摘要
基于高功率微波(HPM)混合气体传输模型,系统阐述了考虑磁效应条件下HPM窄波束在低电离层中传输时的聚焦与散焦原理,推导了考虑外加磁场和HPM热效应情况下,窄波束在低电离层中传输的非线性几何光学方程及聚焦和散焦特性描述参数,并对低电离层中的波束发散特性进行了仿真分析。仿真结果表明:低电离层表现出的散焦特性,使HPM窄波束发散,L,R,O,X波均发生了波束发散现象,且R波的波束发散角最大,O,X波次之,L波最小,但随着入射波频率的增加,这种差别逐渐减小;相同条件下,入射波频率越高,散焦现象越弱;一定入射波频率条件下,波束轴线上的场强越大,波束发散现象越明显。
Based on the theory of HPM propagating in mixed-atmosphere,studies are conducted on the phenomenon and principle of self-focusing/defocusing of the narrow HPM beam propagating in ionospheric plasma.The nonlinear propagating equation,and focusing/defocusing parameters have been derived with nonlinear heating effects being considered.The dependence of beam width on the frequency and intensity of HPM has been illustrated in the presence of magnetic field.Simulations show that the lower ionosphere mainly represents a defocusing medium.The divergent phenomenon occurs for L-wave,R-wave,O-wave and X-wave.And the angle of divergence is the maximum for R-wave and the minimum for L-wave.But the difference will decrease with the increase of the frequency of incident wave.Defocusing effect weakens with the increase of incident frequency when other conditions are fixed,while it is enhanced with the increase of the amplitude of on-axis electric field at the same incident frequency.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2011年第2期449-453,共5页
High Power Laser and Particle Beams
基金
国家高技术发展计划项目
关键词
高功率微波
混合气体
磁化等离子体
聚焦
散焦
high-power microwave
mixed-atmosphere
magnetized plasma
self-focusing
self-defocusing
