Energy differential cross sections for the triple photoionization of lithium

Energy differential cross sections from the triple photoionization of lithium are calculated using the non-perturbative time-dependent close-coupling method. Collision probabilities are found by projection of the time-evolved nine-dimensional coordinate space wavefunction onto a fully antisymmetric product of spatial and spin functions representing three outgoing Coulomb waves. We then derive a differential cross section that is a function of the energy sharing between all three ejected electrons moving in the Coulomb field of the nucleus; i.e. four-body Coulomb break-up. At an incident photon energy of 300 eV, the energy differential cross section for lithium is bowl shaped with magnitudes generally below 10-3 barns/(eV)2; certainly a challenge for future advanced light source experiments