The 23Πg–b3Πuand 13Δg–b3ΠuTransitions in7Li2: Analysis of theb3ΠuState forv= 0–27

Abstract

Two double resonance techniques, perturbation facilitated optical–optical double resonance (PFOODR) and collision induced fluorescence (CIF), have been used to excite the 23Πg(PFOODR only) and 13Δgstates of7Li2. Fluorescence from each of these states to theb3Πustate has been studied at high resolution using Fourier transform spectroscopy. Transitions were observed and analyzed up tov= 27 in theb3Πustate, and the PFOODR and CIF data have been combined to give an improved set of Dunham coefficients from which an RKR potential has been calculated. Predissociation by thea3Σu+state, which broadens and shifts the b3Πulevels, has been studied in detail. The level shifts tov= 27 have been calculated and the observed values are shown to follow the theoretically predicted pattern. The isotope effect on the predissociation has also been examined. The 13Δgstate has been analyzed for 0 ≤v≤ 25 and molecular constants and an RKR potential have been calculated.