Cathode seat structure for a plasma source

Abstract

The application relates to the technical field of plasma, and discloses a cathode seat structure of a plasma source, which comprises a cathode seat and a plurality of cathode needle assemblies; a discharge gas can be introduced into a discharge chamber through the gas inlet channel; since the insertion depths of the plurality of ionization needles in the discharge chamber are at least two, and the ionization needles with different insertion depths are arranged at intervals, the plurality of ionization needles can ionize the gas at different positions in the discharge chamber, and compared with the gas ionized at the same height region, the ionization rate can be further improved. A plurality of cooling channels arranged along the axial direction of the discharge chamber are arranged around the outer periphery of the discharge chamber, so that the inner walls of the discharge chamber at different height positions can be cooled, the ionization needles with different insertion depths are matched to effectively cool the inner walls of the discharge chamber and the cathode seat, and therefore the ionization rate is improved, and the cooling efficiency of the cathode seat is improved.

Description

Technical Field

[0001] This invention relates to the field of plasma technology, and in particular to a cathode holder structure for a plasma source. Background Technology

[0002] During the operation of magnetic confinement fusion devices, complex interactions occur between the boundary plasma and the first wall of the fusion reactor. The divertor target impact area must withstand the dual effects of ultra-high ion flux and steady-state heat load, leading to a series of complex physicochemical reactions such as material erosion, sputtering, surface morphology changes, and vacancy defects. This severely shortens the service life of the fusion reactor materials and restricts the long-term stable operation of the fusion device. However, due to the high experimental costs and stringent discharge operating conditions of fusion devices, it is difficult to conduct systematic studies on the interaction between the boundary plasma and materials directly through the fusion device. Therefore, the industry typically uses linear plasma devices to simulate the boundary plasma environment of the fusion reactor and conduct plasma irradiation experiments using the high-density plasma beams they generate.

[0003] The plasma source is the core component in a linear plasma device that generates a high-density plasma beam. In the plasma source, the cathode generates plasma by ionizing discharge gas; its ionization rate directly affects the discharge efficiency of the plasma source and the size of the plasma beam. In some previous plasma sources, a single cathode was typically used for ionization discharge, which resulted in only a small portion of the discharge gas within the discharge chamber being ionized, leading to a low ionization rate.

[0004] Chinese patent application CN110402010A discloses a cascaded arc cathode structure with large-area, highly uniform active cooling. It includes a cathode substrate with multiple electrode tips fixedly mounted on its front side. The tip-induced arc ionization of the discharge gas over a large area is achieved by simultaneously ionizing the discharge gas, thereby increasing the ionization rate. However, because the multiple electrode tips are positioned at the same height, it is still insufficient to effectively ionize the discharge gas at different heights within the discharge chamber, resulting in a low ionization rate. Furthermore, it lacks a structure to cool the peripheral walls of the discharge chamber. The large amount of plasma generated by the ionization of the multiple electrode tips collides with the inner wall of the surrounding cathode base, subjecting the cathode base to extremely high heat loads. If the accumulated heat cannot be removed in time, the cathode base will burn out, leading to the malfunction of both the plasma source and the linear plasma device. Summary of the Invention

[0005] The purpose of this invention is to provide a cathode holder structure for a plasma source to solve the problems of low ionization rate and insufficient cooling efficiency of existing cathode holder structures.

[0006] To achieve the above objectives, the present invention provides a cathode seat structure for a plasma source, which includes a cathode seat and a plurality of cathode needle assemblies. The cathode holder has a discharge chamber extending axially and penetrating its lower surface; the cathode holder also has an installation channel, an air inlet channel, a cooling channel, a water inlet, and a water outlet; multiple installation channels, the same number as the cathode needle assembly, are spaced apart, one end of each installation channel is located on the upper surface of the cathode holder, and the other end communicates with the discharge chamber; one end of each air inlet channel is located on the outer surface of the cathode holder, and the other end communicates with the discharge chamber; the water inlet and water outlet are respectively located on opposite outer peripheral surfaces of the cathode holder; multiple cooling channels are spaced apart along the extension direction of the discharge chamber, each cooling channel surrounds the outer periphery of the discharge chamber and is isolated from the discharge chamber, and all cooling channels are connected to the water inlet and water outlet; The cathode needle assembly includes an ionizing needle, which is sealed and insulatedly inserted into the mounting channel such that a portion of the ionizing needle is located in the discharge chamber; a plurality of ionizing needles are arranged at least two different insertion depths in the discharge chamber, and the ionizing needles with different insertion depths are spaced apart.

