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

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 functions, on laser 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 1014-1016 W/cm2 of the incident 1.2-ps laser pulse. (author)