Numerical Simulation Of The Transportation Process Of Strong Laser Pulse In A Class Of Low Density Nonuniform Plasma

The transportation of strong laser pulses in plasma is an important and rapidly developing field in plasma physics,which will produce rich extreme physical phenomena and nonlinear phenomena.In this thesis,an efficient numerical method,time splitting Fourier-Galerkin spectrum method,is designed for the transportation of strong laser pulses in a class of low density inhomogeneous plasma.The numerical method is used to simulate the physical phenomenon of strong laser pulse transmission in plasma.In the early studies,the physical phenomena of strong laser pulse transportation in low density inhomogeneous plasma can be described by models such as Maxwell equations and fluid equations,but these models are too complex.In this thesis,s simplified nonlinear Schrodinger equation(NLSE)is used to describe the transmission of super-strong short pulse laser beams in plasma.In the process of solving NLSE,the method of time splitting Fourier-Galerkin spectrum is adopted,that is,the time splitting method is first used in time,and then the Fourier-Galerkin spectrum method is used in space.Finally,the approximate solution of the original NLSE is obtained,and the unknown information in the physical model is described by the approximate solution.Compared with the traditional time splitting finite difference method,the time splitting Fourier-Galerkin spectrum method has the advantages of high accuracy,easy understanding,good computational complexity and good stability.It has spectral accuracy in space,does not require additional complexity to deal with linear problems,and is also suitable for calculation.In addition,the total particle number,total energy and total impulse of the equation can be conserved to a certain extent.The time splitting Fourier-Galerkin spectrum method is a general method,which can solve the problem of high intensity laser pulse propagation in plasma.An effective numerical method is introduced for researchers who study the high intensity laser pulse propagation in plasma.