Neutral fragmentation of superexcited oxygen molecules - art. no. 032718

The mechanisms of neutral dissociation of oxygen molecules in the excitatio n energy range 15-25 eV have been studied in a dispersed fluorescence exper iment. By detecting the fluorescence from excited oxygen atoms, we find tha t neutral superexcited O-2 states below 20 eV dissociate into O(g.s.) + O(3 s,3p). At higher excitation energies (h nu = 20-25 eV) the curve-crossing i nteractions following excitations to members of the Rydberg c (4)Sigma(u)(- ) series also yield atoms in Rydberg states (nl,n greater than or equal to 4). The experimental data are analyzed on the ground of many-body perturbat ion theory, calculations which indicate the structure of the predissociatin g states converging to the experimentally observed ones.