Fig. 3: Results of 2-D particle-in-cell simulations.
From: Spatiotemporal dynamics of fast electron heating in solid-density matter via XFEL
a Simulated electron temperature and (b) average ionization state profiles averaged over a 2 μm thick solid Cu foil from 2D PIC simulations (see Fig. 9). The evolution of these profiles is presented from 0.16 ps to 1.44 ps. Deviations of the ionization state profile from the temperature profile indicate the contribution of electron impact ionization. c Comparison of the widths of the measured transmission-affected area with simulated ionization states. The circle and square symbols represent the data at 9.05 keV and 8.92 keV, respectively. A dashed line indicates the speed of light (v = c) for reference. The error bars in time are ± 0.1 ps based on the uncertainty of the XFEL and the optical laser timing jitter, while the errors in width are ± 7.9 μm due to averaging of the experimental line profiles. The solid lines are results from the PIC simulation, and a constant extension of the simulation is assumed as extended dashed lines after ~1.4 ps.
