Hot Electron Generation from Laser-Cone Target Interactions in Fast Ignition*

We present recent 2D PIC simulations for the cone-in-shell integrated fast ignition experiments on the Omega laser facility [W. Theobald et al., Phys. Plasmas, May 2011]. The initial plasma density profile in the PIC simulations is taken from hydrodynamic simulations, including the pre-plasma inside the gold cone generated by the prepulse. The main pulse of Omega-EP has a peak intensity of 10$^{19}$W/cm$^2$, duration of 10 ps and total energy of 1 kJ. Hot electron generation from laser-pre-plasma interactions and electron transport in under-100nc plasmas are studied. An artificial drag is applied to hot electrons above 30kev in the $>$100 nc region to facilitate the establishment of an return current and allow the simulations to run close to 10ps. The simulation results show a large average divergence angle of 57 degree and high absorption rate of $\sim $50{\%} for the hot electrons generated.