When plasma surrounds a surface on different potential than the plasma potential, the sheath layer is formed. The sheath layer is well described for surfaces with simple geometry and steady-state.
Our main focus is to study dynamic transition between two steady-states with use of simple geometry. Finally, our goal is to determine the rate of sheath changes.
If plasma does not have enough time to stabilize in the time varying environment, it can lead to incorrect data interpretation or, in the worst case, some instability may occur. We decided to use computational physics for this study, which gave us a possibility to quickly adjust plasma parameters.
Since our goal was related to the sheath, we had to model it on microscopic level and the best choice was PIC-MCC model. This allowed us to have the desired resolution in medium pressure.
The results show that the rate of sheath changes is in our case around 10 µs.