Figure 12.
Simulated Auger electron momentum distribution resulting from core-level ionization with a 300 as X-ray pulse in the presence of a 2.4 μm (TL = 8 fs), circularly polarized streaking field. The simulation is done in the strong-field approximation with a streaking field with Up = 2.5 eV, and assumes an isotropic distribution of Auger electron emission. (a) An Auger lifetime of 1 fs, so that, τX < τA < TL. In (b), the Auger lifetime is 4 fs and comparable to the streaking laser period, i.e. τX < τA∼TL. As in figure 9, the Auger electron momentum distribution intensity is normalized to 1. (Online version in colour.)