Mixtures of FN3, I-2, HF, and He were shock heated by reflection of an Ma similar to 2 incident wave to generate peak metastable NF* concentrations > 10(16)/cm(3). Time profiles of the NF(a), NF(b), I-2, and I* concentrations were optically measured and fit to a chemical kinetics and gas dynamic model of the reaction process. Approximately six NF* molecules were consumed per I-2 molecule dissociated, and energy transfer from NF(a) to I* was both fast and efficient. Attempts to achieve lasing on the 1315 nm (I* --> I) atomic transition were unsuccessful, however, due to rapid E-V quenching of I* by the NF species present.