ROLE OF SCREENING AND ANGULAR-DISTRIBUTIONS IN RESONANT X-RAY-EMISSION OF CO

Resonantly excited carbon and oxygen x-ray-emission spectra of gaseous carbon monoxide are presented. Emission spectra obtained with selecti ve excitation to the pi valence orbital and to various Rydberg levels are compared to satellite-free nonresonant spectra. Screening effects caused by the excited electron, creating energy shifts and intensity variations in the resonant spectra compared to the nonresonant spectra , are observed, as well as an angular dependence of the resonantly exc ited spectra. The experimental spectra are compared to simulated spect ra where the vibronic part is computed by means of a lifetime-vibratio nal interference formalism. The electronic intensities are analyzed by a separate-state, self-consistent-held method and a formalism for res onant inelastic x-ray scattering, focusing On screening and angular de pendence.