Preparation equipment of ultrahigh vacuum lanthanum hexaboride cathode

Abstract

The present application relates to a kind of preparation equipment of ultra-high vacuum lanthanum hexaboride cathode, belong to electrode manufacturing technical field, solve the problem of one of existing preparation equipment in single vacuum chamber to complete different processes to produce cross contamination, insufficient vacuum, cathode quality stability is poor and preparation efficiency is low.This application includes vacuum chamber and vacuum pumping system;Vacuum chamber includes powder room degassing baking chamber, cathode degassing baking chamber and transition pumping chamber;Powder room degassing baking chamber is used to form lanthanum hexaboride powder degassing sintering;Cathode degassing baking chamber is used to activate lanthanum hexaboride cathode degassing and;Powder room degassing baking chamber and cathode degassing baking chamber are communicated with transition pumping chamber;Vacuum pumping system provides ultra-high vacuum working environment for powder room degassing baking chamber and / or cathode degassing baking chamber.This application can carry out different preparation processes in chamber, improve the degassing effect of lanthanum hexaboride crystal, improve the quality of lanthanum hexaboride cathode and preparation efficiency.

Description

Technical Field

[0001] This invention relates to the field of electrode manufacturing technology, and in particular to an apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode. Background Technology

[0002] Lanthanum hexaboride (LaB6) is a core electrode material for high-end electronic devices and has been widely used in fields such as electron microscopes, vacuum electronic devices, electron beam lithography systems, electron accelerators, and ion sources.

[0003] Currently, the traditional thermal reduction method remains the most commonly used process for preparing lanthanum hexaboride cathodes. This involves mixing metallic lanthanum powder and boron powder, reacting them at high temperatures to synthesize lanthanum hexaboride powder, and then performing a series of processes including forming and sintering, processing, cathode sealing, cathode degassing, and activation to obtain the finished cathode. The powder forming, degassing, sintering, cathode degassing, and activation processes all need to be carried out in a vacuum environment. However, existing vacuum preparation equipment still has the following problems: First, the preparation equipment usually carries out the sintering process of lanthanum hexaboride powder and the cathode degassing and activation process in the same vacuum chamber. The gas residues generated by the different processes can cause cross-contamination of lanthanum hexaboride powder or cathode, resulting in cathode emission poisoning or contamination of cathode insulation components.

[0004] Secondly, the vacuum level of the preparation equipment is insufficient, making it impossible to completely remove the residual active gases within the vacuum chamber. During the high-temperature preparation process, the residual gases react with lanthanum hexaboride to generate impurities, reducing the purity of the electrode material. On the other hand, the residual gases trapped in the intergranular spaces of lanthanum hexaboride grains cannot escape after thermal expansion, forming high-pressure bubbles within the crystal, which disrupts the stability of the crystal structure. Ultimately, this leads to decreased conductivity, low electron emission efficiency, poor stability, and shortened lifespan of the cathode, failing to meet the requirements for long-term stable operation of electronic equipment and increasing equipment operating costs.

[0005] In addition, the existing preparation equipment has low efficiency. It generally takes several hours to more than ten hours or even longer to complete the preparation of a single lanthanum hexaboride cathode. Although plasma sintering can significantly shorten the sintering process time, the time for cathode degassing and activation cannot be compressed. Moreover, plasma sintering equipment is expensive, which increases the production cost of the cathode and limits the promotion and application of lanthanum hexaboride cathodes in the field of high-end electronic equipment. Summary of the Invention

[0006] Based on the above analysis, the present invention aims to provide an ultra-high vacuum lanthanum hexaboride cathode preparation apparatus to solve one of the problems of existing preparation equipment that easily leads to cross-contamination, insufficient vacuum, poor cathode quality stability, and low preparation efficiency when different processes are completed in a single vacuum chamber.

[0007] The objective of this invention is mainly achieved through the following technical solutions: An ultra-high vacuum lanthanum hexaboride cathode preparation apparatus includes a vacuum chamber and a vacuum pumping system; the vacuum chamber includes a powder degassing and baking chamber, a cathode degassing and baking chamber, and a transition pumping chamber; the powder degassing and baking chamber is used for shaping, degassing, and sintering lanthanum hexaboride powder; the cathode degassing and baking chamber is used for degassing and activating the lanthanum hexaboride cathode; both the powder degassing and baking chamber and the cathode degassing and baking chamber are connected to the transition pumping chamber; The vacuum pumping system is used to pump the powder chamber degassing baking chamber and / or the cathode degassing baking chamber to an ultra-high vacuum and maintain the ultra-high vacuum state. It also includes a cathode turntable assembly for mounting a lanthanum hexaboride cathode; the cathode turntable assembly is mounted on the cathode degassing and baking chamber; The cathode turntable assembly includes a cathode clamping device, which includes a first clamping block, a second clamping block, and a positioning element. The two mounting pins of the lanthanum hexaboride cathode are respectively fixed to the first clamping block and the second clamping block by the positioning element.

[0008] Furthermore, the cathode clamping device also includes a first spacer and a second spacer, and the first clamping block and the second clamping block are insulatedly connected through the first spacer and the second spacer.

[0009] Furthermore, the cathode turntable assembly also includes a multi-position tooling table, which is horizontally arranged at the center of the cathode degassing and baking chamber.

[0010] Furthermore, the multi-position tooling table includes copper plate groups, an insulating workpiece tray, and terminals; two sets of copper plate groups are arranged in parallel, and the insulating workpiece tray is installed between the two sets of copper plate groups; the two sets of copper plate groups and the insulating workpiece tray are fixedly connected by multiple terminals.

