强激光与粒子束, 2010, 22 (9): 2115, 网络出版: 2010-09-21
非均匀等离子体对平面电磁波的衰减
Attenuation of planar electromagnetic waves by inhomogeneous plasma
等离子体 电磁波 隐身 时域有限差分法 衰减 plasma electromagnetic wave stealth finite-difference time-domain attenuation
摘要
利用荧光灯排列形成非均匀等离子体层(面积约60 cm×52 cm,消耗功率约400 W),研究了其对1~8 GHz E波(电矢量方向平行于灯轴方向的入射波)的反射和透射的影响。结果表明,该等离子体对1~4 GHz的E波具有强吸收和弱反射的特性,单程衰减最高可达8 dB。利用2维分段线性电流密度递归卷积时域有限差分计算式,模拟了E波传播及其在非均匀等离子体内推进的瞬态过程,计算了等离子体对电磁波的反射和透射衰减,并与实验结果拟合,得到等离子体电子数密度峰值约9.72×1016 m-3,电子与中性粒子碰撞频率约4 GHz。
Abstract
Based on the possible application of low power, large area, inhomogeneous plasma to radar stealth, many standard commercial fluorescent lamps placed directly against each other were used to produce a inhomogeneous plasma layer (area 60 cm×52 cm, power 400 W). The reflection and transmission of E-waves (electric field of the waves was parallel to tube axis ) in the frequency range of 1 to 8 GHz were investigated both experimentally and numerically. The strong absorption and weak reflection of E-waves were observed near 1 to 4 GHz, and the one-way attenuation trended to a peak of 8 dB. The two-dimensional piecewise linear current density (JE) recursive convolution finite-difference time-domain (PLJERC-FDTD) algorithm was applied to simulate the transient progress of E-waves traveling through the inhomogeneous plasma. The reflection and transmission attenuations of the waves were calculated, and they had a similar developmental tendency as measurement. Through the comparison of calculation and measurement, the maximal electron number density and electron-neutral collision frequency were proved to be about, respectively, 9.72×1016 m-3 and 4 GHz.
何湘, 陈建平, 倪晓武, 吴莹, 陈玉东, 曾小军, 秦海潮. 非均匀等离子体对平面电磁波的衰减[J]. 强激光与粒子束, 2010, 22(9): 2115. He Xiang, Chen Jianping, Ni Xiaowu, Wu Ying, Chen Yudong, Zeng Xiaojun, Qin Haichao. Attenuation of planar electromagnetic waves by inhomogeneous plasma[J]. High Power Laser and Particle Beams, 2010, 22(9): 2115.