ENERGY-DISTRIBUTIONS OF EMITTED ION FRAGMENTS FOLLOWING C(1S) EXCITATIONS IN CO

Ion-branching ratios following the relaxation of C (1s(-1)pi,nl lambd a,upsilon') synchrotron light-excited, vibrationally resolved resonanc es in CO have been measured using a time-of-flight spectrometer at hig h extraction voltages. Additional measurements at low extraction volta ges (higher kinetic-energy resolution) have enabled an estimate of the kinetic-energy distributions (KED's) of the emitted C+, O+, C2+ and O 2+ ions. Large differences in these distributions are observed at vari ous resonances and, for instance, a doorway-state dependence of the KE D has been found for the 3s sigma and 3p pi Rydberg resonances. While the results give some different information concerning the involved re laxation processes, more theoretical calculations are needed to get a more quantitative understanding.