Clamping device for high-frequency negative hydrogen ion source immersion antenna

Abstract

The invention discloses a clamping device for a high-frequency negative hydrogen ion source immersion type antenna. The clamping device comprises two T-shaped pressing sleeves and pressing blocks, wherein the two T-shaped pressing sleeves are used for high-frequency antenna supporting legs to penetrate through respectively, and the pressing blocks are buckled on the two T-shaped pressing sleeves in a pressing mode. The flat end parts of the two T-shaped pressing sleeves are provided with radial sealing grooves distributed in the radial direction of the axial through holes of the two T-shaped pressing sleeves and axial sealing grooves distributed in the axial direction of the axial through holes of the two T-shaped pressing sleeves. The pressing block is provided with two antenna supporting leg via holes which are coaxial with the T-shaped pressing sleeve respectively, and the diameter size of the two antenna supporting leg via holes can reduce the probability of high-frequency sparking or capacitive coupling discharge between the pressing block and the high-frequency antenna supporting leg to the maximum extent; the T-shaped pressing sleeve and a core element integrating multiple functions are introduced and matched with the pressing block to form a stable and reliable clamping structure, the mechanical stability of the high-frequency antenna under complex working conditions is ensured, and high-frequency ignition and capacitance coupling discharge are effectively restrained.

Description

Technical Field

[0001] This invention relates to the fields of high-frequency negative hydrogen ion source technology and mechanical and vacuum technology, and in particular to a clamping device for a high-frequency negative hydrogen ion source immersion antenna. Background Technology

[0002] High-current negative hydrogen ion sources are widely used in high-current proton accelerators, power semiconductor hydrogen ion implantation processes, and controlled nuclear fusion neutral beam injection heating. By using a high-frequency electromagnetic field to replace the traditional hot cathode arc discharge method for generating hydrogen plasma, the contradiction between the current intensity and lifespan of the negative hydrogen ion source device is fundamentally resolved because the hot cathode structure immersed in the plasma is eliminated.

[0003] The high efficiency of a high-frequency negative hydrogen ion source depends on the control of the specific coupling mode of the high-frequency drive discharge and the high efficiency of the high-frequency power feed itself. The coupling mode of the high-frequency drive discharge and the distribution of different discharge modes at different positions in the ion source discharge cavity also affect the efficiency of the high-frequency power feed itself. Therefore, to achieve a working condition conducive to the generation of negative hydrogen ions inside the negative hydrogen ion source discharge cavity, it is necessary to employ both a reasonable high-frequency antenna configuration design and a high-frequency antenna connection method that facilitates the efficient feed of high-frequency power into the discharge cavity and establishes a suitable distribution of inductively coupled plasma.

[0004] For a pulse-mode multi-peak field built-in antenna radio frequency high-current negative hydrogen ion source and other similar devices within the scope of authorization, the built-in radio frequency antenna used consists of a helical segment with 2.5 to 3.5 turns, a diameter of about 58 mm, a height of about 40 to 50 mm, and a straight segment with a leg spacing of about 25 mm. The outside is coated with an enamel coating with a thickness of about 0.6 to 0.7 mm. It is fixed to the upper cover plate of the built-in radio frequency antenna of the ion source by a vacuum sealing device of a radio frequency negative hydrogen ion source built-in radio frequency enamel antenna. The legs of the high-frequency antenna pass through two holes left for them in the upper cover plate of the ion source. The fixation and vacuum sealing functions of the high-frequency antenna are achieved by two lower floating flanges and an upper floating flange pressed by floating flange clamping blocks.

[0005] However, for applications requiring high-power pulsed or continuous wave (CW) feeds and sensitive to efficiency and lifespan, the embodiment described in the invention patent "A vacuum sealing device for a radio frequency negative hydrogen ion source with a built-in radio frequency enamel antenna (application publication number: CN117766996 A)" has poor tolerance to high frequencies and high power. High-frequency power is easily deposited between the high-frequency antenna and the upper cover plate 1, the upper magnet seat 2, the lower floating flange 6, the upper floating flange 7, and the floating flange clamping block 11. Even when feeding high power into the ion source, it can cause the enamel coating on the legs of the high-frequency antenna to break down and be damaged. This causes the high-frequency power to continue discharging at the damaged enamel coating, greatly reducing the discharge power inside the ion source discharge cavity. Gradually, this leads to vacuum seal failure, damage to the high-frequency antenna, and manifests as abnormal emission of high-frequency electromagnetic waves and a sudden increase in high-frequency reflected power in the system.