[0007] Furthermore, the cathode holder includes an upper seat body and a lower seat body that are arranged sequentially from top to bottom and connected together; The upper body is provided with an installation channel and an air intake channel that run through its upper and lower surfaces; The lower body has a discharge chamber that extends through its upper and lower surfaces. The lower body also has a cooling chamber. The cooling chamber surrounds the discharge chamber and extends through the upper surface of the lower body. The cooling chamber and the discharge chamber are isolated from each other and do not communicate with each other. The side wall of the cooling chamber closest to the discharge chamber is defined as the inner ring wall. Multiple cooling channels are provided on the inner ring wall. The lower body has water inlets and outlets on its opposite outer peripheral surfaces, and the water inlets and outlets are respectively connected to the cooling cavity.

[0008] Furthermore, it also includes a heat sink assembly, which includes a partition ring and a diversion ring arranged sequentially from the outside to the inside; The side wall of the cooling chamber away from the discharge chamber is defined as the outer ring wall. The outer circumferential surface of the partition ring is in contact with the outer ring wall, so that the upper surface of the partition ring and the wall of the cooling chamber enclose a water inlet area, and the lower surface of the partition ring and the wall of the cooling chamber enclose a water outlet area. The water inlet is connected to the water inlet area, and the water outlet is connected to the water outlet area; The outer wall of the diversion ring is fitted with the inner wall of the partition ring, and the inner wall of the diversion ring is fitted with the circumferential wall of the inner ring; the diversion ring has a plurality of inlet channels and outlet channels that penetrate its radial two-sided surfaces, the inlet channels and outlet channels are spaced apart, and the inlet channels are connected to the inlet area, and the outlet channels are connected to the outlet area; The inlet and outlet water channels are connected through the cooling channel.

[0009] Furthermore, the upper surface of the diversion ring is provided with a plurality of first water grooves spaced apart, the first water grooves penetrate the inner and outer surfaces of the diversion ring, and the inner wall of the first water grooves encloses to form the water inlet channel; The lower surface of the diversion ring is provided with a plurality of second water tanks, the same number as the first water tank, and the first and second water tanks are staggered; the second water tanks penetrate the inner and outer surfaces of the diversion ring, and the inner wall of the second water tanks encloses to form the water outlet channel.

[0010] Furthermore, the cooling channel is composed of multiple wide sections and multiple narrow sections connected in an alternating manner.

[0011] Furthermore, the ionization needle includes a cathode column and an ionization needle tip; The cathode column and the ionization needle tip are arranged sequentially from top to bottom and connected together; The upper surfaces of the cathode columns of the plurality of cathode needle assemblies are flush with each other, and the axial dimensions of the plurality of ionizing needle tips are set to at least two different sizes, such that the plurality of ionizing needles have at least two different insertion depths in the discharge chamber.

[0012] Furthermore, the cathode needle assembly also includes an insulating tube, which is hollow with openings at both ends; The insulating tube is sealed and inserted into the installation channel; the ionization needle is sealed and inserted into the insulating tube.

[0013] Furthermore, the cathode needle assembly also includes a mounting tube, a mounting sleeve, a first sealing ring, and a second sealing ring; The mounting tube is hollow with openings at both ends, and one end is inserted into the mounting channel; the upper outer circumference of the insulating tube is provided with a first protrusion; the first sealing ring is disposed between the first protrusion and the upper end of the mounting tube. The ionization needle is inserted into the mounting tube, and a second protrusion is provided around its outer periphery, the second protrusion being located above the first protrusion; the second sealing ring is disposed between the second protrusion and the first protrusion; The mounting sleeve is fitted around the outer periphery of the mounting tube and pressed against the upper side of the second protrusion; the outer periphery of the mounting tube is provided with external threads, and the mounting sleeve is threadedly connected to the mounting tube.

[0014] Furthermore, the cathode needle assembly also includes a discharge wire and a fastening nut; The discharge wire is wound around the upper outer circumference of the ionization needle and is electrically connected to the ionization needle; the two fastening nuts are respectively located on the upper and lower sides of the discharge wire and screwed to the ionization needle to press the discharge wire tight.

[0015] Furthermore, the plurality of said mounting channels are arranged at circumferential intervals along the discharge chamber; The air intake channel is coaxially arranged with the discharge chamber.

