Electronically excited iodine atoms, I(52P½). Diffusion in noble gases, the mean radiative lifetime and atomic recombination

Abstract

Electronically excited iodine atoms, I(5²P_½), generated by the pulsed irradiation of CF₃I, have been monitored by time-resolved emission, I(5²P_½)→I(5²P)+hv(1315 nm). The decay of the excited atoms in noble gases gives rise initially to a first-order kinetic region followed by removal indicative of more complex kinetics. Analysis of the first-order region yields the diffusion coefficients of I(5²P_½) in the gases He, Ne, Ar and Kr, together with the mean radiative lifetime for the emission. The complete decay curve can be quantitatively described using numerical integration in terms of a model involving quenching of I(5²P_½) by I₂ formed from the recombination of two ground-state atoms.