiment of the sample stage is shown.

[0017] Reference numerals: 10-Plasma source; 11-Cathode; 12-Anode tube; 13-Outer shell tube; 131-First tube segment; 132-Second tube segment; 1321-Second flexible segment; 14-Third molecular pump; 15-First magnet coil; 16-Second magnet coil; 20-Sample chamber; 21-Vacuum chamber; 22-Observation window; 23-Third magnet coil; 24-Fourth magnet coil; 30-Sample stage assembly; 31-Sample stage 312-Bearing surface; 311-Water-cooled cavity; 32-Water-cooling mechanism; 321-Inlet pipe; 322-Outlet pipe; 33-First sealing plate; 34-Connecting pipe; 341-First flexible section; 35-Cover plate; 40-First position adjustment assembly; 41-First horizontal adjustment mechanism; 411-First drive motor; 412-First lead screw; 413-First lead screw nut; 414-First support plate; 415-Base plate; 416-First Guide rail; 4161-First fixed rail; 4162-First moving rail; 42-Second horizontal adjustment mechanism; 421-Second drive motor; 422-Second lead screw; 423-Second lead screw nut; 424-Second support plate; 425-Second guide rail; 4251-Second fixed rail; 4252-Second moving rail; 43-Vertical adjustment mechanism; 431-Third drive motor; 432-Third lead screw; 433-Third lead screw nut; 434-Horizontal wedge; 435-Vertical wedge; 436-Limiting rail; 437-Third support plate; 50-Second position adjustment assembly; 60-Molecular pump assembly; 61-First molecular pump; 62-Second molecular pump; 63-Main pipeline; 64-Branch pipeline; 70-Slide valve; 80-Support frame; 81-Supporting rail; 90-Fixing frame assembly; 91-Fixing screw; 92-Fixing frame; 921-Limiting hole; 93-Fixing nut. Detailed Implementation

[0018] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0019] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0020] This embodiment discloses a linear plasma device, such as... Figure 1 , Figure 2As shown, the system may include: a plasma source 10, a sample chamber 20, a sample stage assembly 30, a first position adjustment assembly 40, and a detection assembly; the sample chamber 20 has a sealed vacuum chamber 21; the sample stage assembly 30 includes a sample stage 31 and a connecting tube 34, the sample stage 31 is used to support and fix the sample material, the sample stage 31 can extend into the vacuum chamber 21, the connecting tube 34 is coaxially sleeved on the outside of the sample stage 31, there is a gap between the sample stage 31 and the connecting tube 34, the first end of the connecting tube 34 is sealed to the vacuum chamber 21, and the second end of the connecting tube 34 is sealed; the plasma source 10 can generate a plasma beam, the plasma source 10 is sealed to the vacuum chamber 21, and the plasma beam can enter the vacuum chamber 21 and irradiate the sample material; the detection assembly includes a temperature sensor, the temperature sensor is disposed in the vacuum chamber 21 and can detect the temperature distribution of the sample material; the first position adjustment assembly 40 is connected to the sample stage assembly 30 and can drive the sample stage 31 so that the physical center of the sample material coincides with the temperature center.

[0021] It should be noted that the plasma source 10 can excite a specific gas into plasma, and under the confinement of a specific magnetic field, it can form a plasma beam moving in a straight line. To confine the movement of the plasma beam, multiple magnet coils are usually arranged sequentially along the extension direction of the vacuum chamber 21 on the outside of the vacuum chamber 21. Both the plasma source 10 and the sample chamber 20 are in a vacuum state to form plasma. The detection components are used to detect various parameters within the linear plasma device, such as vacuum level and plasma electron density. The temperature sensor can detect the temperature distribution of the sample material during the experiment; specifically, it can be visualized for easy adjustment. The connecting tube 34 can be coaxially arranged with the vacuum chamber 21 so that the connected sample stage 31 is located on the central axis of the vacuum chamber 21, allowing the plasma beam to pass through the vacuum chamber 21 along the central axis and irradiate the sample material.

[0022] The plasma source 10 is connected to and sealed with the sample chamber 20, thus providing a relatively stable vacuum environment for the experiment. The plasma source 10 can generate plasma from the introduced gas. The plasma can form a plasma beam under the confinement of a magnetic field and irradiate the sample material fixed on the sample stage assembly 30. The temperature distribution of the sample material is detected by a temperature sensor to obtain its temperature center position. The first adjustment component is used to support the sample stage assembly 30 and drive the movement of the sample stage assembly 30, thereby adjusting the position of the sample stage 31 and thus the position of the sample material. Generally speaking, the temperature center position is the position where the plasma beam spot irradiates the sample material. By aligning the physical center of the sample material with its temperature center position, the plasma beam spot can be aligned with the geometric center of the sample material.

