Investigation on the Frequency Dependence of the Correlation Between Discharge Current and Gap Voltage in Helium Dielectric Barrier Discharges at Atmospheric Pressure

This article presents a systematic investigation on the frequency dependence of the discharge current J
_g
versus the gap voltage V
_g
in the atmospheric-pressure helium dielectric barrier discharges (DBDs) by means of numerical simulation based on a 1-D fluid model. The DBDs are excited by a sinusoidal voltage with frequencies from several tens of kHz to MHz. This article concludes the following. There is a characteristic frequency f
_c
located in a range, smaller than the lower limit of which the J
_g
-V
_g
curve universally behaves as a pinched hysteresis loop, and higher than the upper limit of which it changes to a nonpinched one, and an estimation of f
_c
has been given. Smaller than the lower limit of f
_c
, in spite of its J
_g
-V
_g
pinched hysteresis loop, the discharge plasma part in the DBD cannot be described as a memristor, but exhibits a memory effect. With the increase infrequency, the J
_g
-V
_g
curves display two typical shapes similar to a hockey stick and a quasi-triangle, corresponding to a Townsend discharge and a glow discharge, respectively. Higher than the upper limit of f
_c
, the J
_g
-V
_g
curve is no longer a pinched hysteresis loop, and its evolution with frequency is in a change between symmetry and asymmetry. These evolution behaviors of the J
_g
-V
_g
curves are mainly due to the charges remained in the gap when the frequency is higher.