[0011] Furthermore, the insulating workpiece disk is provided with multiple rectangular notches; the two sets of copper plate groups and the multiple rectangular notches form multiple lanthanum hexaboride cathode mounting stations.

[0012] Furthermore, the copper plate assembly includes multiple concentric fan-shaped ring copper plates, and multiple terminals pass through conductive holes on the multiple fan-shaped ring copper plates to fix and connect the two copper plate assemblies and the insulating workpiece disk; the multiple terminals provide circuit connections for each lanthanum hexaboride cathode mounting station.

[0013] Furthermore, the vacuum pumping system includes a vacuum pump group, which includes a pre-pump, an auxiliary pump, and a main pump; the pre-pump, the auxiliary pump, and the main pump are all connected to the transition pumping chamber.

[0014] Furthermore, the vacuum pumping system also includes a station vacuum valve, which is used to separate different vacuum working areas; station vacuum valves are provided between the powder degassing and baking chamber and the transition pumping chamber, as well as between the cathode degassing and baking chamber and the transition pumping chamber.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. The ultra-high vacuum lanthanum hexaboride cathode preparation equipment of the present invention uses a powder chamber degassing and baking chamber to form, degas, and sinter lanthanum hexaboride powder, and a cathode degassing and baking chamber to degas and activate the lanthanum hexaboride cathode. By performing different preparation processes in separate chambers, cross-contamination is effectively reduced, and the preparation efficiency of the lanthanum hexaboride cathode is improved. The vacuum pumping system enables the ultimate vacuum degree of the vacuum chamber to reach 1×10⁻⁶. -8 Pa is used to effectively remove the residual active gas in the vacuum chamber and improve the degassing effect on the lanthanum hexaboride crystal, thereby improving the quality and stability of the lanthanum hexaboride cathode.

[0016] 2. The ultra-high vacuum lanthanum hexaboride cathode preparation equipment of the present invention allows the powder chamber degassing and baking chamber and the cathode degassing and baking chamber to work simultaneously or independently. When one working chamber needs to be evacuated or degassed, it does not affect the state of other working chambers, thus improving the preparation efficiency of the equipment. By using a multi-position tooling stage, multiple lanthanum hexaboride cathodes can be degassed and activated simultaneously, increasing the number of lanthanum hexaboride cathodes that can be produced simultaneously and further improving the preparation efficiency.

[0017] 3. The ultra-high vacuum lanthanum hexaboride cathode preparation equipment of the present invention simplifies the installation and disassembly of the lanthanum hexaboride cathode in the cathode degassing and baking chamber by detachably connecting the cathode clamping device to the multi-position tooling table; when the cathode clamping device is inserted into the lanthanum hexaboride cathode installation position, the two installation pins of the lanthanum hexaboride cathode are connected to the corresponding terminals, realizing plug-and-play, simplifying the power-on wiring operation of the lanthanum hexaboride cathode in the cathode degassing and baking chamber, making the installation or replacement of the lanthanum hexaboride cathode convenient and quick and saving operation time.

[0018] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the specification or be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained from the content specifically pointed out in the text and accompanying drawings. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. Figure 1 This is an overall structural diagram of the equipment for preparing the ultra-high vacuum lanthanum hexaboride cathode according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the vacuum pumping system and protective gas system according to an embodiment of the present invention; Figure 3 This is a structural diagram of the cathode turntable assembly and cathode lead system according to an embodiment of the present invention; Figure 4 This is an exploded view of the assembly of the cathode clamping device, the multi-position tooling stage, and the gas equalization component according to an embodiment of the present invention. Figure 5 The above view and partial cross-sectional view are of the cathode clamping device and the multi-position tooling stage according to an embodiment of the present invention. Figure 6 for Figure 5 A schematic diagram of the series connection of the lanthanum hexaboride cathode installation station, unfolded in the X direction; Figure 7 for Figure 5 FF sectional view; Figure 8 These are a top view and a partial sectional view of the positioning component in Embodiment 3 of the present invention; Figure 9 This is a schematic diagram of the positioning component structure in Embodiment 3 of the present invention; Figure 10 This is a cross-sectional view of the positioning component in Embodiment 3 of the present invention; Figure 11 This is a schematic diagram of the rotating positioning component structure in Embodiment 3 of the present invention.

[0020] Figure label: 1-Vacuum chamber; 11-Powder degassing and baking chamber; 12-Cathode degassing and baking chamber; 13-Transition evacuation chamber; 14-Operating port; 15-Observation window; 2-Cathode turntable assembly; 21-Cathode clamping device; 211-First clamping block; 212-Second clamping block; 213-First septum; 214-Second septum; 215-Positioning element; 2151-First spring plate; 2152-Second spring plate; 2153-Secondary clamping frame; 2154-Rotational positioning element; 21541-First clamping plate; 21542-Second clamping plate; 2155-Bracket; 22-Multi-position tooling table; 221-Copper plate assembly; 222-Insulated workpiece tray; 223-Terminal terminal; 23-Lifting and rotating mechanism; 231-Lifting assembly; 232-Rotating assembly; 24-Gas equalization component; 241-Ventilation rod; 242-Upper gas equalization component; 2421-Upper air outlet; 243-Lower gas equalization component; 2431-Lower air outlet; 244-Diffuser rod; 3-Cathode lead system; 31-Ceramic sealing terminal; 32-Lead; 4-Protective gas system; 41-Gas cylinder; 42-Flow controller; 5-Vacuum pumping system; 51-Vacuum pump set; 511-Pre-pump; 512-Auxiliary pump; 513-Main pump; 52-Station vacuum valve. Detailed Implementation

