Study On Some Nonlinear Collective Behaviors In Muliticomponent Complex Plasma

Since the discovery of plasma,the research on the characteristics of plasma is increasingly deepening.Many kinds of nonlinear collective behaviors and nonlinear wave processes of plasma system are one of the frontier problems in the field of plasma physics.With the development of plasma research,these research results have been widely used in many frontier fields,such as experimental plasma,space plasma and so on.In this paper,based on the theory of MHD,the plasma is simulated from two different aspects:1.The motion characteristics of(2+1)-dimensional nonlinear ion acoustic solitary waves in a typical multicomponent complex thermal plasma containing positive ions,negative ions and nonextensive electrons are studied.Firstly,based on the basic theory of magnetohydrodynamics,a set of dimensionless equations of ion acoustic waves are given.Then,by using the reduced perturbation method,we obtain the Kadomtsev-Petviashvili(KP)equation and its solitary wave solution,which is used to describe the(2+1)-dimensional nonlinear ion acoustic waves in complex thermal plasma.Finally,numerical simulation is carried out by using mathematical software to discuss the problem.The important influence of different system parameters on the nonlinear characteristics of(2+1)-dimensional nonlinear ion acoustic waves and the solitary wave wavefrom,amplitude and width is discussed.2.The variation of plasma density and magnetic field with time after implosion induced by Z-pinch of single wire aluminum is studied.Z-pinch is the Lorentz force produced by the plasma under the action of axial(Z)current,and the self pinch affect caused by the Lorentz froce in the radial(r).As one of the important means to study Z-pinch,MHD numerical simulation is of great significance to understand the generation and development of plasma instability and plasma collapse in the process of Z-pinch implosion,and to optimize the design of Z-pinch experiment.In this part,combined with the experimental datas of"Qiangguang-1" accelerator,an initial sinusoidal disturbance is added to the magnetic field,two kinds of initial disturbance amplitudes are given,and the numerical simulation of single wire aluminum driven by different current is carried out.The simulation results are helpful to understand the physical process of wire-array load Z-pinch.