Fokker-Planck simulations of ultrashort-pulse laser-plasma interactions

Abstract

The interaction of ultrashort laser pulses with a fully ionized plasma is investigated in the plane geometry by means of numerical simulation. The impact of the space oscillations in the amplitude of the laser electric field on the shape of the electron distribution function, on laser beam absorption, and on electron heat transport is demonstrated. Oscillations in the absorption rate of laser radiation with the minima coincident to the maxima of the laser electric field lead to a further decrease in the absorption of laser radiation. Heat flux in the direction of increasing temperature in the underdense region is caused by the modification of the electron distribution function and by the density gradient. A limitation of heat flux to the overdense plasma is observed with the flux limiter in range 0.03-0.08, growing moderately with the intensity 10 14 -10 16 W/cm 2 of the incident 1.2-ps laser pulse.

Study of flux limiter using Fokker–Planck and fluid simulations of planar laser-driven ablation

“…Actually, Fokker-Planck (FP) simulations can be exploited to carry out ab initio study of the electron thermal transport, and several FP codes have been developed in the past three decades for this purpose [13,[16][17][18][19][20]. The flux limiter can also be investigated in virtue of FP simulations.…”

A simple model for electron temperature and penetration depth in interaction of ultra-short laser pulses with solid targets

“…where Q Sp is the Spitzer heat flux and Q L is an upper limit to the heat flux given by Q L = f Q f s (f ≤ 0.1), f being the so-called 'flux limiter' and Q f s the local free-streaming heat flux [10][11][12][13]. In our model we take the heat flux as follows [14]:…”