微波等离子推力器同轴谐振腔内的电磁场特性

为了研究同轴谐振腔内导体的头部形状、位置对腔内电磁场分布的影响规律,用时域有限差分法(FDID)对微波等离子推力器(MPT)TEM谐振模式的同轴谐振腔中的电磁场进行了数值模拟,并结合实验现象对数值模拟的结果进行了分析讨论。结果表明,内导体头部形状的改变,改变了同轴腔内电磁场的分布规律和电场强度最大集中区域的位置。内导体位置的改变,只改变电磁场强度的大小,且内导体愈接近同轴腔的底面(即：放电间隙δ愈小),腔内电场强度愈强。同时,锥形头部的内导体,更有利于MPT的启动和稳定工作,为采用同轴谐振腔的MPT工程样机的研制提供了依据。

Characteristics of electromagnetic field within the coaxial resonant cavity of microwave plasma thruster

In order to research the influence of shape and position of inner conductor on electromagnetic field within coaxial resonant cavity with TEM resonant model, the numerical simulation was conducted by use of FDTD and the results were compared with the experiment phenomena. Results show that the shape of inner conductor not only makes the distribution of electromagnetic field change but also makes the zone position of the maximal electric field change. The position of inner conductor makes the strength of the electromagnetic field change only and the less the aperture between the inner conductor and the bottom of coaxial resonant cavity, the more the strength of electromagnetic field. The cone shape of the inner conductor is propitious to start and work steadily for MPT. These results can be used for design of MPT" s project prototype with coaxial resonant cavity.