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

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 DP=1.20± 0.11 cm2 μ sec−1 torr was determined. This DP value corresponds to a momentum-transfer cross section Qm=0.82× 10−16 cm2 at an energy ε=0.0258 eV if it is assumed that Qm ∞ ε1/2. This thermal value of Qm is ∼40% lower than the lowest values reported from other techniques.