Kinetic Coefficients of Electrons in Weakly Ionized Plasma of Mixtures of Air with Water Vapor in a Strong Electric Field

Abstract

Using a numerical solution of the Boltzmann equation, the electron drift velocity, the coefficients of their longitudinal and transverse diffusion, as well as the ionization and dissociative attachment coefficients in weakly ionized plasma of mixtures of air with water vapor are calculated in a wide range of reduced electric fields (1–650 Td, 1 Td = 10^–17 V cm²) and mole fractions of water vapor (0–1). The calculation results are compared with new experimental data, and good agreement between them is obtained. It is shown that for all coefficients and the average electron energy, their dependence on the gas composition changes with increasing electric field. At low reduced fields, an increase in the content of H₂O water molecules in mixtures leads to a decrease in the transport coefficients and average electron energy, while the opposite trend is observed at high fields. It is shown that for the drift velocity and electron attachment coefficient there are electric fields, in which these coefficients in gas mixtures can be greater than the coefficients in dry air and water vapor. A qualitative explanation is given for the obtained dependences of the electron coefficients on the electric field and H₂O content in the mixtures.