[0023] To observe the experimental process, the vacuum chamber 21 may be equipped with an observation window 22. The observation window 22 is positioned directly opposite the sample material fixed on the sample stage 31, allowing observation as needed. Figure 4 As shown, multiple observation windows 22 can be provided, such as front-view observation windows 22 and top-view observation windows 22, so that the sample material can be observed from different angles. Figure 1-2 Alternatively, the entire device can be mounted on a support frame 80 of a certain height for easy operation. A support rail 81 can be provided on the support frame 80, and multiple components of the linear plasma device can be sequentially mounted on the support rail 81 via sliders, allowing them to slide along the support rail 81, thus facilitating adjustments to the experimental setup, sample mounting, and other operations.

[0024] Specifically, because the device itself has a support structure, slight deformations occur in this structure over prolonged use. Although the deformation is small, the experiments conducted with linear plasma devices require high precision; otherwise, it is difficult to achieve the experimental objectives. Furthermore, these deformations introduce unexpected experimental errors, leading to decreased repeatability and requiring numerous repetitive tests and additional work. To correct these errors, the drive mechanism of the first adjustment component should employ a high-precision structure, enabling fine dimensional adjustments.

[0025] like Figures 7-13 As shown, the first adjustment assembly may include a first horizontal adjustment mechanism 41 that drives the sample stage 31 to move in a first horizontal direction, and a second horizontal adjustment mechanism 42 that drives it in a second horizontal direction. The first and second directions may be perpendicular to each other. The first adjustment assembly may also include a vertical adjustment mechanism 43 that drives the sample stage 31 to move in a vertical direction. To achieve high adjustment accuracy, the first horizontal adjustment mechanism 41, the second horizontal adjustment mechanism 42, and the vertical adjustment mechanism 43 may employ high-precision lead screws as their motion transmission mechanisms. Furthermore, high-precision guide rails may be provided to ensure accurate movement direction, thereby further improving adjustment accuracy.

[0026] like Figure 8 , Figure 9 , Figure 10As shown, the first horizontal adjustment mechanism 41 includes a first drive motor 411 and a first lead screw 412 connected to the output shaft of the first drive motor 411. A first lead screw 412 nut is sleeved on the first lead screw 412 and connected to a first support plate 414. The first horizontal adjustment mechanism 41 also includes a base plate 415 disposed at the bottom. A first guide rail 416 is disposed on the base plate 415 in the same direction as the extension of the first lead screw 412. The first guide rail 416 includes a first fixed rail 4161 and a first movable rail 4162. The first fixed rail 4161 is fixedly connected to the base plate 415, and the first movable rail 4162 is fixedly connected to the first support plate 414. The first movable rail 4162 is fitted to the first fixed rail 4161 and can slide relative to the first fixed rail 4161. When the first drive motor 411 moves, it can drive the first lead screw 412 to rotate, thereby enabling the nut of the first lead screw 412 to move along the extension direction of the first lead screw 412, and thus drive the first support plate 414 to move.

[0027] like Figure 11As shown, the first support plate 414 has a first bearing surface 312 capable of supporting the second horizontal adjustment mechanism 42. The first bearing surface 312 is horizontally arranged. The second horizontal adjustment mechanism 42 can be arranged on the first bearing surface 312 of the first support plate 414. Specifically, the second horizontal adjustment mechanism 42 includes a second drive motor 421 arranged on the first support plate 414. The output end of the second drive motor 421 is provided with a second lead screw 422. The extension direction of the second lead screw 422 has a certain angle with the extension direction of the first lead screw 412. Preferably, the extension direction of the second lead screw 422 and the extension direction of the first lead screw 412 are both horizontal and perpendicular to each other. A second lead screw 422 nut is sleeved on the second lead screw 422. The second lead screw 422 nut is connected to the second support plate 424. Similar to the first adjustment mechanism, a second guide rail 425 may be provided on the first support plate 414 in the same direction as the extension of the second lead screw 422. The second guide rail 425 includes a second fixed rail 4251 and a second moving rail 4252. The second fixed rail 4251 is disposed on the first bearing surface 312 of the first support plate 414, and the second moving rail 4252 is connected to the second support plate 424. The second moving rail 4252 can slide relative to the second fixed rail 4251. When the second drive motor 421 is driven, it can drive the second lead screw 422 to rotate, thereby driving the nut of the second lead screw 422 to move along the extension direction of the second lead screw 422, and further driving the second support plate 424 to move. Since the second horizontal adjustment mechanism 42 is set on the first support plate 414, the second support plate 424 can move relative to the first support plate 414. And the extension directions of the first lead screw 412 and the second lead screw 422 have an angle. Therefore, the moving direction of the first support plate 414 and the moving direction of the second support plate 424 constitute a horizontal coordinate system. The second support plate 424 can move to any position in this coordinate system. Therefore, by driving the first drive motor 411 and the second drive motor 421 respectively, the specific position of the second support plate 424 in the horizontal direction can be adjusted.