[0021] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] Example 1 To address the problem of cross-contamination that easily occurs when different processes are completed in a single vacuum chamber in existing preparation equipment, a specific embodiment of the present invention is as follows: Figure 1 As shown, an ultra-high vacuum lanthanum hexaboride cathode preparation apparatus is disclosed, including a vacuum chamber 1 and a vacuum pumping system 5. The vacuum chamber 1 provides a sealed working space and an ultra-high vacuum pumping channel for the preparation of the lanthanum hexaboride cathode. The vacuum pumping system 5 is used to provide an ultra-high vacuum working environment for the vacuum chamber 1. The vacuum chamber 1 includes a powder degassing and baking chamber 11, a cathode degassing and baking chamber 12, and a transition pumping chamber 13. The powder degassing and baking chamber 11 is used to form, degas, and sinter lanthanum hexaboride powder, sintering the lanthanum hexaboride powder into lanthanum hexaboride blocks. The cathode degassing and baking chamber 12 is used to degas and activate the lanthanum hexaboride cathode. Both the powder degassing and baking chamber 11 and the cathode degassing and baking chamber 12 are connected to the transition pumping chamber 13. By performing the sintering, degassing, and activation processes in the powder degassing and baking chamber 11 and the cathode degassing and baking chamber 12 respectively, the cross-contamination caused by gas residues generated in different processes is reduced.

[0023] It should be noted that lanthanum hexaboride powder is sintered to obtain lanthanum hexaboride bulk material, which is then mechanically processed and sealed with a cathode to obtain a lanthanum hexaboride cathode. After degassing and activation, the lanthanum hexaboride cathode becomes an applicable finished product.

[0024] Furthermore, to address the issues of insufficient vacuum in existing preparation equipment and poor quality stability of the lanthanum hexaboride cathode, such as... Figure 1 and Figure 2As shown, the vacuum pumping system 5 includes a vacuum pump group 51, which includes a pre-pump 511, an auxiliary pump 512, and a main pump 513. The pre-pump 511, auxiliary pump 512, and main pump 513 are all connected to the transition pumping chamber 13. The pre-pump 511 is used to perform rough vacuuming on the powder chamber degassing and baking chamber 11 and / or the cathode degassing and baking chamber 12. The auxiliary pump 512 is used to pump the powder chamber degassing and baking chamber 11 and / or the cathode degassing and baking chamber 12 to a high vacuum state, achieving a high vacuum level that meets the operating conditions of the main pump 513. The main pump 513 is used to pump the powder chamber degassing and baking chamber 11 and / or the cathode degassing and baking chamber 12 to an ultra-high vacuum state and maintain this ultra-high vacuum state. Through the staged vacuuming of the vacuum pumping system 5, the vacuum level of the preparation equipment is improved, enabling the ultimate vacuum level of the powder chamber degassing and baking chamber 11 and / or the cathode degassing and baking chamber 12 to reach 1×10⁻⁶. -8 The system is designed to effectively remove residual active gases from the powder degassing and baking chamber 11 and / or the cathode degassing and baking chamber 12, thereby improving the degassing effect on lanthanum hexaboride crystals and enhancing the finished product quality and stability of lanthanum hexaboride cathodes. Furthermore, the powder degassing and baking chamber 11 and the cathode degassing and baking chamber 12 share a single vacuum pumping system 5 to achieve an ultra-high vacuum working environment, thus reducing production costs.

[0025] Furthermore, the leakage rate of vacuum chamber 1 is ≤1×10⁻⁶. -10 Pa.m 3 / s.

[0026] Furthermore, to reduce contamination of the vacuum chamber 1 by the preparation equipment, the vacuum pump unit 51 adopts a clean, oil-free type of equipment.

[0027] Preferably, the pre-pump 511 is a dry pump; the auxiliary pump 512 is a molecular pump; and the main pump 513 is an ion pump.

[0028] Furthermore, to improve the preparation efficiency of the preparation equipment, such as... Figure 1 As shown, it also includes a cathode turntable assembly 2, which is used to install a lanthanum hexaboride cathode. The cathode turntable assembly 2 is installed on the cathode degassing and baking chamber 12.

[0029] like Figure 3As shown, the cathode turntable assembly 2 includes a multi-position tooling stage 22 and a lifting and rotating mechanism 23. The lifting and rotating mechanism 23 is vertically mounted on the cathode degassing and baking chamber 12. The multi-position tooling stage 22 is fixedly connected to the lifting and rotating mechanism 23. The lifting and rotating mechanism 23 is used to drive the multi-position tooling stage 22 to achieve up-and-down movement and rotational movement. The multi-position tooling stage 22 is horizontally set at the center of the cathode degassing and baking chamber 12. The multi-position tooling stage 22 has multiple lanthanum hexaboride cathode installation positions, so that the cathode degassing and baking chamber 12 can simultaneously degas and activate multiple lanthanum hexaboride cathodes. The multi-position tooling stage 22 increases the number of lanthanum hexaboride cathodes prepared simultaneously, thereby improving the efficiency of lanthanum hexaboride cathode preparation.

[0030] Furthermore, such as Figure 3 and Figure 5 As shown, the multi-position tooling stage 22 in this embodiment has four lanthanum hexaboride cathode mounting stations, which are denoted as A, B, C and D.

[0031] It should be noted that the lanthanum hexaboride cathode includes a cathode body, mounting pins, and discharge pins; the cathode body is a cylinder, and the mounting pins and discharge pins are respectively vertically arranged on the two end faces of the cathode body; there are two mounting pins and two discharge pins.

