Figure 2
Plasma bubble evolution and electron microbunching. Snapshots of the electron density at the injection time (\(0.5 \;{\mathrm{ps}}\) left panel) and during the acceleration process (\(1.4 \;{\mathrm{ps}}\) and \(2.3\;{\mathrm{ps}}\), centre and right panels, respectively). The red line in the left panel represents the end of the initial density down-ramp. Only a central part of the simulation box is shown. The upper insets show a zoom of the bunch structure, the bottom insets show a projection of the trapped particles density on the x-axis.
