Photoelectron–photofragment ion recoil vector correlations in the dissociative photoionization of PF3 at He i and Ne i ionizing wavelengths

A comparative study of the photoionization and dissociation of the A state of PF3+ at two different resonance line ionizing wavelengths (He i and Ne i) is presented. Using a photoelectron–photoion coincidence (PEPICO) technique, energy selected ions are prepared and fragment ion kinetic energy distributions derived. The energetics and dynamics of the ion fragmentation process are discussed and a simple impulsive dissociation model is proposed. An angular correlation between the recoil directions of ejected electrons and fragment ions is identified and is especially pronounced for the He i data. An interpretation in terms of an anisotropic body-frame photoelectron angular distribution is presented, from which the likely presence of a shape resonance in the A state photoionization dynamics around λ=584 Å is inferred. This accords with the observation of resonances in core photoionization studies of PF3.