Reaction dynamics of three-body dissociations in triatomic molecules from single-photon double ionization studied by a time- and position-sensitive coincidence method

Application of the position-sensitive photoelectron - photoion - photoion (PSD-PEPIPICO) method to dissociative double-ionization processes in and at photon energies of 40.8 and 48.4 eV provides measurements of total kinetic energy releases and complete descriptions of the kinematics for three-body dissociations of the type . Comparisons of experimental observations with predictions from sequential and concerted bond breaking mechanisms suggest a unified model in which both bonds break on a time scale of , and electron ejection may be either faster (direct ionization) or competitive (indirect) on this time scale.