NONLOCAL HEAT-TRANSPORT EFFECTS ON THE FILAMENTATION OF LIGHT IN PLASMAS

The nonlocal nature of electron heat transport in hot coronal plasmas is investigated. Its effect on the linear theory of laser filamentation is reviewed. The nonlinear evolution of filaments is modeled with the two-dimensional Fokker-Planck code SPARK, for the conditions of recent filamentation experiments. Simulation results agree with experimental data and imply the dominance of thermal over ponderomotive filamentation. The increased importance of the thermal filamentation mechanism is attributed to heat flux inhibition arising from nonlocal electron transport. The potential implications of filamentation for inertial-confinement-fusion target designs are discussed.