On the Discharge Mode of Pulsed DBD in Nitrogen at Atmospheric Pressure

In this paper, we study the discharge modes of pulsed dielectric barrier discharge (DBD) in atmospheric nitrogen by means of a 1-D self-consistent fluid model. The results show that different from the atmospheric nitrogen discharges driven by sinusoidal voltages, which usually operate in Townsend discharge mode, the pulsed atmospheric nitrogen discharges can be generated in glow mode over a wide parameter range. Base on the numerical data, the discharge mode seriously depends on the voltage changing rate (dV/dt) at the rising and falling phases, and with the decrease of the voltage changing rate, the discharge can transfer from glow mode to Townsend mode. In the glow discharge mode, the numerical data show the density of N
₂
⁺
is much larger than that of N
₄
⁺
, indicating the direct ionization of N
₂
by electron impact is the primary ionization mechanism, however, the Penning ionizations between two metastable molecules play a dominate role in the Townsend discharge mode, resulting in the concentrations of N
₄
⁺
ion much higher than that of N
₂
⁺
ion.