DISSOCIATION KINETICS OF IODINE IN OXYGEN-CONTAINING ELECTRICAL-DISCHARGE PLASMAS

Results are presented from an experimental study and numerical simulat ions of the kinetics of the dissociation of iodine in self-sustained v olume discharges in high-pressure O2:Ar:I2 mixtures. It is shown that the well-studied mechanism for dissociation based on excitation of iod ine molecules in successive collisions with singlet oxygen and excited iodine atoms is supplanted by a substantially different mechanism inv olving the creation and loss of 10 radicals when the densities of atom ic oxygen and ozone are high enough. It is also shown that iodine frac tions as low as approximately 10(-3) in the mixture lead to rapid loss of ozone molecules while less than 18% of the discharge energy is exp ended in the production of singlet oxygen.