磁等离子体发动机中离子回旋共振天线参数优化

Parameter Optimization of Ion Cyclotron Resonance Antenna in Magnetoplasma Rocket Engine

磁等离子体发动机(Magnetoplasma Rocket Engine,MPRE)的离子回旋共振加热(Ion Cyclotron Resonance Heating,ICRH)单元中射频天线是能量注入元件,其参数直接影响能量耦合效率。为优化ICRH天线参数,建立了ICRH中粒子模拟(Particle In Cell,PIC)计算的缩比准则,以缩比PIC模型对ICRH单元进行了仿真计算,分析了天线位置、天线构型、天线输入频率对加热效果的影响,并在30kW MPRE样机上进行了羽流离子能量诊断实验。研究结果表明:天线起始位置位于0.125m (仿真中2.5mm)处加热效果最佳,左旋天线优于右旋天线,双带天线优于单带天线,四分之一扭转天线优于二分之一扭转天线,天线参数优化后离子能量升高到优化前的5.35倍;在螺旋波源功率4kW,ICRH功率8.0kW下,羽流诊断实验中离子能量达50.23eV,表明能量已成功耦合到等离子体中,天线优化方案有效。

The RF antenna is the energy injection component of Ion Cyclotron Resonance Heating stage(ICRH)in Magnetoplasma Rocket Engine(MPRE),its parameters have direct influence on the energy coupling efficiency. In order to optimize the parameters of ICRH antenna,the scaling law of particle simulation(PIC)in ICRH was proposed,the ICRH stage was simulated by scaled PIC model and the effects of antenna position,antenna configuration,antenna input frequency on heating effect were analyzed,and the plume ion energy diagnosis experiment was carried out on 30kW MPRE prototype. The results indicate that:the heating effect is best when the antenna start position is 0.125m(2.5mm in simulation),the left-hand antenna is better than right-hand antenna,double-strip antenna is better than single-strip antenna,quarter-twist antenna is better than half-twist antenna. After optimization,ion energy increases by 5.35 times. Applying 4kW RF power to helicon plasma source and 8kW RF power to ICRH,ion energy reached 50.23eV in plume diagnosis experiment,it shows that the energy has coupled to plasma,the antenna optimization scheme is effective.