| Fast Ignition of inertially confined targets is one of the most foreseen applications for ultra-high intensity laser-matter interactions. It is based on the use of an intense charged particle beam to isochorically heat a small volume of a compressed nuclear fuel pellet to thermonuclear temperatures. It requires lower adiabat compression than conventional direct or indirect drive targets, requiring much less laser energy and less implosion symmetry requirements. Fast ignition intrinsic high gain makes it an ideal candidate for energy production purposes at the industrial level. The European Project HiPER aims at developing a high repetition rate energy source based on Inertial Confinement Fusion. It demands the use of a high-repetition-rate high-power laser system capable of delivering an energy in the level of 100 kJ in 20 ps, focused to 1020 W/cm2 intensity. This communication is related to the experimental efforts carried out in the framework of HiPER in order to assess the feasibility of the electron-driven fast ignition scheme. Fast electron transport experiments were conducted in targets driven in both planar and cylindrical geometries, creating warm and dense plasma conditions, close to those near the fast electron source in a full-scale fast ignition target. The experimental data concern the energy deposition rate of a fast electron jet as a function of the penetration length in such plasmas, as well the angular collimation of the jet by self-generated magnetic fields. The data discussion is supported by an extensive numerical description including hydrodynamic, PIC and hybrid and simulations of respectively the target compression, fast electron generation and fast electron transport. |
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