22 results about "Secondary electron emission coefficient" patented technology

The present invention discloses a method for controlling the surface potential of an insulating material under high vacuum, which uses an ultraviolet light source to irradiate an insulating material sample to generate radiation-induced conductivity, and discharges the charge by discharging the charge to the ground. In the present invention, an ultraviolet light source is used to irradiate an insulating material sample to generate radiation-induced conductivity, and discharges the charge by discharging the charge to the ground, which can effectively eliminate the surface potential formed by the accumulated charge on the surface of the insulating material sample, without the need to additionally equip expensive equipment such as electron guns and ion sources, thereby reducing the cost of potential control, eliminating complex external circuit design, and increasing test reliability; ultraviolet irradiation is used to achieve surface potential control of the insulating material under high vacuum conditions, and the surface potential neutralization operation can be completed without contacting the sample surface, thereby avoiding damaging the sample surface morphology and thus affecting its secondary electron emission characteristics, increasing test stability, and improving the accuracy of secondary electron emission coefficient measurement.

An electrostatic chuck assembly is provided that is less prone to spatial discharge within a gas passage plug. This electrostatic chuck assembly comprises a ceramic plate having an upper surface on which a wafer is placed and a lower surface opposite to the upper surface, and incorporating internal electrodes which are ESC electrodes and / or RF electrodes; a cooling plate attached to the lower surface of the ceramic plate; a plug placement hole penetrating the ceramic plate from the lower surface to the upper surface; a gas passage plug provided to close the plug placement hole and configured to allow gas to pass through its interior; and a gas introduction passage provided in the cooling plate and communicating with the plug placement hole. At least a portion of the gas-contactable surface within the gas passage plug is made of a low SEEC material having a secondary electron emission coefficient (SEEC) of 5.0 or less.

This application discloses a novel polyimide composite film material with high surface electrical strength, comprising a polyimide base layer and an electrospun polyimide composite nanofiber surface layer, wherein the electrospun polyimide composite nanofiber surface layer contains a metal compound; the thickness of the polyimide composite film material is 25–250 μm. The polyimide composite film material provided in this application is composed of a polyimide resin base layer and an electrospun polyimide composite nanofiber surface layer, which are ultimately subjected to high-temperature imidization. After a chemical reaction, the layers are bonded together to form a single unit, exhibiting strong interlayer adhesion. This novel polyimide composite film material, while maintaining excellent mechanical properties, possesses a lower secondary electron emission coefficient, higher surface conductivity, and faster surface charge dissipation capability, thereby improving the surface electrical strength of the polyimide film material through multiple pathways, meeting the needs of spacecraft manufacturing for insulating materials.

The application provides a method and system for measuring a secondary electron emission coefficient of a medium material, the method comprising the following steps: obtaining a total primary electron beam current, and cutting the total primary electron beam current to obtain a primary electron beam current; obtaining a beam cutting current and a sampling current, and calculating a ratio of the primary electron beam current to the beam cutting current; obtaining the beam cutting current and the sampling current of the medium material to be measured, and obtaining the secondary electron emission coefficient of the medium material to be measured under primary electron incidence energy; neutralizing accumulated charges on the surface of the medium material to be measured by using a first neutralizing electron gun and a second neutralizing electron gun; measuring the secondary electron emission coefficient under different primary electron incidence energies to obtain a secondary electron emission coefficient curve. The accumulated charges on the surface of the medium material to be measured are neutralized and removed by using the neutralizing electron gun, the problems that a long time is consumed in the previous medium material measurement process and the measurement of the secondary electron emission coefficient less than 1 cannot be realized are solved, and the complete curve of the secondary electron emission coefficient of the medium material is rapidly and accurately measured.

This invention discloses a method for designing the optimal secondary electron emission coefficient (SEEC) rectangular slot array structure size, comprising the following steps: S1, establishing the size and variation range characterizing the regular array rectangular slot structure; S2, calculating and obtaining the maximum SEEC and SEEC curve based on the size of the regular array rectangular slot structure; S3, calculating the surface impedance based on the operating frequency and the size of the regular array rectangular slot structure; S4, treating the size of the regular array rectangular slot structure as an individual in a population, calculating the fitness value of each particle, and obtaining the optimal combination of rectangular slot array structure sizes. This method can simultaneously reduce the SEEC and surface impedance, and can be used to reduce the SEEC of metal surfaces, providing support for suppressing micro-discharge in high-power microwave components in space.

