By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam elec...By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam electrons with immobile neutralized positive ions.Numerical analyses have identified that EA waves with a sufficiently large amplitude tend to trap cold electrons.Because EA waves are dispersive,where the wave modes with different wavenumbers have different phase velocities,the trapping may lead to the nlixing of cold electrons.The cold electrons finally get thermalized or heated.The investigation also shows that the excited EA waves give rise to a broad range of wave frequencies,which may be helpful for understanding the broadband-electrostatic-noise spectrum in the Earth's auroral region.展开更多
The linear characteristics of the unstable mode of ion-acoustic waves are examined in an electrostatic electron-ion plasma composed of streaming hot electrons,non-streaming cold electrons and dynamical positive ions.T...The linear characteristics of the unstable mode of ion-acoustic waves are examined in an electrostatic electron-ion plasma composed of streaming hot electrons,non-streaming cold electrons and dynamical positive ions.The plasma under consideration is modeled by using a non-gyrotropic nonextensive q-distribution function in which the free energy source for wave excitation is provided by the relative directed motion of streaming hot electrons with respect to the other plasma species.In the frame work of kinetic model,a linearized set of Vlasov-Poisson's equations are solved to obtain the analytical expressions for dispersion relation and Landau damping rate.The threshold condition for the unstable ion-acoustic wave is derived to assess the stability of the wave in the presence of nonextensive effects.Growth in the wave spectrum and nontrivial effects of q-nonextensive parameter on the ion-acoustic waves can be of interest for the readers in the regions of Saturns's magnetosphere.展开更多
基金the support from Chinese Academy of Science(CAS)TWAS for his Ph.D studies at the University of Science and Technology of China in the category of a 2016 CAS-TWAS President’s Fellowship Awardee(Series No.2016-172)+1 种基金partially supported by National Natural Science Foundation of China(Nos.41331067,41774169,and 41527804)the Key Research Program of Frontier Sciences,CAS(QYZDJ-SSW-DQC010)
文摘By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam electrons with immobile neutralized positive ions.Numerical analyses have identified that EA waves with a sufficiently large amplitude tend to trap cold electrons.Because EA waves are dispersive,where the wave modes with different wavenumbers have different phase velocities,the trapping may lead to the nlixing of cold electrons.The cold electrons finally get thermalized or heated.The investigation also shows that the excited EA waves give rise to a broad range of wave frequencies,which may be helpful for understanding the broadband-electrostatic-noise spectrum in the Earth's auroral region.
文摘The linear characteristics of the unstable mode of ion-acoustic waves are examined in an electrostatic electron-ion plasma composed of streaming hot electrons,non-streaming cold electrons and dynamical positive ions.The plasma under consideration is modeled by using a non-gyrotropic nonextensive q-distribution function in which the free energy source for wave excitation is provided by the relative directed motion of streaming hot electrons with respect to the other plasma species.In the frame work of kinetic model,a linearized set of Vlasov-Poisson's equations are solved to obtain the analytical expressions for dispersion relation and Landau damping rate.The threshold condition for the unstable ion-acoustic wave is derived to assess the stability of the wave in the presence of nonextensive effects.Growth in the wave spectrum and nontrivial effects of q-nonextensive parameter on the ion-acoustic waves can be of interest for the readers in the regions of Saturns's magnetosphere.
