Effect of Gas Purity on the Current of a Non-Self Sustained Discharge in Nitrogen

Abstract

Commercial nitrogen contafns about 0,01 the concentrations of all positive ions $ of oxygen, whereas nitrogen of special in the discharge, i are the corresponding B purity (s.p.), only 0.001 %. ~t turns out coefficients of recombination of the i-th that even so small admixtures may essenti-ion with electrons of the discharge ZPd= L ally alter the energy characteristics of = pel , [?el is the discharge-electron den-

Negative differential conductivity of electrons in He - Xe mixtures

“…It is possible to observe the NDC effect in self-sustained and electron-beam-sustained discharges (Lopantseva et al 1979) where it should manifest itself as the Gunn-like instability followed by the generation of oscillations in discharge current with frequencies in the range 0.1-1 MHz. the instability takes place at γ < 0.…”

“…Negative differential conductivity (NDC) is defined as the decrease in the drift velocity of electrons with increasing electric field is known to induce spontaneous oscillations in externally sustained direct-current (dc) gas discharges (Lopantseva et al 1979, Dem'yanov et al 1980, Aleksandrov et al 1990 and in semiconductors (Jacobini and Reggiani 1983). This phenomenon is important for gas lasers (Ault 1975, Garscadden 1981) and devices detecting nuclear radiation (Mathieson and El-Hakeem 1979, Christophorou et al 1982, Al-Dargazelly et al 1981.…”

Plasma parameter bi-stability in e-beam sustained discharge in Xe

“…where α r is recombination rate coefficient calculated by solving (1). The momentum transfer cross-section for electron scattering from Xe atoms was taken from [20].…”

“…During the last few decades, electron kinetics in gas discharge and post-discharge plasma was comprehensively investigated both theoretically and experimentally, and a number of phenomena relating to the non-equilibrium behaviour of the electron energy distribution function (EEDF) in such a plasma were found. The following effects can be mentioned as examples: negative differential electron conductivity in gas mixtures with heavy inert gases [1,2] and in pure heavy inert gases in the presence of electron-electron (e-e) collisions [3]; strong coupling between the electron and vibrational temperatures in molecular gas post-discharges [4,5]; negative electron mobility under different physical conditions (see first papers [6,7] and review [8] for more references); unexpectedly large spatial relaxation lengths of plasma parameters in atomic gases [9].…”

“…The following effects can be mentioned as examples: negative differential electron conductivity in gas mixtures with heavy inert gases [1,2] and in pure heavy inert gases in the presence of electron-electron (e-e) collisions [3]; strong coupling between the electron and vibrational temperatures in molecular gas post-discharges [4,5]; negative electron mobility under different physical conditions (see first papers [6,7] and review [8] for more references); unexpectedly large spatial relaxation lengths of plasma parameters in atomic gases [9].…”