Near-threshold site-selected dissociative ionization of core-excited carbon dioxide

Abstract

The ionization and fragmentation of C and O 1s core excited CO2 has been studied using soft X-rays, threshold electron analysis to define the initial core hole and a triple coincidence technique to examine the final dissociated ion state. The excitation of the O 1s electron results in a single decay channel, CO++O+, corresponding to the breaking of a single C-O bond. At the C 1s edge, the same channel is seen together with a weaker channel, corresponding to the triply ionized three-body fragmentation O++C++O+. Moreover, the angular distribution of ions from the CO++O+ channel is seen to depend on the excited-core state.