Electron distribution function in a laser-produced hot spot

Summary form only given, as follows. In order to better understand the physics of localized heating of laser produced plasmas, the evolution of the electron distribution function (EDF) in a single hot spot has been studied by using Fokker-Planck simulations. The EDF is studied at different spatial locations with respect to the center of the hot spot. It found to be dependent on the interplay between the effects of flattening due to inverse bremsstrahlung heating (Langdon effect), electron-electron collisions which provide maxwellization of the tails, and nonlocal spatial transport which enriches the EDF by hot tail particles. The EDF within a hot spot is compared with predictions from the homogeneous inverse bremsstrahlung heating theory of Ref. E. Fourkal et al., Phys. Plasmas 8,550 (2001). Significant high-energy tails of the EDF are found outside the hot spots, which may have strong impact on plasma wave Landau damping in non-uniformly heated laser plasmas. The anisotropy of the EDF and the growth rate of the return current instability are discussed.