Surface synergistic treatment and three-dimensional arrangement based dynode electron multiplier and method

Abstract

The application discloses a kind of based on surface synergistic treatment and three-dimensional arrangement's punch electrode electron multiplier and method, belong to vacuum electron device field;Including in three-dimensional space through three kinds of connection unit combination arrangement of same direction connection type, vertical connection type and reverse connection type multistage box grid type punch electrode, form three-dimensional serpentine electron multiplication channel;Each level punch electrode surface is outward from base in turn provided with mechanical fine polishing layer, electroplating full bright nickel layer and high-temperature hydrogen purification layer, and the multilayer composite film of titanium primer layer, silver conductive layer and magnesium oxide emission layer deposited in turn by magnetron sputtering;Including fine polishing, electroplating full bright nickel, high-temperature hydrogen purification, magnetron sputtering deposition multilayer film and three-dimensional assembly etc.;Through three-dimensional arrangement, electron is accurately focused in punch electrode central target area, simultaneously surface synergistic treatment makes the target area have optimal secondary electron emission performance, structure optimization and material performance precision match produce synergistic gain effect.

Description

Technical Field

[0001] This invention belongs to the field of vacuum electronic device technology, specifically relating to a separate duracell electron multiplier, and more particularly to a technical solution and its preparation method that improves the secondary electron emission performance of the duracells by arranging them in a three-dimensional space and simultaneously performing synergistic treatment on the duracell surfaces to enhance their secondary electron emission performance, thereby achieving an order-of-magnitude increase in the overall gain of the device. Background Technology

[0002] When an initial electron with a certain energy bombards a solid material, the incident electron is inelastically scattered inside the material, thereby exciting the electrons inside the material to form internal secondary electrons with a certain energy distribution. Some of the internal secondary electrons move towards the surface. During the movement, they interact with the solid and lose some energy. When they reach the surface, some electrons overcome the surface potential barrier and escape from the surface to become secondary electrons. This process is called secondary electron emission.

[0003] An electron multiplier is a core vacuum device that uses the secondary electron emission effect to linearly amplify weak electron (or ion) signals by a high factor, typically achieving a gain of up to 10. 6 ~10 8 It is not only the "heart" of scientific instruments such as mass spectrometers and residual gas analyzers, but also a key component involved in the detection of weak signals, such as rubidium atomic clocks, photomultiplier tubes, and microchannel plate image intensifiers. It plays an irreplaceable role in fields such as space exploration, national defense and security, environmental monitoring, and life sciences.

[0004] Separate tampon electron multipliers are the most widely used type of multiplier due to their comprehensive advantages such as high gain, wide dynamic range, strong anti-saturation capability, and long lifespan. Their working principle is as follows: In a vacuum, initial electrons (or ions) accelerated by an electric field bombard the secondary electron emitter on the surface of the first-stage tampon, exciting a multiplied number of secondary electrons. These secondary electrons, under the influence of the inter-electrode electric field, fly towards and bombard the second-stage tampon, exciting even more electrons. This process is cascaded between dozens of tampon stages, ultimately outputting a current signal amplified tens of thousands or even millions of times by the collecting electrode. Summary of the Invention

[0005] The purpose of this invention is to provide a darad electron multiplier based on surface synergistic processing and three-dimensional arrangement and its gain enhancement method, so as to solve the bottlenecks existing in the prior art and systematically and synergistically improve the total gain of the electron multiplier.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A dynamo electron multiplier, comprising: The cathode plate is arranged in a three-dimensional space with multiple levels of cathodes. Each level of cathodes adopts a box grid structure with a square grid and the arc radius of the cathode plate is equal to the height of the cathode plate. The multi-stage electrodes are combined and connected in three-dimensional space through at least one of the three basic connection units: co-directional connection, vertical connection, and reverse connection, forming a three-dimensional serpentine electron multiplication channel. Along the electron multiplication channel, the cathode plate and / or upper and lower baffles of each stage of the daddy electrode are sequentially provided from the substrate outward with: a mechanically finely polished layer, an electroplated bright nickel layer, a high-temperature hydrogen burning purification layer, and a multilayer composite film consisting of a titanium substrate, a silver conductive layer, and a magnesium oxide emitting layer deposited sequentially by magnetron sputtering.

