RC01		15min8:30

A. J. MARR AND T. C. STEIMLE, Dept. of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604.

An intense pulsed supersonic molecular beam sample of CaCH₃ was produced using a laser ablation/reaction source. The high resolution (50 MHz FWHM) laser induced fluorescence spectrum of the (K'= 1 - K''= 0) A²E-X² A₁ band system (origin = 14743 cm^-1) was recorded and fitted to produce an improved set of spectroscopic parameters. The resultant parameters were in agreement with those obtained in a previous Doppler limited study. A number of the transitions involving the lowest J levels were also recorded in the presence of variable static electric field. The Stark shifts and splittings were fitted to obtain dipole moments of 2.62(3) D and 1.69(1) D for the X² A₁ and A²E states, respectively. The dipole moments were predicted using an electrostatic polarizability model\footnoteT. T\ddotorring, W. E. Ernst and J. Kl\ddotander, J. Chem. Phys. 90, 4927 (1989).^, that had successfully predicted the dipole moments of CaCCH . The predicted values, 1.78 D X² A₁ and 1.20 D A²E, are in reasonable agreement with experiment.