高功率微波与大气击穿等离子体相互作用的数值研究

项目名称： 高功率微波与大气击穿等离子体相互作用的数值研究

项目编号： No.61501358

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 赵朋程

作者单位： 西安电子科技大学

项目金额： 19万元

中文摘要： 高功率微波的强电场极易引起大气发生电离、甚至击穿，而伴随产生的等离子体将严重影响高功率微波的辐射与传播。因此，开展高功率微波与大气击穿等离子体相互作用研究具有重要的意义。本项目拟采用电子流体模型数值模拟高功率微波在大气击穿环境中的辐射与传播特性。分别基于动力学模型与粒子模型研究合理的电子能量分布函数，改进电子流体模型的模拟精度。针对由电子流体模型限定的非线性方程体系，采用时域有限差分方法的思想对其进行处理，导出按时间步进的差分格式，实现电离率、碰撞率等输运系数的时间动态计算，并推导差分格式的稳定性条件。研究高功率微波在大气传播中的电离、击穿阈值、传输、吸收和反射问题，揭示高功率微波大气传播规律；研究喇叭天线近场击穿等离子体的时域演化过程及其对天线辐射的影响；评估高功率微波大气击穿的抑制方法。本项目的研究将为高功率微波的天线设计、传播及其它方面的应用提供重要的理论支持和参考依据。

中文关键词： 高功率微波；大气击穿等离子体；电子流体模型；电子能量分布函数；时域有限差分方法

英文摘要： The intense electric field of a high-power microwave may cause the air ionization and breakdown, and lead to the production of plasma, which may severely affect the radiation and transmission of the high-power microwave. Therefore, it is very important to study the interaction of the high-power microwave with air breakdown generated plasma. In this project we will adopt the electron fluid model to simulate numerically the radiation and propagation characteristics of the high-power microwave in the air breakdown environment. The kinetic model and the particle model are employed to study the reasonable electron energy distribution function, respectively, in order to improve the accuracy of the electron fluid model. The nonlinear equations restricted by the electron fluid model are solved using the finite-difference time-domain method, the difference schemes in which all components and transport coefficients such as ionization frequency and collision frequency are updated with time-step are obtained, and the stability conditions for the difference schemes are deduced. The ionization and breakdown threshold of air, and the transmission, absorption and reflection of the high-power microwave propagating in the air breakdown are investigated, and the law of the high-power microwave propagation in the atmosphere is revealed; the time evolution of the air breakdown generated plasma in the near field of the horn antenna and its effect on the radiation are investigated; the methods for the suppression of the high-power microwave breakdown are evaluated. Our study will be helpful to the design of the high-power microwave antenna, the high-power microwave propagation and other applications.

英文关键词： high-power microwave;air breakdown generated plasma;electron fluid model;electron energy distribution function;finite-difference time-domain method