[0007] As a further preferred embodiment of the electron multiplier of the present invention, the thickness of the electroplated bright nickel layer is 0.5~2 μm; the thickness of the titanium underlayer is 40~60 nm; the thickness of the silver conductive layer is 250~350 nm; the thickness of the magnesium oxide emitting layer is 700~900 nm; and the surface roughness Ra of the mechanically finely polished layer is less than 0.1 μm.

[0008] As a further preferred embodiment of the electron multiplier of the present invention, the three-dimensional arrangement of the multi-stage dats in three-dimensional space makes the spatial equivalent distance d2 between two adjacent dats greater than the planar geometric distance d1, thereby reducing the electric field disturbance of the lower-stage dats on the outlet region of the upper-stage dats, causing the electric field lines to converge longitudinally, and the single-stage average electron collection efficiency η reaches more than 98.9%.

[0009] As a further preferred embodiment of the electron multiplier of the present invention, the electron multiplier has a seven-stage structure and a total gain of 1.25 × 10⁻⁶ at a total operating voltage of 1800 V. 6 above.

[0010] A method for fabricating a darad electron multiplier includes the following steps: Step 1: Perform mechanical fine polishing on the cathode plate, upper baffle and lower baffle of the electrode to make its surface roughness Ra less than 0.1 μm; Step 2: Perform ultrasonic deep cleaning and degreasing on the polished parts; Step 3: Electroplating the cleaned parts with bright nickel plating to obtain a nickel plating layer with a thickness of 0.5~2 μm on the surface of the parts; Step 4: The nickel-plated parts are subjected to high-temperature hydrogen burning treatment in a protective atmosphere of 800~1000°C to obtain an active surface with atomic-level cleanliness. Step 5: Load the components treated with high-temperature hydrogen burning into the magnetron sputtering equipment and evacuate to a back vacuum level of 4.0 × 10⁻⁶.-5 Below Pa, heat to 350~450°C and hold at that temperature; Step 6: Introduce argon gas and turn on the bias power supply to perform glow discharge plasma cleaning on the surface of the component. Step 7: Using magnetron sputtering technology, titanium film, silver film and magnesium oxide film are sequentially deposited on the surface of the component to form a multilayer composite secondary electron emission film; Step 8: After deposition, the darad electrode is arranged and assembled in three dimensions with the ceramic plate, focusing electrode, transition element and collecting electrode to form a three-dimensional serpentine electron multiplication channel of the multi-stage darad electrode. Step 9: Weld the voltage divider resistor network and vacuum encapsulate it to obtain the finished electron multiplier.

[0011] As a further preferred embodiment of the preparation method of the electron multiplier of the present invention, the mechanical fine polishing in step 1 is performed using a sisal wheel or a cloth wheel, and the polishing time is 20-30 minutes. After polishing, the surface roughness Ra is stable between 0.06 and 0.09 μm.

[0012] As a further preferred embodiment of the preparation method of the electron multiplier of the present invention, the electroplating of bright nickel in step 3 uses a Watt-type nickel plating solution with a current density of 2~5 A / dm², a temperature of 50~60°C, and an electroplating time of 3~5 minutes.

[0013] As a further preferred embodiment of the preparation method of the electron multiplier of the present invention, the specific process of the high-temperature hydrogen burning treatment in step 4 is as follows: first, the air in the furnace tube is purged with high-purity nitrogen or hydrogen, then the temperature is raised to 900-1000°C at a heating rate of 8-12°C / min and held for 15-25 minutes, maintaining a protective atmosphere throughout the process, and after the holding period, the furnace is cooled to room temperature under the protective atmosphere.

