ExperimentalAΠ2potentials for Li-He and Li-Ne molecules

The well depths of the $A{}_{}{}^2{}_{}{}^{}\Pi$ potentials for Li-He and Li-Ne molecules have been determined by the observation of the intensity of the red wing of the Li $D$ lines, perturbed by He and Ne, as a function of temperature and with the use of the quasistatic theory of line broadening. Significant enhancement of the fluorescence signal was achieved by the use of cw dye-laser excitation and by the operation of the fluorescence cell at low temperatures. For Li-He, we obtained $D_e=850\mathrm{}\left(100\right)\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$; for Li-Ne, we obtained $D_e=225\mathrm{}\left(30\right)\mathrm{}$ ${\mathrm{cm}}^{-1\mathrm{}}$.