Finite-difference time domain simulation of electromagnetic wave transformation in a dynamic, inhomogeneous, bounded, and magnetized plasma

The electromagnetic wave transformations in a dynamic, inhomogeneous, bounded, and magnetized plasma medium are studied by using the Finite-Difference Time-Domain method (FDTD). A Lorentz plasma model is used and the source frequency of the waves is considered high enough that ion motions are neglected. The frequency shifting characteristics are extensively presented. The successive reduction method is developed to find frequencies and amplitudes of the fields generated by the FDTD simulation.;In one-dimensional problems, time-only formulation is used for unbounded problems and for the periodic problems, one unit cell space formulation is used. For the plasma slab, total field/scattered field formulation and an absorption boundary condition are used to implement compact size FDTD code. The FDTD method is compared with approximate analytical methods (perturbation method and WKB method) and the validity ranges of those analytical methods are obtained.;It is shown that the source wave is modified when the change of plasma density is slow while new modes are generated when the change of the plasma density is fast. It is also verified that when the source wave is a whistler wave, collapsing of the plasma medium generates frequency upshifting with power intensification and the switching off the external magnetic field generates a wiggler wave.;In the three-dimensional cavity, a new FDTD formulation is implemented to avoid simultaneous equations, which results in minimum computer resource requirement.