Electron acceleration by self focused quadruple Gaussian laser beams in thermal quantum plasma: effect of relativistic optical nonlinearity of plasma

A method for achieving relativistic electron acceleration using intense laser beams has been introduced. As intense laser beams propagate through plasmas, they induce an electron plasma wave (EPW) at the pump frequency. Electrons externally introduced into this EPW and subsequently trapped undergo acceleration, reaching exceedingly high energies. To optimize the coupling of laser energy with the plasma, the irradiance across the beam cross-section is modeled using a Quadruple Gaussian (Q.G) profile. The impact of self-focusing of the laser beam on electron energy gain has been thoroughly examined. Applying variational theory based on Lagrangian formulation and a hydrodynamic fluid model of plasma, coupled differential equations governing the evolution of the laser beam's width and the energy of accelerated electrons have been derived. It is observed that the uniformity of irradiance across the beam cross-section significantly enhances the energy acquired by electrons.