[0032] Furthermore, in order to solve the problem of cumbersome installation of lanthanum hexaboride cathodes, such as... Figure 4 and Figure 5 As shown, the cathode turntable assembly 2 also includes a cathode clamping device 21, which is used to fix the lanthanum hexaboride cathode. The cathode clamping device 21 includes a first clamping block 211, a second clamping block 212, and a positioning member 215. The first clamping block 211 and the second clamping block 212 are both provided with mounting through holes. The two mounting pins of the lanthanum hexaboride cathode are respectively inserted into the mounting through holes on the first clamping block 211 and the second clamping block 212. The two mounting pins are respectively fixed on the first clamping block 211 and the second clamping block 212 by the positioning member 215.

[0033] For example, the positioning member 215 in this embodiment is a threaded fastener; both the first clamping block 211 and the second clamping block 212 are provided with positioning holes perpendicular to the mounting through hole, and the positioning member 215 abuts against the mounting pin through the positioning hole and fixes the position of the mounting pin.

[0034] The cathode clamping device 21 also includes a first spacer 213 and a second spacer 214; the first spacer 213 is disposed between the first clamping block 211 and the second clamping block 212, and the second spacer 214 is disposed in the inner hole of the second clamping block 212. The first clamping block 211, the second clamping block 212, the first spacer 213 and the second spacer 214 are fixedly connected, and a gap is left between the first clamping block 211 and the second clamping block 212 through the first spacer 213.

[0035] Furthermore, the first clamping block 211 and the second clamping block 212 are made of conductive metal material; the first spacer 213 and the second spacer 214 are made of ceramic insulating material; the first clamping block 211 and the second clamping block 212 are insulatedly connected through the first spacer 213 and the second spacer 214, so that there is no conductivity between the two mounting pins of the lanthanum hexaboride cathode.

[0036] The cathode clamping device 21 is detachably connected to the multi-position tooling table 22. After the lanthanum hexaboride cathode is installed on the cathode clamping device 21, the cathode clamping device 21 can be inserted into the corresponding lanthanum hexaboride cathode installation position of the multi-position tooling table 22, or removed from the lanthanum hexaboride cathode installation position. This simplifies the installation and disassembly of the lanthanum hexaboride cathode in the cathode degassing and baking chamber 12, making the installation or replacement of the lanthanum hexaboride cathode convenient, quick, and time-saving.

[0037] Furthermore, the number of cathode clamping devices 21 is determined based on the number of lanthanum hexaboride cathode installation stations on the multi-position tooling table 22 and the production requirements of lanthanum hexaboride cathodes. In this embodiment, four sets of cathode clamping devices 21 can be installed simultaneously on a multi-position tooling table 22; by setting multiple sets of reserved cathode clamping devices 21, the lanthanum hexaboride cathode can be quickly replaced to meet the needs of continuous production.

[0038] Furthermore, in order to solve the problem of the cumbersome wiring operation for energizing multiple cathodes, such as Figure 4 and Figure 7 As shown, the multi-position tooling table 22 includes a copper plate group 221, an insulating workpiece tray 222, and terminal blocks 223. The copper plate group 221 includes multiple concentric fan-shaped copper plates with gaps between adjacent fan-shaped copper plates. Conductive holes are provided on the fan-shaped copper plates. Two sets of copper plate groups 221 are arranged in parallel, and the insulating workpiece tray 222 is installed between the two sets of copper plate groups 221. Multiple terminal blocks 223 pass through the conductive holes on the multiple fan-shaped copper plates to fix the two sets of copper plate groups 221 and the insulating workpiece tray 222. The multiple terminal blocks 223 provide circuit connections for each lanthanum hexaboride cathode installation position.

[0039] Furthermore, the number of sector-shaped ring copper plates in a group of copper plates 221 is one more than the number of lanthanum hexaboride cathode mounting positions; such as Figure 5 As shown, in this embodiment, a set of copper plates 221 is provided with five fan-shaped ring copper plates, and corresponding terminals 223 are also provided with five terminals, the positions of each terminal 223 are denoted as a, b, c, d and e.

[0040] like Figure 4 and Figure 5As shown, the insulating workpiece disk 222 has a flat plate structure. Multiple rectangular notches are provided on the outer periphery of the insulating workpiece disk 222. The positions of the multiple rectangular notches correspond to the gap positions between multiple fan-shaped copper plates. When the copper plate group 221 and the insulating workpiece disk 222 are installed together, the multiple rectangular notches on the two copper plate groups 221 and the insulating workpiece disk 222 form multiple lanthanum hexaboride cathode installation positions. In use, the cathode clamping device 21 is inserted into the rectangular notch on the insulating workpiece disk 222. The two copper plate groups 221 clamp and fix the cathode clamping device 21, thus realizing the installation of the cathode clamping device 21 on the multi-position tooling table 22.

[0041] The gap between two adjacent sector-shaped copper ring plates is larger than the gap between the first clamping block 211 and the second clamping block 212, but smaller than the size of the rectangular notch on the insulating workpiece disk 222; thus, the upper and lower sector-shaped copper ring plates contact the first clamping block 211 and the second clamping block 212 of the two adjacent lanthanum hexaboride cathode mounting positions to form a conductive path, such as... Figure 6 As shown, the four lanthanum hexaboride cathodes at mounting stations A, B, C, and D are connected in series; thus, multiple terminals 223 can be used to individually or simultaneously energize the multiple lanthanum hexaboride cathodes, ultimately enabling the multiple lanthanum hexaboride cathodes to be degassed and activated individually or synchronously.

