Nanosecond kinetic study of the rotational temperature decay of the CH(A2Δ→X2Π), emission produced by pulse radiolysis of CH4 and C2H2

Abstract

A 10^–9 s pulse radiolysis study of the discrete rotational levels of the CH(A²Δ–X²Π) emission gives the kinetics of the rotational temperature decay of CH(A²Δ) during fluorescence; variations of the rate for rotational de-excitation of the discrete levels are determined for ten rotational levels of the (0–0) band. The CH(A²Δ) radical is produced initially from CH₄, with 0.07 eV and from C₂H₂ with 0.6 eV rotational energy. The electronic radiative lifetime has been measured for 3 rotational bands: the values vary from 480 to 575 ns.