[0006] The challenge in designing and implementing a clamping device for an immersion antenna of a high-frequency negative hydrogen ion source lies in ensuring a vacuum seal between the clamping device and the high-frequency antenna, as well as between the clamping device and the top cover of the ion source. At the same time, it is necessary to reduce the deposition of high-frequency power between the high-frequency antenna, the top cover, and the floating flange clamping block within the compact space where the clamping device is installed, and to prevent arcing or capacitive coupling discharge during high-power feeding. This will enable the high reliability of the entire high-frequency negative hydrogen ion source and the long lifespan of the immersion high-frequency antenna. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention proposes a clamping device for a high-frequency negative hydrogen ion source immersion antenna. The purpose is to solve the problem that high-frequency power easily deposits between the ion source high-frequency antenna and components such as the upper cover plate, upper magnet base, lower floating flange, upper floating flange, and floating flange clamping block, thereby causing damage to the coating of the immersion high-frequency antenna, failure of vacuum sealing, and abnormal discharge state.

[0008] To solve its technical problems, the present invention proposes the following technical solutions:

[0009] A clamping device for a high-frequency negative hydrogen ion source immersion antenna is characterized in that the clamping device includes two "T"-shaped clamping sleeves for the high-frequency antenna legs to pass through, and a clamping block clamping the two "T"-shaped clamping sleeves; the flat ends of the two "T"-shaped clamping sleeves are machined with radial sealing grooves arranged radially along their axial through holes and axial sealing grooves arranged axially along their axial through holes; the clamping block is provided with two antenna leg through holes coaxially arranged with the "T"-shaped clamping sleeves. The diameter of the antenna leg through-hole can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna leg; the straight sections of the two "T"-shaped clamping sleeves penetrate downwards through the upper cover plate and the upper magnet seat, respectively, and the lower surface of the flat end of the "T"-shaped clamping sleeve abuts against the upper surface of the upper cover plate; the clamping blocks at the top of the two "T"-shaped clamping sleeves are fixed to the upper cover plate through which the two "T"-shaped clamping sleeves penetrate by screws, thereby forming a clamping device for a high-frequency negative hydrogen ion source immersion antenna.

[0010] Furthermore, the diameter of the two antenna leg through holes can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna leg. Specifically, the diameter of the two antenna leg through holes is not less than the outer diameter of the radial sealing groove of the "T"-shaped clamping sleeve.

[0011] Furthermore, the two "T"-shaped clamping sleeves are machined using "T"-shaped ceramic sleeves, wherein the inner diameter of the axial through hole is greater than the maximum value of the outer diameter of the antenna coating of the high-frequency antenna leg, and sufficient positive tolerance should be reserved.

[0012] Furthermore, the clamping block is made of 304 non-magnetic stainless steel, thereby avoiding any impact on the magnetic field of the permanent magnet array installed between the upper cover plate and the upper magnet seat, while reducing the processing difficulty, controlling the workpiece cost, and achieving high strength and durability.

[0013] Furthermore, the flat ends of the two "T"-shaped clamping sleeves are machined with radial sealing grooves arranged radially along their axial through holes; that is, radial sealing grooves are machined by extending radially along the axial through holes of the flat ends.

[0014] Furthermore, the flat ends of the two "T"-shaped compression sleeves are machined with axial sealing grooves arranged radially along their axial through holes, that is, an annular axial sealing groove is machined inwardly on the lower surface of the flat ends.

[0015] Furthermore, the radial sealing ring is an "X"-shaped (i.e. star-shaped) sealing ring, which is used to hold the antenna coating on the high-frequency antenna leg tightly through the two sealing lips, and through its star-shaped cross-section, it ensures that the sealing ring itself will not roll when the antenna leg passes through the radial sealing ring, thereby affecting the vacuum sealing effect.

[0016] Furthermore, the radial sealing ring is installed in the radial sealing groove, and the dimensions of both the radial sealing ring and the radial sealing groove are selected to match the outer diameter of the antenna coating.

[0017] Furthermore, the axial sealing ring is installed in the axial sealing groove, and the dimensions of both the axial sealing ring and the axial sealing groove are selected to match the outer diameter d of the straight section of the "T"-shaped compression sleeve and the outer diameter D of the flat end of the "T"-shaped compression sleeve.

