Laser-induced (5145 Å) B 1Πu→X 1Σ+g fluorescence of Na2

Abstract

Laser-induced emission of the Na2 molecule consisting of discretemolecular fluorescence series was observed in the gas phase atan excitation wavelength of 5145.308 Å from anargon-ion laser. Eighteen fluorescence series for theB 1Πu→X 1Σ+g band system have beenobserved and analysed. Several fluorescence series are reported for thefirst time. The radiative transition probabilities for the observedfluorescence series were calculated using experimentally based hybridpotential energy curves for theB 1Πu and X 1Σ+g states constructed up todissociation and a B-X transition dipole moment function. Radiativelifetimes for the rovibrational levels of the upper states pumped by thelaser line have also been calculated. The transition probabilities andlifetimes agree with the corresponding observed measurements usuallywithin the experimental uncertainty. A strong rotational satellitestructure, with jumps withΔJ' = ±1,±2,...,±16 in some cases, for the mostintense bands of several fluorescence series was also analysed. Absoluteintegral cross sections for collision-induced rotational transitions,whenNa2*(v',J') in theB 1Πu state collides with Na atoms, for some v'-v''vibrational bands of intense fluorescence series, are also reported.