Self-Consistent Analysis of the Spatial Relaxation of a Disturbed Neon Glow Discharge

Abstract

The response of a neon glow discharge plasma on a disturbance caused by a floating Langmuir probe is studied by a fully self-consistent, spatially one-dimensional hybrid method as well as by measurements. The theoretical description is based on the coupled solution of the hydrodynamic equations of electrons, ions, and excited atoms and the Poisson equation. The space-dependent transport and rate coefficients of the electron component are determined by a strict solution of the non-uniform electron kinetic equation. For the measurements, a probe was inserted in radial direction into the discharge several cm in front of the anode. The spatial evolution of the densities of the excited atoms in the 1s 3 , 1s 5 , and 2p 8 states was determined by spectroscopic methods. Pronounced modulations of basic plasma parameters have been observed around the probe, decaying periodically and damped toward the anode. The measured density profiles of the excited atoms agree well with the numerically determined ones. The analysis of the electron kinetic quantities shows that the response of the plasma to the disturbance is widely determined by the nonlocal behaviour of the electrons in the distinctly disturbed electrical field.

Striated microdischarges in an asymmetric barrier discharge in argon at atmospheric pressure

“…[14,16] is required. Because of the complexity of a such self-consistent approach, a study of the electron kinetics at given discharge parameters has been performed.…”

“…Frequently, the striated structure within the plasma channel at low pressure appears as a result of a relaxation process induced by a local disturbance, which can be caused, for example, by a probe, a short laser pulse, or a discharge constriction [14][15][16][17]. However, these instabilities are not yet fully understood for atmospheric-pressure plasmas, which have been the subject of extensive research in the last decade [18].…”

Electron Kinetics and Self‐Consistent Description of Inhomogeneous and Nonstationary Plasmas

“…In particular, with regard to the self-consistent analysis of spatially one-dimensional problems substantial progress could be reached in recent years. Representative problems during the last period of the collaborative research activities dealt with (i) axial inhomogeneities in the anode region of dc glow discharges [40], (ii) the response of glow discharge plasmas to local disturbances [41], (iii) spatial structures in cylindrical hollow-cathode discharges [42], (iv) radially inhomogeneous structures in the column plasma of dc glows [6,[43][44][45][46] and (v) the additional impact of a longitudinal magnetic field on such discharges [45,46]. In the following representation some results of the successful self-consistent analyses are briefly illustrated by two examples concerning (iii) and (v).…”

Two-dimensional positive column structure in a discharge tube with radius discontinuity

“…10,11 Formation of the spatially periodical structures in low-pressure discharges behind any perturbation of positive column is of great interest itself. [12][13][14][15] At the present time, the multi-dimensional simulations of glow discharges based on ether the particle-in-cell technique or the moments approach. Particle-in-cell method requires large computational resources and is applicable for discharges with relatively simple structures.…”

“…16,17 But this approach fails in the stratified low-pressure discharge, where the EVDF is not in equilibrium with the local electric field and depends on the electron history. 15,18 The multi-modal EVDF in stratum is far from any solution for uniform electric field and cannot be parameterized by one or two parameters.…”