The induction plasma chemical reactor: Part II. Kinetic model

A kinetic model has been developed for the prediction of the concentration gelds in an rf plasma reactor. A sample calculation for a SiCl4/H2 system is then performed. The model considers the mixing processes along with the kinetics of seven reactions involving the decomposition of these reactants. The results obtained are compared to those assuming chemical equilibrium. The predictions indicate that an equilibrium assumption will result in lower predicted temperature fields in the reactor. Furthermore, for the chemical system considered here, while differences exist between the concentration fields obtained by the two models, the differences are not substantial

The induction plasma chemical reactor: Part I. Equilibrium model

A mathematical model is presented for the numerical simulation of the flow, temperature, and concentration fields in an rf plasma chemical reactor. The simulation is performed assuming chemical equilibrium. The extent of validity of this assumption is discussed. The system considered is the reaction of SiCl4 and NH3 for the production of Si3N4

Stationary supersonic plasma expansion : continuum fluid mechanics versus direct simulation Monte Carlo method

Supersonically expanding stationary thermal plasma, formed by a thermal cascaded arc is studied. Due to the low chamber pressure (20-100 Pa) the results of continuum mechanics model can be doubtful. This is why these results are validated against kinetic Monte Carlo simulation and experimental data obtained by means of laser induced fluorescence. The analysis proves that continuum mechanics is still applicable for the velocity and temperature field predictions downstream of the shock region. However, the shock formation and some non-equilibrium effects typical for supersonic flow can be correctly studied only with the help of kinetic simulations. We show that the errors in the results using continuum mechanics can be attributed to the presence of flow gradients. These errors diminish when the shock regions are thickened due to rarefaction, viscosity and heat conductivity. Besides, both methods show that the effect of the chamber geometry on the plasma flow field is important