Dynamical charging of a dielectric surface exposed to a plasma jet : quantitative comparison between experiments and simulations

In this work, we study through a quantitative comparison between fluid modeling and experiments, the transient charging of a surface under exposure of a non-equilibrium plasma jet at atmospheric pressure. For mono-polar pulses with variable pulse duration and amplitude, the electric filed inside the target is measured. We show that the charging time (i.e. the time from impact of the ionization wave till the fall of the high voltage pulse) is crucial to understand the plasma-surface interaction. When the charging time is kept relatively short (less than 100 ns), the surface spreading of the discharge and consequently the surface charge deposition are limited. When the charging time is relatively long (up to microseconds), the increased surface spreading and charge deposition significantly change the electric field to which the target is exposed to, during the charging time, and when the applied voltage returns to zero.