Boltzmann equation analysis of electron swarm behaviour in nitrogen

Abstract

The electron swarm behaviour in nitrogen is studied for E/ rho 0 from 20 to 200 V cm-1 Torr-1 by a Boltzmann equation method. A set of electron collision cross sections is determined using newly published data. The modification of these cross sections when necessary is kept to within experimental error. Moreover, the validity of the vibrational excitation cross sections obtained theoretically by Hazi and co-workers (1981) is examined. The results show that the calculated swarm parameters are in close agreement with those obtained by a photon flux experiment of Wedding and co-workers (1985). This suggests that the set of electron collision cross sections determined in the present work is an appropriate one as far as the swarm parameter analysis is concerned. The electron energy distribution and electronic excitation coefficients and frequencies to various excited states are also calculated and discussed.

Characteristics of TiO2Surfaces Etched by Capacitively Coupled Radio Frequency N2and He Plasmas

“…In the model of plasma discharge, movement of charge particles, e − and N 2 + , which is dominated by the Newton and Poisson laws, was simulated [15]. The simulation takes account of the elastic, excitation, and ionizing reactions of e − with N 2 gas [16,18], as well as the elastic and charge transfer reactions of N 2 + with N 2 gas [16,19]. As a result, a change in energy of the impinging N 2 + ions with gas pressure was calculated.…”

“…The lower flux of N 2 + is probably because the N 2 plasma density, which is proportional to the flux, is lower than the He plasma density. The lower density of N 2 plasma is attributed to the phenomenon that reaction of vibration excitation of N 2 by electron impact is more pronounced than that of the ionization [18]. Figure 2 shows the spectra of UV light emitted from the N 2 and the He plasmas at various gas pressures.…”

Electron acceleration in gas by impulse electric field and its application to selective promotion of an electron–molecule reaction

“…This species is known for its long lifetime of over 10 s (Radzig and Smirnov 1985), and can be used as an energy source for moderate plasma-surface reactions; the excitation energy Erneta is about 6.2 eV. Figure 2 shows the electron collision cross-sections of N2 taken from Ohmori et al (1988). The target crosssection is indicated as qrneta.…”

“…The presence of such a range contributes significantly to the selective promotion of the target reaction. (Ohmori et al 1988). qel, elastic collision; qvib,j, vibrational excitation; qrneta, excitation to metastable state A 3~t; qex,j, the other electronic excitations; qdis, dissociation; and qion, ionisation.…”

Timesaving techniques for decision of electron–molecule collisions in Monte Carlo simulation of electrical discharges

“…Some collision cross section sets include more than 10 cross sections; e.g. n is 19 for CHF 3 [5], 20 for Xe [6], 27 or 31 for Ar [2,7,8], 31 for He [6], and 32 for N 2 [9]. Under tendencies that electronic excitation levels and vibrational excitation modes are identified in detail and that the dissociation processes of molecular gases are distinguished by the product species, n would increase more and more.…”