Influence of the dissociation process of oxygen on the electron swarm parameters in oxygen

Abstract

Previous theoretical studies assumed that the energy loss of a colliding electron has a discrete value for dissociative excitation of molecular oxygen. In the calculation of the rate coefficients for oxygen atom yields using the Boltzmann equation, the previous reports have used discrete energy loss values of 6.1 eV for A3Σ+u and 8.4 eV for B3Σ−u. In this paper, we take account of the fact that the excitation to B3Σ−u has a continuum energy loss spectrum and describe the effects on calculated swarm parameters that are important in the simulation of ozonizer discharges. It can be seen that the use of a continuum electron energy-loss spectrum as opposed to a discrete electron energy loss associated with excitation to the B3Σ−u state makes no significant difference in the calculated values of electron swarm parameters in oxygen. We also calculate the ozone yield as a function of E/N obtained from the analysis of the energy balance equation. In this case, the partial cross section for dissociation via B3Σ−u assuming a continuum electron energy-loss spectrum can have significant effects on the atomic oxygen yields at different E/N.

Electron transport coefficients in low current molecular gas discharges

“…Figure 5 shows the electron drift velocity W e as a function of E/N for O 2 . Over the whole E/N range of available data good agreement occurs with Naidu and Prasad [17] and Kajita et al [18]. There is also good agreement with Al-Amin et al [19] below 100 Td, but large disagreement above, where their electron drift velocities are larger compared to the present results.…”

“…These discrepancies are believed to be due to the non-equilibrium regions close to the cathode at low pd values, which were accounted for in the present investigation (as demonstrated in figure 3) but not necessarily by Aschwanden [11]. Prior to the present results for E/N > (E/N) c , experimental data only existed •: present results; dark blue open triangle: Kajita et al [18]; red closed inverted triangle: Al-Amin et al [19]; green open square: Naidu and Prasad [17]. Itoh et al [20]; magenta open triangle: Itoh et al [16]; green closed inverted triangle: Aschwanden [11]; red open square: Chatwiti [14].…”

Influence of trace oxygen on He(2 3S) density in a He–O2microwave discharge at atmospheric pressure: behaviour of the time afterglow

“…Indeed, the cross section at 300 K for the dissociative process has a maximum of 2.0 × 10 −18 cm 2 located close to 6 eV [33] with a threshold close to 4 eV. Then, when the temperature increases, dissociative attachment is possible by electrons with lower energy.…”

Experimental and Theoretical Studies on the Characteristics of Atmospheric Pressure Glow Discharge with Liquid Cathode

“…The cross-sectional areas of O 2 , Ar and H 2 O were taken from the literature [22][23][24]. The set of N 2 was obtained from reference [18].…”