Figure 1

(Color online) Snapshots showing the distribution of ions in the longitudinal phase space $p_x$ at $t=30{\tau }_0$ and $40{\tau }_0$. (a) The case when a shock wave is formed for $a_0=5$, $n_0=20n_c$, and $L=1.5{\lambda }_0$. A test ion located initially near $x=7.58{\lambda }_0$ (marked by arrows) is accelerated by the shock wave as marked by the open circles for different time. (b) The case when a solitary wave is formed for $a_0=5$, $n_0=10n_c$, and $L=1.5{\lambda }_0$. A test ion marked by open squares is not accelerated efficiently by the solitary wave. Plot (c) shows the initial shock speed and the Mach number versus target thicknesses, where line I represents the calculated Mach number; lines II and III are the shock speeds from 1D PIC simulations and model calculation, respectively, for a circularly polarized laser pulse of $a_0=5$ and plasma density $n_0=20n_c$; lines IV and V are similar to lines II and III, respectively, but with $a_0=16$ and $n_0=10n_c$; and lines VI and VII are shock speeds found by 2D PIC simulations with circular and linear polarized laser pulses, respectively, at $a_0=5$ and $n_0=20n_c$.Reuse & Permissions

Figure 2

(Color online) (a) Snapshot of the ion density in 2D space at $t=40{\tau }_0$. (b) The space-time evolution of the laser fields $\left(E_z\right)$. The ion density contour lines of $45n_c$ are also overplotted. (c) The longitudinal density distributions of the ions and electrons, and the longitudinal electric field on the laser axis at $t=30{\tau }_0$. (d) The space-time evolution of the ion density distribution on the laser axis. The used parameters are the same as in Fig. 1a.Reuse & Permissions

Figure 3

(Color online) (a) The longitudinal field $\left(E_x\right)$ experienced by an accelerated ion and its longitudinal momentum $\left(p_x\right)$ (dashed line) as functions of time. (b) The ion energetic spectra accelerated by the shock wave and the sheath field, and their summed spectrum. The simulation parameters for (a) and (b) are the same as in Fig. 1a. (c) The $E_x$ experienced by an ion located initially inside plasma and its $p_x$ (dashed line) as functions of time. (d) The $E_x$ experienced by an ion located initially at the rear side and its $p_x$ (dashed line) as functions of time. The simulation parameters for (c) and (d) are the same as in Fig. 1b.Reuse & Permissions

Figure 4

(Color online) (a) The space-time evolution of the longitudinal electrostatic field $\left(E_x\right)$ along the laser axis. Two ion trajectories are also overplotted with one (marked II) accelerated by the shock wave and another (marked I) not accelerated. The simulation parameters are the same as in Fig. 1a. (b) The space-time evolution of $E_x$ along the laser axis. Two ion trajectories are shown with one (marked IV) accelerated by the solitary wave together with the sheath field, and another (marked III) not accelerated. The simulation parameters are the same as in Fig. 1b. The dashed lines are the initial boundaries of the plasma targets.Reuse & Permissions