ANALYSIS OF THE HYPERFINE STRUCTURE IN THE [18.9] 4 - X 4 TRANSITION OF COBALT MONOFLUORIDE.

1. A. G. Adam, L.P. Fraser, W.D. Hamilton, and M.C. Steeves, Chem. Phys. Lett. 230, 82 (1994).Author Institution: University of New Brunswick, Fredericton, N.B., Canada E3B 6E2The electronic spectroscopy of the cobalt monofluoride molecule has been studied using a pulsed molecular beam apparatus. The molecules were produced by chemical reaction of laser-ablated cobalt atoms in a pulsed helium expansion seeded with $SF_{6}$. Low resolution $(\sim 0.05 cm^{-1} bandwidth)$ results for this molecule have recently been $published^{1}$ and we now report on our first high-resolution $(\sim 0.006 cm^{-1} FWHM)$ findings. Two bands were probed at sub-Doppler resolution using a single mode dye laser. Hyperfine structure arising from the cobalt nuclear spin, $I = 7/2$, was well resolved. The most intense band, centered at 529 nm, furnished about 40 measurable P, Q, and R lines yielding both $\Delta F = \Delta J$ and $\Delta F \neq \Delta J$ hyperfine transitions. Unfortunately, the second band accessible with our cw dye laser was too weak to allow the hyperfine transitions to be measured. A non-linear least-squares fit of some 500 hyperfine lines from the 529 nm band furnished effective $T_{0}, B$, and D values for the upper ${^{3}}\Phi$ state and an effective B value for the lower ${^{3}}\Phi$ state, as well as a hyperfine `h' parameter for each state. We will also report on calibrated low-resolution measurements of several other electronic transitions in the region 450 to 500 nm