Harmony Between Simple Fluid and Particle Models of Radio-Frequency Parallel-Plate Discharge

Parallel-plate radio-frequency (RF) discharge in low-pressure pure helium is studied using two different models: (1) a local, one-electron group fluid model, and (2) single-particle dynamics with Monte Carlo collisions assuming a harmonic oscillatorlike ambipolar field. It is found that the field parameters in the particle model can be selected in order to fit the experimental eedf in the bulk plasma. The bulk field found is near that of the fluid model. With change to a molecular gas (nitrogen), this two-stage approach allows for self-consistent coupling of the electron dynamics with the vibrational kinetics. When molecules are deactivated mainly through superelastic collisions with electrons, the coupling with the vibrational kinetics changes the eedf in the bulk plasma.