Attempt to verify experimental Einstein A-coefficient used for O2(1Δg) determination in COIL

This paper is a contribution to the current discussion on radiative lifetime, or the Einstein coefficient for spontaneous emission of singlet delta oxygen [O2(1(Delta) g)]. A verification of widely-used the A-coefficient by Badger et al. (2.58 X 10-4 s-1) in emission spectroscopy for determination of O2(1(Delta) g) concentration in Chemical Oxygen-Iodine Laser (COIL) was examined. Two independent comparative techniques, the EPR and emission spectroscopy, completed by a proposed mathematical model for calculation of O2(1(Delta) g) concentration from emission measurements, were employed. Singlet oxygen was generated chemically by a conventional way used in COIL. Within the accuracy of the both experimental techniques, the value of the Einstein A-coefficient estimated by this investigation is equal to (2.31 plus or minus 0.51) X 10-4 s-1, that is slightly less than the Badger et al. value.