Dissociative decay of n = 3 levels in H2. II. Excited by laser from the metastable c 3Pi/sub u/- state of H2

Fast-beam photofragment spectroscopy has been applied to study the photodissociation of metastable H2 molecules in the c 3Pi/sub u/- state, formed by charge exchange of H2+ with Cs vapor. Transitions leading to radiatively dissociated or predissociated levels of the g, h, i, and j triplet gerade states of H2 are observed. The decay mechanisms, level positions, and, in the case of predissociations, the lifetimes are established for (ro-)vibrational levels (v≥4). The transitions to v≥5 levels of the j 3Δ/sub g/ state appear as asymmetric peaks with widths of around 50 cm/sup -1/ (N = 2). A calculation of the rotational coupling of the j state to the vibrational continuum of the i 3Pi/sub g/ state confirms this very rapid predissociation (tau≅10/sup -13/ s). For v = 4 of the j state, which couples to the continuum via the quasibound v = 5 level of the i state, a relatively slow predissociation (tau≅10/sup -8/ s) is observed