[0016] The cathode holder structure for a plasma source provided by this invention has the following advantages compared with the prior art: This invention provides a cathode holder structure for a plasma source, comprising a cathode holder and multiple cathode needle assemblies. Discharge gas can be introduced into the discharge chamber through the gas inlet channel. Since the multiple ionizing needles are inserted into the discharge chamber at at least two different depths, and the needles at different insertion depths are spaced apart, the gas at different locations within the discharge chamber can be ionized by the multiple ionizing needles, further improving the ionization rate compared to ionizing gas at the same height. By arranging multiple cooling channels around the outer periphery of the discharge chamber along its axial direction, the inner walls of the discharge chamber at different heights can be cooled. This facilitates effective cooling of the inner walls of the discharge chamber and the cathode holder in conjunction with the ionizing needles at different insertion depths, thereby improving both the ionization rate and the cooling efficiency of the cathode holder. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural schematic diagram of the cathode seat structure of the plasma source according to an embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of the cathode seat structure of the plasma source according to an embodiment of the present invention; Figure 3 This is a partial cross-sectional schematic diagram of the cathode seat structure of the plasma source according to an embodiment of the present invention; Figure 4 This is another cross-sectional schematic diagram of the cathode seat structure of the plasma source according to an embodiment of the present invention; Figure 5 yes Figure 4 Enlarged view of region A in the middle; Figure 6 This is a three-dimensional structural diagram of the lower seat and the fixing ear according to an embodiment of the present invention; Figure 7 This is a three-dimensional structural schematic diagram of the shunt ring according to an embodiment of the present invention.

[0018] In the diagram, 100 is the cathode holder structure of the plasma source; 1 is the cathode holder; 10 is the discharge chamber; 101 is the mounting channel; 102 is the air inlet channel; 1021 is the air inlet section; 1022 is the diffuser section; 103 is the cooling channel; 104 is the water inlet; 105 is the water outlet; 11 is the upper seat; 110 is the groove; 12 is the lower seat; 120 is the cooling chamber; 121 is the protrusion; 13 is the fixing lug; 2 is the cathode needle assembly; 21 is the ionization needle; 211 is the cathode column; 212 is the ionization... 213. Needle tip; 214. Second protrusion; 215. Cathode column; 22. Insulating tube; 226. First protrusion; 23. Mounting tube; 24. Mounting sleeve; 25. First sealing ring; 26. Second sealing ring; 27. Discharge wire; 28. Fastening nut; 3. Heat sink assembly; 31. Separating ring; 301. Water inlet area; 302. Water outlet area; 32. Diverting ring; 321. Water inlet channel; 322. Water outlet channel; 4. Air inlet pipe; 5. Water inlet and outlet assembly; 51. Water inlet pipe; 52. Water outlet pipe. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0020] like Figures 1-3 As shown, a cathode seat structure 100 of a plasma source according to an embodiment of the present invention includes a cathode seat 1 and a plurality of cathode needle assemblies 2. The cathode holder 1 has a discharge chamber 10 extending axially and penetrating its lower surface. The cathode holder 1 also has an installation channel 101, an air inlet channel 102, a cooling channel 103, a water inlet 104, and a water outlet 105. Multiple installation channels 101, the same number as the cathode needle assembly 2, are spaced apart. One end of each installation channel 101 is located on the upper surface of the cathode holder 1, and the other end communicates with the discharge chamber 10. One end of each air inlet channel 102 is located on the outer surface of the cathode holder 1, and the other end communicates with the discharge chamber 10. The water inlet 104 and water outlet 105 are respectively located on opposite outer peripheral surfaces of the cathode holder 1. Multiple cooling channels 103 are spaced apart along the extending direction of the discharge chamber 10. Each cooling channel 103 surrounds the outer periphery of the discharge chamber 10 and is isolated from and does not communicate with the discharge chamber. All cooling channels are connected to the water inlet 104 and the water outlet 105. The cathode needle assembly 2 includes an ionization needle 21, which is sealed and insulatedly inserted into the mounting channel 101, such that a portion of the ionization needle 21 is located in the discharge chamber; a plurality of ionization needles 21 are arranged at least two different insertion depths in the discharge chamber 10, and the ionization needles 21 with different insertion depths are spaced apart.

[0021] Based on the above technical solution, discharge gas can be introduced into the discharge chamber 10 through the air inlet channel 102. Since the plurality of ionization needles 21 have at least two different insertion depths in the discharge chamber 10, and the ionization needles 21 with different insertion depths are arranged at intervals, the gas at different positions in the discharge chamber 10 can be ionized by the plurality of ionization needles 21. Compared with the prior art method of ionizing gas in the same height region, the present invention can further improve the ionization rate. By arranging a plurality of cooling channels 103 arranged along the axial direction of the discharge chamber 10 around the outer periphery of the discharge chamber 10, and communicating with the cooling channels 103 through the water inlet 104 and the water outlet 105, cooling medium can be introduced into the cooling channels 103, thereby cooling the inner wall of the discharge chamber 10 at different height positions. This facilitates cooperation with the ionization needles 21 with different insertion depths to achieve effective cooling of the inner wall of the discharge chamber 10 and the cathode seat 1, thereby improving the ionization rate and the cooling efficiency of the cathode seat 1.

