Kinetics of metastable states in high-pressure nitrogen plasma pumped by high-current electron beam

Abstract

An effective method for calculating the electron energy distribution function in a plasma pumped by an electron beam is suggested. The electron impact excitation rates of different N2 and Hg states are obtained. The evolution of populations of the N2 excited states and of the Hg radiative states in a N2-Hg mixture is considered. The characteristic time tau e of equilibrium establishment is shown to be strongly dependent on the pressure of the mixture. The variation of the N2(A3 Sigma ) population is found to be determined by the dynamics of the Hg emissions if the measurement time is longer than tau e.

On the possibility of O2(a 1 g) production by a non-self-sustained discharge for oxygen–iodine laser pumping

“…For describing electron beam interaction with gas we used the results of [23,24], where it was shown that the rates of ionization, dissociation and excitation of different oxygen states by a high-energy electron beam could be written as:…”

“…where E loss are electron energy losses on a unit of the length (depending on the electron energy), j b is the beam current density and U k are the energy costs of the corresponding loss processes [23,24]. The kinetic model for argon-oxygen mixtures included the basic kinds of charged and neutral particles: electrons, negative ions, positive ions (both oxygen and argon), oxygen molecules in the ground-O 2 (X…”

“…In this work, to determine the rate constants of the electronic processes in quasi-neutral plasma volume at the given E/N, the EEDF was found by solving the Boltzmann equation in a two-term approximation that can be done due to the rather low values of the reduced electric field. The rates of ionization, dissociation and excitation by fast beam electrons were found according to expression (3) in which the data on electron energy losses E loss are obtained from the electron degradation spectrum calculations by the Monte Carlo technique [24].…”

On electric field measurements based on intensity ratio of 1 − and 2 + systems of nitrogen in discharges with high specific deposited energy

“…For example, additional population by vibrational relaxation of N 2 (C 3 Π u , v > 0) states recently suggested by [4] is not relevant at the conditions of present work: the time of vibrational relaxation of N 2 (C 3 Π u , v = 1, 2) is about 110-120 ns. It should also be noted that the main population of N 2 (C 3 Π u ) in the discharge afterglow occurs in the self-quenching reaction of N 2 (A 3 Σ + u ) molecules and during the electron-ion recombination N + 4 + e → N 2 (C 3 Π u ) + N 2 [49]. The decay of a given electronic state, in case of low specific deposited energy discharges at moderate pressure, is determined by the radiative decay and by the quenching by background gas only.…”

Detection of metastable excited molecules N2(A3Σu+) in an atmospheric pressure nitrogen discharge by Raman scattering

“…Determination of the concentration of N 2 (A 3 Σ u + ) by combining emission spectroscopy measurements with modeling of the generation and decay of excited molecules, atoms, and ions has also been reported [16,17]. Modeling based on pure calculations without using optical emission data has also been performed [18][19][20], but these focus on the low-pressure regions commonly used in plasma processes.…”