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 E & B-fields computed by the implicit moment method, while dragging on the ``cold'' background electrons and scattering off the local ions. Picosecond pulses at ~10²⁰ W/cm² can produce highly divergent electron emission in Cu foils and in pre-pulsed cone targets. 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.

Work supported by the USDOE under SBIR GRANT DE-SC0006342.