[0022] Furthermore, such as Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, the cathode holder 1 includes an upper seat body 11 and a lower seat body 12 arranged and connected from top to bottom; The upper seat 11 has an installation channel 101 and an air intake channel 102 that penetrate its upper and lower surfaces; The lower seat 12 has a discharge chamber 10 extending through its upper and lower surfaces. The lower seat 12 also has a cooling chamber 120. The cooling chamber 120 surrounds the discharge chamber 10 and extends through the upper surface of the lower seat 12. The cooling chamber 120 and the discharge chamber 10 are isolated from each other and do not communicate with each other. The side wall of the cooling chamber 120 near the discharge chamber 10 is defined as the inner ring wall, and a plurality of cooling channels 103 are provided on the inner ring wall. It should be noted that the cooling chamber 120 is isolated from the discharge chamber 10 and is not connected to each other, so that the cooling channel 103 provided on the inner circumferential wall of the cooling chamber 120 is not connected to the discharge chamber 10.

[0023] The lower seat 12 has water inlet 104 and water outlet 105 on its opposite outer peripheral surfaces, and the water inlet 104 and water outlet 105 are respectively connected to the cooling cavity 120.

[0024] Understandably, since the cooling channels 103 need to be arranged around the outer periphery of the discharge chamber 10, in order to enable the fabrication of the cooling channels 103, the cathode holder 1 is configured as an upper body 11 and a lower body 12 arranged sequentially from top to bottom and connected together, with the mounting channel 101 and the air inlet channel 102 directly disposed in the upper body 11. A cooling chamber 120 is formed in the lower body 12, thereby providing multiple cooling channels 103 on the inner circumferential wall of the cooling chamber 120, and through the cooling chamber 120, the multiple cooling channels 103 are connected to the water inlet 104 and the water outlet 105.

[0025] Preferably, such as Figure 4 As shown, the upper surface of the inner circumferential wall of the cooling cavity 120 is provided with a protrusion 121 that protrudes upward, and the protrusion 121 is annular; the lower surface of the upper seat 11 is provided with an annular groove 110, and the protrusion 121 is inserted into the annular groove 110; thereby facilitating the alignment and connection of the lower seat 12 and the upper seat 11.

[0026] Preferably, such as Figure 4 and Figure 6 As shown, the cathode holder 1 also includes fixing ears 13, and a plurality of fixing ears 13 are fixedly disposed at intervals along the circumferential direction of the lower seat body 12 on the outer periphery of the lower seat body 12; so as to facilitate connection with other structures of the plasma source through the fixing ears 13.

[0027] Furthermore, such as Figures 2-4 As shown, the cathode seat structure 100 of the plasma source also includes a heat sink assembly 3. The heat sink assembly 3 includes a partition ring 31 and a diversion ring 32 arranged sequentially from the outside to the inside. There is a gap between the upper surface of the partition ring 31 and the diversion ring 32 and the lower surface of the upper seat body 11, and there is a gap between the lower surface of the partition ring 31 and the diversion ring 32 and the upper surface of the lower seat body 12. The side wall of the cooling chamber away from the discharge chamber is defined as the outer ring wall. The outer circumferential surface of the partition ring 31 is in contact with the outer ring wall, and the upper surface of the partition ring 31 and the peripheral wall of the cooling chamber 120 enclose the water inlet area 301, and the lower surface of the partition ring 31 and the peripheral wall of the cooling chamber 120 enclose the water outlet area 302. The inlet 104 is connected to the inlet area 301, and the outlet 105 is connected to the outlet area 302; The outer wall of the diversion ring 32 is fitted with the inner wall of the partition ring 31, and the inner wall of the diversion ring 32 is fitted with the circumferential wall of the inner ring. The diversion ring 32 has a plurality of water inlet channels 321 and water outlet channels 322 penetrating its radially side surfaces. The water inlet channels 321 and water outlet channels 322 are spaced apart, such that the water inlet channel 321 is connected to the water inlet area 301, and the water outlet channel 322 is connected to the water outlet area 302. The inlet channel 321 and the outlet channel 322 are connected through the cooling channel 103.

[0028] It should be noted that the inner wall of the diversion ring 32 is fitted to the inner ring peripheral wall, so that the water inlet channel 321 and the water outlet channel 322 are respectively connected to the cooling channel 103, thereby enabling the water inlet channel 321 and the water outlet channel 322 to be connected through the cooling channel 103.

[0029] It is understood that the flow divider ring 32 can divide the cooling chamber 120 into an inlet area 301 and an outlet area 302 that are not directly connected to each other, so as to avoid the cooling medium before cooling and the cooling medium after heating from mixing with each other, which would result in low cooling efficiency.

