Experimental and kinetic simulation studies of radio-frequency and direct-current breakdown in synthetic air

Abstract

We report a combined experimental and modeling study of the breakdown of synthetic air under the influence of static (dc) and time-varying electric fields, up to radio-frequencies (RF). The simulations of the breakdown events are based on a simplified model that makes the problem computationally tractable: only electrons are traced by Monte Carlo simulation. In the dc case the simulation is used for the determination of the effective secondary electron emission coefficient, based on the measured dc Paschen curve. In the RF case we observe a transition between the modes (i) where reproduction of the charges takes place in the gas volume (at electron oscillation amplitudes smaller than the gap size) and (ii) where surface processes—secondary electron emission and electron reflection—play an important role, as most of the oscillating electrons reach the electrode surfaces. The RF (f = 13.56 MHz) simulations, assuming a constant effective secondary electron yield, reproduce well the breakdown curve obtained in the experiment.