[0014] As a further preferred embodiment of the method for preparing the darad electron multiplier of the present invention, the specific process parameters for magnetron sputtering in step 7 are as follows: When depositing titanium thin films, radio frequency sputtering is used with a power of 180~220W, a sputtering time of 4~6 minutes, and a deposition thickness of 40~60 nm. When depositing silver thin films, DC sputtering is used with a power of 80~120W, a sputtering time of 25~35 minutes, and a deposition thickness of 250~350 nm. When depositing magnesium oxide thin films, radio frequency sputtering is used with a power of 350~450W, a sputtering time of 50~60 minutes, and a deposition thickness of 700~900 nm.

[0015] As a further preferred embodiment of the preparation method of the electron multiplier of the dart electrode of the present invention, the specific sequence of the three-dimensional arrangement and assembly in step 8 is as follows: the focusing electrode, the first-stage dart electrode, the second-stage dart electrode... the Nth-stage dart electrode, the transition element and the collecting electrode are connected in sequence by at least one of the following connection methods: co-directional connection, vertical connection and reverse connection, where N is a positive integer greater than or equal to 3; the assembly uses two ceramic plates to clamp and fix each stage of the dart electrode, and the distance and attitude between the electrodes are precisely controlled by screws and support cylinders.

[0016] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects: 1. Order-of-magnitude increase in gain: For a seven-stage structure, the total gain of the electron multiplier of this invention can reach over 1.2 million, which is more than 17 times that of a multiplier using a traditional planar arrangement without synergistic surface treatment (gain of approximately 70,000). This represents a qualitative leap in gain performance. 2. Expanded the ceiling of collection efficiency: Through three-dimensional arrangement, the single-stage electron collection efficiency was successfully increased from 95.5% to 99.1%, clearing the core obstacle for the development of electron multipliers with higher total number of stages (such as more than 20 stages) and ultra-high gain. 3. Enhanced emission performance and stability of dynodes: Through synergistic surface treatment and multilayer thin film design, not only is the secondary electron emission coefficient δ steadily increased from ~3.8 to ~4.6, but the film density and adhesion are also enhanced, the resistance to electron / ion bombardment is significantly improved, and the working life of the device is extended in harsh environments. 4. Provides a complete and reproducible systematic solution: This invention discloses an innovative method that covers the entire chain from microscopic surface treatment to macroscopic structural design and overall device fabrication, rather than a single-stage repair. It is of great significance for promoting the engineering application of high-performance electron multipliers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the 7-stage electron multiplier structure in Embodiment 1 of the present invention; Figure 2 A bar chart comparing the gain of Embodiment 1 of the present invention with that of the original structure. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings: The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0020] The technical solution provided by this invention is composed of the following core components working together: (1) A novel, standardized box-grid tampon structure that supports three-dimensional arrangement Each cathode in this invention employs a box-grid structure, but its key dimensions are clearly defined: the grid is square, and the radius of curvature of the cathode plate is equal to its height. Figure 1 As shown. This design principle ensures that when the dart electrode is connected at any spatial angle, its upper and lower baffles can form a complete, closed multiplication cavity with the cathode plate and grid, without any gaps in electron leakage. This is the geometric basis for realizing complex three-dimensional combinations.

[0021] (2) A three-dimensional arrangement structure for optimizing the electric field and improving collection efficiency This invention breaks the limitation of traditional dynamo electrodes being arranged in the same plane. It constructs a precise three-dimensional serpentine electron multiplication channel by organically combining multiple dynamo electrodes in three-dimensional space through three basic connection units: "co-directional connection", "vertical connection" and "reverse connection".

[0022] The core physical mechanism of this structure lies in altering the electric field distribution between the electrodes. In a planar arrangement, the distance d1 between the outlet of the current stage (Dn) dator and the inlet of the next stage (Dn+1) dator is merely a planar geometric distance. However, in the three-dimensional structure of this invention, due to the spatial change in the dator's attitude, the equivalent spatial distance d2 between the outlet of Dn and the inlet of Dn+1 is significantly greater than d1 (see...). Figure 1 According to the electric field formula E = U / d, this indicates that the electric field disturbance of Dn+1 on the exit region of Dn is reduced, and the electric field lines tend to converge more longitudinally. Therefore, the focusing effect experienced by the secondary electrons emitted from Dn is stronger and more concentrated, causing the impact area on the Dn+1 cathode plate to shrink significantly towards the center. This directly leads to a significant reduction in the number of "extra-stage electrons" crossing Dn+1 and "trapped electrons" returning to Dn, thereby significantly increasing the single-stage average electron collection efficiency η from approximately 95.5% in the conventional structure to over 98.9%.

