Carbon K-shell photoelectron angular distribution from fixed-in-space CO₂ molecules

Measurements of photoelectron angular distributions for carbon K-shell ionization of fixed-in-space CO₂ molecules with the molecular axis oriented along, perpendicular and at 45° to the electric vector of the light are reported. The major features of these measured spectra are fairly well reproduced by calculations employing a relaxed-core Hartree-Fock approach. In contrast to the angular distribution for K-shell ionization of N₂, which exhibits a rich structure dominated by the f-wave (l = 3) at the shape resonance, the angular distribution for carbon K-shell photoionization of CO₂ is quite unstructured over the entire observed range across the shape resonance.