[0030] The cooling medium is then introduced into the cooling channel 103 through the inlet channel 321 in the diversion ring 32. After being cooled and heated in the cooling channel 103, the cooling medium flows out through the outlet channel 322 and enters the outlet area 302. Because the inlet channel 321 and the outlet channel 322 are spaced apart, the flow path of the cooling medium in the cooling channel 103 is shortened, facilitating the rapid discharge of the heated cooling medium from the cooling channel 103.

[0031] Specifically, such as Figure 4 As shown, in this embodiment, the partition ring 31 divides the cooling chamber 120 into a water inlet area 301 and a water outlet area 302 that are spaced apart from top to bottom. To accommodate this, the water inlet 104 is located above the water outlet 105.

[0032] Furthermore, a plurality of first water grooves are spaced apart on the upper surface of the diversion ring 32. The first water grooves penetrate the inner and outer surfaces of the diversion ring 32, and the inner wall of the first water grooves encloses to form the water inlet channel 321. The lower surface of the diversion ring 32 is provided with a plurality of second water tanks, the same number as the first water tank, and the first water tanks and the second water tanks are staggered; the second water tanks penetrate the inner and outer surfaces of the diversion ring 32, and the inner wall of the second water tanks encloses to form the water outlet channel 322.

[0033] It is understood that, to facilitate adaptation to the vertically spaced inlet and outlet water zones 301 and 302, a first water tank is formed on the upper surface of the diversion ring 32, so that the inner wall of the first water tank encloses and forms the inlet channel 321. This allows the cooling medium to flow from the first water tank to the cooling channel 103, and after cooling in the cooling channel 103, it flows out through the outlet channel 322 formed by the inner wall of the second water tank. Furthermore, because the first and second water tanks are staggered, the inlet channel 321 and outlet channel 322 are also staggered, shortening the flow path of the cooling medium and allowing the heated cooling medium to quickly flow out of the cooling channel 103.

[0034] Specifically, such as Figure 7 As shown, in this embodiment, the diversion ring 32 has a square wave-like structure with its ends connected. The square wave-like structure with its ends connected can form water inlet channels 321 and water outlet channels 322 that are spaced apart and not connected to each other. On the other hand, it can make the cross-section of the water inlet channels 321 and water outlet channels 322 in the radial direction of the diversion ring 32 square. Compared with other irregular cross-sections, the cooling medium can flow into the cooling channel 103 quickly and stably, and the heated cooling medium can flow out of the cooling channel 103 quickly and stably.

[0035] Furthermore, such as Figure 6 As shown, along the circumference of the discharge chamber 10, the cooling channel 103 is formed by multiple wide segments and multiple narrow segments connected alternately.

[0036] It is understood that by alternating the wide and narrow sections of the cooling channel 103, the diameter of the cooling channel 103 can be continuously changed. Such changes can repeatedly alter the flow state of the cooling medium, thereby improving cooling efficiency compared to a flow channel with a constant size.

[0037] Furthermore, such as Figure 4 and Figure 5 As shown, the ionization needle 21 includes a cathode column 211 and an ionization needle tip 212; The cathode column 211 and the ionization needle tip 212 are arranged and connected from top to bottom; The upper surfaces of the cathode columns 211 of the plurality of cathode needle assemblies 2 are flush with each other, and the axial dimensions of the plurality of ionizing needle tips 212 are set to at least two different sizes, such that the plurality of ionizing needles 21 have at least two different insertion depths in the discharge chamber 10.

[0038] It is understood that, in order to facilitate the realization of at least two different insertion depths and to facilitate the alignment of ionization needles 21 with the same insertion depth, the ionization needles 21 are configured as cathode columns 211 and ionization needle tips 212 arranged and connected sequentially from top to bottom; the alignment of ionization needles 21 with the same insertion depth can be achieved simply by making the upper surfaces of the cathode columns 211 flush with each other; and by using at least two ionization needle tips 212 with different axial dimensions, different insertion depths can be achieved in the discharge chamber 10, thereby achieving the ionization of gas in different regions of the discharge chamber 10.

[0039] Preferably, in this embodiment, two different sizes of ionization needle tips 212 are provided, so that the ionization needles 21 have two different insertion depths in the discharge chamber 10. Specifically, the two different insertion depths of ionization needles 21 are arranged alternately to improve the uniformity of the plasma generated by ionization. Specifically, the difference in axial length between the two different sizes of ionization needle tips 212 is 5mm-10mm.

[0040] Preferably, the ionization needle tip 212 is made of tungsten.

