Distributions of Accumulated Charges in Atmospheric Pressure Oxygen Dielectric Barrier Discharges

Recently, atmospheric pressure dielectric barrier discharges (DBDs) have been widely applied to various research fields, but the details of DBD development have not been clarified yet. Because the phenomena occur under atmospheric pressure in nanosecond time scale, and the discharges are significantly affected by the surface of dielectric conditions. One of the main conditions is the secondary electron emission coefficient. The secondary electron emission coefficients of dielectrics have been trying to measure for many years. Recently, some researchers have measured secondary ionization coefficients
¹
, but the secondary electron emission coefficients (SEECs) are unknown yet. And accumulated charges also affect to the discharges. In this paper, to clarify the effect of secondary electron emission on accumulated charges have been investigated in atmospheric pressure oxygen DBD using a two dimensional fluid model
^{2, 3}
. And evolutions of local accumulated charges were examined, such as on the streamer and off the streamer. The simulations have been performed with the conditions of driving frequency 200kHz, pressure 760Torr, high and low SEEC case and 100% oxygen gas.