Electron acceleration by self-focused ultraintense q-Gaussian laser pulse in an under dense plasma

Electron acceleration by self-focused q-Gaussian laser pulse in an underdense plasma has been investigated. The saturation in nonlinear plasma dielectric function causes periodic self-focusing of the laser beam. The formulation is based on numerical solution of nonlinear Schrodinger wave equation in W.K.B approximation followed by moment theory approach. An electron initially on the laser axis and at the front of the self-focusing pulse gains energy from the pulse until it is run over by the pulse peak. By the time electron reaches the tail, if pulse begins diverging, the deceleration of the electron is slower and the electron is left with net energy gain. Numerical simulations have been carried out to envision the effect of laser as well as plasma parameters on energy gained of the electron. It has been found that the radial intensity profile of the laser pulse has significant effect on energy gained by the electron. (author)