Study of Fast Electron Propagation in Ultra-Intense Laser Pulse Interaction with Solid Targets Using Rear Side Optical Self-Radiation and Reflectivity-Based Diagnostics

Experimental results are reported on transport through a solid target of fast-electrons created by an ultra-intense laser pulse interaction. In particular, the goal was to determine the heating induced in the material by the fast electrons. Such a study is of great interest within the context of the Fast Igniter [1] approach to Inertial Confinement Fusion, where the heating needed to ignite nuclear reactions is supposed to be achieved by a sub-ps fast electron bunch. Experimentally, the main point is therefore to observe the propagation geometry of the fast electron beam and to estimate the amount of energy which can be carried and deposed in dense matter by a given electron source. So far, theory and simulations have not yet provided a complete picture of the prop-agation phenomena. Therefore, experimental work is requried in order to understand and dis crimed the basic processes involved.