Three body conversion reactions in pure rare gases

Abstract

Measurements of the conversion reaction coefficients, beta , for the three body conversion of krypton and xenon atomic to molecular ions in pure rare gas afterglow plasmas have been made. The values for beta at 300 K are (342+or-15) Torr-2s-1 in krypton, and (447+or-22) Torr-2s-1 in xenon. Preliminary investigations in the case of krypton indicate that beta is essentially the same at gas temperatures of 180 K and 300 K, but that there is a marked decrease in beta as the gas temperature is increased to 510 K. These results, coupled with the previous measurements, in this laboratory, of beta in helium, neon and argon have allowed an assessment to be made of the validity of several theoretical models. It is shown that good agreement exists between the experimental values and those calculated using the theoretical approach of Mahan (1965).