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

Abstract

X-ray-emission threshold-electron coincidence spectroscopy has been applied to ${\mathrm{N}}_{2}$, ${\mathrm{O}}_{2}$, and ${\mathrm{N}}_{2}\mathrm{O}$. 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.