The present invention discloses a method for determining the secondary electron emission coefficient of a random dot matrix, including: establishing a three-dimensional position model of the dot matrix spatial structure; determining a standard incident electron set; calculating the number of secondary electrons generated when N incident electrons with an initial incident energy of E 0 , an initial incident angle of θ 0 are incident on the three-dimensional position model of the dot matrix spatial structure; calculating the secondary electron emission coefficient of the three-dimensional position model of the dot matrix spatial structure at an initial incident energy of E 0 , an initial incident angle of θ 0 ; obtaining the experimental value of the secondary electron emission coefficient obtained through experiments and determining a correction coefficient; changing the initial incident energy and the initial incident angle of the incident electrons, calculating the secondary electron emission coefficients of the three-dimensional position model of the dot matrix spatial structure at different initial incident energies E k , different initial incident angles θ k , and outputting the results after correction. The present invention realizes the determination of the secondary electron emission coefficient of a 3D printed random dot matrix, and has the advantages of stable physical structure and excellent combination with devices.

Provided is an electrostatic chuck assembly in which space discharge does not readily occur in a gas passage plug. This electrostatic chuck assembly comprises: a ceramic plate having a top surface on which a wafer is to be placed and a bottom surface opposite the top surface, and incorporating an internal electrode that is an ESC electrode and / or an RF electrode; a cooling plate attached to the bottom surface of the ceramic plate; a plug placement hole penetrating the ceramic plate from the bottom surface to the top surface; a gas passage plug provided so as to close up the plug placement hole and configured to allow a gas to pass therethrough; and a gas introduction passageway provided in the cooling plate and communicating with the plug placement hole. At least a portion of a gas-contactable surface in the gas passage plug is formed from a low secondary electron emission coefficient (SEEC) material having a SEEC of 5.0 or less.

An electrostatic chuck assembly is provided that, while equipped with a gas passage plug, is less prone to surface discharge at the interface between the gas passage plug and the ceramic plate. This electrostatic chuck assembly comprises a ceramic plate having an upper surface on which a wafer is placed and a lower surface opposite the upper surface, and incorporating internal electrodes which are ESC electrodes and / or RF electrodes; a cooling plate attached to the lower surface of the ceramic plate; a plug placement hole penetrating the ceramic plate from the lower surface to the upper surface; a gas passage plug press-fitted into the plug placement hole and configured to allow gas to pass through its interior; and a gas introduction passage provided in the cooling plate and communicating with the plug placement hole. At least one side surface of the gas passage plug and the plug placement hole is made of a low SEEC material having a secondary electron emission coefficient (SEEC) of 5.0 or less.

The present invention relates to the field of plasma probe calibration, and provides a plasma probe array calibration method based on radiation spectroscopy and infrared imaging. The surface temperature of the probe array is measured, and the plume parameters of the stably operating Hall thruster are measured using the probe array to obtain the volt-ampere characteristic curve collected by the probe array at this time. An infrared imager is then used to measure the surface temperature of the probe array to obtain the temperature difference of the probe heated by bombardment. Combined with the secondary electron emission coefficient of the probe surface, the secondary current value is calculated. Combined with the ion current value measured by the probe itself, the electron current value is corrected to obtain a true volt-ampere characteristic curve, and the accurate electron temperature density is calculated. A spectrometer is used to measure the electron temperature electron density at this time through spectroscopy, and the electron temperature electron density measured by the modified probe is compared to achieve calibration of the plasma probe array. This is used to solve the problem that the probe measurement results lack calibration and the accuracy is difficult to assess.

Methods and apparatus for forming an integrated circuit structure, comprising: delivering a process gas to a process volume of a process chamber; applying low frequency RF power to an electrode formed from a high secondary electron emission coefficient material disposed in the process volume; generating a plasma comprising ions in the process volume; bombarding the electrode with the ions to cause the electrode to emit electrons and form an electron beam; and contacting a dielectric material with the electron beam to cure the dielectric material, wherein the dielectric material is a flowable chemical vapor deposition product. In embodiments, the curing stabilizes the dielectric material by reducing the oxygen content and increasing the nitrogen content of the dielectric material.

Methods and apparatuses for processing a substrate are provided herein. For example, a method of processing a substrate includes: applying at least one of low frequency RF power or DC power to an upper electrode disposed adjacent to a processing volume, the upper electrode formed of a high secondary electron emission coefficient material; generating a plasma in the processing volume, the plasma including ions; bombarding the upper electrode with the ions to cause the upper electrode to emit electrons and form an electron beam; and applying a bias power to a lower electrode disposed in the processing volume to accelerate the electrons in the electron beam toward the lower electrode, the bias power including at least one of low frequency RF power or high frequency RF power.

