Fig. 4: Analysis of specific resonant excitations for Xe²⁵⁺ at 1250 eV [peak J in Fig. 2c].

A fixed fluence of 1.6 × 10¹¹ photons/μm², which provides the maximum yield for Xe²⁵⁺ at 1250 eV, is employed. a A normalised histogram of the precursor charge states at which the last resonant excitation resulting in Xe²⁵⁺ occurs. The relative frequency shown is the number of Monte Carlo trajectories in which the 3d ⟶ 6f transition in a given charge state is the last resonant transition, divided by the total number of such Monte Carlo trajectories. Different colours indicate the relative number of M-shell core holes present at the time of the last resonant excitation. b An exemplary ionisation pathway corresponding to peak J, specifically involving five core holes in the precursor charge state of +17. For the given ionisation pathway, the time evolution of the number of M-shell core holes (right y axis) is represented by the blue area. Note that the x axis is on a logarithmic scale after 10 fs.