On the Discharge Parameters of a Glow-Mode DBD at Medium and Atmospheric Pressure

In this paper, we report on the behavior of a glow-mode pulsed barrier discharge working at different gas pressure (25-760 torr) in helium and helium-oxygen gas mixture. The experimental setup consists of a plane-parallel geometry of a dielectric barrier discharge (DBD) system, excited by positive monopolar voltage pulses. The discharge properties were characterized by electrical measurements and emission spectroscopy. Our investigations showed that the discharge consists of two current pulses, with different polarities, corresponding to each voltage pulse. The main results referred to the effect of pressure and oxygen percentage on the discharge parameters. The time-resolved spectroscopy of the DBD plasma working at different pressure pointed out the differences between the discharge mechanism at medium pressure and that close to atmospheric pressure. Moreover, at medium pressure (25 torr), the oxygen atoms are efficiently created for about 2% of molecular oxygen added to gas mixture.