[0028] In one specific implementation, the second support plate 424 may be provided with a second bearing surface 312, and the vertical adjustment mechanism 43 may be disposed on the second bearing surface 312. The vertical adjustment mechanism 43 may include various implementations, such as using a telescopic rod, a cylinder, a hydraulic cylinder, or a rack and pinion, or it may adopt a method such as... Figure 12 , Figure 13In the illustrated embodiment, the vertical adjustment mechanism 43 includes a third drive motor 431 and a third lead screw 432 connected to the output end of the third drive motor 431. The third lead screw 432 is horizontally arranged, and a matching third lead screw 432 nut is fitted onto the third lead screw 432. The third lead screw 432 nut is connected to a horizontal wedge block 434. The horizontal wedge block 434 has a first inclined surface that gradually slopes downward along the extension direction of the third lead screw 432. The first inclined surface is located at the top of the horizontal wedge block 434. The vertical adjustment mechanism 43 also includes a vertical wedge block 435, and the bottom surface of the vertical wedge block 435 has a second inclined surface that matches the first inclined surface. The vertical adjustment mechanism 43 also includes a limiting rail 436 extending vertically. The vertical wedge 435 matches the limiting rail 436. When the third drive motor 431 drives the third lead screw 432 to rotate, it can drive the nut of the third lead screw 432 to move along the extension direction of the third lead screw 432, thereby driving the horizontal wedge 434 to move. When the horizontal wedge 434 gradually extends below the vertical wedge 435, due to the action of the first and second inclined surfaces, the horizontal pushing force can be converted into a vertical pushing force, thereby pushing the vertical wedge 435 to move upward. Conversely, the vertical wedge 435 can move downward under the action of gravity. The top of the vertical wedge 435 is used to connect with the sample stage 31, thereby driving the sample stage 31 to move. Furthermore, the first horizontal adjustment mechanism 41, the second horizontal adjustment mechanism 42, and the vertical adjustment mechanism 43 are actually stacked sequentially along the vertical direction. The specific arrangement can be selected according to the actual situation.

[0029] In the above embodiments, the first drive motor 411, the second drive motor 421, and the third drive motor 431 can also be handwheels, which drive the lead screw to rotate. Since the adjustment distance of the first adjustment component is usually short but requires precise operation, the handwheel can be directly operated manually, making adjustment more convenient. In the above embodiments of the first adjustment component, on the one hand, the position of the sample stage 31 connected to it can be adjusted; on the other hand, since there is no rotation adjustment process, it does not change the orientation of the sample stage 31, ensuring that the adjusted sample stage 31 still faces the irradiation direction of the plasma beam.

[0030] Because the vacuum chamber 21 needs to be kept sealed during the experiment to maintain it in a vacuum state, as a specific implementation method, such as Figures 3-6 As shown, the sample stage assembly 30 also includes a first sealing plate 33, the sample stage assembly 30 is fixedly connected to the first sealing plate 33, and the first sealing plate 33 is sealed to the side of the connecting pipe 34 away from the vacuum chamber 21; the connecting pipe 34 includes a first flexible section 341 disposed in the middle of the connecting pipe 34, and the first flexible section 341 can also extend and retract along the extension direction of the connecting pipe 34.

