Heat transport and electron distribution function in laser produced plasmas with hot spots

Abstract

Using Fokker–Planck and particle-in-cell simulations, the evolution of a single hot spot and multiple hot spot systems have been studied in laser produced plasmas. A practical formula for nonlocal heat flux has been derived as a generalized expression of a nonlocal linear approach [Bychenkov et al., Phys. Rev. Lett. 75, 4405 (1995)] and is tested in simulations. The electron distribution function is studied at different spatial locations with respect to a localized heating source. The electron distribution function displays several non-Maxwellian features which depend on the interplay between the effects of inverse bremsstrahlung heating and nonlocal transport. In particular, significant high-energy tails are found. They may have impact on the behavior of parametric instabilities in nonuniformly heated laser plasma.