Nonlocal electron kinetics and densities of excited atoms in S and P striations

Abstract

A numerical solution of the Boltzmann kinetic equation involving elastic and inelastic collisions as well as spatial gradients along the electric field is obtained for the experimentally measured fields in S and P striations. The peculiarities of formation of the distribution function are analyzed. They are connected with the displacements of one distinctive peak in the electron distribution function (EDF) for S striations or two peaks for P striations in accordance with the resonance trajectories. A descriptive model is constructed for the processes of excitation of neon 2p(5)3s and 2p(5)3p atomic states and ionization in striations. The presence of phase shifts between ionization rate and electron density is shown, which can cause ionization wave propagation. Measurements and calculations of the excited state densities are carried out for different striation phases. Comparison of theory and spectroscopic measurements shows a good description of fast electrons by the distribution function in striations. Comparison of theory and probe measurements of the distribution function shows that the main features of the EDF in an energy range below the excitation threshold are experimentally observed.