We study the transport and energy deposition of superthermal electrons in high-density plasma, starting from the basic physics of relativistic particle collisions, considering relativistic Coulomb collisions and the collective effect, combined with the background plasma electron return and temperature equation, developed a hybrid model of the electronic relativistic Fokker-Planck equation. The finite volume algorithm of the Fokker-Planck equation in the rectangular-momentum spherical coordinate system is constructed, and the numerical algorithm and numerical simulation program are verified by calculating the energy deposition and magnetic field generation process of the monoenergetic electron beam in the high-density plasma. For evaluating of the preheat effects of superthermal electrons during the implosion process, the energy deposition processes and energy distributions in the implosion target under the single-energy and bi-Maxwellian energy spectrum are calculated.

This work introduces our recent research works on the propagation of intense laser and transport of relativistic electron beam in inhomogeneous plasmas. First of all, we investigated the propagation of intense laser pulse in plasma with randomly uneven density distribution and found a new nonlinear branched flow regime of intense laser propagation in inhomogeneous plasma. In particular, we identify the important effects played by the laser photoionization and relativistic motion of electrons. In addition, we also investigated the plasma density gradient effect on evolution of electrostatic wave excited by ultra-relativistic electron beam in inhomogeneous plasma. It is found that the local region wavenumber and phase velocity of the excited wave varies with time because of the plasma inhomogeneity. Independent of the positive and negative density gradient, the wavenumber finally increases with time. As a result, Landau damping gradually becomes dominant in the whole region of inhomogeneous plasma, and leads to transfer of the wave energy to background plasma electrons, presenting a novel energy dissipation regime caused by the plasma density gradient.