介质管内等离子体表面波传播特性研究

Axial Propagation of Surface Wave of Plasma Columns in Medium Tube

研究了同轴对称表面波沿介质管内的等离子体轴向传播的特性,导出了介质管内外的电磁场表达式,数值计算并仿真模拟了等离子体密度、信号频率、介质管内径、碰撞频率等因素对表面波在等离子体中传播的影响。结果显示,密度在1016m-3~1017m-3量级的等离子体更接近金属导体,介质管半径在11 mm^19 mm之间更有利于表面波的传播,而碰撞频率的影响并不明显。此结果对实验具有重要的指导意义。

The propagation of the axisymmetric surface wave of the plasma column inside the medium tube was theoretically studied. The analytical expression of the electromagnetic field distribtions, in-and outside the medium tube was derived. The influence of various key variables, including the plasma density, signal frequency, inner diameter of the medium tube,and collision frequency, on the surface wave propagation was numerically simulated. The results show that the plasma density, ranging from 1016 cm^-3 to 1017 cm^-3 and resembling a conductor, and the inner wall diameter, from 22 mm to 38 mm, favorably affect the surface wave propagation, whereas negligible impact of the collision frequency can be observed. Possible mechanisms were also tentatively discussed.