[0042] Furthermore, to solve the sealing problem of power supply introduction into the ultra-high vacuum environment, such as... Figure 3 and Figure 5 As shown, it also includes a cathode lead system 3, which includes a ceramic sealing terminal block 31 and a lead 32; the ceramic sealing terminal block 31 is used to connect an external power supply to the ultra-high vacuum environment of the cathode degassing baking chamber 12; the ceramic sealing terminal block 31 is sealed and installed on the cathode degassing baking chamber 12; the ceramic sealing terminal block 31 includes multiple terminals, and the multiple terminals are connected one-to-one with multiple terminals 223 through the lead 32.

[0043] Once the cathode clamping device 21 is inserted into the lanthanum hexaboride cathode mounting station, it connects the two mounting pins of the lanthanum hexaboride cathode to the corresponding terminals 223, and connects it to an external power supply through the cathode lead system 3. This achieves plug-and-play functionality, simplifies the power-on wiring operation of the lanthanum hexaboride cathode in the cathode degassing and baking chamber 12, and further improves the efficiency of lanthanum hexaboride cathode preparation.

[0044] Furthermore, in this embodiment, a multi-channel constant current power supply is used to power the lanthanum hexaboride cathode.

[0045] Furthermore, the insulating workpiece disc 222 is made of ceramic insulating material.

[0046] Furthermore, in order to solve the problem of difficulty in adjusting the position of the multi-position tooling table 22, such as Figure 3 As shown, the lifting and rotating mechanism 23 includes a lifting component 231 and a rotating component 232. The lifting component 231 is used to drive the multi-position tooling table 22 to move up and down, and the rotating component 232 is used to drive the multi-position tooling table 22 to rotate. The lifting and rotating mechanism 23 can adjust the position of the multi-position tooling table 22 in the vertical and circumferential directions to facilitate the installation and removal of the lanthanum hexaboride cathode on the multi-position tooling table 22.

[0047] Furthermore, the rotating assembly 232 includes a rotating drive and a rotating rod, the rotating drive providing a driving force for the rotation of the rotating rod; the rotating drive, the rotating rod, and the cathode degassing baking chamber 12 are coaxially arranged.

[0048] Furthermore, the lifting assembly 231 and the rotating assembly 232 are arranged in parallel; the lifting assembly 231 includes a lifting drive component, a lead screw, a fixed frame, and a lifting connecting plate. The lifting drive component and the lead screw are mounted on the fixed frame, and the fixed frame is fixedly connected to the sealing flange of the mounting hole above the cathode degassing baking chamber 12; the lifting drive component is connected to the lead screw and is arranged vertically and coaxially; the lifting connecting plate is sleeved on the lead screw and fixedly connected to the rotating drive component. The lead screw is driven to rotate by the lifting drive component, thereby driving the lifting connecting plate and the rotating drive component to move up and down synchronously.

[0049] Furthermore, the rotating assembly 232 employs a magnetohydrodynamic rotary seal, which improves the sealing reliability and service life in ultra-high vacuum environments.

[0050] Furthermore, to further improve the lifespan and operational efficiency of the preparation equipment, such as... Figure 1 As shown, both the powder chamber degassing baking chamber 11 and the cathode degassing baking chamber 12 are equipped with an operation port 14 and an observation window 15. The operation port 14 provides a channel for manual operation inside the powder chamber degassing baking chamber 11 and / or the cathode degassing baking chamber 12, while the observation window 15 is used to observe the working conditions inside the powder chamber degassing baking chamber 11 and / or the cathode degassing baking chamber 12 under ultra-high vacuum conditions. The observation window 15 is fixedly installed, and the operation port 14 uses an ultra-high vacuum valve that can quickly complete the opening and closing action without repeated disassembly and assembly. Compared with the structure where operation and observation are carried out through a single window, the operation port 14 and the observation window 15 can achieve operation and observation without interference, and can reduce the impact of repeated disassembly and assembly on the ultra-high vacuum sealing of the powder chamber degassing baking chamber 11 and / or the cathode degassing baking chamber 12, thereby improving the service life of the preparation equipment and the efficiency of operation.

[0051] Furthermore, to improve the preparation efficiency of the preparation equipment, the vacuum pumping system 5 also includes a station vacuum valve 52, which is used to separate different vacuum working areas; a station vacuum valve 52 is provided between the powder chamber degassing and baking chamber 11 and the transition pumping chamber 13; a station vacuum valve 52 is provided between the cathode degassing and baking chamber 12 and the transition pumping chamber 13, so that the powder chamber degassing and baking chamber 11 and the cathode degassing and baking chamber 12 can work simultaneously or independently; when one of the working chambers needs to be evacuated or ventilated, it does not affect the state of other working chambers, thereby improving the preparation efficiency of the preparation equipment.

[0052] Furthermore, there are two cathode degassing and baking chambers 12, which can work independently or simultaneously, further improving the preparation efficiency of the preparation equipment.

[0053] Furthermore, to address the issue of the long time required to restore the ultra-high vacuum environment after cavitation failure, which affects preparation efficiency, a pre-evacuation bypass and a bypass valve (not shown in the figure) are respectively installed between the powder chamber degassing and baking chamber 11 and the cathode degassing and baking chamber 12 and the pre-evacuation pump 511. When one of the working chambers needs to be restored to an ultra-high vacuum environment after cavitation failure, the pre-evacuation pump 511 performs rough evacuation of the working chamber through the pre-evacuation bypass. When the vacuum level of the chamber reaches the opening pressure difference of the corresponding station vacuum valve 52, the station vacuum valve 52 of the chamber opens and connects to the transition evacuation chamber 13. The chamber is then evacuated to an ultra-high vacuum state through the auxiliary pump 512 and the main pump 513.

