Papers by Keyword: Charged Particles

Abstract: The simulation of glow discharge in N₂ in a needle-plane configuration with PIC/MCC method is presented. In the discharge channel the electric field driven by space charges is solved by PIC method, and various collisions between particles are described with MCC method. The electric field intensity, the electric potential and the net charge distribution in the discharge area are obtained. The numerical results are consistent with the corresponding features of glow discharge. This work can provide references to further study of glow discharge.

Abstract: The purpose of the present work consists in the elaboration of numerical computing program allowing the simulation of various species behaviour present in plasma reactor during films formation by cold plasma in DC glow discharge. After application of some simplifying hypotheses, we have developed a simulation model based on a fluid approximation. The elaborated model was based on finite differences method solved by MATLAB software. We applied the model to simulate the plasma in the case of atomic gases (Ar) and molecular (CH4) gases. The simulation results are given in terms of spatial distribution of charge densities, electric potential and electric field between electrodes space. The effect of some discharge parameters such as the pressure, and the density of the gas was also investigated.

Abstract: The electrical and optical signal waveforms of nitrogen/hydrogen glow discharges used for plasma nitriding process were recorded and analyzed. The shape of the discharge voltage and current signals is dependent on the process parameters, pulse plasma generator properties and cathode geometry. It has been found that the dynamic parameters of the electrical signal waveforms contain information related to the charged particles generation, which is relevant to the homogeneity of different gas discharge surface treatment processes. On the other hand, information related to the active species generation responsible for thermochemical processes at the cathode surface is stored in the optical emission waveforms. The generation and quenching of the active ingredients during the voltage pulses switch on and off influence the shape of the emitted light signals. From the optical signal analysis it was found that the thermochemical processes are influenced by the plasma generator properties such as pulse duty cycle, frequency, applied discharge voltage level and process parameters like working gas composition, operating temperature and pressure.