NEAR-THRESHOLD SITE-SELECTED DISSOCIATIVE IONIZATION OF CORE-EXCITED CARBON-DIOXIDE

The ionization and fragmentation of C and O 1s core excited CO2 has be en studied using soft x-rays, threshold electron analysis to define th e initial core hole and a triple coincidence technique to examine the final dissociated ion state. The excitation of the O 1s electron resul ts 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 toget her with a weaker channel, corresponding to the triply ionized three-b ody fragmentation O+ + C+ + O+. Moreover, the angular distribution of ions from the CO+ + O+ channel is seen to depend on the excited-core s tate.