[0023] (3) A synergistic treatment process for dynode surfaces to improve the secondary electron emission coefficient δ While optimizing the structure and achieving efficient electron focusing, this invention performs a complete "triple surface synergistic pretreatment" on the target surface bombarded by the focused electrons—the cathode plate and upper and lower baffles of the darad electrode—aiming to create an ideal growth substrate with atomic-level cleanliness and flatness for the subsequent deposition of secondary electron emission films.

[0024] The first step is mechanical fine polishing. A sisal wheel or cloth wheel is used to finely polish the surface of the component for an extended period until the surface roughness Ra is less than 0.1 μm, achieving a mirror finish. This process eliminates microscopic "valleys" in the geometric structure, providing a flat path for the free escape of secondary electrons.

[0025] The second step is electroplating with bright nickel. A 0.5~2μm thick bright nickel film is electroplated onto the polished surface. Its functions are: a) to further fill micro-cracks and pinholes that cannot be eliminated by polishing; b) to provide a uniform and dense transition layer in terms of physical and chemical properties, isolating the substrate material; c) nickel itself has good affinity and conductivity for a variety of emitter materials.

[0026] The third step is high-temperature hydrogen burning treatment. The nickel-plated components are subjected to hydrogen burning treatment at 800-1000°C under a nitrogen or hydrogen protective atmosphere. Its core function is purification: at high temperatures, low-melting-point impurities (especially carbon) within the substrate material and at the plating interface gain sufficient energy to diffuse to the surface and be carried away by the reactive gas flow. Simultaneously, the natural oxide layer on the surface is reduced and removed, ultimately resulting in a "new" interface with high surface activity and atomic-level cleanliness. This interface is crucial for the perfect nucleation and growth of subsequent emission thin films.

[0027] (4) Preparation of a high-performance multilayer composite secondary electron emission thin film On an ideal substrate with the aforementioned synergistic pretreatment completed, this invention employs magnetron sputtering technology to sequentially deposit three functional thin films: a titanium film (underlayer to enhance adhesion), a silver film (intermediate layer to provide conductivity and stress buffering), and a magnesium oxide film (top layer to provide a high secondary electron emission coefficient δ). This composite film design combines the high adhesion of Ti, the high conductivity of Ag, and the high emission performance of MgO. Through precise control of sputtering process parameters, the film's density, uniformity, and long lifetime resistance to ion bombardment are ensured.

[0028] (5) The “synergistic gain” mechanism of structure and surface The core innovation of this invention lies not only in proposing the aforementioned optimization schemes, but also in revealing the profound synergistic effect among them. The three-dimensional arrangement allows the high-incidence region of electron multiplication to be spatially and precisely focused on the central area of ​​the lower-level darad cathode plate; while the surface synergistic treatment precisely makes this central area the region with the highest and most perfect secondary electron emission coefficient δ value on the entire plate. This precise matching of "using the best steel on the blade" ensures that the actual multiplication factor g = η × δ for each darad electrode reaches the dual optimization limits of structure and materials, thereby generating a synergistic amplification effect of 1+1>2, achieving a leap in total gain by an order of magnitude.

[0029] Based on the above-mentioned inventive concept, the present invention also provides a complete process flow for preparing the above-mentioned high-gain electron multiplier. The process steps are clear, highly operable, and have good repeatability, which can meet the requirements of industrialization and small-batch laboratory development.

[0030] Compare with Example 1: a traditional planar arrangement of a seven-stage electron multiplier without surface co-treatment; Density component processing: The cathode plate and baffle, of the same size and material (304 stainless steel) as in the embodiment, were used, but without any fine polishing, nickel plating, or hydrogen burning treatment. They were simply ultrasonically cleaned with acetone and alcohol to remove processing oils, following standard procedures. After cleaning and drying, a magnesium oxide film was deposited directly on its surface using a magnetron sputtering process with the same parameters as in the embodiment.

