VIBRATIONAL POPULATION DISTRIBUTIONS OF THE GROUND STATE OF BARIUM OXIDE

Abstract

Author Institution: Quantum Institute, University of CaliforniaThe vibrational population distributions of ground state BaO formed by the reactions $Ba + O_{2}$ and $Ba + N_{2}O$ at 0.3 to 10 Torr have been measured. A scanning rhodamine 6G cw dye laser is used to pump $X^{1}\Sigma(\nu^{\prime\prime}) \rightarrow A^{1}\Sigma(\nu ^{\prime})$ transitions from sequential ground state vibrationa1 levels $(\nu^{\prime\prime}_{i})$, while a 3 nm resolution monochromator detects only the photo-luminescence originating from this $A^{1}\Sigma(\nu ^{\prime})$ in a band outside the dye laser region. Shown below are the relative populations, determined from laser induced fluorescence intensities, of the $\nu ^{\prime} = 0$ through $\nu ^{\prime} = 7$ vibrational levels of $BaO X^{1}\Sigma$ formed in the $Ba + 0_{2}$ reaction at 0.3 Torr. [FIGURE] Similar data for the $Ba + N_{2}O$ reaction suggest that a population inversion may exist between $BaO\ \ A^{1}\Sigma(\nu^{\prime} = 1)^{1}$ and $X^{1}\Sigma(\nu^{\prime\prime}= 7)$ at 16 Torr