Ablation Pressure Driven by an Energetic Electron Beam in a Dense Plasma

An intense beam of high energy electrons may create extremely high pressures in solid density materials. An analytical model of ablation pressure formation and shock wave propagation driven by an energetic electron beam is developed and confirmed with numerical simulations. In application to the shock-ignition approach in inertial confinement fusion, the energy transfer by fast electrons may be a dominant mechanism of creation of the igniting shock wave. An electron beam with an energy of 30 keV and energy flux $2–5\mathrm{PW}/{\mathrm{cm}}^2$ can create a pressure amplitude more than 300 Mbar for a duration of 200–300 ps in a precompressed solid material.

Figure 1

Density and temperature profiles in the stationary laser ablation regime (a) and in the hot electron beam ablation nonstationary regime after the loading time (b).

Figure 2

Snapshots of distributions of the plasma pressure (a) and the density (b). The numbers near the curves indicate the time in picoseconds. The electron beam energy is 30 keV and the intensity is $1\mathrm{PW}/{\mathrm{cm}}^2$.

Figure 3

Snapshots of distributions of the plasma pressure (a) and the density (b). The numbers near the curves indicate the time in picoseconds. The electron beam energy is 100 keV and the intensity is $10\mathrm{PW}/{\mathrm{cm}}^2$. Dashed line in panel b shows the self-similar solution (3).