Radiative lifetimes of OH(A2Σ) and Einstein coefficients for the A-X system of OH and OD

doi:10.1016/0022-4073(79)90014-1

Journal of Quantitative Spectroscopy and Radiative Transfer

Volume 21, Issue 3, March 1979, Pages 233-241

https://doi.org/10.1016/0022-4073(79)90014-1 Get rights and content

Abstract

Radiative lifetimes of individual rotational states of OH(A²Σ) were observed using a delayed coincidence technique. The values obtained were scaled to a theoretical functional form to give τ_rad(A²Σ, v = 0, N = 1, J = $32$ = 686 ± 14 ns. Einstein A and B coefficients for the A-X system of OH and OD were computed, using numerical integrals of a transition moment of the form Re(r) = 3.75 × 10^-30 (1-0.75 r) C … m and vibrational wavefunctions obtained from numerical solutions of the radial Schrödinger equations (including centrifugal terms) for RKR potentials for the two electronic states. Matrix elements in Hund's case b were transformed to intermediate coupling for the X state to yield proper oscillator strengths for computation of the Einstein coefficients. Tables of the A and B coefficients for the 0-0 vibrational transitions are included. Extended tables are available on microfiche or microfilm from the authors.

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Citation Excerpt :
The observed OH* emission is due to this process. The radiative lifetime of OH* was taken from Dimpfl and Kinsey [36]. Figure 5 shows several normalized OH* profiles from the H2NO2 mixture.
Shock-tube experiments were performed in a mixture of 0.222% H₂/0.392% NO₂/Ar between 1535 and 2003 K near 1.1 atm. Time histories of OH* chemiluminescence from the A→X band near 307 nm were recorded and showed poor agreement with predictions from a recent hydrocarbon/NO_x model when only the OH*-forming reactions N₂O + H ⇆ N₂ + OH* (R2) and O + H (+M) ⇆ OH* (+M) (R3) were included. Since chemiluminescence is strongly correlated with heat release and since the reaction NO₂ + H ⇆ NO+OH is known to be primarily responsible for heat release during H₂NO₂ oxidation, the chemiluminescent reaction
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