Cs+-electron recombination in the presence of N2, O2, and CO2 at 300 K

Abstract

The mechanism and rate constants associated with three-body recombination of Cs+ and electrons have been determined by monitoring the disappearance of electrons using a movable double Langmuir probe in a flowtube apparatus. The ambipolar diffusion rate constant for the dilute plasma in argon and helium was measured to be 380±30 cm2 s−1 and 650±200 cm2 s−1, respectively. Electron-ion recombination was measured in the presence of molecular nitrogen, oxygen, and carbon dioxide. From the kinetics of the electron disappearance along the flowtube, plasma recombination in nitrogen can be explained by the formation of a complex ion, recombination in oxygen proceeds through the formation of the O−2 followed by dissociative attachment in which the latter step is the rate determining step, and recombination in CO2 can be attributed to a direct three-body process.