Results of experiments on iodine dissociation in active medium of oxygen-iodine laser

Abstract

Results of experiments on dissociation of iodine molecules in the presence of singlet oxygen molecules are presented for wide range of oxygen-iodine media composition. Rate constants values have been obtained: 4.3⋅10-17cm3/s for the reaction O2(1Δ)+O2(1Δ)→O2(1Σ) +О2(3Σ) − (1), 2.8⋅10-13 cm3/s for the reactionO2(1Δ)+I(2P1/2)→O2(1Σ)+I(2P3/2) − (4) and 8.3⋅10-11 cm3/s for the reaction O2(1Σ) +I2→О2(3Σ)+2I − (2). Analysis of experiments shows that for the wide range of oxygen-iodine medium composition the dissociation occurs via the chain of reactions (1), (2), O2(1Δ)+I(2P3/2)→О2(3Σ)+I(2P1/2), (4) and via cascade process I2+I(2P1/2)→I2(v)+I(2P3/2), I2(v)+O2(1Δ)→2I+О2(3Σ). Contributions of each mechanism in the dissociation of the iodine are comparable for the typical composition of the active medium of the supersonic chemical oxygen-iodine laser. The experiments did not reveal the contribution of vibrationally excited oxygen molecules in the dissociation of iodine. Thus, the experiments and the following conclusions are fully confirmed iodine dissociation mechanism previously proposed by Heidner et al. (J. Phys. Chem., 87, 2348 (1983)).