Study Of Nonlinear Wave In Space Plasmas Containing Kappa Distributed Electrons

At present,with the rapid progress of aerospace technology,astrophysics researches have also obtained great development.The related research topics of space plasma in astrophysics have also become a hot topic and frontier of the majority for scientific researchers.It is well known that the study of the collective behavior in the space plasma is with great significance for understanding the origin of human beings and developing new clean energy sources.According to the results of space detection,there are many kinds of non-standard Maxwell-Boltzmann distribution of electrons,protons,neutral particles and dust particles in space plasma.The results of researches show that the particles with non-standard Maxwell-Boltzmann distribution have an important influence on the nonlinear fluctuation waves process in space plasma.In this paper,a research model is established based on the theory of magnetic fluid dynamics,and the typical propagation characteristics of nonlinear fluctuation process in space plasma containing Kappa distribution electrons are discussed by the theoretical derivation and the numerical simulation.The main contents include:Firstly,the propagating characteristics of small-amplitude nonlinear ion acoustic waves in a space plasma containing Kappa distributed electrons are studied by using the reduced perturbation method.The Zakharov-Kuznetsov(ZK)equation is derived to describe the nonlinear ion acoustic wave motion process.The corresponding twodimensional dynamical system equation and Sagdeev potential function of the system are obtained.Finally,the expression of solitary wave solution is obtained.With the help of mathematical software,the nonlinear coefficient of the nonlinear ion ZK equation,the phase diagram of the two-dimensional dynamical system,the Sagdeev potential function and the basic variation law of the solitary waves with Kappa distributed electrons are obtained.The relationship between the amplitude,the width and the propagationng characteristics of nonlinear ion acoustic solitary waves and other system parameters in space plasma containing Kappa electrons is analyzed in detail.Secondly,the Sagdeev potential method is used to study the large-amplitude nonlinear ion acoustic waves in space plasma containing Kappa distributed electrons.By theoretical derivation,the two-dimensional dynamical system equation,the Sagdeev potential equation and the solitary wave solutions are obtained to describe the nonlinear ion acoustic waves.The effects of Kappa electron distributed electrons on the nonlinear dispersion relation,the phase diagram of the two-dimensional dynamical system and the Sagdeev potential function for the nonlinear ion acoustic wave with large amplitude are obtained by using mathematical software.In addition,the relationship between the typical propagation characteristics such as the amplitude,width and the waveform of the nonlinear ion acoustic solitary waves and the nonlinear ion acoustic shock waves with the system parameters have also been discussed.