[0054] By independently completing the processes of lanthanum hexaboride powder forming, degassing and sintering, and cathode degassing and activation in separate chambers under ultra-high vacuum, the next batch of lanthanum hexaboride powder can be formed, degassed and sintered while multiple cathodes in one batch are being degassed and activated. This saves time between batches and improves the efficiency of the preparation process.

[0055] Example 2 To address the problem of poor quality stability of lanthanum hexaboride cathodes, another specific embodiment of the present invention, such as... Figure 2 and Figure 3 As shown, based on Embodiment 1, a protective gas system 4 is also included; the cathode turntable assembly 2 also includes a gas equalization assembly 24, which is vertically installed at the bottom of the rotating rod of the rotating assembly 232; the gas equalization assembly 24 is used to fix the multi-position tooling stage 22 on one hand, and to connect to the protective gas provided by the protective gas system 4 on the other hand, and to blow the protective gas evenly around the lanthanum hexaboride cathode; the protective gas is used to prevent the lanthanum hexaboride cathode from being oxidized during degassing and activation, and to create a stable discharge environment for the lanthanum hexaboride cathode, thereby improving the stability of the lanthanum hexaboride cathode quality.

[0056] like Figure 4 and Figure 7 As shown, the gas equalization assembly 24 includes a venting rod 241, an upper gas equalization component 242, and a lower gas equalization component 243. The top end of the venting rod 241 is fixedly connected to the bottom end of the rotating rod of the rotating assembly 232. The venting rod 241, the upper gas equalization component 242, and the lower gas equalization component 243 are coaxially arranged and fixedly connected in sequence along the axial direction. The venting rod 241, the upper gas equalization component 242, and the lower gas equalization component 243 are interconnected to form a protective gas passage, and the venting rod 241 is connected to an external protective gas pipeline. The upper gas equalization component 242 is provided with multiple radial upper vent holes 2421, which correspond to the installation position direction of the lanthanum hexaboride cathode. The protective gas is blown to one side of the installation pin of the lanthanum hexaboride cathode through the multiple upper vent holes 2421, which can reduce the oxidation of the lanthanum hexaboride cathode.

[0057] like Figure 4 and Figure 7 As shown, the lower gas equalizer 243 includes a straight cylindrical section and a hemispherical section; the insulating workpiece disk 222 is sleeved on the outside of the upper gas equalizer 242 and placed on the upper surface of the straight cylindrical section of the lower gas equalizer 243, and the insulating workpiece disk 222 is fixedly connected to the lower gas equalizer 243; the hemispherical section of the lower gas equalizer 243 is a hollow hemispherical shell, and the open end of the hemispherical section is fixedly connected to the lower surface of the straight cylindrical section. The hemispherical section is provided with multiple lower gas outlet holes 2431, and the protective gas is blown to the discharge pin side of the lanthanum hexaboride cathode through the multiple lower gas outlet holes 2431, which can improve the stability of the discharge environment of the lanthanum hexaboride cathode.

[0058] Furthermore, the insulating workpiece disk 222 is provided with horizontal vent holes in the direction corresponding to the lanthanum hexaboride cathode installation position, and the upper vent holes 2421 are provided in two rows, with the lower row of upper vent holes 2421 corresponding to the vent holes of the insulating workpiece disk 222, so that the protective gas is blown from the vent holes to the lanthanum hexaboride cathode in the corresponding lanthanum hexaboride cathode installation position.

[0059] Furthermore, when the vacuum pumping system 5 maintains an ultra-high vacuum environment in the cathode degassing and baking chamber 12, the amount of protective gas dynamically injected instantaneously from the upper outlet 2421 and lower outlet 2431 near or facing the ultra-high vacuum pumping direction is greater than the amount injected away from or away from the ultra-high vacuum pumping direction. To solve the problem of uneven injection of protective gas in multiple directions, such as... Figure 7 As shown, the gas equalization assembly 24 also includes a diffuser rod 244, which is vertically disposed in the axial center hole of the upper gas equalization component 242 and the lower gas equalization component 243. The diffuser rod 244 is used to divide the protective gas passage in the upper gas equalization component 242 and the lower gas equalization component 243 into multiple directional branches, so that the protective gas diffuses and is blown out from the corresponding upper outlet hole 2421 and lower outlet hole 2431 along the branch, thereby improving the uniformity of the instantaneous dynamic injection amount of the protective gas in multiple lanthanum hexaboride cathode installation positions.

[0060] Furthermore, such as Figure 4 As shown, the diffuser rod 244 is a cylindrical hollow rod. Multiple continuous ribs are provided on the outer cylindrical surface of the diffuser rod 244 along the circumference radially. The ribs abut against the inner wall of the axial central hole of the straight cylindrical section of the upper gas equalizer 242 and the lower gas equalizer 243, and the protective gas passage is separated by the ribs.

[0061] Furthermore, such as Figure 7 As shown, a flange is also provided on the outer cylindrical surface of the diffuser rod 244. The outer surface of the flange is engaged with the axial center hole of the straight cylindrical section of the lower gas equalizer 243. The flange separates the protective gas passages of the upper air outlet 2421 and the lower air outlet 2431. The protective gas is blown out from the lower air outlet 2431 through the axial center hole of the diffuser rod 244.