[0041] Furthermore, such as Figure 4 and Figure 5 As shown, the cathode needle assembly 2 also includes an insulating tube 22, which is hollow with openings at both ends; The insulating tube 22 is sealed and inserted into the installation channel 101; the ionization needle 21 is sealed and inserted into the insulating tube 22.

[0042] It should be noted that the insulating tube 22 is made of insulating material, which can be ceramic or other materials that can achieve insulation. In this embodiment, the insulating tube 22 is made of ceramic.

[0043] It is understood that by sealing the insulating tube 22 into the installation channel 101 and then sealing the ionizing needle 21 into the insulating tube 22, the insulating effect between the ionizing needle 21 and the cathode seat 1 is achieved through the insulating effect of the insulating tube 22.

[0044] Furthermore, such as Figure 4 and Figure 5 As shown, the cathode needle assembly 2 also includes a mounting tube 23, a mounting sleeve 24, a first sealing ring 25, and a second sealing ring 26; The mounting tube 23 is hollow with openings at both ends, and one end is inserted into the mounting channel 101; the insulating tube 22 is inserted into the mounting tube 23, and a first protrusion 221 is provided around its upper outer periphery; the first sealing ring 25 is provided between the first protrusion 221 and the upper end of the mounting tube 23. The ionization needle 21 has a second protrusion 213 around its outer periphery, which is located above the first protrusion 221; the second sealing ring 26 is disposed between the second protrusion 213 and the first protrusion 221. The mounting sleeve 24 is fitted around the outer periphery of the mounting tube 23 and pressed against the upper side of the second protrusion 213; the outer periphery of the mounting tube 23 is provided with external threads, and the mounting sleeve 24 is threadedly connected to the mounting tube 23.

[0045] It is understood that, since the first sealing ring 25 is located between the first protrusion 221 and the upper end of the mounting tube 23, and the second sealing ring 26 is located between the second protrusion 213 and the first protrusion 221; through the threaded connection between the mounting sleeve 24 and the mounting tube 23, the relative position of the mounting sleeve 24 and the mounting tube 23 can be changed by changing the screw-in depth of the mounting sleeve 24, thereby pressing the mounting sleeve 24 against the upper side of the second protrusion 213, thereby driving the second protrusion 213 to move towards the mounting tube 23, thereby squeezing the second sealing ring 26 between the second protrusion 213 and the first protrusion 221 and the first sealing ring 25 between the first protrusion 221 and the upper end of the mounting tube 23, thereby achieving the sealed installation of the ionizing needle 21 and the insulating tube 22, and the sealed installation of the insulating tube 22 and the mounting tube 23, thus achieving the sealed insertion of the ionizing needle 21 into the mounting channel 101.

[0046] Preferably, such as Figure 4 and Figure 5 As shown, from the outside to the inside, the upper surface of the mounting tube 23 is inclined downwards, so that the upper surface of the mounting tube 23 is a slope, which facilitates the compression of the first sealing ring 25 to achieve a seal.

[0047] Preferably, the mounting sleeve 24 is made of ceramic to provide insulation.

[0048] Furthermore, such as Figure 4 and Figure 5 As shown, the cathode needle assembly 2 also includes a discharge wire 27 and a fastening nut 28; The discharge wire 27 is wound around the upper outer periphery of the ionization needle 21 and is electrically connected to the ionization needle 21; the two fastening nuts 28 are respectively located on the upper and lower sides of the discharge wire 27 and are screwed to the ionization needle 21 to press the discharge wire 27.

[0049] It is understood that the discharge wire 27 is wound around the outer periphery of the ionization needle 21 and electrically connected to the ionization needle 21, thereby energizing the ionization needle 21 to ionize the discharge gas. To prevent the discharge wire 27 from detaching from the outer periphery of the ionization needle 21, fastening nuts 28 are respectively provided on the upper and lower sides of the discharge wire 27. By changing the screw-in position of the two fastening nuts 28 on the outer periphery of the ionization needle 21, the distance between the two fastening nuts 28 can be changed, thereby clamping the discharge wire 27.

[0050] Furthermore, such as Figure 1 As shown, multiple mounting channels 101 are arranged at circumferential intervals along the discharge chamber 10; The air intake channel 102 is coaxially arranged with the discharge chamber 10.

[0051] It is understood that by coaxially arranging the air intake channel 102 with the discharge chamber 10, and by arranging the plurality of mounting channels 101 circumferentially spaced along the discharge chamber 10, the plurality of mounting channels 101 surround the air intake channel 102, thereby making the plurality of ionization needles 21 evenly distributed in the discharge chamber 10, improving the uniformity of ionization, and thus improving the uniformity of the plasma generated by ionization.

