Design and application of three coordinate precisi

2022-08-16
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Design and control of three coordinate precision worktable in electron beam analysis system

Abstract: a measurement method of electron beam analysis by beam sampling in three-dimensional space using collector is proposed, and the design and control of three coordinate precision mobile worktable in electron beam analysis system are introduced. This method can comprehensively measure and analyze the structural parameters and working performance of the electron beam emission system, and provide an experimental means for the development of UHF high-power electronic devices

Keywords: electron beam analysis system three coordinate workbench measurement and control

design and control of 3-D Precision table in electron beam analyzer system

dong Mingli et al

abstract:a measuring method for analyzing electron beam by using collectors (Faraday cups) To collect beams in a 3-D space is presented.the design and control of a 3-D Precision table in the system are introduced.this method can measure and analyze structure parameters and perfo is characterized by non-contact measurement of an electric beam launching system, And can provide a test method for developing ultra high frequency (UHF) and high power electronic components.

keywords:electron beam analyzer system 3-D table measurement and control

1. introduction

with the rapid development of semiconductor industry, semiconductors have gradually replaced most electronic tube devices because of their small size, low energy consumption, stable performance and other advantages, However, in modern radio engineering system, high-power and UHF electronic devices still occupy an irreplaceable position. In radio and radar transmitting systems, magnetron, klystron, traveling wave tube, EBS tube and other high-power high-frequency electronic transmitting tubes are indispensable core devices. Among such devices, the most important component is the electron beam. Its main function is to transform the power energy into high-frequency oscillation energy in the high-intensity layer suppression process of clean, dry, vibration free room supplies, office furniture and other markets that interact with electromagnetic fields and are manufactured by Gordon composites Co., Ltd. (1) the experimental machine should be installed in the room supplies, office furniture and other markets with room temperature controlled at (10 ~ 35) ℃. The quality of a transmitting system mainly depends on the performance of the electron emitting tube, and the RF performance, frequency agility performance, heat dissipation performance, power, gain, efficiency and so on of the electron emitting tube all depend on the performance of the electron beam. Therefore, it is of great significance to study the structure and parameters of the electron beam, analyze the cross-sectional size of the electron beam and the current density distribution, pulsation, the trajectory of each electron layer and the trajectory of each electron in order to improve the performance of the electron emission tube. The electron beam analysis system is designed and developed according to the above requirements. The system can carry out experimental research on the structure and performance of the electron beam, and complete the comprehensive measurement of various parameters of the electron beam

2. Working principle of electron beam analysis system

the working principle of electron beam analysis system is shown in Figure 1. The system is mainly composed of the electron gun to be tested, the collector, the XYZ three coordinate precision moving workbench, the current amplifier, the A/D converter, the computer data acquisition system and the information processing system. The electron gun to be tested is an electron beam emission system, which is composed of filament, cathode, modulation anode (or control grid) and focusing electrode. The electron gun emits a beam of electron flow through the cathode. Through the modulation of modulation anode (or control grid), the electron beam is formed through the focusing electrode. The collecting pole and XYZ three coordinate precision moving table are the most critical components in the electron beam analysis system. In order to accurately analyze the structure of the electron beam and the characteristics of various parameters, it is necessary to measure the total beam current of the electron beam, the current at various points on different cross sections of the electron beam The current density distribution, cross-sectional area size and axial variation distribution will "Improve the customer experience law and other parameters. In order to meet the measurement requirements, we designed two Faraday cups with inlet diameters of 0.1mm and 20mm as the collector. Using a large-diameter collector to measure the total beam current of the electron beam, the electron beam can be completely loaded into the collector to prevent electrons from escaping from the inlet; using a small-diameter collector to measure the current density distribution of the electron beam, the sampling points on the electron beam section can be increased to improve the measurement accuracy. In the structural design of the collector, it should be considered that secondary electrons are generated and reflected electrons are prevented from escaping due to the electron beam bombarding its surface after the electron beam enters its interior. The movement of the collector in the three coordinate directions in the three-dimensional space is completed by the XYZ three coordinate precision moving workbench. The computer system sends out instructions according to the measurement requirements, and the stepper motor drives the coordinate axis of the precision mobile workbench to drive the collector to move in three-dimensional space and obtain sampling information. The electrons from the collector are input into the computer after current amplification and a/D conversion. The computer system analyzes and processes the sampled data, obtains the electron beam parameters and working characteristics, and prints the data, tables and curves

Figure 1 working principle diagram of electron beam analysis system

3. Design of three coordinate precision mobile workbench

three coordinate precision mobile workbench is the core part of the whole electron beam analysis system, and it is also the most difficult part of the design. When measuring the cross-sectional size of the electron beam, the current density distribution and the axial characteristic distribution of the electron beam, the technical indicators such as the spacing retention, sampling uniformity and the spatial positioning accuracy of the collector point by point in the three-dimensional space completely depend on the performance of the three-dimensional precision moving workbench. In addition, the vacuum has a great impact on the performance of the electron beam, when the true vacuum is less than 1.33 × At 10-3pa, serious ion accumulation effect and neutralization between ions and electrons will be formed near the electron beam axis, resulting in ion spots in the cathode center of the electron gun. The existence of ion spots will make the electron beam show obvious non laminar fluidity and strong divergence, significantly change the current density distribution and transverse velocity distribution in the electron beam, and increase the electrons intercepted by the anode, which will greatly affect the performance of the device. Therefore, in the electron beam analysis system, electrons

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