[0018] Advantages and effects of the present invention

[0019] 1. Effectively suppresses high-frequency arcing and capacitive coupling, improving operational reliability: In existing technologies, high-frequency power easily accumulates between the antenna and metal components such as the top cover, causing high-frequency arcing and capacitive coupling discharge, leading to damage to the antenna coating and sealing failure. This invention optimizes the structure by providing a sufficiently large diameter antenna leg through-hole on the clamping block. Specifically, the diameter of this through-hole is set to a larger value, within the principle of not exceeding the inner diameter of the axial sealing ring, thereby significantly increasing the gap between the clamping block and the antenna leg. This design greatly reduces the possibility of high-frequency discharge or capacitive coupling between the two, effectively avoiding faults caused by power accumulation and significantly improving the reliability of the device under high-power operating conditions. Furthermore, since the inner diameter of the compression sleeve through hole is slightly larger than the outer diameter of the antenna leg coating, the two are fixed and sealed by a radial sealing ring. This allows for vacuum sealing through the compression sleeve and two sealing rings even when the parallelism of the two antenna legs is poor or the wheelbase is slightly different from that of the through hole in the upper cover plate. At the same time, it is protected by the straight section of the compression sleeve, which reduces the possibility of high-frequency discharge or capacitive coupling between the antenna legs and the ion source upper cover plate and the upper magnet seat. This effectively avoids faults caused by power deposition and significantly improves the reliability of the device under high-power operating conditions.

[0020] 2. Achieving a reliable double vacuum seal to prevent gas leakage: To solve the common sealing failure problem in existing technologies, this invention adopts an innovative double sealing structure. First, a radial sealing groove is machined on the flat end of the "T"-shaped clamping sleeve, and a star-shaped sealing ring with an "X"-shaped cross-section is used to tightly grip the coating surface of the antenna leg, forming an effective radial dynamic seal. Second, an axial sealing groove is machined on the same flat end of the "T"-shaped clamping sleeve, and an axial sealing ring is installed, achieving a static axial seal between the clamping sleeve and the ion source cover plate. This combined radial and axial double sealing design fundamentally ensures the vacuum seal of the clamping device itself and its connection with the cover plate, effectively preventing gas leakage.

[0021] 3. Simple structure, readily available and easily processed materials, and low cost: The "T"-shaped clamping sleeve is preferably made of alumina (Al2O3) ceramic. Its axial through-hole inner diameter must be larger than the maximum value of the antenna coating's outer diameter with sufficient positive tolerance. Al2O3 ceramic possesses high dielectric strength, low high-frequency loss, and advantages such as low processing difficulty, controllable cost, high strength, and good durability. This material compatibility allows the clamping device to adapt to diverse performance requirements and application scenarios.

[0022] Meanwhile, compared to the more common Feedthrough and high-frequency window designs, this invention, for existing coated antennas, only requires the finishing of the compression sleeve and the provision of standardized off-the-shelf products (axial and radial sealing rings). However, using Feedthrough requires at least the following additional processes or structures: ① A detachable or welded-to-the-top-cover water pipe penetrating the wall (Feedthrough body), which needs to be customized and incorporates ceramic metallization and welding processes; ② Achieving a detachable and seamless connection between the antenna and the water pipe inside the discharge cavity, such as using VCR or compression fittings. The main problem with this is that it will cause issues with the discharge cavity. Introducing a large amount of exposed metal into the discharge cavity takes up a lot of space in an already compact environment. It is also not conducive to controlling capacitive coupling discharge and preventing arcing. Furthermore, these exposed metals will affect the discharge state of the ion source. There are also concerns about the risk of water leakage caused by plasma erosion and heating. The structure using a high-frequency window also involves peeling off the antenna coating and welding the antenna to the high-frequency window ceramic. At the same time, it is necessary to design a structure to fix it to the upper cover plate (upper magnet base) from inside the discharge cavity. This is also difficult to design and affects the discharge. In addition, each antenna needs to be welded with a ceramic window, resulting in high implementation costs for both individual components and the whole system.

[0023] 4. Significantly Extends the Service Life of High-Frequency Antennas: Through the above measures, this invention effectively reduces the damage caused by high-frequency arcing and capacitive coupling discharge to high-frequency antennas (especially their surface enamel coating). This significantly extends the antenna's service life and reduces the frequency of replacements and maintenance costs due to antenna damage.