[0031] The flexible segment can be made of flexible materials, or as... Figure 3 , Figure 4 As shown, a corrugated pipe, a flexible and deformable structure, is used to achieve its bending and expansion functions. One end of the connecting pipe 34 is connected to the vacuum chamber 21. The connecting pipe 34 can be configured to move along the extension direction of the vacuum chamber 21, thereby causing the sample stage 31 connected to it to extend into or leave the vacuum chamber 21, facilitating the assembly and disassembly of sample materials. Since the sample stage 31 needs to be placed inside the vacuum chamber 21, it is difficult to directly connect to it and drive its movement without disrupting the vacuum environment. Therefore, this application utilizes the presence of a first flexible segment 341 in the connecting pipe 34, allowing the second end of the connecting pipe 34 to move within a certain range relative to its first end without disrupting the vacuum sealing environment. A first sealing plate 33 connects the sample stage 31 to the second end of the connecting pipe 34. By driving the first sealing plate 33, the sample stage 31 connected to it can be moved relative to the first end of the connecting pipe 34, effectively adjusting the relative position of the sample stage 31 with respect to the vacuum chamber 21 or the plasma beam. To ensure the stability of the device during the experiment, a support frame 80 can be provided at the position where the first end of the connecting pipe 34 is connected to the vacuum chamber 21.

[0032] To prevent misalignment at both ends of the connecting tube 34 during the experiment, the connecting tube 34 can be limited by the fixing bracket assembly 90. Specifically, as follows: Figure 4 , Figure 5 As shown, fixing brackets 92 are fixedly installed at both ends of the connecting pipe 34. Each fixing bracket 92 has a limiting hole 921. The two ends of the fixing screw 91 pass through the limiting holes 921, and then matching fixing nuts 93 are installed at each end. There is a gap between the outer circumference of the limiting hole 921 and the fixing screw 91, thus preventing structural conflicts between the fixing screw 91 and the limiting hole 921 after relative movement and adjustment of the two ends of the connecting pipe 34, which would affect the adjustment. The fixing bracket assembly 90 generates an axial force on the fixing screw 91 after it is fitted with the fixing nuts 93 installed at both ends of the fixing screw 91 through threaded engagement. This force, combined with friction with the fixing bracket 92, achieves the fixing effect. During fixing, the limiting hole 921 does not need to contact the fixing screw 91.

[0033] Due to structural deformation caused by prolonged use of the linear plasma device, the same applies to the plasma source 10. This results in a shift in the plasma beam relative to the central axis of the vacuum cavity 21 or the sample material. To address this issue, as... Figure 1 , Figure 2 , Figure 14As shown, the plasma source 10 includes an outer shell tube 13, an anode tube 12, and a cathode 11. The anode tube 12 is fitted inside the outer shell tube 13. The cathode end face of the cathode 11 is fitted inside one end of the anode tube 12, and a gap is provided between it and the inner wall of the anode tube 12. The diameter of the cathode end face of the cathode 11 is not less than the length of the inner wall of the anode tube 12, and the ratio between the two is in the range of 1:1 to 1:5. The linear plasma device also includes a second position adjustment component 50, which is connected to the cathode 11 and can drive the central axis of the cathode 11 to coincide with the central axis of the vacuum chamber 21.

[0034] Since the center position of the plasma beam mainly depends on the position of the cathode 11 in the plasma source 10, the position of the plasma beam can be adjusted by adjusting the relative position of the cathode 11. Utilizing the gap between the cathode 11 and the anode tube 12, the cathode 11 can move relative to the anode tube 12 to a certain extent, and under the drive of the second position adjustment component 50, fine adjustments can be made, so that the plasma beam can accurately irradiate the sample material along the central axis of the vacuum cavity 21. The second position adjustment component 50 can adopt the same implementation as the first position adjustment component 40 described above, and will not be repeated here. In a plasma source, the longer the anode length, the more likely the magnetic field lines passing through the cathode surface can reach the inner surface of the anode. However, in practice, it is impossible to make the inner wall of the anode infinitely long. Therefore, as a preferred option, the ratio of the cathode end face diameter of the cathode 11 to the inner wall length of the anode tube 12 can be set to 1:5.

[0035] In order to generate plasma, the outer casing tube 13 is provided with an inlet for introducing a specific gas and an interface for connecting to a vacuum pump.

[0036] In some embodiments, such as Figure 14 As shown, the plasma source 10 also includes a second sealing plate, which is used to connect the side of the outer shell tube 13 away from the vacuum chamber 21 and the side of the cathode 11 away from the vacuum chamber 21. The outer shell tube 13 includes a flexible second flexible section 1321 disposed in the middle of the outer shell tube 13. The flexible second flexible section 1321 can also extend and retract along the extension direction of the vacuum chamber 21.

