Quenching of the lowest‐lying metastable excimer of argon by N2and effects of ’’three‐body’’ Ar(1s) quenching on the yield of Ar2(3Sgr;+u)

摘要

Fast absorption spectrophotometry has been used to monitor the growth and decay of the Ar2(3Sgr;+u) excimer species at 992 nm in argon–nitrogen mixtures following passage of single pulses of a high current, high energy electron beam. The rate constant for electronic energy transfer to N2is equal to 2.24 (±0.08)10−12cm3molecule−1s−1at 294 K. The yield of Ar2(3Sgr;+u) is found to be markedly enhanced relative to predictions based on the total quenching efficiencies of N2for the Ar(1s) atoms. This enhancement is attributed to ’’three‐body’’ quenching by N2, i.e., vibrational and rotational relaxation of dissociative excimer molecules formed by two‐body Ar(1s)+Ar(1S0) combinations.