Thermal and Near-Thermal Electron Transport Coefficients in O2 Determined with a Time-of-Flight Swarm Experiment Using a Drift-Dwell-Drift Technique

Abstract

The drift‐dwell‐drift (DDD) or pulsing technique has been successfully applied to the study of low‐energy electron transport coefficients in oxygen in spite of significant attachment at these energies. A thermal value of the electron diffusion coefficient times pressure $\text{DP=1.20± 0.11\hspace{0.17em}}{\mathrm{cm}}^2\mathrm{\hspace{0.17em}\mu }{\sec }^{\text{−1}}\hspace{0.17em}\mathrm{torr}$ was determined. This DP value corresponds to a momentum‐transfer cross section $Q_m{\text{=0.82× 10}}^{\text{−16}}\hspace{0.17em}{\mathrm{cm}}^2$ at an energy ε=0.0258 eV if it is assumed that Q_m ∞ ε^1/2. This thermal value of Q_m is ∼40% lower than the lowest values reported from other techniques.