Computer simulation of particle acceleration in thin foil by ultrashort laser pulses

Abstract

Particles acceleration triggered by relativistic laser pulses consisting of only a few optical cycles has been studied with 2D particle-in-cell (PIC) simulations. The electrons are accelerated predominantly in forward direction for preplasma longer than the pulse length. The most effective electron acceleration takes place when the preplasma scale length is comparable to the pulse-duration. The tails of electron distribution functions are well approximated by the Maxwellian distribution with a hot temperature of MeV range. The electrons accelerated in the underdense plasma penetrate deep inside or through the target and set up a strong electrostatic field which accelerates ions forward and decelerates electrons. Because ions are more heavier than electrons, a quite long laser pulse is needed to accelerate them.