The singlet delta pooling rate has been measured in a chemical generator using gas phase laser Raman spectroscopy.
The measured rate is four times the currently accepted pooling rate constant. Our measurement also agrees with recent
ab initio rate calculations. This rate is one of the most important losses in the COIL laser and is believed responsible for
the production of vibrationally excited singlet delta oxygen. The vibrationally excited oxygen is thought to play a role in
the iodine dissociation process. A higher rate for this process will enhance dissociation at the cost of increased transport
losses. The previous experimental measurement was reviewed and an over simplification of the data analysis identified.
Collision-induced absorption spectra have been measured in a wide temperature (80 - 300 K) and pressure (10 - 150 atm) range for the a ← X and b ← X absorption bands of oxygen. The peak and integrated absorption coefficients and monomolecular and multimolecular collision-induced cross-sections are measured for an oxygen density range of 4x1020 cm-3 to liquid. No temperature dependence was found in the absorption of the high density oxygen.
A kinetics model to describe the behavior of singlet delta O2 in optically pumped liquid oxygen has been developed and tested against experimental data. The model was developed to study alternative methods of O2(a1Δg) production for the Chemical Oxygen Iodine Laser (COIL), and has been used in conjunction with experimental data to determine a value for the pooling rate constant in liquid oxygen of 1± 0.5 x 10-17 cm3molecule-1s-1.