[0031] Device assembly: The components processed above are arranged in a linear planar manner with the highest traditional gain, mounted and fixed on a ceramic frame, a resistor network is welded to form a voltage divider, and vacuum degassing and encapsulation are performed.

[0032] Example 1: A seven-stage high-gain electron multiplier employing all the synergistic optimization schemes of this invention This embodiment illustrates in detail the complete preferred process for implementing the present invention.

[0033] Fine polishing: Take the original 304 stainless steel arc-shaped cathode plate, upper baffle, and lower baffle stamping parts with a surface roughness Ra of approximately 0.4 μm. Use newly installed white cloth wheels to finely polish the inner surfaces of each component for 20-30 minutes. The polished components exhibit a mirror-like finish. Using a white light interferometer, the surface roughness Ra values ​​measured at multiple points are consistently between 0.06 and 0.09 μm. After polishing, the surface is purged with high-pressure nitrogen to remove residual polishing paste and fibers.

[0034] Multi-stage ultrasonic deep cleaning and degreasing: Preparation of the cleaning solution: Dilute RBS 50 concentrated cleaning agent 50 times with deionized water. Immerse the polished parts in the solution and heat to 55°C in an ultrasonic cleaner for 30 minutes. After removal, rinse with 55°C deionized water under running water for 10 minutes. Then, place the parts in a beaker containing fresh deionized water and ultrasonically clean at 55°C for 5 minutes. Repeat this step 4 times until no foam appears on the surface of the cleaning solution. Next, ultrasonically clean with anhydrous ethanol and acetone sequentially for 10 minutes each at 55°C. Afterward, remove the parts from the acetone and quickly place them in a 70°C vacuum oven to dry for 30 minutes.

[0035] Electroplating of bright nickel: Electroplating is performed on the dried parts. A conventional Watt-type nickel plating solution is used, with the current density controlled at 2~5 A / dm², the temperature at 50~60°C, and the plating time at 3~5 minutes. A uniform nickel plating layer of approximately 1.5 μm thickness with a mirror-like shine is obtained on all inner surfaces of the parts. After plating, the parts are rinsed thoroughly with deionized water and dried.

[0036] High-temperature hydrogen burning purification: The nickel-plated and dried components are placed in a quartz boat within a tubular hydrogen burning furnace. First, high-purity nitrogen (99.999%) is used to purge the air from the furnace tubes for 30 minutes. Then, heating begins at a rate of 10°C / min, reaching 950°C and holding for 20 minutes, with high-purity nitrogen continuously circulating for protection throughout the process. After holding, the components are naturally cooled to room temperature under nitrogen flow before being removed. This treatment results in a uniform silver-gray surface with extremely high cleanliness.

[0037] Mounting and Vacuuming: Mount the component processed in step A onto the substrate holder of the magnetron sputtering equipment, ensuring the surface to be coated faces the target. Install 99.999% pure titanium, 99.999% pure silver, and 99.99% pure magnesium oxide ceramic targets at the target locations. Close the vacuum chamber and turn on the mechanical and molecular pumps to achieve a back vacuum of 4.0 × 10⁻⁶. -5 Pa.

[0038] Substrate heating and cleaning: Turn on the substrate heater and heat the component to 400°C and hold for 1 hour to ensure uniform component temperature. Then, introduce high-purity argon gas and adjust the flow rate to stabilize the pressure at 0.3 Pa. Turn on the bias power supply and adjust the power to 150W to perform glow discharge plasma cleaning on the component surface for 15 minutes to remove any trace gas molecules that may have been adsorbed during the transfer process.

