The dynamics of ionization waves formation in a transverse nanosecond plasma-beam discharge with a slotted cathode in argon

Abstract

The article presents the results of an experimental study and numerical simulation of the spatio-temporal dynamics of ionisation processes in the gap between the electrodes and inside the cathode cavity during the formation of a nanosecond discharge in argon at pressures in the chamber from 1 to 10 Torr. The correspondence between the density distribution of charged particles and the optical patterns of the discharge is established. A numerical simulation of the formation of a limited discharge in argon under various external conditions is constructed that accounts for the influence of the charge deposited on the surface of the dielectric wall, the coefficient of secondary emission of electrons from the cathode surface and the effect of the space charge on the distribution of electric potential between the electrodes. The role of the surface charge deposited on the dielectric walls in the formation of the spatial structure of the discharge is determined. The results of numerical simulation are compared with experimental data. It is shown that the electron concentration in a discharge limited by dielectric walls is an order of magnitude higher than in an unlimited discharge under the same external conditions. The general patterns of formation and development of a limited discharge in argon are discussed and the main physical processes affecting the dynamics of development and the spatial structure of the discharge are established.