ELECTRON-ION RECOMBINATION IN HIGH-PRESSURE AR/XE MIXTURES

Electron-ion recombination processes in high pressure (at 5 and 10 atm) Ar/Xe mixtures were investigated experimentally. Measurements of electron drift currents in the gas mixtures initiated by an ionizing short pulse were made. Taking into account the cathode potential drop caused by the space charge, calculations of the signal time histories yielded good fits with measurements for a dissociative recombination rate coefficient k(r) = 6 x 10(-6) (300/T(e)(K))0.6 cm3 s-1. Thus, k(r) at room temperature (300 K) is more than twice that previously measured for the recombination of electron and Xe2+. Based on kinetic considerations, we conclude that the dominant recombination process in high pressure Ar/Xe plasmas is that between electron and triatomic xenon ion Xe3+ (i.e. e + Xe3+ --> Xe* + 2 Xe).