High energy electron transport in dense plasma in fast ignition scenario

Abstract

We investigate the high energy electron transport in dense plasma for different laser intensity by using 3D PIC (Three-Dimensional Particle-In-Cell) simulation. We have observed dependence of electron energy flux on incident laser intensity. The electron energy fluxes normalized by the incident laser flux, I/I0, become ≈ 0.2 for the normalized laser electric field of a = 3, ≈ 0.1 for a = 1 and no visible flux for a = 0.2 in dense plasma region, where a = eE/meω0c. For the case of a = 3, we investigated space and time resolved velocity distribution functions and induced longitudinal electric field. We show that the high energy electrons have beam-like velocity distribution with relativistic thermal spread near the energy flux front. We also discuss the electromagnetic instabilities associated with the high energy electron beam taking the relativistic thermal spread of the beam into account.