[0052] Preferably, such as Figure 4 As shown, the air intake channel 102 includes an air intake section 1021 and a diffuser section 1022 arranged sequentially from top to bottom and connected to each other; the diameter of the diffuser section 1022 gradually increases from top to bottom, thereby facilitating the uniform diffusion of the introduced discharge gas into the discharge chamber 10.

[0053] Preferably, such as Figure 2 As shown, the cathode seat structure 100 of the plasma source also includes an air inlet pipe 4; the air inlet pipe 4 is connected to one end of the air inlet channel 102 away from the discharge chamber 10; so as to allow discharge gas to be introduced into the air inlet channel 102 by connecting the air inlet pipe 4.

[0054] Preferably, such as Figures 1-3 As shown, the cathode seat structure 100 of the plasma source also includes a water inlet / outlet assembly 5, which includes a water inlet pipe 51 and a water outlet pipe 52. The water inlet pipe 51 is connected to the water inlet 104 so as to introduce an external water source into the cooling channel 103 through the water inlet pipe 51. The water outlet pipe 52 is connected to the water outlet 105 so as to lead the heated water out of the cooling channel 103 through the water inlet pipe 51.

[0055] Preferably, the inlet pipe 51 and the outlet pipe 52 are made of 316L stainless steel to have excellent corrosion resistance.

[0056] Preferably, in order to have excellent thermal conductivity and improve cooling efficiency, the upper seat 11, lower seat 12, partition ring 31 and flow divider ring 32 are all made of oxygen-free copper.

[0057] The working process of this invention is as follows: Discharge gas is introduced into the discharge chamber 10 through the air inlet pipe 4; the discharge wire 27 is energized to charge the ionization needle 21, thereby ionizing the gas in the discharge chamber 10 and generating plasma. Since the two ionization needles 21 with different insertion depths simultaneously ionize the gas in the discharge chamber 10, the ionization rate is increased.

[0058] Cooling medium is introduced through the inlet pipe 51, enters the inlet area 301 through the inlet port 104, and then enters the cooling channel 103 through the inlet flow channel 321, thereby cooling the peripheral wall of the discharge chamber 10 and the cathode seat 1; the heated cooling medium flows out to the outlet area 302 through the adjacent outlet flow channel 322, and then flows out to the outlet pipe 52 through the outlet port 105.

[0059] In summary, the embodiments of the present invention provide a cathode seat structure 100 for a plasma source, which includes a cathode seat 1 and a plurality of cathode needle assemblies 2; discharge gas can be introduced into the discharge chamber 10 through the gas inlet channel 102; since the plurality of ionizing needles 21 have at least two different insertion depths in the discharge chamber 10, and the ionizing needles 21 with different insertion depths are arranged at intervals, the gas at different positions in the discharge chamber 10 can be ionized by the plurality of ionizing needles 21. Compared with the prior art method of ionizing gas in the same height region, the present invention can further improve the ionization rate. By providing multiple cooling channels 103 arranged axially around the outer periphery of the discharge chamber 10, and communicating with the cooling channels 103 through the inlet 104 and outlet 105, a cooling medium can be introduced into the cooling channels 103, thereby cooling the inner wall of the discharge chamber 10 at different heights. This facilitates cooperation with ionization needles 21 at different insertion depths to effectively cool the inner wall of the discharge chamber 10 and the cathode seat 1, thereby improving the ionization rate and the cooling efficiency of the cathode seat 1.

[0060] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A cathode holder structure for a plasma source, characterized in that, Includes a cathode holder and multiple cathode needle assemblies; The cathode holder has a discharge chamber extending axially and penetrating its lower surface; the cathode holder also has an installation channel, an air inlet channel, a cooling channel, a water inlet, and a water outlet; multiple installation channels, the same number as the cathode needle assembly, are spaced apart, one end of each installation channel is located on the upper surface of the cathode holder, and the other end communicates with the discharge chamber; one end of each air inlet channel is located on the outer surface of the cathode holder, and the other end communicates with the discharge chamber; the water inlet and water outlet are respectively located on opposite outer peripheral surfaces of the cathode holder; multiple cooling channels are spaced apart along the extension direction of the discharge chamber, each cooling channel surrounds the outer periphery of the discharge chamber and is isolated from the discharge chamber, and all cooling channels are connected to the water inlet and water outlet; The cathode holder includes an upper body and a lower body arranged sequentially from top to bottom and connected to each other; the lower body has a discharge chamber extending through its upper and lower surfaces, and the lower body also has a cooling chamber, which surrounds the discharge chamber and extends through the upper surface of the lower body, and the cooling chamber and the discharge chamber are isolated from each other and do not communicate with each other; the side wall of the cooling chamber closest to the discharge chamber is defined as the inner ring wall, and a plurality of cooling channels are provided on the inner ring wall; The cathode needle assembly includes an ionizing needle, which is sealed and insulatedly inserted into the mounting channel such that a portion of the ionizing needle is located in the discharge chamber; a plurality of ionizing needles are arranged in the discharge chamber at at least two different insertion depths, and the ionizing needles with different insertion depths are spaced apart. The ionization needle includes a cathode column and an ionization needle tip; The cathode column and the ionization needle tip are arranged sequentially from top to bottom and connected together; The upper surfaces of the cathode columns of the plurality of cathode needle assemblies are flush with each other, and the axial dimensions of the plurality of ionizing needle tips are set to at least two different sizes, such that the plurality of ionizing needles have at least two different insertion depths in the discharge chamber.

