Potential Well Dynamics of Self Focusing of Quadruple Gaussian Laser Beams in Thermal Quantum Plasma

This paper presents theoretical study on self-action effects of intense laser beams interacting with fusion plasmas. Particularly the phenom-ena associated with the nonlinear refraction of the laser beam have been investigated in detail. In order to see the effect of uniformity of the illumination over the beam phase fronts on its propagation character-istics the irradiance profile of the beam has been modeled by quadru-ple Gaussian (Q.G) profile. Following Variational theory approach, the nonlinear partial differential equation (PDE) for the beam envelope has been reduced to a set of coupled ordinary differential equations for the evolution of beam width and axial phase. The equations so obtained have been solved numerically to envision the effect of laser as well as medium parameters on the propagation characteristics of the laser beam.