Relativistic high-current electron beams in dense plasmas in the context of the fast ignition of inertially confined fusion targets

We present the results of two similar experiments on laser generated relativistic electron beam (REB) transport in aluminum samples related to the fast ignition (FI) of inertially confined fusion targets. Their goal was to characterize high current density REB energy losses in solid and compressed samples, as the viability of the FI scheme is highly determined by the amount of such energy losses. The experiments were performed on the JLF-Titan laser system. A REB was generated by an intense ps laser beam > 10²⁰ W.cm^-2 in planar targets compressed by a ns laser beam > 10¹³ W.cm^-2 leading to REB current densities j_h ~ 10¹¹ A.cm^-2 in the aluminum sample under study. A variation of resistive energy losses between solid and compressed samples was observed for the thickest ones as predicted by numerical hybrid simulations.