Electron Swarm Coefficients in $\hbox{CO}_{2}$–$\hbox{N}_{2}$ and $\hbox{CO}_{2}$–$\hbox{O}_{2}$ Mixtures

Abstract

The electron swarm coefficients (i.e., drift velocity, longitudinal diffusion coefficient, and effective ionization coefficient) have been measured using a time-resolved pulsed Townsend technique in O2, N2, and CO2 and their mixtures CO2-N2 and CO2-O2, with CO2 shares of 20%, 50%, and 80%. Simultaneously, these swarm data have been calculated from an adequate multiterm solution of the Boltzmann equation, using previously validated sets of electron-molecule collision cross sections. We have found good agreement between measurements and calculations, both for the pure gases and mixtures, particularly for the case of the calculated mean electron drift velocity Wm, which takes into account the effects of longitudinal diffusion and effective ionization. An effort has been placed in covering as high an E/N range as possible (0.01 Td up to 1000 Td) on specific electron swarm data such as transverse and longitudinal characteristic energies, which are also needed for a better understanding of the electrohydrodynamic and kinetic behavior of nonthermal atmospheric pressure electrical discharges.