Experimental Studies of the NaCs 5$^{3}\Pi _{0}$ and 1($a)^{3}\Sigma ^{+}$ States

We present experimental studies of the NaCs molecule that are currently underway in our laboratory. The optical-optical double resonance method is used to obtain Doppler-free excitation spectra for several excited states. Selected data from the 5$^{3}\Pi _{0}$ electronic state are used to obtain Rydberg-Klein-Rees (RKR) and Inverse Perturbation Approach (IPA) potential curves. We are also mapping the repulsive wall of the 1($a)^{3}\Sigma ^{+ }$potential using many resolved bound-free fluorescence spectra from individual ro-vibrational levels of the 5$^{3}\Pi _{0}$ electronic state to the 1($a)^{3}\Sigma ^{+}$ state. Using the determined 5$^{3}\Pi _{0}$ state potential we fit the repulsive wall of the 1($a)^{3}\Sigma ^{+}$ state to reproduce the experimental spectra using LeRoy's BCONT program. A slightly modified version of BCONT is also used to fit the relative transition dipole moments, \textit{$\mu $}$_{e}(R)$, as a function of internuclear separation $R$, for the various bound-free electronic transitions.