The invention discloses a vacuum insulator with a three-level micro-nano structure on the surface and a preparation method of the vacuum insulator, and mainly solves the technical problems of poor inhibition effect on vacuum surface flashover, unobvious vacuum surface voltage resistance improvement effect and the like in the prior art. The vacuum insulator comprises an insulator base body and a three-stage micro-nano structure arranged on the surface of the insulator base body, the first-stage structure is a zigzag structure and is composed of a plurality of triangular grooves which are formed in the surface of the insulator base body and are continuously arranged, and the surfaces of the triangular grooves are plated with polydopamine transition layers; the second-stage structure is a three-dimensional network structure and is formed by interweaving micron wires on the surface of the transition layer; and the third-level structure is a nano-level molecular film which covers the surface of the microwire. According to the three-level micro-nano structure, multi-scale and multi-level cooperative inhibition can be carried out on secondary electron multiplication in the flashover development process, the secondary electron emission coefficient of an insulating material is reduced, and the vacuum surface flashover voltage of an insulator is greatly improved.

This invention discloses a photomultiplier tube (PMT) dynode film preparation system and method belonging to the field of PMT technology. The system includes a PMT, a vacuum system, and an alkali source assembly. The alkali source assembly includes an external glass tube and internal K, Na, and Cs sources. One end of the glass tube is closed, and the other end is connected to the vacuum system via a tail tube. One end of the PMT is also closed, and the other end is connected to the vacuum system via a tail tube. The K, Na, and Cs sources are connected to pin electrodes via nickel wires to form a circuit. Eleven pin electrodes are led out from the inside of the PMT. This invention can accurately and effectively monitor the secondary electron emission capability of the dynode film, solving the problem of lack of quality control in the dynode preparation process. Furthermore, it improves the secondary electron emission coefficient of the dynode film, resulting in a significant increase in overall PMT gain and achieving good consistency.

The invention discloses a high-gain copper beryllium alloy secondary electron emitter and a preparation method thereof, and relates to the technical field of material preparation, and the preparation method comprises the following steps: carrying out pulse electrolytic polishing surface pretreatment on a punch-formed copper beryllium alloy base material, then putting the copper beryllium alloy base material subjected to surface pretreatment into a tubular furnace, and heating the tubular furnace to obtain a copper beryllium alloy secondary electron emitter; after argon and hydrogen mixed gas is introduced for gas washing, vacuumizing is conducted, then the tubular furnace is heated, low-oxygen-pressure thermal activation treatment is conducted on the copper-beryllium alloy base material in two steps, a beryllium oxide active layer with the high secondary electron emission coefficient is formed on the surface, and the high-gain copper-beryllium alloy secondary electron emitter is obtained. The beryllium oxide active layer is uniform, compact and low in roughness, the copper beryllium alloy secondary emitter is high in secondary electron emission coefficient and stable in performance, and the problem that a conventional copper beryllium alloy secondary electron emitter is insufficient and unstable in performance is effectively solved.

The invention discloses a vacuum insulator with a three-dimensional microstructure on the surface and a preparation method of the vacuum insulator, and aims to solve the technical problems of limited application range, complicated operation, high equipment requirement and the like of the conventional method for increasing the vacuum surface flashover voltage of the insulator. The insulator comprises an insulator base body, a transition layer and a three-dimensional microstructure, wherein the transition layer and the three-dimensional microstructure sequentially coat the insulator base body from inside to outside; the transition layer is made of polydopamine; the three-dimensional microstructure is formed by interweaving micron wires in a three-dimensional space on the surface of the transition layer, and molecular groups with high pressure resistance are grafted on the surface layers of the micron wires. The structure can absorb and restrain electron multiplication in the whole three-dimensional space in the flashover development process, the secondary electron emission coefficient of the insulator is reduced, the development of vacuum surface flashover on the surface of the insulator is restrained, and the surface voltage withstanding level of the insulator is greatly improved.

The invention discloses a micro-channel plate for improving spatial resolution. The micro-channel plate comprises an input electrode, a multiplication channel and an output electrode, the input electrode is located at the input end of the multiplication channel, the output electrode is located at the output end of the multiplication channel, and the input electrode is a nickel-chromium electrode; the multiplication channel is made of lead-containing glass with secondary electron emission performance; and the output electrode is made of a material of which the maximum secondary electron emission coefficient is smaller than that of the nickel-chromium electrode. The spatial resolution of the microchannel plate can be greatly improved under the effects of reducing the maximum secondary electron emission coefficient of the output electrode and increasing the immersion depth of the output electrode.

Provided is an electrostatic chuck assembly in which creepage discharge is unlikely to occur at the interface between a gas passage plug and a ceramic plate while being provided with the gas passage plug. This electrostatic chuck assembly comprises: a ceramic plate having an upper surface on which a wafer is to be placed and a lower surface facing the upper surface, the ceramic plate also having built therein an internal electrode that is an electrostatic chuck (ESC) electrode and / or a radio frequency (RF) electrode; a cooling plate attached to the lower surface of the ceramic plate; a plug arrangement hole penetrating the ceramic plate from the lower surface to the upper surface; a gas passage plug configured to be press-fitted into the plug arrangement hole and allow gas to pass therethrough; and a gas introduction pathway provided in the cooling plate and communicating with the plug arrangement hole. At least one of a side surface of the gas passage plug and the plug arrangement hole is composed of a low secondary electron emission coefficient (SEEC) material having a SEEC of 5.0 or less.