[0062] The protective gas path is diffused through the diffuser rod 244 in different lanthanum hexaboride cathode mounting positions, as well as in the mounting pin and discharge pin directions of the lanthanum hexaboride cathode, thereby improving the uniformity of the protective gas around the lanthanum hexaboride cathode.

[0063] Furthermore, to address the challenge of balancing the uniformity of the instantaneous injection volume and the uniformity of the steady-state density distribution of the protective gas, the installation direction of the lanthanum hexaboride cathode on the multi-position tooling stage 22 is not aligned with the ultra-high vacuum evacuation port. Consequently, the outlets of the upper gas equalizer 242 and the lower gas equalizer 243 do not directly face the ultra-high vacuum evacuation port. The lower outlet 2431 of the lower gas equalizer 243 is inclined and faces the lanthanum hexaboride cathode. The diameter of the outlet on the side closer to the ultra-high vacuum evacuation port is smaller than that on the other sides. This further improves the uniformity of the instantaneous injection volume and the steady-state density distribution of the protective gas under ultra-high vacuum conditions.

[0064] Furthermore, to address the challenge of balancing the amount of protective gas required in a stable discharge environment with maintaining ultra-high vacuum purity, such as... Figure 2 As shown, the protective gas system 4 includes a gas cylinder 41 and a flow controller 42. The flow controller 42 is used to control the flow rate of the protective gas released from the gas cylinder 41. By improving the accuracy of the control of the amount of protective gas charged, the stability of the lanthanum hexaboride cathode discharge environment can be improved without compromising the purity of the ultra-high vacuum.

[0065] Furthermore, in this embodiment, the preferred protective gas is argon (Ar).

[0066] Example 3 To address the issues of poor compatibility and cumbersome installation of lanthanum hexaboride cathodes of different sizes, based on Example 1, another specific embodiment of the present invention is as follows: Figure 8 and Figure 9As shown, the structures of the first clamping block 211, the second clamping block 212, and the positioning member 215 in the cathode clamping device 21 of Embodiment 1 are replaced.

[0067] Furthermore, the positioning element 215 is provided in two sets, the two sets of positioning elements 215 have the same structure, and are respectively installed on the first clamping block 211 and the second clamping block 212.

[0068] Furthermore, to accommodate adjustments to the distance between the two mounting pins of the lanthanum hexaboride cathode, such as... Figure 8 As shown, both the first clamping block 211 and the second clamping block 212 in this embodiment 3 are provided with U-shaped mounting grooves. When the first clamping block 211 and the second clamping block 212 are connected and fixed together, the two U-shaped mounting grooves are arranged on the same straight line and have opposite opening directions. The positioning member 215 is installed in the U-shaped mounting groove, and the two mounting pins of the lanthanum hexaboride cathode are fixed on the first clamping block 211 and the second clamping block 212 by two sets of positioning members 215.

[0069] Furthermore, to address the cumbersome installation of lanthanum hexaboride cathodes, such as... Figure 9 and Figure 10 As shown, the positioning component 215 includes a first spring plate 2151, which has a single-arched structure. Two first spring plates 2151 are symmetrically installed on the two side walls of the U-shaped mounting groove, and the two first spring plates 2151 protrude from the U-shaped mounting groove. The arc apex generatrix of the two first spring plates 2151 is horizontally set. When the mounting pin is inserted into the U-shaped mounting groove, it will squeeze the first spring plate 2151, and the elastic squeezing force of the first spring plate 2151 will fix the mounting pin in the U-shaped mounting groove. Through the U-shaped mounting groove, when the distance between the two mounting pins of the lanthanum hexaboride cathode is adjusted, it can still be installed on the first clamping block 211 and the second clamping block 212. The first spring plate 2151 improves the convenience of installing the lanthanum hexaboride cathode.

[0070] Furthermore, to accommodate the diameter range adjustment of the two mounting pins of the lanthanum hexaboride cathode, such as... Figure 9 and Figure 10As shown, the positioning component 215 also includes a second spring plate 2152 and a secondary clamping frame 2153. The secondary clamping frame 2153 has a U-shaped shell structure and can slide vertically within the U-shaped mounting groove. The second spring plate 2152 has the same structure as the first spring plate 2151. Two second spring plates 2152 are provided and are respectively installed on the inner side walls of the secondary clamping frame 2153. When the diameter of the two mounting pins of the lanthanum hexaboride cathode is smaller than the distance between the arc apex generatrices of the two first spring plates 2151, the mounting pins are clamped by the secondary clamping frame 2153 and the second spring plate 2152, thereby enabling the positioning component 215 to clamp mounting pins of different diameters and improving the applicability of the cathode clamping device 21.

[0071] Furthermore, to address the cumbersome installation and removal of the secondary clamping bracket 2153 within the U-shaped mounting slot, such as... Figure 10 As shown, the bottom surface of the secondary clamping frame 2153 is open and the top surface is provided with a sealing plate. The positioning component 215 also includes a rotating positioning component 2154 and a bracket 2155. The rotating positioning component 2154 forms a rotatable connection with the sealing plate of the secondary clamping frame 2153. The rotating positioning component 2154 is used to drive the secondary clamping frame 2153 to move up and down in the U-shaped mounting groove and to fix the secondary clamping frame 2153 in its working position or placement position.

[0072] It should be noted that, as Figure 10 As shown, when the secondary clamping frame 2153 is inserted into the U-shaped groove of the first clamping block 211 and / or the second clamping block 212, and the bottom end of the secondary clamping frame 2153 is flush with the bottom surface of the first clamping block 211 and / or the second clamping block 212, this is the working position of the secondary clamping frame 2153; Figure 9 As shown, the secondary clamp 2153 is in the placement position when it is raised, and the bracket 2155 is used to fix the secondary clamp 2153 in the placement position.