[0039] Multilayer Thin Film Deposition: Step 1 (Deposition of Titanium Transition Layer): Turn off the bias power supply, turn on the titanium target baffle, set the RF sputtering power to 200W, and the sputtering time to 5 minutes. Deposit a titanium film of approximately 50nm on the clean nickel layer surface as a high-adhesion underlayer. Step 2 (Deposition of Silver Conductive Layer): Turn off the titanium target baffle, turn on the silver target baffle, set the DC sputtering power to 100W, and the sputtering time to 30 minutes. Deposit a silver film of approximately 300nm on the titanium layer as a conductive buffer layer. Step 3 (Deposition of Magnesium Oxide Emitter Layer): Turn off the silver target baffle, turn on the magnesium oxide target baffle, set the RF sputtering power to 400W, and the sputtering time to 55 minutes. Deposit a high-quality magnesium oxide film of approximately 800nm ​​on the silver layer to form the final secondary electron emission functional layer.

[0040] Post-processing: After deposition is complete, the magnesium oxide target baffle and RF power supply are turned off in sequence, the argon gas supply is stopped, and the component is allowed to cool naturally to below 100°C under vacuum. Dry nitrogen gas is then introduced into the vacuum chamber, and the component is removed, thus completing the entire processing of the datta electrode component.

[0041] Component Cleaning: Place all structural components, including the ceramic plate, focusing electrode, collecting electrode, transition components, support cylinder, and screws, in a clean beaker. Clean them sequentially with analytical grade acetone and analytical grade alcohol, each for 15 minutes using ultrasonic cleaning. After removal, use lint-free paper soaked in anhydrous ethanol to carefully wipe all surfaces until no residue or scratches remain. Dry them in a clean oven at 80°C for later use.

[0042] Positioning and Installation: Using precision tweezers and clamps, the focusing electrode, the prepared first to seventh stage electrodes, the transition piece, and the collecting electrode are precisely inserted into the pre-drilled fixing holes on a ceramic plate in sequence. The connection sequence is: "First stage - same direction - Second stage - vertical - Third stage - same direction - Fourth stage - vertical - Fifth stage - same direction - Sixth stage - vertical - Seventh stage".

[0043] Tightening: Align and cover the second ceramic plate. First, put a flat washer on the screw, then pass it through the hole in the upper ceramic plate, the support sleeve, and the hole in the lower ceramic plate. Finally, screw the fastening sleeve into the screw from the other end. By tightening each screw symmetrically and stepwise, the two ceramic plates can firmly clamp the internal electrodes of each stage, and precisely control the distance and posture between the electrodes.

[0044] Electrical Connections: On the outside of the ceramic plate, the two ends of multiple 1MΩ high-temperature vacuum resistors are soldered one-to-one to the leads of the adjacent dynamo, focusing electrode, and collecting electrode to form a voltage divider network. Finally, three high-voltage leads with insulating sleeves are soldered to the corresponding solder points of the first-stage dynamo, the transition piece (connecting to the seventh-stage dynamo), and the collecting electrode, respectively.

[0045] Vacuum sealing: The assembled core is placed in the oven of a vacuum degassing station and baked at 350°C for an extended period (>12 hours) to remove gas. After degassing, it is then sealed under ultra-high vacuum (<1×10⁻⁶). -6 The final sealing is performed under a pressure of Pa) to obtain the finished electron multiplier of the present invention.

[0046] The electron multipliers prepared in Comparative Example 1 and Example 1 were subjected to performance tests on the same standard test platform. The test conditions were: operating vacuum 5 × 10⁻⁶. 6 Pa, the total operating voltage (high voltage terminal voltage) is scanned from 1000V to 1800V.

[0047] Secondary electron emission coefficient δ test: A dedicated secondary electron emission coefficient (SEEF) meter was used to test planar samples processed in the same batch as the multiplier. The results showed that the maximum SEEF δmax of the pure magnesium oxide film in Control Example 1 was 3.8. In contrast, the Ti / Ag / MgO multilayer composite film prepared through synergistic processing in Example 1 of this invention achieved a SEEF δmax of 4.6, representing an increase of 21%. More importantly, its SEEF decayed more smoothly in the high-energy range (>200 eV), exhibiting superior stability.

[0048] Total Gain Test: The input current (Iin) and output current (Iout) of the multiplier were measured using a picoammeter, and the gain G = Iout / Iin was calculated. At a total operating voltage of 1800V, the gain compared to Example 1 (planar layout + conventional processing) was 7.05 × 10⁻⁶. 4 .

