Simulation Study on Pulse-Modulated RF-Driven Atmospheric Pressure Argon Dielectric Barrier Discharge

The characteristics of pulse-modulated RF-driven atmospheric pressure argon (Ar) dielectric barrier discharge (DBD) have been investigated, on the basis of a 1-D coupled fluid model. Time-domain variations of the voltage and the charge density on the dielectric surface (
$V_{\text{k}}$
and
$\sigma)$
were obtained for different radio frequency (RF) voltage amplitudes (
$V_{\text{RF}})$
. Furthermore, the minimum voltage amplitudes of RF maintenance discharge (
$V_{\text{RF},\min})$
changing with the pulse duty cycle (
$D_{\text{R}})$
and pulse modulated frequency (
$f_{\text{RF},\text{p}})$
were discussed, and the variation of spatiotemporal average electron density with spatiotemporal average sheath voltage during the low-frequency period was studied for various
$D_{\text{R}}$
and
$f_{\text{RF},\text{p}}$
. It was found that
$V_{\text{k}}$
and
$\sigma$
cannot reach a periodic steady state for smaller
$V_{\text{RF}}$
. When it increases to
$V_{\text{RF},\min}$
, or even greater than
$V_{\text{RF},\min},V_{\text{k}} $
and
$\sigma$
reach the steady state and the time for both to reach the steady state is advanced. When
$V_{\text{RF}}$
is 600 V, it is shortened to 2.36
$\times$
10
$^{-6}$
s (about 32 RF periods), comparing with that when
$V_{\text{RF}}$
is 280 V.
$V_{\text{RF},\min}$
decreases as
$D_{\text{R}}$
increasing from 20% to 100%. The discharge is only in
$\gamma$
mode for smaller
$D_{\text{R}}$
while it exists in
$\alpha$
and
$\gamma $
modes for greater
$D_{\text{R}}$
. In addition,
$V_{\text{RF},\min}$
increases along with
$f_{\text{RF},\text{p}}$
growing from 0.01937 to 0.1356 MHz. When
$f_{\text{RF},\text{p}}$
is higher, the
$\gamma$
mode exists for discharge, while when it is lower, there are two modes:
$\alpha$
and
$\gamma $
.