A simulation analysis method for space charge distribution of a spacecraft dielectric medium comprises the steps that actual operation environment parameters of the spacecraft dielectric medium are obtained and calculated, and the actual operation environment parameters comprise interaction of electron energy, flow and a dielectric material; a self-consistent electron transmission model considering drift diffusion is established, ballistic transport, sinking and desinking of carriers in a medium and recombination of electrons and holes are considered, and the electrons penetrate through a potential barrier at an interface to become real secondary electrons; the sinking probability of a carrier under the influence of a trap is emphatically considered in the model; the method comprises the following steps: collecting structural parameters and intrinsic attributes of a spacecraft dielectric medium, setting material parameters and boundary conditions of an electric field, and establishing a charge transport equation; a charge transport equation is calculated, and simulation results of the internal body charge, the electric field, the sample current and the secondary electron emission coefficient of the spacecraft dielectric medium are obtained through sequential iteration of the continuity equation of the transient solver.

The application relates to the technical field of surface treatment of collecting electrode, and provides a low secondary electron emission coefficient collecting electrode surface treatment method, which comprises the following steps: processing a graphite-doped metal into a collecting electrode part through a mechanical processing mode; removing the impurities remaining on the surface of the collecting electrode part after processing through an acetone ultrasonic cleaning mode; performing hydrogen burning purification treatment on the collecting electrode part; performing copper plating treatment on the welding area of the graphite-doped metal material; and assembling the collecting electrode by using a low-vapor-pressure gold-based alloy solder as filling solder for an electric vacuum device. Compared with the collecting electrode prepared from oxygen-free copper in the prior art, the low secondary electron emission coefficient and the weight of the electrode are reduced by adopting the lightweight new material graphite-doped metal. The connection between the lead wire of the collecting electrode and the collecting electrode is realized through local copper plating and vacuum heat treatment on the graphite-doped metal collecting electrode part, so that the power supply requirement of each electrode of the collecting electrode is met.

A method for simulating and analyzing the spatial charge distribution of a spacecraft dielectric is disclosed. The method obtains and calculates the actual operating environment parameters of the spacecraft dielectric, including the interaction between electron energy, flow rate, and dielectric material. A self-consistent electron transport model considering drift diffusion is established, which accounts for the ballistic transport of carriers within the dielectric, trapping, detrapping, and recombination of electrons and holes, as well as the passage of electrons through potential barriers at interfaces to become true secondary electrons. The model focuses on the trapping probability of carriers under the influence of traps. The structural parameters and intrinsic properties of the spacecraft dielectric are collected, and the material parameters and electric field boundary conditions are set to establish a charge transport equation. The charge transport equation is calculated, and the simulation results of the internal volume charge, electric field, sample current, and secondary electron emission coefficient of the spacecraft dielectric are obtained by sequentially iteratively solving the continuity equation of a transient solver.

The application provides a photon transport process analysis method and device for complex structure medium streamer simulation, electronic equipment and storage medium, belongs to the technical field of high-voltage streamer generation and simulation, and comprises the following steps: calculating the number of photons radiated by all profiled nodes in a simulation region; randomly calculating the absorption distance and direction of all photons, and determining a target absorption node; if the photons are not blocked by a solid medium, generating secondary electrons generated by photon-induced oxygen molecule ionization at the target absorption node; if the photons are blocked by the solid medium, performing photon and solid medium collision ionization process treatment, randomly generating secondary electrons generated by photon-induced solid medium ionization according to a secondary electron emission coefficient; obtaining the number of secondary electrons of all profiled nodes in the simulation region, and updating the number of electrons of all profiled nodes. The application can improve the accuracy of streamer development process simulation and realize the randomness of streamer development process simulation.

The invention provides a photon transmission process analysis method and device for complex structure medium stream simulation, electronic equipment and a storage medium, and belongs to the technical field of high-voltage stream generation and emulation.The photon transmission process analysis method comprises the steps that the number of photons radiated by all subdivision nodes in a simulation area is calculated; randomly calculating absorption distances and directions of all photons, and determining a target absorption node; if the photons are not blocked by the solid medium, the photons are generated at the target absorption node to induce secondary electrons generated by oxygen molecule ionization; if the photons are blocked by the solid medium, carrying out collision ionization process treatment on the photons and the solid medium, and randomly generating the photons according to a secondary electron emission coefficient to induce secondary electrons generated by ionization of the solid medium; and obtaining secondary electron numbers of all the subdivision nodes in the simulation area, and updating the electron numbers of all the subdivision nodes. According to the method and the device, the accuracy of streamer development process simulation can be improved, and the randomness of streamer development process simulation can be realized.