Characteristics of Atmospheric-Pressure Helium Barrier Pulse Discharges

The mechanism and evolution of atmospheric-pressure dielectric barrier discharge (DBD) in pure helium excited by repetitive voltage pulses have been numerically studied using a 1-D fluid model. The temporal and spatial distributions of the characteristic quantities, i.e., electron density, ion density, electron temperature, and gap electric field, are calculated, and the following characteristics are observed. There are many electrons in the gap before each of the two pulse discharges in one circle of the applied voltage pulse, the significant difference between the electron densities before each pulse discharge makes the two discharge modes in asymmetry, the breakdown in the second discharge is weaker than that in the first discharge, and a wide area of quasi-neutral plasma bulk can be obtained. In addition, the effects of the key parameters of the applied voltage pulse, such as amplitude, pulsewidth, frequency, rising time, and falling time, on the DBD are analyzed systematically, and in particular, the multipeak behavior and the structure transition of distribution of the charged particle densities are observed.