TOF-SIMS 5kV直流高压电源设计

发布时间：2019-05-21 22:20

【摘要】：飞行时间二次离子质谱仪(Time of fly-secondary ion mass spectrometry,简称TOF-SIMS)利用高能一次离子束轰击物质表面产生二次离子,根据不同核质比的二次离子在质量分析器中飞行时间不同而得知样品表面元素的质谱图,实现对被检样品分析。TOF-SIMS以其高分辨率、高灵敏度的特性而广泛应用于地质学研究、生物样品分析以及食品化学等领域。直流高压电源是TOFSIMS的重要组成部分,通过在提取电极和透镜电极上施加不同的高压实现对二次离子的提取和聚焦,其中提取电极和透镜电极施加的电压对二次离子运动情况和仪器性能影响很大,研制适用于该仪器的高压电源具有重要意义。本论文立足于“国家重大科学仪器设备开发专项-同位素地质年代学专用TOF-SIMS科学装置”项目,旨在为TOF-SIMS仪器设计一款直流高压电源,并基于现行的高压电源研制技术,从主电路拓扑结构的选取、单元电路的设计、电源的仿真与参数优化等多个方面对高压电源进行设计。根据TOF-SIMS对直流高压电源的要求,首先提出高压电源的总体技术方案为高频升压变压器与倍压电路相结合。其次,对比不同种类的电源主电路拓扑结构,并根据高压电源的设计要求及适用条件等因素,确定高压电源的主电路拓扑结构,即斩波调压与全桥逆变的拓扑结构。同时,根据模块化电路的设计思想,对包括整流滤波电路、斩波调压电路、逆变电路、控制电路、倍压电路等单元电路进行了详细设计,并重点阐述斩波电路中关键器件功率电感的参数设计,以及通过面积积法对高频高压变压器的设计与制作进行了深入研究。再次,基于Multisim软件,对主电路中主要功能电路进行仿真分析,并深入探讨斩波电路及倍压电路中不同参数对输出纹波的影响,探讨其形成原因,并给出减小纹波的解决方案,验证本设计方案的可行性。最后,根据抗电磁干扰的PCB设计原则绘制电源线路板,对焊接制作完成的直流高压电源进行单元电路测试与整体性能测试,包括阻性负载测试、纹波测试、时漂测试与温度测试,以及TOF-SIMS应用测试并对测试结果进行了分析。
[Abstract]:The time-of-flight secondary ion mass spectrometer (Time of fly-secondary ion mass spectrometry, (TOF-SIMS) produces secondary ions by bombarding the surface of the material with high energy primary ion beam. According to the different flight time of the secondary ions with different nuclear-mass ratio in the mass analyzer, the mass spectrum of the elements on the surface of the sample is obtained, and the analysis of the tested sample is realized. TOF-SIMS with its high resolution, High sensitivity is widely used in geological research, biological sample analysis and food chemistry. DC high voltage power supply is an important part of TOFSIMS. The secondary ion is extracted and focused by applying different high voltage to the extraction electrode and lens electrode. The voltage applied by the extraction electrode and lens electrode has a great influence on the movement of secondary ions and the performance of the instrument. It is of great significance to develop a high voltage power supply suitable for the instrument. This paper is based on the project of "National Major Scientific instrument and equipment Development Project-Isotope Geological Geochronology Special TOF-SIMS Scientific device". The purpose of this paper is to design a DC high voltage power supply for TOF-SIMS instrument, and based on the current high voltage power supply development technology. The design of high voltage power supply is carried out from many aspects, such as the selection of main circuit topology, the design of unit circuit, the simulation of power supply and the optimization of parameters. According to the requirements of TOF-SIMS for DC high voltage power supply, the overall technical scheme of high voltage power supply is put forward, which is the combination of high frequency boost transformer and double voltage circuit. Secondly, the main circuit topology of different kinds of power supply is compared, and according to the design requirements and applicable conditions of high voltage power supply, the main circuit topology of high voltage power supply is determined, that is, chopping voltage regulation and full bridge inverter topology. At the same time, according to the design idea of modular circuit, the unit circuits, including rectifier and filter circuit, chopper voltage regulating circuit, inverter circuit, control circuit, voltage doubling circuit and so on, are designed in detail. The parameter design of power inductance of key devices in chopping circuit is emphasized, and the design and manufacture of high frequency and high voltage transformer are deeply studied by area product method. Thirdly, based on Multisim software, the main functional circuits in the main circuit are simulated and analyzed, and the influence of different parameters in chopping circuit and voltage doubling circuit on the output ripples is deeply discussed, the causes of its formation are discussed, and the solutions to reduce the ripples are given. Verify the feasibility of the design. Finally, according to the PCB design principle of anti-electromagnetic interference, the power supply circuit board is drawn, and the unit circuit test and the overall performance test of the DC high voltage power supply made by welding are carried out, including resistive load test and wave test. Time drift test and temperature test, as well as TOF-SIMS application test, and the test results are analyzed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH843

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