[0024] 5. Ensuring stable operation of the discharge chamber: Improved reliability and sealing of the clamping device directly guarantee the stability of the internal environment of the ion source discharge chamber. This helps avoid problems such as discharge power fluctuations, abnormal high-frequency electromagnetic wave emission, and increased reflected power caused by clamping failures, thereby ensuring the continuous and stable operation of the negative hydrogen ion source.

[0025] In summary, by optimizing the key structural parameters and sealing design of the clamping device and introducing flexible material selection schemes, this invention systematically solves the core problems of high-frequency arcing, capacitive coupling and vacuum sealing failure in the prior art, and significantly improves the overall reliability, lifespan of key components and operational stability of the high-frequency negative hydrogen ion source. Attached Figure Description

[0026] Figure 1 A schematic diagram of the clamping device for an existing high-frequency negative hydrogen ion source immersion antenna.

[0027] Figure 2a This is a schematic diagram of the clamping device for the high-frequency negative hydrogen ion source immersion antenna of the present invention.

[0028] Figure 2b This is a top view of the clamping block of the clamping device for the high-frequency negative hydrogen ion source immersion antenna of the present invention.

[0029] Figure 2c This is a cross-sectional view of the "T"-shaped clamping sleeve of the clamping device of the present invention;

[0030] Figure 2d The image shows a perspective view of the "T"-shaped clamping sleeve of the clamping device of the present invention.

[0031] Figure 2e This is a schematic diagram of the radial and axial sealing rings of the compression sleeve of the present invention;

[0032] Figure 3 Schematic diagram of a high-frequency negative hydrogen ion source immersion antenna;

[0033] In the diagram, 1: clamping block; 1-1: first countersunk hole; 1-2: second countersunk hole; 1-3: third countersunk hole; 1-4: fourth countersunk hole; 1-5: fifth countersunk hole; 1-6: sixth countersunk hole; 1-7: first antenna leg through hole; 1-8: second antenna leg through hole; 2: clamping sleeve; 2-1: axial through hole; 2-2: radial sealing ring; 2-3: axial sealing ring; 4: high-frequency antenna; 4-1: high-frequency antenna leg; 4-2: antenna layer; 4-3: high-frequency antenna helical segment; 5: upper cover plate; 6: upper magnet base. Detailed Implementation

[0034] Innovation of this invention

[0035] 1. Introduction of "T-shaped clamping sleeve" for functional integration: The core innovation of this invention is the design of a unique "T"-shaped clamping sleeve. This component is not a simple fastener, but a core element integrating multiple functions: ① Physical isolation function: Its "T"-shaped structure effectively isolates the high-frequency antenna legs from metal components such as the top cover and magnet base, cutting off the direct path of high-frequency power deposition to these components and reducing energy loss at the source. ② Structural support and clamping function: In conjunction with the clamping block, it forms a stable and reliable clamping structure, ensuring the mechanical stability of the high-frequency antenna under complex operating conditions.

[0036] 2. Innovative Sealing Mechanism: Dual-Seal Ensures High Vacuum Reliability: Addressing the issue of vacuum seal failure, this invention features an innovative dual-sealing system on the "T"-shaped compression sleeve: ① Radial Sealing: A static seal is achieved between the high-frequency antenna leg and the "T"-shaped compression sleeve via a radial sealing groove and sealing ring. ② Axial Sealing: A static seal is achieved between the "T"-shaped compression sleeve and the ion source cover plate via an axial sealing groove and sealing ring. ③ Optimal Sealing Ring: Furthermore, a star-shaped sealing ring with an "X"-shaped cross-section is preferred. This ensures that the sealing ring itself does not roll when the antenna leg passes through the radial sealing ring, thus preventing it from affecting the vacuum sealing effect. Simultaneously, the two sealing lips on the star-shaped cross-section provide a better sealing effect under atmospheric pressure and high vacuum pressure difference, avoiding a decrease in negative hydrogen ion production due to impurities in the discharge gas.

[0037] 3. Refined Design to Suppress High-Frequency Discharge: To directly address high-frequency arcing and capacitive coupling discharge, key dimension optimizations were employed: the diameter of the antenna leg vias on the clamping block was precisely optimized. This design maximizes the discharge creepage distance and reduces parasitic capacitance, thereby significantly reducing the probability of high-frequency arcing or capacitive coupling discharge, further ensuring effective power feed.

