  This paper investigates the self-pulsing of Dielectric Barrier Discharges
(DBDs) at low driving frequencies. In particular, (a) the dependence of current
on the product pd of gas pressure p and the gas gap length d, (b) the effects
of lossy dielectrics (in resistive discharges) and large dielectric
permittivity (in ferroelectrics) on current dynamics, (c) the transition from
Townsend to a dynamic Capacitively Coupled Plasma (CCP) discharge with changing
pd values, and (d) the transition from Townsend to a high-frequency CCP regime
with increasing the driving frequency. A one-dimensional fluid model of Argon
plasma is coupled to an equivalent RC circuit for lossy dielectrics. Our
results show multiple current pulses per AC period in Townsend and CCP
discharge modes which are explained by uncoupled electron-ion transport in the
absence of quasineutrality and surface charge deposition at dielectric
interfaces. The number of current pulses decreases with an increasing applied
frequency when the Townsend discharge transforms into the CCP discharge. The
resistive barrier discharge with lossy dielectrics exhibits Townsend and glow
modes for the same pd value (7.6 Torr cm) for higher and lower resistances,
respectively. Finally,we show that ferroelectric materials can amplify
discharge current in DBDs. Similarities between current pulsing in DBD, Trichel
pulses in corona discharges, and subnormal oscillations in DC discharges are
discussed. 1
