磁化碰撞等离子体对雷达波的共振吸收

RESONANT ABSORPTION OF RADAR WAVES BY A MAGNETIZED COLLISIONAL PLASMA

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。

The propagation of radar waves in a magnetized collisional plasma slab is studied numerically.It is found for uniform plasma that: first, the wave attenuation and absorbed power show a peak value,i.e.,resonant absorption when the collision frequency f en=0.1,0.5,1GHz and the wave frequency nears upper hybrid frequency.Secondly, the attenuation,absorbed,and transmitted power curves become flat at f en=5,10GHz.Thirdly, the attenuation and absorbed power increase with plasma density,and the attenuation and the proportion of absorbed power can reach 100 dB and 80%, respectively, at the plasma density n=10 11cm -3.For nonuniform plasma,the peak value of reflected power is larger than that in uniform plasma.So,uniform magnetized plasma is of more benefit to plasma cloaking.