LIPS-300离子推力器栅极热变形特点实验分析

为探究LIPS-300离子推力器在工作过程中栅极热变形的规律与特点,设计了大气环境下离子推力器双栅极热变形实验,以一环形加热器模拟实际工作时的等离子体热源。实验研究发现:球面栅极在加热过程中急剧变形,同时屏栅变形量大于加速栅,导致栅极间距减小;在冷却过程中,双栅迅速回复变形,栅极间距同步回复。其次,研究发现栅极中心位移在加热过程中的峰值回落现象,与在冷却过程中的负位移现象,同时发现冷却速率对负位移的大小有着不容忽视的影响。为研究上述现象的起因,对栅极组件的径向位移进行了采集,发现栅极安装环的变形是其根本原因。在结构与温度的综合影响下,栅极安装环的变形相较球面栅极更为缓慢,而其受热膨胀会拉伸球面栅极,导致球面栅极中心拱高减小,中心位移峰值回落。     

重力场测量卫星应用电推进技术

全球重力场的精确测量对于地球物理学、卫星定轨等均有至关重要的意义。对于全球重力场测量卫星而言,其姿态和轨道的保持精度直接影响着全球重力场测量的精度。从重力场测量卫星要求出发,对卫星参数进行了假设,对重力场测量卫星采用离子推进技术的适用性进行了分析。     

Radiative transitions in few-electron quasi-molecules

The review is aimed at the discussion of recent results on spectral profiles produced in collisions of few-electron atoms/ions. Calculations of spectral profiles produced by atom/ion collisions need some preliminary quantum-chemical information such as potential energy surfaces, dipole transition moments, etc. The main advantage of few-electron systems is that all input data can be obtained ab initio or analytically, thus the profiles calculated do not include any fit parameters. Two specific examples have been discussed. The first one deals with radiative transitions accompanying charge-exchange in collisions of one-electron ions with bare nuclei. The second example concerns radiative transitions produced by H⁻ + H collisions.     

离子推进器和流量控制单元

使用电动电源线确保使用电力,它等于几十千瓦。 建议它应该高达10000秒。 Keldysh研究中心（KeRC）正在开发推进系统。 35千瓦离子推进器和FCU-500流量控制单元。 IT-500和FCU-500的2000小时寿命测试是 离子推进器大部分运行2018小时,使用40千克氙气。 本文还介绍了磁场和离子光学的改进以及石墨网格的发展状况。     

Residual Stress Measurement for Ion-implanted NiTi Alloy by Using Moiré Interferometry and Hole-drilling Combined Method

Residual stresses in ion-implanted NiTi alloy are measured by a combined method of Moiré interferometry and hole-drilling. Oxygen ions are implanted into the NiTi alloy under a voltage of 30 kV by a dose of 1.0×1017 ions/cm2 for one hour. Subsequently, in order to avoid dimensional error, a hole is drilled exactly in the center of the sample. The distribution of residual stresses around the hole is measured. It is indicated that the method which combines the Moiré interferometry with hole-drilling is able to be used to measure residual stresses produced by ion implantation.     

Ptolemy – an Instrument to Measure Stable Isotopic Ratios of Key Volatiles on a Cometary Nucleus

A fundamental goal of cometary studies is to determine the exact relationship between these bodies and the Solar System – the question(s) can be summarised as follows: did comets originate during the same events that spawned the Sun and planets, are they more primitive bodies that record a pre-solar history, or are they interstellar materials collected in relatively more recent times? Now, whatever the origin of comets, it is entirely possible that they could, in part, contain interstellar or pre-solar components – indeed, it seems rather likely in light of the fact that primitive meteorites contain such entities. These particular components are likely to be refractory (dust, macromolecular organic complexes, etc.). Of more relevance to the issues above are the volatile constituents, which make up the bulk of a comet's mass. Since these materials, by their very nature, volatilise during perihelion passage of a comet they can, in some instances, be detected and measured spectroscopically. Perhaps the most useful species for isotopic investigations are C₂, HCN and CN. Unfortunately, spectroscopic measurements can only currently be made with accuracies of ±10 to ±20%. As such it is very often not practical to conclude anything further than the fact that isotopic measurements are compatible with ‘`solar’' values, which tends to imply an origin from the margins of the solar accretion disk. But there is another problem with the spectroscopic measurements – since these are made on gaseous species in the coma (and relatively minor species at that) it is impossible to be certain that these represent the true nuclear values. In other words, if the processes of sublimation, active jetting, and photochemistry in the coma impart isotopic fractionation, the spectroscopic measurements could give a false impression of the true isotope ratios. What is required is an experiment capable of measuring isotopic ratios at the very surface of a comet. Herein we describe the Ptolemy instrument, which is included on the Philae lander as part of the Rosetta mission to 67P/Churyumov-Gerasimenko. The major objective of Ptolemy is a detailed appraisal of the nature and isotopic compositions of all materials present at the surface of a comet.     

Detector of Micrometeoroid and Artificial Space Debris Particles

The mathematical model of a space debris detector based on inflatable metal-dielectric-metal (MDM) film structure is presented. The efficiency of its implementation for detection of space debris particles at different altitudes is estimated, and the information obtained by the detector is investigated.     

光学加工射频离子源的去除函数与稳定性研究

在研究了射频离子源的结构、工作原理和性能的基础上,进行了光学镜面抛光离子束的去除效率与稳定性测试。实验结果表明射频离子源去除函数的形状为回转高斯形,利用Φ15mm的栅网,在靶距为30mm、离子能量900eV时,去除函数的峰值去除率为194nm/min,体积去除率为19.2×10-3mm3/min,半峰全宽值为9.2mm;并且去除函数的峰值去除率与体积去除率的变化均在3%以内,半峰全宽值的变化在1.7%以内。因此,射频离子源具有光学镜面抛光加工所需的去除效率,而且射频离子源具有好的稳定性,具备光学加工的潜能。     

离子束加工中工件吸收热功率分析与建模研究

利用束流修正理论和蒙特卡罗模拟法对离子束加工中某一工艺参数下工件吸收的功率进行理论建模,然后采用测温实验对理论模型进行验证.设计实验时,利用有限元仿真确定了一种合理的轰击靶材铜,简化了实验并且方便了计算.     

氯化氢气在氨水中浸没喷射的研究

对ＨＣｌ气在氨水中浸没喷射进行了半经验理论分析与试验研究，确定了影响反应进行及温度变化的主要因素及其主次顺序，并建立了气体在可与之发生化学反应的液体中浸没喷射的射流长度关系式。