含有非热电子和陷俘离子的复杂等离子体中非线性尘埃声波的传播特征  

Propagation characteristics of nonlinear dust acoustic solitary waves in complex plasma with nonthermal electrons and trapped ions

作　　者：林麦麦[1] 宋晨光 王明月 陈富艳 Lin Mai-Mai;Song Chen-Guang;Wang Ming-Yue;Chen Fu-Yan(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]西北师范大学物理与电子工程学院,兰州730070

出　　处：《物理学报》2024年第7期252-261,共10页Acta Physica Sinica

摘　　要：本文研究了同时含有非热(nonthermal)电子和陷俘(trapped)离子分布的复杂等离子体系统中非线性尘埃声波的传播特征.首先,利用线性化方法推导得到非线性尘埃声波的色散关系.接着,借助Sagdeev势方法推导得到表征非线性尘埃声波运动的二维自治系统、Sagdeev势方程和Sagdeev势函数的具体表达式.然后,依据数值模拟的方法分析了多种系统因素对二维自治系统相图的重要影响.结果表明:含有nonthermal电子和trapped离子的复杂等离子体系统中同时存在线性周期波、非线性周期波和孤立波.接下来,通过讨论Sagdeev势函数随系统参数的变化规律发现:该复杂等离子体系统中仅存在振幅大于零的压缩型孤立波.最后,探讨多种系统因素对非线性尘埃声孤波的振幅、宽度和波形等传播特征的重要影响.结果显示:马赫数、nonthermal电子和trapped离子以及尘埃颗粒未扰动的数密度、温度及荷电量等参数对该复杂等离子体系统中非线性尘埃声孤波的振幅、宽度和波形等传播特性均具有显著影响,且该结果与Sagdeev势函数的分析结果保持一致.The propagation characteristics of nonlinear dust acoustic solitary waves in a complex plasma system with nonthermal electrons and trapped ions are investigate in this work.The nonlinear dispersion relation of dust acoustic waves is obtained by using the linear method,and the two-dimensional autonomous system governing the motion of nonlinear dust acoustic waves is derived by using the Sagdeev potential method.At the same time,the specific expression of the Sagdeev potential function is obtained based on the Sagdeev potential equation.The numerical simulations are used to analyze the phase portraits of the two-dimensional autonomous system,revealing the linear periodic wave orbits,nonlinear periodic wave orbits,and homoclinic orbits coexisting in the complex dusty plasma system with nonthermal electrons and trapped ions.Furthermore,from the variations of the Sagdeev potential function with different system parameters it follows that only the compressive solitary waves exist in this complex plasma system.The significant influences of various system parameters on the amplitude,width,and waveform of the nonlinear dust acoustic solitary wave in the complex plasma system are discussed in detail.The results demonstrate that the Mach number,the nonthermal electrons and trapped ions,undisturbed dust particle number density,temperature,and charge have important effects on the propagating characteristics of the nonlinear dust acoustic solitary waves in a complex plasma with nonthermal electrons and trapped ions.

关 键 词：非线性尘埃声孤波 Sagdeev势方法 非热电子分布 陷俘离子分布 

分 类 号：O53[理学—等离子体物理]