Knowledge Bank

High spin (triplet) NaK dimers have been successfully prepared on the surface of helium clusters through a pick-up process in which a He cluster beam passes through two independent alkali pick-up cells, each containing an alkali vapor at pressures around $102$ Pa. Excitiation and emission spectra have been recorded for both the $23\Sigma g+-13\Sigma u+$ and $13\Pi g-13\Sigma u+$ transitions. Comparisions of the experimental spectra with the theoretical calculations of Stevens et al.$13\Pi g$ and of Jeung et $al.2$ have been made obtaining information on the potenntial of the upper $13\Pi g$ state. Similar comparisons with the work of Kowalczyk et $al.3$ have made for the $23\Sigma g+-13\Sigma u+$ transition. Several different emission channels have beeen detected for each system following excitation, including atomic fluorescence and non-adiabatic corssings into the singlet manifold of the dimer. The emission spectra provide evidence of vibrational relaxation of the dimer on the He surface occuring on a time scale shorter than that of the molecular fluorescence.