Optical guiding and electron acceleration in the laser wakefield accelerator

The laser wakefield acceleration concept is studied using a general 2D formulation based on relativistic fluid equations. Simulations of an intense laser pulse propagating in a plasma address both optical guiding and wakefield generation issues. It is shown that relativistic guiding is ineffective in preventing the diffraction of short pulses and long pulses are broken up into beamlet segments due to wakefield effects. The use of preformed plasma density channels or tailored pulse profiles allows intense laser propagation over many Rayleigh lengths. The ponderomotive force associated with the laser pulse envelope generates large amplitude accelerating and focusing wakefields over long distances to achieve electron trapping, acceleration and focusing.