Energy transfer in collisions of Ar( 3P 0,2 metastable atoms with H( 2S) atoms. I. Total rate constant and mechanism

Abstract

The Ar(4s, 3P 2) + H(1S, 2S) reaction, which gives excited H( n=2) atoms, has been studied. The room temperature rate constant for Lyman-α (2p-1s) excitation was measured as 2.4 × 10 −10 cm 3 mol −1 s −1. The method was based upon comparison of the Lyman-α emission intensity with the Kr resonance emission intensity produced from Ar( 3P 2) + Kr, which has a known rate constant. The H atom excitation, which has a large energy defect of 1.3 eV, is discussed in terms of a curve crossing mechanism.