We study a finite volume solver for radiation hydrodynamical models in two space dimensions. For nonlinearity of radiation pressure and radiation energy, it is not a trivial task to develop a numerical scheme for radiation hydrodynamics compared to Euler equations. The current strategy is that the convective part is solved by MUSCL-Hancock schemes, while the diffusive part is handled through an alternative form of TR/BDF2 (trapezoidal rule with second order backward difference formula) method. An asymptotic analysis for the grey nonequilibrium diffusion model in time is presented. Numerical experiments are given to show performance of the IMEX scheme.

Electromagnetic propagation through a magnetized plasma is studied with the finite-difference time-domain (FDTD) method by means of Z transforms. The propagation direction is perpendicular to the biasing magnetic filed and the electric field is parallel to the biasing magnetic filed. The dependence of the reflection and transmission coefficients on frequency is obtained by discrete Fourier transform. A comparison with analytical values of homogeneous magnetized plasma is made. The reflection and transmission coefficients in an inhomogeneous magnetized plasma layer are calculated as well.

A mathematical method of Using the Code of direct question to Solve inverse question is described. With this method on the basis of free-boundary toroidal MHD equilibrium Code SWEQU^[1] We developed our own Code SWSTAB, Which can be used to calculate vertical instability of Tokamak plasma with noncircular cross section. Practical examples show that Some physical results are obtained by this method more easily than by others.