A microwave (MW) plasma channel (filament, plasmoid, and plasma dipole) shows promise for its applications for off-body non-electrode modification of a gas flow (plasma aerodynamics) and in the plasma assisted combustion process. A full-scale study of the plasma channel evolution requires a self-consistent solution of Maxwell's equations, plasma chemical kinetics equations, and gasdynamics equations. An attempt is made to develop a simple electrodynamic (based on the solution of Maxwell's equations) “fast” model for studying the evolution of the plasma channel in conjunction with a fairly complete system of plasma chemical reactions. The model is based on a simplifying assumption about the shape of the channel, which converts a 3D problem into a 1D one. The results of numerical calculations in air within the pressure range P = 20–150 Torr are presented. An experimental study of plasmoid development was carried out to verify the predictions of the model. The calculated results agree well with all available experimental data within the pressure range P = 20–150 Torr. The proposed electrodynamic approach made it possible to reveal (i) the mechanism of self-organization during the development of a MW streamer and (ii) the reason for a sharp decrease in the velocity of its elongation, as well as to obtain relations connecting the main characteristics of the streamer (the amplitude of the electric field in the channel and on its heads, the velocity of ionization waves, and the characteristic scale of their fronts). The proposed model will be useful both for estimating the channel parameters and for deciphering the dynamics of radiation scattered by the plasma dipole. The development of such an approach will allow one to study the evolution of multiplasmoid structures of a high-pressure MW discharge.

中文翻译：

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使用新的半解析模型研究微波流注演化

微波 (MW) 等离子体通道（灯丝、等离子体团和等离子体偶极子）显示出其在气流（等离子体空气动力学）的离体非电极改性和等离子体辅助燃烧过程中的应用前景。等离子体通道演化的全面研究需要麦克斯韦方程、等离子体化学动力学方程和气体动力学方程的自洽解。尝试开发一个简单的电动力学（基于麦克斯韦方程组的解）“快速”模型，用于结合相当完整的等离子体化学反应系统研究等离子体通道的演变。该模型基于对通道形状的简化假设，将 3D 问题转换为 1D 问题。给出了在压力范围 P = 20-150 Torr 内空气中的数值计算结果。进行了等离子体团发展的实验研究以验证模型的预测。计算结果与压力范围 P = 20-150 Torr 内的所有可用实验数据一致。所提出的电动力学方法可以揭示 (i) MW 流注发展过程中的自组织机制和 (ii) 其伸长速度急剧下降的原因，以及获得连接流光的主要特征（通道内和其头部的电场幅度、电离波的速度及其锋面的特征尺度）。所提出的模型将有助于估计通道参数和破译等离子体偶极子散射的辐射动力学。这种方法的发展将允许人们研究高压 MW 放电的多等离子体结构的演变。