[0038] 4. Material Selection Strategy, Balancing Electrical and Mechanical Performance: The material selection for the "T"-shaped clamping sleeve reflects a targeted solution. The "T"-shaped clamping sleeve is preferably made of alumina (Al2O3) ceramic, with its axial through-hole inner diameter exceeding the maximum outer diameter of the antenna coating and allowing for sufficient positive tolerance. Al2O3 ceramic possesses high dielectric strength and low high-frequency loss, while also offering advantages such as low processing difficulty, controllable cost, high strength, and good durability. The clamping block offers greater flexibility in material selection, employing 304 non-magnetic stainless steel or other readily available non-magnetic metals. This ensures sufficient mechanical strength while avoiding interference from magnetic materials on the ion source's magnetic field, while also offering lower cost and better durability.

[0039] Design principle of the invention

[0040] 1. High-Frequency Power Deposition Suppression: ① "T"-shaped clamping sleeve + clamping block. This changes the traditional clamping method, dispersing the concentrated clamping force and high-frequency electric field, fundamentally avoiding breakdown caused by capacitive coupling discharge and local dielectric concentration. ② Antenna leg through-hole > sealing groove outer diameter. By increasing the physical distance between the clamping block and the antenna leg, the electric field strength between them is directly reduced, thereby effectively suppressing high-frequency arcing and capacitive coupling discharge. ③ Material selection: Alumina ceramic: Excellent insulator, low high-frequency loss, robust and durable structure, controllable processing difficulty and cost. Non-magnetic stainless steel (such as 304): Avoids interference with surrounding magnetic fields, balancing strength, machinability, and cost.

[0041] 2. Vacuum sealing reliability: Radial sealing relies on the star-shaped sealing ring (X-shaped cross-section) on the "T"-shaped sleeve to tightly hold the antenna coating, forming the first line of defense. Axial sealing relies on the clamping force between the sleeve and the upper cover plate, achieving a second layer of sealing through the axial sealing ring.

[0042] 3. Dual Compensation Design Principle: During installation, the parallelism and axial distance of the high-frequency antenna leg 4-1 may deviate from the holes on the upper cover plate 5 and the upper magnet seat 6. This deviation can lead to misalignment, making installation difficult and potentially compromising the vacuum seal. First Compensation – Compensation between the leg and the sleeve: The inner diameter of the axial through-hole 2-1 of the "T"-shaped clamping sleeve 2 is larger than the outer diameter of the antenna coating 4-2. This allows for an angular deviation between the axis of the high-frequency antenna leg and the axis of the "T"-shaped clamping sleeve. The leg can be "tilted" at a certain angle within the sleeve, thus compensating for the parallelism error. A special "X"-shaped star-shaped sealing ring within the radial sealing groove 2-2 deforms and clamps the leg when compressed, achieving a seal. Second Compensation – Compensation between the sleeve and the mounting plate: The outer diameter of the straight section of the "T"-shaped clamping sleeve 2 is slightly smaller than the inner diameter of the holes on the upper cover plate 5 and the upper magnet seat 6. This allows the entire "T"-shaped clamping sleeve to move slightly within its mounting hole, thereby compensating for the wheelbase error of the outriggers. Because the sleeve can float, the clamping force can always ensure that the flat end face of the sleeve is fully in contact with the plane of the upper cover plate 5, forming a uniform axial seal.

[0043] In summary, the core innovation of this invention lies in its combination of a "T"-shaped clamping sleeve and a clamping block of a specific size, which simultaneously overcomes the two major challenges of "high-frequency power suppression" and "vacuum sealing." The structural design and dimensional fit physically reduce the electric field strength in critical components. The double-sealing design ensures vacuum integrity under harsh environments. It balances structural strength, ease of use, maintainability, and cost. This significantly improves the operational reliability of the high-frequency negative hydrogen ion source and the lifespan of the immersion antenna.

