Short-pulse high-intensity laser-generated fast electron transport into thick solid targets

摘要: The transport of fast electrons generated by 1 ps, $\ensuremath{\mu}\mathrm{m}$ wavelength laser pulses focused to spot diameters 20 and peak intensities up $2\ifmmode\times\else\texttimes\fi{}{10}^{18}$ W ${\mathrm{cm}}^{\ensuremath{-}2}$ on solid aluminum targets is considered using a relativistic Fokker-Planck equation, which solved reducing it an equivalent system stochastic differential equations. background represented $\mathbf{E}=\ensuremath{\eta}{\mathbf{j}}_{b},$ where $\ensuremath{\eta}$ the resistivity ${\mathbf{j}}_{b}$ current density. Collisions, electric magnetic fields, changes in due heating are included. Rotational symmetry assumed. treatment valid for electron number densities much less than that background, energies greater temperature, time scales short enough diffusion thermal conduction negligible. neglect ionization also limits validity model. at fields become important evaluated. field lowers energy penetrating target. reduces radial spread, increases penetration intermediate electrons, reflects lower electrons. Changes significantly affect generation. implications $K\ensuremath{\alpha}$ emission diagnostics discussed.