Predissociation lifetimes of OH A sup 2. Sigma. sup + ( v prime =3) obtained from optical--optical double-resonance linewidth measurements

Journal Article · Fri Nov 15 04:00:00 EST 1991 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.461433· OSTI ID:5045914

Gray, J A; Farrow, R L ^[1]

---

1. Combustion Research Facility, Sandia National Laboratories, Livermore, California (USA)

The excitation of rapidly predissociating {ital v}{prime}=3 levels in the {ital A} {sup 2}{Sigma}{sup +} state of OH has recently been suggested as a means of avoiding collisional quenching corrections when performing laser-induced fluorescence (LIF) measurements in flames. We report measurements of predissociation rates of several rotational levels in {ital v}{prime}=3, obtained from linewidths in optical--optical double-resonance (OODR) spectra. The magnitude of the observed predissociation rates places an upper limit on the pressures at which OH LIF can be considered quench-free.'' In addition, analysis of spectral line shapes suggests that {ital rotational} {ital transfer} can significantly affect LIF quantum yields at pressures of 1 atm and higher. We conclude that variations of the predissociation rate with rotational level in {ital v}{prime}=3 must be included in determinations of rotational temperatures from LIF.

• OSTI ID: 5045914
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 95:10; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
DISSOCIATION
DOUBLE RESONANCE METHODS
DYE LASERS
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLUORESCENCE
HYDROGEN COMPOUNDS
HYDROXIDES
LASERS
LIFETIME
LINE WIDTHS
LIQUID LASERS
LUMINESCENCE
MEDIUM PRESSURE
OXYGEN COMPOUNDS
PREDISSOCIATION
ROTATIONAL STATES
TUNING
VIBRATIONAL STATES
YIELDS