Study of hot electron production and transport as a function of preplasma filling of hollow cone targets

Laser facilities for fast ignition will require in excess of 50 kJ of short pulse laser energy. Based on the current contrast estimate for the NIF ARC laser system at LLNL, ignition scale systems will have pre-pulses at the ~J level. This will produce a large scale-length plasma inside the reentrant fast ignition cone that could significantly influence the generation and transport of hot electrons towards the compressed fuel core. We present a study of cone wall and cone tip fluorescence measurements due to intense short pulse laser irradiation, as a function of pre-pulse from 1 mJ - 1 J. These experiments were performed using the Titan laser (2??10²⁰W/cm²) at the Lawrence Livermore National Laboratory and the Vulcan laser (6??10²⁰W/cm²) at the Rutherford Appleton Laboratory. The implicit hybrid particle-in-cell code LSP is used to translate these observables into estimates of hot electron production efficiency and transport.