磁化碰撞等离子体对雷达波的共振吸收

使用平板几何对雷达工作频段的电磁波在磁化碰撞等离子体中的传播作了数值计算。计算结果表明 ,在均匀等离子体中 ,当等离子体碰撞频率fen =0 .1,0 .5 ,1GHz及电磁波频率接近高混杂频率时 ,电磁波衰减和被吸收功率出现最大峰值 ,即出现共振吸收 ;当fen =5 ,10GHz时 ,电磁波衰减、被吸收功率和透射功率曲线变得很平坦 ;衰减和吸收功率随等离子体密度的增大而增大 ,在n =10 11cm-3 时 ,衰减可达 10 0dB ,吸收比可达 80 %。在非均匀等离子体中 ,电磁波的反射功率峰值比在均匀等离子体中大。因此 ,磁化均匀等离子体比非均匀等离子体更有利于等离子体隐身。

（2＋1）-Dimensional Electron Acoustic Solitary Waves in an Unmagnetized Collisionless Plasma with Vortex-Like Hot Electrons

In this paper, （2＋1）-dimensional electron acoustic waves （EAW） in an unmagnetized collisionless plasma have been studied by the linearized method and the reductive perturbation technique, respectively. The dispersion relation and a modified Kadomtsev-Petviashvili （KP） equation have been obtained for the EAW in the plasma considering a cold electron fluid and a vortex-like hot electrons. It is found from some numerical results that the parameter β（the ratio of the free hot electron temperature to the hot trapped electron temperature） effects on the amplitude and the Width of the electron acoustic solitary waves （EASW）. It can be indicated that the free hot electron temperature and the hot trapped electron temperature have very important effect on the characters of the propagation for the EASW.