[0049] Under identical voltage conditions, the gain of Embodiment 1 (3D arrangement + collaborative processing) of the present invention is 1.25 × 10⁻⁶. 6 (1.25 million).

[0050] Gain enhancement contribution decomposition analysis: In order to clarify the respective contributions of structural optimization and surface treatment, we conducted a detailed simulation and experimental decoupling analysis.

[0051] Based on computer simulation of three-dimensional electromagnetic fields and particle tracking, the average electron collection efficiency η of a single stage in the three-dimensional arrangement structure of this invention was calculated. The simulation result shows that ηthree-dimensional = 99.1%. Compared with the planar arrangement simulation of Example 1, ηplanar = 95.5%. The improvement in collection efficiency brought about by structural optimization increases the total gain of the seven stages by a factor of (0.991 / 0.955) ≈ 1.30 times.

[0052] In the same planar arrangement structure, the effect of surface synergy treatment was verified individually. Experiments showed that the total gain achievable by the surface-synergistically treated danovic electrode was 2.1 times that of the untreated danovic electrode. For example... Figure 2 As shown.

[0053] If the structure and surface effects were simply superimposed, the total gain should be 1.30 × 2.1 ≈ 2.73 times. However, the actual total gain is 1.25 million / 70,500 ≈ 17.7 times. 17.7 >> 2.73, this huge difference irrefutably proves that the structure-surface synergistic optimization achieved by this invention produces a powerful synergistic effect of 1+1>2. Its physical essence lies in the fact that the three-dimensional electric field efficiently focuses electrons to the central target region of the lower-level electrode, while the surface treatment precisely maximizes the δ value of this central target region. The precise spatial overlap of high η and high δ nonlinearly amplifies the multiplication capability of each stage, ultimately resulting in a leap in the total gain by orders of magnitude.

[0054] In summary, the present invention successfully achieves its objective, providing a darad electron multiplier with revolutionary performance improvements and a systematic gain enhancement method thereof. The above embodiments should not be considered as limitations on the present invention. Any modifications based on the ideas of the present invention, such as increasing or decreasing the number of darad stages, adjusting the specific connection sequence, or fine-tuning the coating parameters, all fall within the protection scope of the present invention.

[0055] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention. All technical features in this embodiment can be freely combined according to actual needs.

[0056] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement, characterized in that, include: The cathode plate is arranged in a three-dimensional space with multiple levels of cathodes. Each level of cathodes adopts a box grid structure with a square grid and the arc radius of the cathode plate is equal to the height of the cathode plate. The multi-stage electrodes are combined and connected in three-dimensional space through at least one of the three basic connection units: co-directional connection, vertical connection, and reverse connection, forming a three-dimensional serpentine electron multiplication channel. Along the electron multiplication channel, the cathode plate and / or upper and lower baffles of each stage of the daddy electrode are sequentially provided from the substrate outward with: a mechanically finely polished layer, an electroplated bright nickel layer, a high-temperature hydrogen burning purification layer, and a multilayer composite film consisting of a titanium substrate, a silver conductive layer and a magnesium oxide emitting layer deposited sequentially by magnetron sputtering.

2. The darad electron multiplier based on surface synergistic processing and three-dimensional arrangement according to claim 1, characterized in that: The thickness of the electroplated bright nickel layer is 0.5~2 μm; the thickness of the titanium underlayer is 40~60 nm; the thickness of the silver conductive layer is 250~350 nm; the thickness of the magnesium oxide emitting layer is 700~900 nm; and the surface roughness Ra of the mechanically finely polished layer is less than 0.1 μm.

3. The darad electron multiplier based on surface synergistic processing and three-dimensional arrangement according to claim 1, characterized in that, The three-dimensional arrangement of the multi-stage tampones in space makes the equivalent spatial distance d2 between two adjacent tampones greater than the planar geometric distance d1, thereby reducing the electric field disturbance of the lower-stage tampon to the outlet region of the upper-stage tampon, causing the electric field lines to converge longitudinally, and the average electron collection efficiency η of a single stage reaches over 98.9%.

