时变磁化等离子体的LTJEC-FDTD方法研究

Analysis of Time-varying Magnetic Plasma by Using LTJEC-FDTD Method

基于拉普拉斯变换的电流密度卷积技术(LTJEC),构造了时变磁化等离子体的新型时域有限差分方法(LTJEC-FDTD)。借助于高斯脉冲在磁化等离子体中的传播实例,验证了LTJEC-FDTD算法的准确性及高效性。进一步,研究了Whistler波在一维时变磁化等离子体中的具体传播特性。结果表明,当离子体频率随时间指数衰减后,输出波的频率上升、极化方式不变,而电场增强、磁场减弱。同时,通过优化磁化等离子体参数,可进一步提高Whistler波的输出频率,获得了频率为300 GHz的圆极化太赫兹波。研究结果可为利用磁化等离子体产生太赫兹波源提供相关的技术支持。

The Laplace transfer current density convolution finite difference time domain（LTJEC-FDTD） was used to study the medium of time - varying magnetic plasma. A Gaussian-derivative pulsed plane wave was simulated in magnetic plasma by the method of LTJEC-FDTD. The numerical results show that the method of LTJEC-FDTD not only ensure the accuracy but also has higher computational efficiency. By simulating the propagation characteristics of a Whistler wave in the one-dimensional time - varying magnetic plasma, a output wave with higher frequency and enhanced electric field is obtained after switch off the plasma source. Finally, a terahertz wave with 300 GHz is obtained which theoretically verifies that the terahertz wave can be generated from the microwave by the time-varying magnetized plasma. These conclusions provide some theoretical bases for the generation of terahertz wave.