[0037] Specifically, it can be like Figure 14 As shown, the outer casing tube 13 actually comprises two sequentially connected tube segments. The first tube segment 131 is connected to the vacuum chamber 21, while the second flexible segment 1321 is disposed on the second tube segment 132. The first tube segment 131 and the second tube segment 132 are sealed together. The second flexible segment 1321 can adopt the same implementation as the first flexible segment 341 described above, allowing the two ends of the second flexible segment 1321 to move relative to each other within a certain range, thereby ensuring the movement of the cathode 11 while maintaining a seal.

[0038] In current technologies, a mean magnetic field configuration is used in plasma discharge processes. However, this design is detrimental to the stable and repeatable operation of the plasma source 10 during prolonged use, causing difficulties in experimental reproducibility. To address this issue, as one implementation, a first magnet coil 15 and a second magnet coil 16 are disposed on the outer side of the outer casing tube 13. The first magnet coil 15 and the second magnet coil 16 are coaxially arranged and spaced apart along the extension direction of the outer casing tube 13. The second magnet coil 16 is located on the side of the first magnet coil 15 closest to the vacuum cavity 21. The magnetic flux of the second magnet coil 16 is less than that of the first magnet coil 15. The magnetic flux range of both the first magnet coil 15 and the second magnet coil 16 is 0.01-0.1T, and the magnetic flux of the first magnet coil 15 is not less than that of the second magnet coil 16. The ratio of the magnetic flux of the first magnet coil 15 to the second magnet coil 16 is set to be greater than 1:1 and less than or equal to 5:1. Preferably, the ratio is 2:1, in which case most of the magnetic field lines passing through the cathode end face of the cathode 11 pass through the inner wall of the anode tube 12.

[0039] In this embodiment, the plasma source 10 utilizes a relatively long internal anode length (the length of the anode tube 12 can be set to 15-25 cm), and a divergent magnetic field configuration formed by a strong first magnet coil 15 and a weak second magnet coil 16. This allows the surface of the cathode 11 and the inner wall surface of the anode to be fully connected through magnetic field lines. Electrons and ions emitted from the cathode and anode surfaces can reach the surfaces of the anode and cathode 11 respectively along the magnetic field lines and form a stable current loop. This stable loop allows for the generation of a more stable plasma under the same input parameters of the plasma source 10. Simultaneously, the existence of this loop allows for stable and higher input parameters of the plasma source 10, such as 100V and 100A, meaning higher energy power coupled into the plasma, thereby generating high-density plasma, which is more conducive to the experiment. Specifically, the operating current of the first magnet coil 15 can be set to 50-80A, and the operating current of the second magnet coil 16 can be set to 30-50A.

[0040] It should be noted that, on the outside of the sample chamber 20, multiple magnet coils are also arranged at intervals along its extending direction, such as... Figure 1 , Figure 2 As shown, it is equipped with two magnets, namely the third magnet coil 23 and the fourth magnet coil 24. The operating current of the third magnet coil 23 and the fourth magnet coil 24 is set to be the same as the current of the first magnet coil 15.

[0041] In a single experiment, the molecular pump used to provide a vacuum environment needs to run continuously to ensure the vacuum level within the device. However, during long-term operation, the efficiency of the plasma source 10 slowly decreases due to the performance degradation of the cathode 11 and the increase in the chamber vacuum level, i.e., the stability of the plasma source 10 is insufficient. This leads to reduced research efficiency, increased costs, and longer time consumption. As an alternative implementation method, such as... Figure 1 , Figure 2 As shown, the linear plasma device also includes a molecular pump assembly 60 connected to the vacuum chamber 21. The molecular pump assembly 60 includes a main pipeline 63, a branch pipeline 64, a first molecular pump 61, and a second molecular pump 62. One end of the main pipeline 63 is connected to the vacuum chamber 21, and the other end is connected to the first molecular pump 61. The second molecular pump 62 is connected to the main pipeline 63 through the branch pipeline 64. The branch pipeline 64 includes a telescopic section that can extend and retract along the extension direction of the branch pipeline 64, so that the length of the branch pipeline 64 can be changed, thereby allowing the gas pressure to be adjusted between 0.05-0.5 Pa during plasma operation.

