In plasma source ion implantation (PSⅡ), the target immersed directly in a uniform Plasma is biased with high negative voltage pulse.Soaexpanding plasma sheath forms between the plasma and the surface of solid material and implant ions into the target. A numerical simulation model in one-dimensional planar geometry is developed to determine the temporal and spatial evolution of the sheath for the voltage pulse of rectangular and trapezoidal wave forms. Especially, the sheath evolution is simulated at the fall time of a trapezoidal voltage pulse.By numerical results the forcing of the presheath exhibits to be related to the pulse length and the applied voltage.

A self-consistent Monte Carlo simulation method that includes charge exchange and elastic scattering is developed to calculate the energy and angle distributions of ions in cathode sheath of a DC argon gas discharge for the different pressures. Cross sections of the charge exchange and the momentum transfer that depend on the ion energy are taken into account precisely. It is found that, as the ions move towards the cathode, the high energy portions of ion energy distributions are enhanced gradually and the small-angle portions of the angle distributions increase. A strong field accelerates the ions to higher speed and ensures that more ions move along the lines of force. The self-consistent electric field spatial variation in the sheath is nonlinear.

A Monte Carlo simulation method that includes charge exchange and elastic scattering is used to calculate the energy and angular distribution of ions striking the cathode in a DC argon glow discharge. For the case that charge exchange is the only collision process, the Monte Carlo results can be checked by the analytical solution of the Boltzmann equation. In that case, both methods yield the same ion impact energy distribution. The results of the simulation show that the most of ions almost vertically incident on the cathode.

In this paper, electron movement in the cathode fall region of a glow discharge in Argon has been simulated using the three dimensional Monte Carlo method, which has taken advantage of a null-collision technique. The electron distribution functions and the macroscopic electron parameters including the mean electron energy, the mutiplication coefficient and the Townsend inoizion coefficient are given and compared with those obtained with the one dimensional computer model. The results have shown that the angular scattering has significantly affected the electron behavour.

Electron energy distributions of direct-curent argon discharges at low pressures were calculated by numerically solving the homogeneous Baltzmann equation. The calculations cover the whole range of low electron densities to sufficiently high electron densities. Typical values of the ratios of the electric field to the gas density in this work are in the renges of 10^-16 < E/N < 10^-15 Vcm². The influence of electron-electron collisions and the electric field on the electron energy distribution function was studied.