MONTE-CARLO SIMULATION OF NORMAL AND ABNORMAL GLOW-DISCHARGE PLASMAS USING THE LIMITED WEIGHT PROBABILITY METHOD

A self-consistent Monte Carlo modelling technique has been developed t o study normal and abnormal glow discharge plasmas. To simulate nonequ ilibrium particles, a limited weight probability method is introduced and a fine subslab system is used. These two methods are applied to a DC Ar-like gas discharge simulation. The simulations are performed for conditions corresponding to the experimental voltage and current sets of normal and abnormal glow disharges. The characteristic spatial pro files of plasmas for normal and abnormal glow discharges with high non equilibrium electron energy distributions are obtained. The increase i n the current and the voltage from the normal glow leads to the follow ing: (1) the density peak of the ions rises in the cathode region, (2) the density peak of electrons rises and catches up with that of ions and the peak position occurs closer to the cathode simultaneously; ins tead of a small increase of plasma density in the bulk plasma region, (3) reversal field strength next to the cathode fall increases and (4) the two groups of the enregy distribution separates into three groups at the cathode fall edge.