The effect of humidity on the vibrational relaxation of O2(v) and N2(v) in a humid-air pulsed corona discharge is studied using a kinetic model. We previously showed that humidity markedly increases the vibration-to-translation (V-T) rate of molecules in a humid-air pulsed corona discharge by measuring O2(v) density (Ono et al 2010 Plasma Sources Sci. Technol. 19 015009). In this paper, we numerically calculate the vibrational kinetics of O2, N2 and H2O to study the reason behind the acceleration of V-T in the presence of humidity. The calculation closely reproduces the measured acceleration of V-T due to humidity, and shows that the increase in the V-T rate is caused by the fast vibration-to-vibration (V-V) processes of O2-H2O and N2-H2O and the subsequent rapid V-T process of H 2O-H2O. In addition, it is shown that O atom density is also important in the vibrational kinetics owing to the rapid V-T process of O2-O.
ASJC Scopus subject areas
- Condensed Matter Physics