A. Shvydky

Dynamics of a barrier discharge at high overvoltage

The dynamics of a strong barrier discharge is investigated analytically in the simplest model that still keeps the essential discharge features. It is shown that at high overvoltage, the discharge develops into the ionizing wave moving from the anode toward the cathode. The velocity of this wave is found to be controlled mainly by the charge production rate in the cathode fall region and can considerably exceed the characteristic ion velocity. The influence of the capacitor formed by the dielectric layers on the discharge dynamics is analyzed. It is shown that, depending on the magnitude of the capacitance, two qualitatively different charging regimes exist.

Striations in dielectric barrier discharge systems with a hollow anode

The dynamics of the charging of an elongated hollow anode covered with a dielectric layer by an electron current is studied via three-dimensional particle-in-cell/Monte Carlo kinetic simulations. It is shown that this process is accompanied by the successive formation of striations in the plasma created by the electron impact ionization of the background gas. A number of specially designed numerical experiments are performed to further explore the nature of this phenomenon. An experimental setup where this type of striations should be observed is suggested.

Spreading of discharge plasma above cathode covered with dielectric layer

The dynamics of discharges where the plasma spreads over a plane cathode covered with a dielectric layer is studied via particle-in-cell/Monte-Carlo kinetic simulations. There is a region of strong electric field (between the plasma and the still uncharged areas of the dielectric surface) where most of ionization takes place—this region can be naturally called a dynamic cathode fall. The role of the electron and ion diffusion in maintaining the particle balance in the dynamic cathode fall is established. The dependence of the velocity of plasma spreading on the potential difference between the plasma and the cathode, the dielectric layer thickness, and the secondary electron emission coefficient is found for neon gas.

Dynamic positive column in long-gap barrier discharges

A simple analytical model of the barrier discharge in a long gap between opposing plane electrodes is developed. It is shown that the plasma density becomes uniform over a large part of the gap in the course of the discharge development, virtually forming a dynamic positive column. The column completely controls the dynamics of the barrier discharge and determines such characteristics as the discharge current, discharge duration, light output, etc. Using the proposed model, one can easily evaluate many important discharge parameters.

Three-dimensional Monte Carlo/particle-in-cell studies of anode striations and cathode ionization wave in barrier-discharges in AC-PDP cell

The dynamics of the sustain discharge pulse in an ac-PDP cell is studied via the three-dimensional Monte Carlo/Particle-in-Cell simulations. Key phases in the discharge development are identified and thoroughly illustrated with an extensive set of plots. The main effort is focused on the study of the striations above the dielectric surface of the anode and on understanding the mechanisms responsible for the propagation of the cathode ionization wave. Both of these phenomena are representative examples of dielectric-surface charging processes in strongly collisional plasmas of barrier discharges

Three-dimensional PIC/MC simulations of the sustain discharge pulse in an ACPDP

— The strong discharge pulse between coplanar electrodes in an ACPDP cell is investigated using fully kinetic 3-D simulations. Key phases in the discharge development are identified and thoroughly illustrated with an extensive set of plots. The main effort is focused on the study of the anode charging wave and striations formed above the dielectric surface in the anode area. To elucidate these physical phenomena, we perform a number of specially designed numerical experiments.