Electron cyclotron resonance ion thruster (ECRIT) runs on ECR plasma which is produced by microwave energy and magnetic field from two permanent magnetic rings inside the discharge chamber. The ions in ECR plasma are extracted by the sharp potential gap of screen and acceleration grids to produce thrust. ECRIT has the advantages of high specific impulse, electrodelessness and high durability, which make the thruster competitive in the applications of deep space probe and long life satellite. Sections 1 through 3 explain the experimental research mentioned in the title, whose core consists of: " Appropriate magnetic circuit inside the discharge chamber of ECRIT is important for the ihruster reliable operation in that it must generate the magnetic field required by ECR plasma generation and drive plasma density in a uniform distribution near the surface of screen grid for high thrust density and low grid erosion by the accelerated ions, thus operating the discharge chamber with a high efficiency. Within the tapered discharge chamber, two types of magnetic circuit are used to produce argon ECR plasma, of which the electron temperature and ion density are diagnosed by Langmuir probe. " The experimental results, given in Table 1 and Figs. 6, 8 and 9, and their analysis, show preliminarily that, when the magnetic rings approach the major end surface of the discharge, the efficiency and ion density distribution near the screen grid can be improved.%电子回旋共振离子推力器(ECRIT)属于静电型推力器,其工作原理是利用微波能和圆台型放电室内永磁体环产生的外加磁场产生高电离度的电子回旋共振(ECR)等离子体,再通过屏栅和加速栅之间的陡峭电势差加速其中的离子,从而产生推力.由于ECRIT采用了无阴极放电方案,因而它具有寿命长、结构简单的特点.ECRIT放电室内恰当的放电室磁路结构对于推力器的可靠工作非常重要,一方面它要产生满足ECR等离子体形成需要的磁场位形；另一方面要使栅极附近的等离子体分布比较均匀,从而提高推力密度,降低离子对栅极的冲刷；再者还要求放电室能在比较高的能量利用效率下工作.在圆台型放电室内,文章采用了两种磁路结构,分别开展了真空环境下放电室内ECR等离子体的产生实验；认为放电室中的离子未被磁化,采用朗缪尔探针直接诊断两种磁路结构放电室内的电子温度和离子密度,分析氩等离子体场的结构.实验的结果是:靠近放电室大端面的永磁体环能够使推力器的能量利用效率提高,同时能够使栅极附近的等离子体分布更均匀,从而提高推力密度、降低离子对栅极的冲刷.
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