The problem is effect of electromagnetic wave. When electromagnetic wave obliquely transmitted through two different medias ,electromagnetic wave undergoes reflection and refraction at the interface and inside the media. Computation of electromagnetic wave is well known by Maxwell`s equation. There are two cases solving questions. One is constant of £g¡B£`¡B£m.Another is variable of £g¡B£`¡B£m. In case one, use D`Alembertian equation and Helmholtz equation transforming Maxwell`s equation. And solve by ILHI`s(incomplete Lips-chitz-Hankel integrals) and FFT(fast Fourier transform). In case two,if £g¡B£`¡B£m are variables ,we can simplify Maxwell`s equation. It is similar to wave equation with source. We use Finite Element Method(FEM) getting Numerical solution by setting absorbing boundary and mesh. Using results by ILHI`s would get exact solution obliquely incident on two medias. Proof numerical solution by exact solution.

This study uses the PIC (Particle-in-cell) method to simulate unsteady three-dimensional dynamics of particles in argon plasma under low pressure, high density, and weak ionization between two planar electrodes subject to a sudden biased voltage. Plasma has been widely used in materials processing, film manufacturing, nuclear fusion, lamps, etc. Properties of plasmas are also becoming important area for research. This work includes elastic collisions between electrons and neutrals, ions and neutrals, and inelastic collisions resulting in ionization from impacting neutrals by electrons, and charge exchange between ions and neutrals, and Coulomb collisions between electrons and ions. The model ignores secondary electron emission, recombination between ions and electrons, and assumes uniform distribution of the neutrals having velocity of Maxwellian distribution. The computed results show the effects of elastic and inelastic collisions on the characteristics of plasma and sheath (space charge region) in front of the workpiece surface. Unsteady mass, momentum and energy transport from the bulk plasma through sheath to the workpiece is confirmatively and exploratorily studied after successful comparison between PIC prediction and experimental data has been made.