2. The cathode holder structure of the plasma source as described in claim 1, characterized in that, The upper body is provided with an installation channel and an air intake channel that run through its upper and lower surfaces; The lower body has water inlets and outlets on its opposite outer peripheral surfaces, and the water inlets and outlets are respectively connected to the cooling cavity.

3. The cathode holder structure of the plasma source as described in claim 2, characterized in that, It also includes a heat sink assembly, which includes a partition ring and a diversion ring arranged sequentially from the outside to the inside; The side wall of the cooling chamber away from the discharge chamber is defined as the outer ring wall. The outer circumferential surface of the partition ring is in contact with the outer ring wall, so that the upper surface of the partition ring and the wall of the cooling chamber enclose a water inlet area, and the lower surface of the partition ring and the wall of the cooling chamber enclose a water outlet area. The water inlet is connected to the water inlet area, and the water outlet is connected to the water outlet area; The outer wall of the diversion ring is fitted with the inner wall of the partition ring, and the inner wall of the diversion ring is fitted with the circumferential wall of the inner ring; the diversion ring has a plurality of inlet channels and outlet channels that penetrate its radial two-sided surfaces, the inlet channels and outlet channels are spaced apart, and the inlet channels are connected to the inlet area, and the outlet channels are connected to the outlet area; The inlet and outlet water channels are connected through the cooling channel.

4. The cathode holder structure of the plasma source as described in claim 3, characterized in that, The upper surface of the diversion ring is provided with a plurality of first water grooves spaced apart. The first water grooves penetrate the inner and outer surfaces of the diversion ring, and the inner wall of the first water grooves encloses to form the water inlet channel. The lower surface of the diversion ring is provided with a plurality of second water tanks, the same number as the first water tank, and the first and second water tanks are staggered; the second water tanks penetrate the inner and outer surfaces of the diversion ring, and the inner wall of the second water tanks encloses to form the water outlet channel.

5. The cathode holder structure of the plasma source as described in any one of claims 1-4, characterized in that, The cooling channel is composed of multiple wide sections and multiple narrow sections connected in an alternating manner.

6. The cathode holder structure of the plasma source as described in any one of claims 1-4, characterized in that, The cathode needle assembly also includes an insulating tube, which is hollow with openings at both ends; The insulating tube is sealed and inserted into the installation channel; the ionization needle is sealed and inserted into the insulating tube.

7. The cathode holder structure of the plasma source as described in claim 6, characterized in that, The cathode needle assembly also includes a mounting tube, a mounting sleeve, a first sealing ring, and a second sealing ring; The mounting tube is hollow with openings at both ends, and one end is inserted into the mounting channel; the upper outer circumference of the insulating tube is provided with a first protrusion; the first sealing ring is disposed between the first protrusion and the upper end of the mounting tube. The ionization needle is inserted into the mounting tube, and a second protrusion is provided around its outer periphery, the second protrusion being located above the first protrusion; the second sealing ring is disposed between the second protrusion and the first protrusion; The mounting sleeve is fitted around the outer periphery of the mounting tube and pressed against the upper side of the second protrusion; the outer periphery of the mounting tube is provided with external threads, and the mounting sleeve is threadedly connected to the mounting tube.

8. The cathode holder structure of the plasma source as described in any one of claims 1-4, characterized in that, The cathode needle assembly also includes a discharge wire and a fastening nut; The discharge wire is wound around the upper outer circumference of the ionization needle and is electrically connected to the ionization needle; the two fastening nuts are respectively located on the upper and lower sides of the discharge wire and screwed to the ionization needle to press the discharge wire tight.

9. The cathode holder structure of the plasma source as described in any one of claims 1-4, characterized in that, The plurality of mounting channels are arranged at circumferential intervals along the discharge chamber; The air intake channel is coaxially arranged with the discharge chamber.

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