Laser Hole Boring into Overdense Plasma and Relativistic Electron Currents for Fast Ignition of ICF Targets

Laser hole boring and relativistic electron transport into plasma of 10 times critical density is studied by means of 2D particle-in-cell simulation. At intensities of $I_0{\lambda }^2{=10\mathrm{}}^{20}\mathrm{W}{\mathrm{cm}}^{-2\mathrm{}}\mu {\mathrm{m}}^2$, a channel $12\lambda$ deep and $3\lambda$ in diameter has formed after 200 laser cycles. The laser driven electron current carries up to 40% of the incident laser power. When penetrating the overdense region, it breaks up into several filaments at early times, but is channeled into a single magnetized jet later on. These features are essential for fast ignition of targets for inertial confinement fusion (ICF).