7 June 1999 O2(1Δg) radiative lifetime: contribution to discussion on the Einstein A-coefficient used in COIL for O2(1Δg) determination from fundamental emission
Author Affiliations +
Abstract
This paper deals with an estimation of the Einstein A-coefficient for spontaneous emission of singlet delta oxygen, 02(1?g), fld contributes to a current discussion that was launched recently about the conventionally used value of 2.58 x 10-4 s-1 by Badger et al.1 (a half-lifetime of O2(1?g) corresponding to 45 min).The A-value is used in a Chemical Oxygen- Iodine Laser (COIL) for an evaluation of O2(1?g) concentration determined from its fundamental emission. The published values of the A-coefficient substantially differ, corresponding to a radiative lifetime of O2(1?g), ??rad from ~53 min to ~151 min. This fact can make questionable an evaluation of COIL performance. In this paper, the Einstein A-coefficient was computed from the comparison of O2(1?g) concentrations obtained by two independent experimental methods - the electron paramagnetic resonance (EPR), and the emission spectroscopy at which a proposed mathematical model for calculation of O2(1?g) concentration was used. Singlet oxygen was generated chemically by the reaction used in a COIL, in contrast to other papers concerned in this fundamental phenomena. A great effort in our work was devoted to the EPR spectra evaluation as it was shown that it affects crucially the resulting value of the A-coefficient. The average value of the Einstein A-coefficient following from our investigation is equal to (2.24 ± 0.40) x 10-4 s-1 that corresponds to ??rad of~ 74 min (a half-lifetime of 51 min)
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jarmila Kodymova, Otomar Spalek, "O2(1Δg) radiative lifetime: contribution to discussion on the Einstein A-coefficient used in COIL for O2(1Δg) determination from fundamental emission", Proc. SPIE 3612, Gas and Chemical Lasers and Intense Beam Applications II, (7 June 1999); doi: 10.1117/12.350643; https://doi.org/10.1117/12.350643
PROCEEDINGS
8 PAGES


SHARE
Back to Top