[0042] At the beginning of the experiment, the entire molecular pump assembly 60 can be turned on, meaning the first molecular pump 61 and the second molecular pump 62 operate together to quickly reduce the vacuum level in the vacuum chamber 21. During the experiment, when a higher vacuum is no longer needed, the first molecular pump 61 can be isolated or turned off, with only the second molecular pump 62 operating independently. In practical use, due to equipment cost constraints—steplessly adjustable molecular pumps are typically expensive—only pumps capable of stepped operation are usually used. However, as the experiment progresses, the vacuum level in the vacuum chamber 21 increases. An excessively high vacuum will also draw out the special gas used to form the plasma, causing the efficiency of the plasma source 10 to gradually decrease. Furthermore, the stepped operation of the molecular pumps cannot adaptively adjust their power to suit the experimental process. However, by utilizing the extendable section, the length of the branch line 64 is altered, which in turn changes the length of the pipe connecting the second molecular pump 62 and the vacuum chamber 21. This allows for adjustment of the operating power of the molecular pump in evacuating the vacuum chamber 21 within a certain range. Lengthening the branch line 64 reduces the vacuum level in the vacuum chamber 21, while shortening it increases the vacuum level. For example, during experiments, the length of the branch line 64 can be lengthened to appropriately adjust the decrease in vacuum level within the vacuum chamber 21, mitigating the problem of increased vacuum level caused by prolonged operation. Since the change in vacuum level due to prolonged operation is not significant, the variable-length portion of the branch line 64 does not need to be very long and can be adaptably configured. As an implementation method, a bellows structure can be used. Because the length change of the extendable section is linear, the adjustment effect on the vacuum level is also linear. This allows a molecular pump with only multiple speed settings to achieve an adjustment effect similar to a continuously variable molecular pump, significantly reducing the cost of the device while improving the stability of the plasma source 10.

[0043] In one implementation, a slider and a matching slide rail can be provided at the bottom of the second molecular pump 62. The second molecular pump 62 can move along the slide rail. Since the molecular pump has a certain weight, the operator can move the molecular pump relatively easily. In addition, the length of the branch line 64 can be adjusted by moving the second molecular pump 62 through the setting of the slide rail.

[0044] In addition, such as Figure 1 As shown, the plasma source 10 also includes a third molecular pump 14 connected to the outer casing tube 13, and the power of the third molecular pump 14 is set to be the same as that of the second molecular pump 62.

[0045] In the experimental preparation stage, the plasma source 10 and the vacuum chamber 21 are operated separately for plasma formation. A vacuum environment is formed in the plasma source 10 before the gas for plasma formation is introduced. However, during the experiment, the plasma source 10 and the vacuum chamber 21 are connected, and it is no longer necessary for too many molecular pumps to run together. Otherwise, an excessively high vacuum would not be conducive to the experiment. Therefore, the power of the third molecular pump 14 is set to be the same as that of the second molecular pump 62. On the one hand, during the experiment, the molecular pump at the plasma source 10 can be turned off, and only the molecular pump connected to the vacuum chamber 21 can run alone to meet the requirements. On the other hand, the power of a single molecular pump is easier to control, which is beneficial for the correction and adjustment of experimental parameters.

[0046] During the experiment, prolonged irradiation of the sample material can lead to excessively high temperatures. To address this issue, a water-cooling component can be installed at the sample stage 31 to cool the sample material. However, in practical use, the sample material does not adhere well to the sample stage 31, resulting in poor cooling performance. As one implementation method, such as... Figure 15 As shown, the sample stage assembly 30 includes a sample stage 31 and a cover plate 35. The sample stage 31 is provided with a bearing surface 312 for bearing a material sample. The cover plate 35 can apply a force toward the bearing surface 312 to the material sample and fix the material sample on the bearing surface 312. The center of the cover plate 35 is provided with a through hole for plasma to pass through. The bearing surface 312 is an arc surface, and the convex direction of the bearing surface 312 is toward the cover plate 35.

[0047] Because the bearing surface 312 has a raised surface, the cover plate 35 can squeeze the sample and cause slight deformation of the sample edge, so that it can fit tightly with the bearing surface 312, thereby improving the water cooling efficiency.

[0048] Specifically, the radius of the arc of the bearing surface 312 is 470mm-490mm.

[0049] In addition, such as Figure 1 As shown, the linear plasma device also includes a gate valve 70 disposed between the plasma source 10 and the sample chamber 20.

