Sylvie Magnier

The K239 2Σg+3 state: Observation and analysis

The K239 2Σg+3 state has been observed by perturbation-facilitated infrared-infrared double resonance spectroscopy and two-photon excitation. Resolved fluorescence spectra into the aΣu+3 state have been recorded. The observed vibrational levels have been assigned as the v=23–25, 27, 28, 31–33, 38–45, 47, and 53 levels by comparing the observed and calculated spectra of the 2Σg+3→aΣu+3 transitions. Molecular constants have been obtained using a global fitting procedure with a comprehensive set of experimental data. Fine and hyperfine splittings have been resolved in the excitation spectra. Perturbations between the 2Σg+3 and 2Πg3 states were observed. The hyperfine patterns of the 2Σg+3 levels are strongly affected by the perturbation. The perturbation-free and weakly perturbed levels follow the case bβS coupling scheme, while the perturbed levels follow case bβJ coupling. A Fermi contact constant, bF=65±10MHz, has been obtained. Intensity anomalies of rotational lines appeared both in the 2Σg+3∼2Πg3←bΠu3 ...

Bound-bound and bound-free X2Σg+ → A 2Πu transitions in Na2+ relevant for experiments in above threshold dissociation

Abstract A preliminarystudy on above threshold dissociation is presented. The specific example is based on the Na 2 + molecular ion, for which accurate potential energy curves and transition dipoles are available. The first step of the process is examined, with a comparison of the bound-bound and bound-free portions of the spectrum.