H-2 DOUBLY-EXCITED-STATE ASSIGNMENT FROM THE DETERMINATION OF THE ORBITAL STATE OF THE H-ASTERISK(N=3) PHOTODISSOCIATION FRAGMENTS

The photodissociation of doubly excited H-2 has been experimentally in vestigated. Using the pulsed character of the incident synchrotron rad iation, the time analysis of the atomic fragment fluorescence Balmer-a lpha (H-alpha) decay was used for identification of the fragments. The measured branching ratios of the H(3l) fragments at a given photon en ergy contain information about the dynamic behavior of the photodissoc iation, The states of the first Rydberg series, Q(1)(2p sigma,nl lambd a), dissociating into H(1S)+H(n=3) lead almost to H(1S)+H(3S) fragment s; the state involved can be identified from the correlation diagram a s the (2p sigma(u),4d sigma(g)) configuration. The photodissociating s tates of the second Rydberg series, Q(2)(2p pi,nl lambda), lead to H(2 p)+H(n = 3), the H(n = 3) fragments being a mixture of H(3S) and H(3D) in a ratio of about 2:1. In order to identify the relevant Q(2) state , the energy ordering in the manifold of the molecular states dissocia ting into H(n=2) and H*(n=3) has been established by calculating the whole dipole-dipole long-range interaction.