[0050] The slide gate valve 70 allows for the separation of the plasma source 10 from the sample chamber 20 during the experimental preparation phase. Once the experiment begins, the slide gate valve 70 is opened to reconnect the two. The slide gate valve 70 is simple and quick to operate, enabling rapid connection or isolation between the plasma source 10 and the sample chamber 20.

[0051] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. A linear plasma device, characterized in that, The linear plasma device includes: Plasma source, sample chamber, sample stage assembly, first position adjustment assembly, and detection assembly; The sample chamber has a sealed vacuum chamber; The sample stage assembly includes a sample stage and a connecting tube. The sample stage is used to support and fix the sample material. The sample stage can extend into the vacuum chamber. The connecting tube is coaxially sleeved on the outside of the sample stage. There is a gap between the sample stage and the connecting tube. The first end of the connecting tube is sealed to the vacuum chamber, and the second end of the connecting tube is sealed. The plasma source is capable of generating a plasma beam, and the plasma source is sealed to the vacuum cavity, allowing the plasma beam to enter the vacuum cavity and irradiate the sample material. The detection component includes a temperature sensor, which is disposed inside the vacuum chamber and is capable of detecting the temperature distribution of the sample material; The first position adjustment component is connected to the sample stage assembly and can drive the sample stage so that the physical center and temperature center of the sample material coincide.

2. The linear plasma device according to claim 1, characterized in that, The sample stage assembly further includes a first sealing plate, the sample stage assembly is fixedly connected to the first sealing plate, and the first sealing plate is sealed to the side of the connecting tube opposite to the vacuum chamber. The connecting pipe includes a first flexible segment disposed in the middle of the connecting pipe, and the first flexible segment is also capable of extending and retracting along the extension direction of the connecting pipe.

3. A linear plasma device according to claim 1, characterized in that, The plasma source includes an outer shell tube, an anode tube, and a cathode. The anode tube is fitted inside the outer shell tube, and the cathode end face is fitted inside one end of the anode tube, with a gap between it and the inner wall of the anode tube. The linear plasma device further includes a second position adjustment component, which is connected to the cathode and can drive the central axis of the cathode to coincide with the central axis of the vacuum cavity.

4. A linear plasma device according to claim 3, characterized in that, The plasma source also includes a second sealing plate, which is used to connect the side of the outer casing tube away from the vacuum cavity to the side of the cathode away from the vacuum cavity; The outer casing tube includes a flexible second flexible segment disposed in the middle of the outer casing tube, and the second flexible segment is also capable of extending and retracting along the extension direction of the vacuum cavity.

5. A linear plasma device according to claim 3, characterized in that, A first magnet coil and a second magnet coil are provided on the outside of the outer shell tube. The first magnet coil and the second magnet coil are coaxially arranged and spaced apart along the extension direction of the outer shell tube. The second magnet coil is located on the side of the first magnet coil closer to the vacuum cavity. The magnetic flux of the second magnet coil is less than that of the first magnet coil.

6. A linear plasma device according to claim 3, characterized in that, The linear plasma device also includes a molecular pump assembly connected to the vacuum chamber, the molecular pump assembly including a main pipeline, branch pipelines, a first molecular pump and a second molecular pump; One end of the main pipeline is connected to the vacuum chamber, and the other end is connected to the first molecular pump. The second molecular pump is connected to the main pipeline through the branch pipeline. The branch pipeline includes a telescopic section that can extend and retract along the extension direction of the branch pipeline, so that the length of the branch pipeline can be changed.

7. A linear plasma device according to claim 6, characterized in that, The plasma source also includes a third molecular pump connected to the outer casing tube, the power of which is set to be the same as that of the second molecular pump.

8. A linear plasma device according to claim 1, characterized in that, The sample stage assembly includes a sample stage and a cover plate. The sample stage is provided with a bearing surface for bearing a material sample. The cover plate can apply a force toward the bearing surface to the material sample and fix the material sample to the bearing surface. The center of the cover plate is provided with a through hole for plasma to pass through. The bearing surface is an arc surface, and the protrusion of the bearing surface is oriented towards the cover plate.

9. A linear plasma device according to claim 8, characterized in that, The radius of the arc of the bearing surface is 470mm-490mm.

10. A linear plasma device according to claim 1, characterized in that, The linear plasma device also includes a gate valve disposed between the plasma source and the sample chamber.

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