Core level ionization dynamics in small molecules studied by x-ray-emission threshold-electron coincidence spectroscopy

X-ray-emission threshold-electron coincidence spectroscopy has been applied to N2, O2, and N2O. The main features of the spectra can be interpreted as conventional core level threshold electron spectra, free from postcollision interaction effects. The relative cross sections for adiabatic ionization of close-lying core hole states and vibrational substates are presented. The results are compared to theoretical predictions and state-of-the-art photoelectron spectra and are discussed in terms of direct threshold ionization and core vacancy rearrangement processes.