Abstract: In order to establish the thermal model for the domestic 20cm diameter discharge chamber of LIPS-200 ring-cusp ion thruster，the generation process of the plasma in the discharge chamber has been investigated. The temperature of the secondary electron，ion density and the distribution of the electron density were obtained numerically. Based on the results obtained，the current deposition model and the energy deposition model of every key component of the chamber were established. According to the calculation results with the thermal model，finite element thermal analysis was performed under the steady state of the thruster，and also the thermal balance experiments were performed. The results indicate that the electron temperature in discharge chamber was in the range of 2～4eV，and ionization mainly appeared near the thruster’s axis ，where the xenon ionization reaction rates and electron temperature were the highest，and ion density was about 1017/m3 in the discharge chamber. The energy depositing on inner surface of the wall chiefly came from the secondary electrons and xenon ions.

Key words: Ring-cusp magnet field；Ion thruster；Thermal model

摘要： 为了建立国内自行研制的20cm口径LIPS-200环型会切磁场离子推力器放电室的热模型，研究了放电室内等离子体的产生过程，得到了二次电子的温度、离子密度以及电子密度分布规律，在此基础上得到放电室各个关键部件的电流沉积和能量沉积热模型。以热模型计算结果为依据，进行了推力器稳态工作下的有限元热分析以及热平衡验证试验。结果显示:推力器处于稳定放电时，放电室内电子温度分布范围为2～4eV；电离基本发生在放电室轴线附近，此处电离产生率和电子温度最高，并且整个放电室内离子密度约为1017/m3；放电室的内表面能量沉积主要来自二次电子及Xe离子。

关键词: 环型会切磁场；离子推力器；热模型