[0044] Based on the above principles, this invention designs a clamping device for a high-frequency negative hydrogen ion source immersion antenna, such as... Figure 1 , Figure 2a , Figure 2b , Figure 2c , Figure 2d , Figure 2e , Figure 3The clamping device is characterized by comprising two "T"-shaped clamping sleeves 2 for the high-frequency antenna legs to pass through, and a clamping block 1 that is fastened onto the two "T"-shaped clamping sleeves; the flat ends of the two "T"-shaped clamping sleeves 2 are machined with radial sealing grooves 2-2 arranged radially along their axial through holes and axial sealing grooves 2-3 arranged axially along their axial through holes; the clamping block 1 is provided with two antenna leg through holes coaxially arranged with the "T"-shaped clamping sleeves 2: a first antenna leg through hole 1-7 and a second antenna leg through hole 1. -8; The diameter of the through holes of the two antenna legs can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna legs; The straight sections of the two "T"-shaped clamping sleeves 2 pass downward through the upper cover plate 5 and the upper magnet seat 6 respectively, and the lower surface of the flat end of the T-shaped clamping sleeve abuts against the upper surface of the upper cover plate; The clamping block 1 at the top of the two "T"-shaped clamping sleeves 2 is fixed to the upper cover plate 5 through which the two T-shaped clamping sleeves pass by screws, thereby forming a clamping device for a high-frequency negative hydrogen ion source immersion antenna.

[0045] like Figure 2a As shown, the diameter of the two antenna leg through holes can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna leg. Specifically, the diameter of the first antenna leg through hole 1-7 and the second antenna leg through hole 1-8 is not less than the outer diameter of the radial sealing groove 2-2 of the "T" shaped clamping sleeve.

[0046] like Figure 2e As shown, the two "T"-shaped clamping sleeves 2 are processed using "T"-shaped ceramic sleeves, wherein the inner diameter of the axial through hole 2-1 is greater than the maximum value of the outer diameter of the antenna coating 4-2 of the high-frequency antenna leg 4-1, and sufficient positive tolerance should be reserved.

[0047] like Figure 2e As shown, the clamping block 1 is made of 304 non-magnetic stainless steel, thereby avoiding the influence on the magnetic field of the permanent magnet array installed between the upper cover plate 5 and the upper magnet seat 6, while reducing the processing difficulty, controlling the workpiece cost, and obtaining high strength and durability.

[0048] like Figure 2c As shown, the flat end portion of the two "T"-shaped compression sleeves 2 is machined with radial sealing grooves 2-2 arranged radially along their axial through holes, that is: the radial sealing grooves 2-2 are machined by extending radially along the axial through holes of the flat end portion.

[0049] like Figure 2c As shown, the flat ends of the two "T"-shaped compression sleeves 2 are machined with axial sealing grooves 2-3 arranged radially along their axial through holes, that is, an annular axial sealing groove 2-3 is machined inwardly on the lower surface of the flat ends.

[0050] like Figure 2e As shown, the radial sealing ring 2-2 is an X-shaped sealing ring, which is used to hold the antenna coating on the high-frequency antenna leg tightly through two sealing lips, and through its star-shaped cross-section, it ensures that the sealing ring itself will not roll when the antenna leg passes through the radial sealing ring, thereby affecting the vacuum sealing effect.

[0051] like Figure 2e As shown, the radial sealing ring is installed in the radial sealing groove 2-2, and the dimensions of the radial sealing ring and the radial sealing groove 2-2 are selected to match the outer diameter of the antenna coating 4-2.

[0052] like Figure 2e As shown, the axial sealing ring is installed in the axial sealing groove 2-3. The dimensions of the axial sealing ring and the axial sealing groove 2-3 are selected to match the outer diameter d of the straight section of the "T"-shaped clamping sleeve 2 and the outer diameter D of the flat end of the "T"-shaped clamping sleeve.

[0053] Additional notes:

[0054] The clamping block 1 has a first countersunk hole 1-1, a second countersunk hole 1-2, a third countersunk hole 1-3, a fourth countersunk hole 1-4, a fifth countersunk hole 1-5, and a sixth countersunk hole 1-6 on both sides and the central axis for screws to pass through and fix to the upper cover plate. It also has a first antenna leg through hole 1-7 and a second antenna leg through hole 1-8 for two high-frequency antenna legs 4-1 to pass through. The countersunk holes are preferably equidistant from the two high-frequency antenna legs 4-1.

