大面积表面波等离子体源微波功率吸收的数值模拟研究

建立了大面积矩形表面波等离子体(SWP)源全尺寸的三维模型,用数值模拟的方法研究了SWP源基于碰撞的功率吸收问题,给出了随等离子体参数变化的微波反射率曲线,分析了不同天线对微波功率沉积的影响,并讨论了微波功率吸收和表面波的定性关系. 结果发现,均匀放电的SWP源功率沉积本质是由表面波等离子体的性质决定的,等离子体密度太大或太小都不利于功率吸收. 在正常工作气压下,SWP源通过碰撞机理即可以实现微波功率的有效沉积,微波吸收率可达80%以上,与已有实验相符. 本研究同时发现,天线阵列激发的表面波模式越紧凑,强度越大,越有利于微波的吸收. 关键词： 时域有限差分法 等离子体表面波 功率吸收 狭缝天线

Numerical simulation of microwave power absorption of large-scale surface-wave plasma source

A full-size three-dimensional model of large-scale rectangular surface-wave plasma (SWP) source was built, the power deposition problems of SWP source based on collision mechanism were investigated through numerical simulations. The microwave reflectivity curves varying with plasma parameters were obtained, and the influence of different antenna arrays on power deposition is analyzed. The results show that the power deposition of uniformly discharged SWP source mainly depends on plasma property, and too big or too small plasma density is unfavorable to the energy absorption. In the range of working gas pressure, SWP source can achieve effective power deposition only through collision mechanism, and the absorption rate of microwave can reach more than 80%, which agrees with the existing experimental result. The results also show that compact and intensive surface wave is more favorable to the absorption of microwave.