基于混合大气模型的高功率微波大气击穿特性研究

Researches on atmospheric ionization, air-breakdown, and nonlinear effects are of great importance to high-power microwave propagation in the atmosphere and its technical applications. In conventional microwave transmission models, the study of different spatial levels usually corresponds to different transmission models. The complexity of the different aspects of the transition zone, and the disruption of an intensive electric field on the transition zone cause great difficulty in the combination and application of conventional microwave transmission models. The high power microwave hybrid atmospheric transmission unified model has made a breakthrough in the nonlinear theory of transmission in the lower atmosphere, the ionosphere and the outer space. The unified model will be able to meet the needs of the HPM atmospheric transmission characteristics and transit self-consistently to each conventional microwave transmission model. .In consideration of the thermally induced rapid electronic effect caused by the high-power microwave, the collision frequency thermal effect and the ionization frequency thermal effect, and based on the high power microwave hybrid atmospheric transmission unified model, the paper provides a unified high power microwave air-breakdown model, a definition of high-power microwave breakdown and a hybrid algorithm formed by combining PSTD and Z-transform for simulation analysis of the air-breakdown threshold and regularities. The experimental device designed is able to preset air-breakdown of different states. Atmospheric transmission and breakdown experiments are carried out under typical conditions to verify the atmospheric transmission model and the air-breakdown theory. The study helps lay a foundation for the HPM source design and atmospheric transmission characteristics.

大气电离、大气击穿等非线性效应研究是高功率微波大气传输及其技术应用的首要内容。常规微波传输模型研究中不同空间层面对应不同的模型，不同层面过渡区的复杂性，以及强电场对过渡区的扰乱，使得常规微波传输模型的组合使用遇到了极大的困难，高功率微波混合大气传输模型突破低层大气、电离层、外层空间传输非线性理论分析难题，提出能够满足HPM大气传输特性研究需求并能自洽过渡到常规微波各传输模型的全链路模型。综合考虑高功率微波作用下的热致快速电子效应、碰撞频率热效应和电离频率热效应，基于高功率微波混合大气传输模型，提出高功率微波混合大气击穿模型，界定高功率微波击穿定义，提出一种PSTD-Z变换的混合算法仿真分析大气击穿阈值与规律。设计能够预置不同状态的HPM大气击穿实验装置，开展典型条件下大气传输特性与击穿实验，验证混合大气传输模型与大气击穿理论，为HPM源设计与大气传输特性研究奠定基础。

大气作为从高功率微波源到目标之间的传输通道，其特性将对高功率微波的应用产生重要的影响。大气电离、大气击穿等非线性效应研究是高功率微波大气传输及其技术应用的首要内容。常规微波传输模型研究中不同空间层面对应不同的模型，不同层面过渡区的复杂性，以及强电场对过渡区的扰乱，使得常规微波传输模型的组合使用遇到了极大的困难，本项目提出了高功率微波混合大气传输全链路模型，能够满足HPM大气传输特性研究需求并能自洽过渡到常规微波低层大气、电离层、外层空间各层面传输模型。基于高功率微波混合大气传输模型，综合考虑高功率微波作用下的热致快速电子效应、碰撞频率热效应和电离频率热效应，提出了高功率微波混合大气击穿模型，界定了高功率微波击穿定义，得到了不同温度、湿度和压强条件下的大气击穿理论阈值与分布规律，发现了30-60km大气击穿易感层区域。设计了能够预置不同状态的HPM大气击穿实验装置，开展了窄带X波段单脉冲大气传输特性与击穿实验，监测到典型大气击穿现象和波形，获得了空间环境对HPM系统发射参数、使用空间、作用范围的限制条件，为HPM走功率合成技术发展路线和总体规划布局等提供了有力的理论和实验支撑。