Numerical research of a 2D axial symmetry hybrid model for the radio-frequency ion thruster

Since the high efficiency discharge is critical to the radio-frequency ion thruster (RIT),a 2D axial symmetry hybrid model has been developed to study the plasma evolution of RIT.The fluid method and the drift energy correction of the electron energy distribution function (EEDF) are applied to the analysis of the RIT discharge.In the meantime,the PIC-MCC method is used to investigate the ion beam current extraction character for the plasma plume region.The beam current simulation results,with the hybrid model,agree well with the experimental results,and the error is lower than 11％,which shows the validity of the model.The further study shows there is an optimal ratio for the radio-frequency (RF) power and the beam current extraction power under the fixed RIT configuration.And the beam extraction efficiency will decrease when the discharge efficiency beyond a certain threshold (about 87 W).As the input parameters of the hybrid model are all the design values,it can be directly used to the optimum design for other kinds of RITs and radio-frequency ion sources.     

LHT-100霍尔推力器滤波设计与放电震荡关系研究

为了对LHT-100霍尔推力器放电震荡进行抑制,研制了与推力器相匹配的放电震荡抑制装置。结合国内外霍尔推力器放电震荡研制背景,通过仿真分析和集成试验两种手段,对LHT-100霍尔推力器放电震荡情况进行了研究。根据试验结果表明滤波参与下放电回路震荡得到了有效抑制,为电推进系统稳定工作提供了可靠保障。     

离子推力器三栅极组件热形变仿真分析及试验研究

栅极组件是离子推力器束流引出、加速和聚焦的核心部件.推力器工作过程中栅极组件的热形变是影响离子推力器工作性能和寿命的关键因素之一.通过建立栅极组件的结构等效模型,模拟了栅极组件的温度分布,运用有限元软件绘制出同一时刻栅极组件表面不同位置沿着径向坐标热形变位移曲线,分别计算出栅极组件中心点处屏栅-加速栅、加速-减速栅极间...     

离子推进器热特性测试与分析

对离子推进器工作状态的热特性进行了测试与分析。测试分析结果表明：离子推进器工作时产生的热量主要以热传导和热辐射向周围环境传递,通过安装环传导到航天器的热量较少,不会对航天器产生影响。热辐射主要向空间辐射,不会对航天器造成热影响。     

Estimate of Lifetime of Ion Thruster Optics Based on Particle Simulation

A three-dimensional particle simulation of ion thruster optics with charge-exchange collision was developed in this study. The simulation code was based on tracking ions using the particle-in-cell method, and the Monte Carlo technique was used to model the charge-exchange collision. Simulations were performed for a 20 cm ion thruster optics. The results were compared with the corresponding experimental data from a test of the ion thruster optics for a duration of 800 hours. The Depth-From-Focus （DFF） method was used to measure the erosion depth of the downstream surface of the accelerator grid. The predicted erosion depth of the accelerator grid was consistent reasonably with the corresponding experimental data. The simulation results showed that the accelerator grid would be burned through after 1333 hours.     

超大型航天器应用电推进系统方案设计

超大型航天器运行在(393±10)公里的近地轨道上,由于受到大气阻尼的减速作用,需要对超大型航天器实施轨道维持。LHT-100霍尔电推进系统是一种可用于超大型航天器轨道维持的高比冲小推力的电推进装置,采用电推进系统,超大型航天器年推进剂需求量可以降低到400kg以下,并需要对载有航天员的超大型航天器的安全性和可靠性进行评估。本文提出了超大型航天器轨道维持霍尔电推进系统方案设计,对霍尔推力器和贮气单元气瓶组件在轨可置换性进行了分析,最后对其可靠性和安全性进行了设计与分析,为我国超大型航天器采用LHT-100霍尔电推进系统进行轨道维持开展系统产品研制奠定了坚实的基础。     

Investigation into the thermal effect of the LIPS-200 ion thruster plume

The distribution of the thermal effects of the ion thruster plume are essential for estimating the influence of the thruster plume, improving the layout of the spacecraft, and for the thermal shielding of critical sensitive components. In order to obtain the heat flow distribution in the plume of the LIPS-200 xenon ion thruster, an experimental study of the thermal effects of the plume has been conducted in this work, with a total heat flow sensor and a radiant heat flow sensor over an axial distance of 0.5–0.9 m and a thruster angle of 0°–60°. Combined with a Faraday probe and a retarding potential analyzer, the thermal accommodation coefficient of the sensor surface in the plume is available. The results of the experiment show that the xenon ion thruster plume heat flow is mainly concentrated within a range of 15°. The total and radial heat flow of the plume downstream of the thruster gradually decreases along the axial and radial directions, with the corresponding values of 11.78 kW m⁻² and 0.3 kW m⁻² for the axial 0.5 m position, respectively. At the same position, the radiation heat flow accounts for a very small part of the total heat flow, approximately 3%–5%. The thermal accommodation factor is 0.72–0.99 over the measured region. Furthermore, the PIC and DSMC methods based on the Maxwell thermal accommodation coefficient model (EX-PWS) show a maximum error of 28.6% between simulation and experiment for LIPS-200 ion thruster plume heat flow, which, on the one hand, provides an experimental basis for studying the interaction between the ion thruster and the spacecraft, and on the other hand provides optimization of the ion thruster plume simulation model.     

变工况下自励磁模式LHT-60霍尔推力器放电特性试验研究

针对低轨互联网星座轨道维持、寿命末期轨道提升任务需求,兰州空间技术物理研究所研制了口径为60 mm的LHT-60霍尔推力器.研究了LHT-60霍尔推力器变工况下的放电特性,进行了自励磁模式下,放电电压200～350 V、质量流量1.1～2.0 mg/s工况的推力器工作特性试验.结果表明,推力器在各工况点均可稳定工作,工...     

Kaufman放电室二次电子温度的计算方法研究

二次电子温度计算是研究Kaufman放电室的核心内容之一。针对Kaufman放电室建立稳态平板非均匀放电模型对二次电子温度进行求解。稳态平板非均匀放电模型从扩散方程出发,重点考虑离子漂移造成的扩散运动和双极性电场对放电室径向密度梯度造成的影响,进一步结合粒子数守恒方程,给出用于求解二次电子温度的方程的解析表达式。代入典型的Kaufman放电室结构参数进行计算的结果表明,用稳态平板非均匀放电模型计算出来的二次电子温度符合实验测量的范围,同时说明在中低压放电条件下,扩散运动和双极性电场是影响放电性能的关键参数。