Relativistic High-Current Electron-Beam Stopping-Power Characterization in Solids and Plasmas: Collisional Versus Resistive Effects
Résumé
We present experimental and numerical results on intense-laser-pulse-produced fast electron beams transport through aluminum samples, either solid or compressed and heated by laser-induced planar shock propagation. Thanks to absolute K-alpha yield measurements and its very good agreement with results from numerical simulations, we quantify the collisional and resistive fast electron stopping powers: for electron current densities of approximate to 8 x 10(10) A/cm(2) they reach 1.5 keV/mu m and 0.8 keV/mu m, respectively. For higher current densities up to 10(12) A/cm(2), numerical simulations show resistive and collisional energy losses at comparable levels. Analytical estimations predict the resistive stopping power will be kept on the level of 1 keV/mu m for electron current densities of 10(14) A/cm(2), representative of the full-scale conditions in the fast ignition of inertially confined fusion targets.