4. The darad electron multiplier based on surface synergistic processing and three-dimensional arrangement according to claim 1, characterized in that, The electron multiplier has a seven-stage structure and a total gain of 1.25 × 10⁻⁶ at a total operating voltage of 1800 V. 6 above.

5. A method for preparing a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Perform mechanical fine polishing on the cathode plate, upper baffle and lower baffle of the electrode to make its surface roughness Ra less than 0.1 μm; Step 2: Perform ultrasonic deep cleaning and degreasing on the polished parts; Step 3: Electroplating the cleaned parts with bright nickel plating to obtain a nickel plating layer with a thickness of 0.5~2 μm on the surface of the parts; Step 4: The nickel-plated parts are subjected to high-temperature hydrogen burning treatment in a protective atmosphere of 800~1000°C to obtain an active surface with atomic-level cleanliness. Step 5: Load the components treated with high-temperature hydrogen burning into the magnetron sputtering equipment and evacuate to a back vacuum level of 4.0 × 10⁻⁶. -5 Below Pa, heat to 350~450°C and hold at that temperature; Step 6: Introduce argon gas and turn on the bias power supply to perform glow discharge plasma cleaning on the surface of the component. Step 7: Using magnetron sputtering technology, titanium film, silver film and magnesium oxide film are sequentially deposited on the surface of the component to form a multilayer composite secondary electron emission film; Step 8: After deposition, the darad electrode is arranged and assembled in three dimensions with the ceramic plate, focusing electrode, transition element and collecting electrode to form a three-dimensional serpentine electron multiplication channel of the multi-stage darad electrode. Step 9: Weld the voltage divider resistor network and vacuum encapsulate it to obtain the finished electron multiplier.

6. The method for fabricating a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement according to claim 5, characterized in that, The mechanical fine polishing described in step 1 is performed using a sisal wheel or a cloth wheel for 20 to 30 minutes. After polishing, the surface roughness Ra is stable between 0.06 and 0.09 μm.

7. The method for preparing a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement according to claim 5, characterized in that, The electroplating of bright nickel in step 3 uses a Watt-type nickel plating solution with a current density of 2~5 A / dm², a temperature of 50~60°C, and an electroplating time of 3~5 minutes.

8. The method for preparing a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement according to claim 5, characterized in that, The specific process of high-temperature hydrogen burning treatment in step 4 is as follows: First, the air in the furnace tube is purged with high-purity nitrogen or hydrogen. Then, the temperature is increased to 900-1000°C at a heating rate of 8-12°C / min and held for 15-25 minutes, maintaining a protective atmosphere throughout the process. After the holding period, the furnace is cooled to room temperature under the protective atmosphere.

9. The method for preparing a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement according to claim 5, characterized in that, The specific process parameters for magnetron sputtering in step 7 are as follows: When depositing titanium thin films, radio frequency sputtering is used with a power of 180~220W, a sputtering time of 4~6 minutes, and a deposition thickness of 40~60 nm. When depositing silver thin films, DC sputtering is used with a power of 80~120W, a sputtering time of 25~35 minutes, and a deposition thickness of 250~350 nm. When depositing magnesium oxide thin films, radio frequency sputtering is used with a power of 350~450W, a sputtering time of 50~60 minutes, and a deposition thickness of 700~900 nm.

10. The method for preparing a darad electron multiplier based on surface synergistic treatment and three-dimensional arrangement according to claim 5, characterized in that, The specific sequence of the three-dimensional arrangement and assembly in step 8 is as follows: the focusing electrode, the first-stage dynamo electrode, the second-stage dynamo electrode... the Nth-stage dynamo electrode, the transition piece and the collecting electrode are connected in sequence through at least one of the following connection methods: unidirectional connection, vertical connection and reverse connection, where N is a positive integer greater than or equal to 3; the assembly uses two ceramic plates to clamp and fix each stage of the dynamo electrode, and the distance and attitude between the electrodes are precisely controlled by screws and support cylinders.

Images