[0055] Example 1

[0056] A clamping device for a high-frequency negative hydrogen ion source immersion antenna comprises a clamping block 1, a "T"-shaped clamping sleeve 2, a radial sealing ring 2-2, and an axial sealing ring 2-3. High-frequency antenna legs 4-1 pass sequentially through holes in the upper magnet seat 6 and the upper cover plate 5 for the two high-frequency antenna legs 4-1 and the "T"-shaped clamping sleeve 2. The "T"-shaped clamping sleeve 2 has a radial sealing ring installed in its radial sealing groove 2-2 and an axial sealing ring installed in its axial sealing groove 2-3. It then slides from the side of the high-frequency antenna leg 4-1 away from the high-frequency antenna helical segment 4-3 until the high-frequency antenna helical segment 4-3 reaches a suitable depth in the ion source discharge cavity. The clamping block 1 is fixed to the upper cover plate 5 by screws, and the "T"-shaped clamping sleeve 2 is clamped on the sealing surface provided on the upper cover plate 5 for the "T"-shaped clamping sleeve 2.

[0057] The "T"-shaped clamping sleeve 2 has a first countersunk hole 1-1, a second countersunk hole 1-2, a third countersunk hole 1-3, a fourth countersunk hole 1-4, a fifth countersunk hole 1-5, and a sixth countersunk hole 1-6 on both sides and the central axis for screws to pass through and fix to the upper cover plate 5. It also has a first wire hole 1-7 and a second wire hole 1-8 for two high-frequency antenna legs 4-1 to pass through.

[0058] The first countersunk hole 1-1, the second countersunk hole 1-2, the third countersunk hole 1-3, the fourth countersunk hole 1-4, the fifth countersunk hole 1-5, and the sixth countersunk hole 1-6 should be equidistantly distributed for the two high-frequency antenna legs 4-1;

[0059] The first wire hole 1-7 and the second wire hole 1-8 are coaxial with the theoretical installation position of the two high-frequency antenna legs 4-1, that is, they are also coaxial with the holes opened on the upper cover plate 5 and the upper magnet seat 6 for the high-frequency antenna legs 4-1 and the "T"-shaped clamping sleeve 2, which facilitates the uniform clamping of the axial sealing ring 2-3 in the axial direction.

[0060] The diameters of the first wire passage hole 1-7 and the second wire passage hole 1-8 should be equivalent to the straight section of the "T"-shaped clamping sleeve 2, and should be larger than the inner diameter of the axial sealing ring 2-3, so as to reduce the probability of high-frequency arcing or capacitive coupling discharge between the clamping block 1 and the high-frequency antenna leg 4-1 without affecting the axial clamping of the axial sealing ring 2-3.

[0061] The clamping block 1 is made of 304 non-magnetic stainless steel, which avoids affecting the magnetic field of the permanent magnet array installed between the upper cover plate 5 and the upper magnet seat 6, while reducing the processing difficulty, controlling the workpiece cost, and obtaining high strength and durability.

[0062] The “T” shaped clamping sleeve 2 is machined using a “T” shaped ceramic sleeve, wherein the through hole 2-1 on the shaft can pass through the high-frequency antenna leg 4-1, the inner diameter should be greater than the maximum value of the outer diameter of the antenna coating 4-2 of the high-frequency antenna leg 4-1, and sufficient positive tolerance should be reserved.

[0063] An axial sealing groove 2-3 for embedding the radial sealing ring 2-2 is machined on one side of the flat end of the "T"-shaped compression sleeve 2 axial through hole 2-1;

[0064] The “T”-shaped clamping sleeve 2 is made of “T”-shaped ceramic sleeve, wherein the through hole 2-1 on the shaft can pass through the high frequency antenna leg 4-1, and on the plane of the sealing surface on the upper cover plate reserved for it, there is an axial sealing groove 2-4 for installing the axial sealing ring.

[0065] The outer diameter of the straight section of the “T”-shaped clamping sleeve 2 is slightly smaller than the inner diameter of the hole opened on the upper cover plate 5 and the upper magnet seat 6, so that the “T”-shaped clamping sleeve 2 can always pass smoothly through the hole and leave a certain off-axis margin.

[0066] Preferably, the "T"-shaped compression sleeve 2 is made of alumina ceramic material with a purity of 99% to obtain good high-frequency loss characteristics, dielectric strength and hardness, while the raw material and processing costs are relatively low.

[0067] The radial sealing ring is an "X" shaped sealing ring, which is used to hold the antenna coating on the high-frequency antenna leg tightly through two sealing lips, and through its star-shaped cross-section, it ensures that the sealing ring itself will not roll when the antenna leg passes through the radial sealing ring, thereby affecting the vacuum sealing effect.

