Fast ignition of fusion targets by laser-driven electrons

We present hybrid PIC simulations of fast electron transport and energy deposition in pre-compressed fusion targets, taking full account of collective magnetic effects and the hydrodynamic response of the background plasma. Results on actual ignition of an imploded fast ignition configuration are shown accounting for the increased beam divergence found in recent experiments (Green et al 2008 Phys. Rev. Lett. 100 015003) and the reduction in the electron kinetic energy due to profile steepening predicted by advanced PIC simulations (Chrisman et al 2008 Phys. Plasmas 15 056309). Target ignition is studied as a function of injected electron energy, distance of cone tip to dense core, initial divergence and kinetic energy of the relativistic electron beam. We found that beam collimation reduces substantially the ignition energies of the cone-guided fuel configuration assumed here.