[0073] like Figure 11 As shown, the rotating positioning component 2154 includes a first clamping plate 21541 and a second clamping plate 21542; the first clamping plate 21541 is disposed between the sealing plate of the secondary clamping frame 2153 and the second clamping plate 21542; the first clamping plate 21541 and the second clamping plate 21542 are cuboid structures and are arranged perpendicular to each other.

[0074] In this embodiment 3, as Figure 10 and Figure 11As shown, when the secondary clamping frame 2153 enters the working position, the first clamping plate 21541 also enters the U-shaped mounting groove. When the second clamping plate 21542 contacts the top surface of the first clamping block 211 and / or the second clamping block 212, the secondary clamping frame 2153 reaches the working position. The second clamping plate 21542 is rotated 90 degrees, thereby driving the first clamping plate 21541 to rotate 90 degrees, so that the first clamping plate 21541 is engaged in the positioning groove of the first clamping block 211 and / or the second clamping block 212, thereby fixing the secondary clamping frame 2153 in the working position.

[0075] like Figure 9 and Figure 11 As shown, when the secondary clamping frame 2153 needs to be removed and placed in the placement position, the second clamping plate 21542 is rotated 90 degrees and pulled, and the first clamping plate 21541 and the secondary clamping frame 2153 are pulled upward in the vertical direction. When the first clamping plate 21541 contacts the bracket 2155, the secondary clamping frame 2153 reaches the placement position. The second clamping plate 21542 has slots at both ends. When the second clamping plate 21542 is rotated 90 degrees, the slots are engaged with the corresponding positioning plates of the bracket 2155, thereby fixing the secondary clamping frame 2153 in the placement position.

[0076] The positioning element 215 and the first clamping block 211 and the second clamping block 212 with U-shaped mounting grooves in this embodiment 3 enable the cathode clamping device 21 to install lanthanum hexaboride cathodes of different sizes, increasing the adaptability of the preparation equipment to the size of lanthanum hexaboride cathodes and improving the ease of installation.

[0077] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for preparing an ultra-high vacuum lanthanum hexaboride cathode, characterized in that, It includes a vacuum chamber (1) and a vacuum pumping system (5); the vacuum chamber (1) includes a powder degassing and baking chamber (11), a cathode degassing and baking chamber (12), and a transition pumping chamber (13); the powder degassing and baking chamber (11) is used for shaping, degassing, and sintering lanthanum hexaboride powder; the cathode degassing and baking chamber (12) is used for degassing and activating the lanthanum hexaboride cathode; both the powder degassing and baking chamber (11) and the cathode degassing and baking chamber (12) are connected to the transition pumping chamber (13); The vacuum pumping system (5) is used to pump the powder chamber degassing baking chamber (11) and / or the cathode degassing baking chamber (12) to an ultra-high vacuum and maintain the ultra-high vacuum state. It also includes a cathode turntable assembly (2), which is used to install a lanthanum hexaboride cathode; the cathode turntable assembly (2) is installed on the cathode degassing and baking chamber (12); The cathode turntable assembly (2) includes a cathode clamping device (21), which includes a first clamping block (211), a second clamping block (212), and a positioning element (215). The two mounting pins of the lanthanum hexaboride cathode are respectively fixed to the first clamping block (211) and the second clamping block (212) by the positioning element (215).

2. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to claim 1, characterized in that, The cathode clamping device (21) further includes a first septum (213) and a second septum (214), and the first clamping block (211) and the second clamping block (212) are insulatedly connected through the first septum (213) and the second septum (214).

3. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to claim 1 or 2, characterized in that, The cathode turntable assembly (2) also includes a multi-position tooling table (22), which is horizontally arranged at the center of the cathode degassing and baking chamber (12).

4. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to claim 3, characterized in that, The multi-position tooling table (22) includes a copper plate group (221), an insulating workpiece tray (222), and terminals (223); two sets of copper plate groups (221) are arranged in parallel, and the insulating workpiece tray (222) is installed between the two sets of copper plate groups (221); the two sets of copper plate groups (221) and the insulating workpiece tray (222) are fixedly connected by multiple terminals (223).

5. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to claim 4, characterized in that, The insulating workpiece disk (222) has multiple rectangular notches; the two sets of copper plate groups (221) and the multiple rectangular notches form multiple lanthanum hexaboride cathode mounting stations.

6. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to claim 4 or 5, characterized in that, The copper plate assembly (221) includes multiple concentric fan-shaped ring copper plates. Multiple terminals (223) pass through conductive holes on the multiple fan-shaped ring copper plates to fix the two copper plate assemblies (221) and the insulating workpiece disk (222) in place. The multiple terminals (223) provide circuit connections for each lanthanum hexaboride cathode mounting station.

7. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to any one of claims 1-2 and 4-5, characterized in that, The vacuum pumping system (5) includes a vacuum pump group (51), which includes a pre-pump (511), an auxiliary pump (512), and a main pump (513); the pre-pump (511), the auxiliary pump (512), and the main pump (513) are all connected to the transition pumping chamber (13).

8. The apparatus for preparing an ultra-high vacuum lanthanum hexaboride cathode according to any one of claims 1-2 and 4-5, characterized in that, The vacuum pumping system (5) also includes a station vacuum valve (52), which is used to separate different vacuum working areas; a station vacuum valve (52) is provided between the powder chamber degassing baking chamber (11) and the transition pumping chamber (13) and between the cathode degassing baking chamber (12) and the transition pumping chamber (13).

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