Energy transfer, collisional quenching and natural lifetime of laser-excitedD1Π state of the NaRb molecule
Mārtiņš Jansons, Janis Klavins, Zh Kharcheva +1 more
NaRb molecules in a thermal cell in a mixture of Na-Rb were excited to the D 1 Π state by means of a 514.5 nm beam from an Ar + laser. The natural lifetime for the NaRb D 1 Π, v' = 0, J' = 44 state, populated by the selective laser excitation, was found to be τ = 22.6 ± 1.8 ns. The kinetics of the molecular fluorescence lines as a function of the Rb atom concentration were also studied. The rate constant for collisional quenching of this molecular level by Rb atoms could be determined to k q = 2.1 · 10 −9 cm 3 s −1 . The experiments at steady state conditions demonstrate that energy transfer to the atomic 4 2 D levels of Rb dominates the collisional quenching with a rate constant of k ET = 1.2 · 10 −9 cm 3 s −1 . The results suggest that such molecule-atom transfer of electronic energy can be used to efficiently populate 2 D levels of alkali metal atoms.
Physica Scripta•Apr 1, 1992•4 citations