Unconditionally Stable CN-FDTD Algorithm For Anisotropic Magnetic Plasma

Plasma is the dissipation and dispersion medium.The relationship between the plasma and the electromagnetic wave is always the focus of attention for domestic and foreign scholars.The plasma would take on electrical anisotropy under the effect of the external magnetic field.For the application of plasma,the magnetic plasma has more prominent characteristics than the unmagnetized plasma.Under the interaction between electromagnetic wave and magnetic plasma,the anisotropic magnetic plasma medium will make the incident electromagnetic wave energy greatly attenuation,and change the direction of propagation and the polarization.The finite-difference time-domain(FDTD)is an effective and simple method to solve the maxwell's equations.However,the time-step of conventional FDTD method is restricted by the Courant-Friedrichs-Lewy(CFL)stability constraint for the plasma medium,which cannot be ignored gradually.Therefore,the unconditionally stable method has received widespread concern.Based on the conclusion and analysis of FDTD algorithm,this paper proposes unconditionally stable CN-FDTD algorithm with high computational efficiency and high accuracy which aims at anisotropic magnetic plasma medium.The research includes:Firstly,it introduces the FDTD algorithm and courant stability condition,the theory of perfectly matched layer(PML),the iterative equation of the conventional Current Density Convolution(JEC-FDTD)algorithm and the conventional auxiliary differential equation(ADE-FDTD)algorithm.Then,this paper starts with traditional JEC-FDTD and ADE-FDTD algorithm,infers two unconditionally stable algorithm of one-dimensional magnetic plasma and gives the numerical example verification to the algorithm.The main research content of this dissertation list as follows:1.The two unconditionally stable algorithms,JEC-CN-FDTD algorithm and ADE-CN-FDTD algorithm,are proposed for one-dimensional anisotropic magnetoplasma.The two methods combined the unconditionally stable CN algorithm to JEC method and the ADE method respectively.The numerical test is provided to verify the effectiveness of the new algorithms,and the simulation results are compared with the conventional FDTD algorithm and the analytical solution.It can be proved that the two new algorithms can greatly improve the computational efficiency and become the unconditionally stable form in the case of preserving the original precision.2.Two unconditionally stable algorithms,JEC-CNAD-FDTD algorithm and ADE-CNAD-FDTD algorithm,are proposed for two-dimensional anisotropic magnetoplasma.The two algorithms are used to discuss the propagation process of the electromagnetic wave in the two-dimensional anisotropic magnetic plasma medium,and the effectiveness of the proposed algorithm is verified by simulation.