稳态原子氧束能谱测量新方法的研究

For accurate measurement of energy spectrum of oxygen atomic beam, the following two kinds of new methods are proposed.. The high intelligent multi-grid energy analyzer: put the steady-state electron gun over the vertical direction with the path of steady-state oxygen atomic beam, then, the electron gun emits electron beam with certain energy. The electron beam bombard oxygen atomic beam, to make it ionization. Then, at the end, we analyze the energy spectrum of oxygen ion flying over by using high sensitive multi-grid ion energy analyzer. And also, we can measure the plasma space potential between the electron beam and multi-grid energy analyzer by using high resolution space electric potential measuring apparatus. The plasma space potential is also useful for correction for ion energy spectrum acquiring by high sensitive ion energy analyzer.. Flying time of intense-nanosecond-electron beam: based on the first method, Electron gun replaces steady-state output with nanosecond pulses, and, at the end, we collect oxygen ion flying over by high sensitive collector. Between electron beam and collector of distance, and of their pulse signal of time differ that reflects the energy spectrum information of atomic oxygen beam.. According to many factors which influence the measurement results and measuring accuracy, such as composition and structure of the system, the high and low degree of vacuum, the electron beam related technical parameters, response and measuring accuracy of the collector, scanning range and measuring accuracy of the ion energy analyzer, especially the plasma space potential influences seriously on energy spectrum measurement of the low-energy atomic beam. We intend to take theoretical analysis combined with experimental verification of the method to resolve it.

为对原子氧束能谱进行准确测量，提出如下两种新方法：.高灵敏多栅能量分析器法：在与稳态原子氧束路径相垂直的方向上放置稳态电子枪，电子枪发射出一定能量的电子束轰击原子氧束，使其离化，在后端用高灵敏多栅离子能量分析器分析飞行过来的氧离子能谱；用高分辨空间电位测量仪测量电子束至多栅能量分析器之间等离子体空间电位，并用以校正高灵敏离子能量分析器获得的离子能谱。.纳秒脉冲电子束飞行时间法：在第一种方法基础上，电子枪用纳秒脉冲替代稳态输出，后端用高灵敏收集器收集飞行过来的氧离子。电子束与收集器之间距离、两者脉冲信号之间的时间差即反映了原子氧束的能谱信息。.针对影响测量效果和测量精度的诸多因素，如系统结构组成、本底真空度高低、电子束相关技术参数、收集器频响与测量精度、离子能量分析器测量精度与扫描范围，尤其是等离子体空间电位对低能原子束能谱测量的影响，拟采取理论分析与实验测试验证相结合的方法予以解决。

为解决分布在几eV-十几eV范围内低地球轨道和空间模拟原子氧源中原子氧能谱准确测量的问题，以对我国航天事业提供有力的技术支持，提出了多栅能量分析器法和纳秒脉冲电子束飞行时间法。. 针对其中影响测量效果和测量精度的诸多因素，如：系统结构组成、本底真空度高低、电子束相关技术参数、收集器频响与测量精度、离子能量分析器测量精度与扫描范围，尤其是等离子体空间电位对低能原子束能谱测量的影响，采取理论分析与实验测试验证相结合的方法予以解决。. 针对上述研究内容及要求，本项目目前已取得的重要结果及关键数据如下：.1).重要结果.a).测出了包含本底气体和原子氧束能谱的“I/V”曲线。该曲线反映了本底气体电离后离子流大小和原子氧束电离后离子流大小；对“I/V”曲线进行一阶微分获得的曲线，即可包含本底气体能谱和原子氧束能谱信息。.b).研制了满足该项目需要的多栅离子能量分析器测量系统，离子能量分析器能达到 1pA 的精度要求，测量误差在 3%以内。.c).改进型朗缪尔探针测量仪的研制，可以测量1nA的电流信号，相对误差小于5%。.d).纳秒级脉冲电子枪电源的研制，主要技术指标满足设计要求。.2).关键数据.a).原子氧源等离子体中的离子能谱。.b).高精度多栅离子能量分析器测量系统的测量精度。.c).改进型朗缪尔探针测量仪的测量精度。.d).发射探针测量仪的测量精度。.e).纳秒级脉冲电子枪电源的脉冲宽度和峰值电压。.f).原子氧束的测量能谱。. 上述重要结果及关键数据表明，实现原子氧束能谱的实时在线测量，可为开展原子氧相关研究与应用提供了强有力的诊断工具，提高其工作效率和水平。而依托该项目研制的朗缪尔探针测量仪、发射探针测量仪、离子能量分析器、纳秒级脉冲电子枪电源，可代替进口产品，广泛应用于等离子体应用领域。