Magnetic, Material and Geometric Focusing Aids in Hot Electron Driven Fast Ignition

We study the effects of B-fields, material interfaces and resistivity on the focusing of hot electrons in various target geometries using the implicit hybrid simulation code ePLAS. The model deposits laser light near critical and generates a hot electron component, either fluid or particle, that moves through \textit{E {\&} B}-fields computed by the implicit moment method [1], while dragging on the ``cold'' background electrons and scattering off the local ions. Picosecond pulses at $\sim $10$^{20}$ W/cm$^{2}$ can produce highly divergent electron emission in Cu foils and in pre-pulsed cone targets [2]. We examine the influence of spontaneous and/or external $B-$fields, resistivity and density changes at target interfaces. We study how target contouring and the pulse history might be optimally configured to aid re-focusing of the hot electron energy for more localized target heating. We compare results for fixed Atomic Number with those from variable Z values determined from the Sesame EOS tables.\\[4pt] [1] R. J. Mason, J. Comp. Phys. \textbf{71,} 429 (1987)\\[0pt] [2] R. J. Mason, PRL \textbf{96,} 035001 (2006).