Figure 4
Transverse dynamics of channel wall and formation of collisionless shocks: (a) Snapshot of the upper half \({He}^{2+}\) density channel at t = 1.1 ps to show an early stage of shock formation. The direction of laser pulse propagation is from left to right. The central axis of the laser pulse is located at \(x = 500c/{\omega }_{0}\). (b, c) Profiles of electron density (black), helium ion density (blue) and transverse electric field (red) at two locations, (b) \(z = 1180 c/{\omega }_{0}\) and (c) \(z = 1850 c/{\omega }_{0}\), indicated by the two black dotted lines in (a). Transverse phase-space of \({He}^{2+}\) (d, f) and protons (e, g) at t = 2.2 ps is plotted, where to plot (f, g) only particles within longitudinal range \(z = 1200 c/{\omega }_{0}\) to \(1250 c/{\omega }_{0}\) is used. Here \({\omega }_{0}^{-1}=0.42 fs\) and \(c/{\omega }_{0}=0.13 \mathrm{\mu m}\).