[0068] The radial sealing ring is installed in the radial sealing groove 2-2 inside the through hole 2-1 of the "T"-shaped compression sleeve 2, and the dimensions of the two are selected to match the outer diameter of the antenna coating 4-2.

[0069] The radial sealing ring is made of fluororubber to achieve reasonable hardness and temperature resistance.

[0070] The axial sealing ring 2-3 is an O-ring that conforms to national or international standards. It is installed in the axial sealing groove 2-3 of the "T"-shaped compression sleeve 2. The dimensions of the two are selected to match the outer diameter d of the straight section and the total outer diameter D of the "T"-shaped compression sleeve 2.

[0071] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A clamping device for a high-frequency negative hydrogen ion source immersion antenna, characterized in that, The clamping device includes two "T"-shaped clamping sleeves (2) for the high-frequency antenna legs to pass through, and a clamping block (1) that is pressed onto the two "T"-shaped clamping sleeves; the flat ends of the two "T"-shaped clamping sleeves (2) are machined with radial sealing grooves (2-2) arranged radially along their axial through holes and axial sealing grooves (2-3) arranged axially along their axial through holes; the clamping block (1) is provided with two antenna leg through holes arranged coaxially with the "T"-shaped clamping sleeves (2): a first antenna leg through hole (1-7) and a second antenna leg through hole (2-7). 1-8), the diameter of the through holes of the two antenna legs can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna legs; the straight sections of the two "T"-shaped clamping sleeves (2) penetrate downward through the upper cover plate (5) and the upper magnet seat (6) respectively, and the lower surface of the flat end of the T-shaped clamping sleeve abuts against the upper surface of the upper cover plate; the clamping block (1) at the top of the two "T"-shaped clamping sleeves (2) is fixed to the upper cover plate (5) through which the two T-shaped clamping sleeves penetrate by screws, thereby forming a clamping device for a high-frequency negative hydrogen ion source immersion antenna.

2. The clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The diameter of the two antenna leg through holes can minimize the probability of high-frequency arcing or capacitive coupling discharge between the clamping block and the high-frequency antenna leg. Specifically, the diameter of the first antenna leg through hole (1-7) and the second antenna leg through hole (1-8) is not less than the outer diameter of the radial sealing groove (2-2) of the "T" shaped clamping sleeve.

3. The clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The two "T" shaped clamping sleeves (2) are processed using "T" shaped ceramic sleeves, wherein the inner diameter of the axial through hole (2-1) is greater than the maximum value of the outer diameter of the antenna coating (4-2) of the high-frequency antenna leg (4-1) and sufficient positive tolerance should be allowed.

4. The clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The clamping block (1) is made of 304 non-magnetic stainless steel, thereby avoiding the influence of the magnetic field on the permanent magnet array installed between the upper cover plate (5) and the upper magnet seat (6), while reducing the processing difficulty, controlling the workpiece cost, and obtaining high strength and durability.

5. A clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The flat end portion of the two "T"-shaped compression sleeves (2) is machined with radial sealing grooves (2-2) arranged radially along its axial through hole, that is: the radial sealing grooves (2-2) are machined on the axial through hole of the flat end portion.

6. A clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The flat end portion of the two "T"-shaped compression sleeves (2) is machined with an axial sealing groove (2-3) arranged along the axial through hole, that is, an annular axial sealing groove (2-3) is machined inward on the lower surface of the flat end portion.

7. A clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The radial sealing ring is an "X" shaped sealing ring, which is used to hold the antenna coating on the high-frequency antenna leg tightly through two sealing lips, and through its star-shaped cross-section, it ensures that the sealing ring itself will not roll when the antenna leg passes through the radial sealing ring, thereby affecting the vacuum sealing effect.

8. A clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The radial sealing ring is installed in the radial sealing groove (2-2), and the dimensions of the radial sealing ring and the radial sealing groove (2-2) are selected to match the outer diameter of the antenna coating (4-2).

9. A clamping device for a high-frequency negative hydrogen ion source immersion antenna according to claim 1, characterized in that: The axial sealing ring is installed in the axial sealing groove (2-3). The dimensions of the axial sealing ring and the axial sealing groove (2-3) are selected according to the outer diameter d of the straight section of the "T"-shaped compression sleeve (2) and the outer diameter D of the flat end of the "T"-shaped compression sleeve.

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