Optical spectroscopy of metal vapors

Absorbance spectra are reported for selected diatomic combinations (Li2, Na2, LiAl, ...) of atomic metal vapors (Li, Na, Al) in support of transmission measurements made in a high-temperature (T ∼ 1,600 to 1,800 degrees K) flow apparatus. The computational model adopted for interpretation of measured data incorporates Voigt lineshapes and rovibronic positions and transition strengths derived from previous spectral measurements or from ab initio potential curves and transition dipole moment functions. Particular attention is addressed to comparison of the calculated high-resolution spectra obtained from state-specific transition intensities with corresponding Franck-Condon approximations and with measurements in Li/Li2 and Na/Na2 vapors. Comments are provided on diagnostic characterization of spatial anisotropies in the flow apparatus employed in these cases, and on detection of previously unobserved metal diatomics