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Nonlinear Electrostatic Ion-Acoustic-Like Instabilities in a System with Two Streaming Ion Components Moving in a Background Plasma
L. Gomberoff
The Open Plasma Physics Journal , 2008, DOI: 10.2174/1876534300801010014]
Abstract: Finite amplitude Alfvén-cyclotron waves are believed to play an important role in coronal heating and nonthermal properties of velocity distribution functions. These effects are thought to be due to parametrically unstable Alfvén-cyclotron waves and electrostatic bursts of ion-acoustic like waves. It is shown here that large amplitude Alfvéncyclotron waves propagating in multi-ion plasmas with relative drift velocities between the ion-species, can lead to a new type of nonlinear electrostatic ion-acoustic like instabilities. These instabilities occur when the phase velocity of a forward propagating ion-acoustic wave supported by one ion species become equal to the phase velocity of a backward propagating ion-acoustic wave supported by another ion species. This phenomenon is only possible when relative to the background plasma there are at least two streaming ion components.
Optical Mixing Controlled Stimulated Scattering instabilities: Suppression of SRS by the Controlled Introduction of Ion Acoustic and Electron Plasma Wave Turbulence  [PDF]
Bedros Afeyan,M. Mardirian,K. Won,D. S. Montgomery,J. Hammer,R. K. Kirkwood,A. J. Schmitt
Physics , 2012,
Abstract: In a series of experiments on the Omega laser facility at LLE, we have demonstrated the suppression of SRS in prescribed spectral windows due to the presence of externally controlled levels of ion acoustic waves (IAW, by crossing two blue beams at the Mach -1 surface) and electron plasma waves (EPW, by crossing a blue and a green beam around a tenth critical density plasma) generated via optical mixing. We have further observed SRS backscattering of a green beam when crossed with a blue pump beam, in whose absence, that (green beam) backscattering signature was five times smaller. This is direct evidence for green beam amplification when crossed with the blue. Additional proof comes from transmitted green beam measurements. A combination of these techniques may allow the suppression of unacceptable levels of SRS near the light entrance hole of large-scale hohlraums on the NIF or LMJ.
Influence of Ion Streaming Instabilities on Transport Near Plasma Boundaries  [PDF]
Scott D. Baalrud
Physics , 2015,
Abstract: Plasma boundary layers are susceptible to electrostatic instabilities driven by ion flows in presheaths and, when present, these instabilities can influence transport. In plasmas with a single species of positive ion, ion-acoustic instabilities are expected under conditions of low pressure and large electron-to-ion temperature ratio ($T_e/T_i \gg 1$). In plasmas with two species of positive ions, ion-ion two-stream instabilities can also be excited. The stability phase-space is characterized using the Penrose criterion and approximate linear dispersion relations. Predictions for how these instabilities affect ion and electron transport in presheaths, including rapid thermalization due to instability-enhanced collisions and an instability-enhanced ion-ion friction force, are also briefly reviewed. Recent experimental tests of these predictions are discussed along with research needs required for further validation. The calculated stability boundaries provide a guide to determine the experimental conditions at which these effects can be expected.
Electron-drift driven ion-acoustic mode in a dusty plasma with collisional effects  [PDF]
R. Singh,M. P. Bora
Physics , 2000, DOI: 10.1063/1.874069
Abstract: Instabilities of ion-acoustic waves in a dusty plasma with electron-drift, collisional, and dust charge fluctuations effects, have been investigated. The regimes are clearly marked out where the theory is applicable. The critical electron-drift velocity required to drive the instability is predicted. It is also shown that electron thermal conductivity and charged grains concentration enhance the growth of the ion-acoustic mode whereas ion-viscosity, ion-thermal conductivity, and dust charge fluctuations have a stabilizing effect.
The electron-ion streaming instabilities driven by drift velocities of the order of electron thermal velocity in a nonmagnetized plasma  [PDF]
Jun Guo,Bo Li
Physics , 2013, DOI: 10.1007/s10509-013-1494-2
Abstract: We examine the electron-ion streaming instabilities driven by drift velocities of the order of the electron thermal velocity in a nonmagnetized plasma by one-dimensional electrostatic particle-in-cell code which adopts an ion-to-electron mass ratio of 1600. An initial state is set up where the ion bulk speed is zero while the electrons drift relative to ions, and where electrons are much hotter. We examine in detail four runs where drift velocity is systematically varied from lower than to larger than the electron thermal velocity. In all runs the Langmuir waves with Doppler-shifted frequencies dominate early on when streaming instabilities are too weak to discern. And then intense ion-acoustic waves or Buneman instabilities appear, which tend to be accompanied by localized electron and ion beams. Ion-acoustic modes and Buneman modes co-exist in the system when the initial drift velocity is just over the electron thermal speed. Beam modes are excited when the localized beams with large enough velocities appear. In the developed stage of instabilities, the direction in which density depressions propagate is always opposite to that of the localized ion beams. When the initial drift velocity is close to the electron thermal speed, categorizing the relevant instabilities is not easy, and one needs to examine in detail the wave dispersion diagrams at various stages of the evolution of the system.
Study of nonlinear ion- and electron-acoustic waves in multi-component space plasmas
G. S. Lakhina, S. V. Singh, A. P. Kakad, F. Verheest,R. Bharuthram
Nonlinear Processes in Geophysics (NPG) , 2008,
Abstract: Large amplitude ion-acoustic and electron-acoustic waves in an unmagnetized multi-component plasma system consisting of cold background electrons and ions, a hot electron beam and a hot ion beam are studied using Sagdeev pseudo-potential technique. Three types of solitary waves, namely, slow ion-acoustic, ion-acoustic and electron-acoustic solitons are found provided the Mach numbers exceed the critical values. The slow ion-acoustic solitons have the smallest critical Mach numbers, whereas the electron-acoustic solitons have the largest critical Mach numbers. For the plasma parameters considered here, both type of ion-acoustic solitons have positive potential whereas the electron-acoustic solitons can have either positive or negative potential depending on the fractional number density of the cold electrons relative to that of the ions (or total electrons) number density. For a fixed Mach number, increases in the beam speeds of either hot electrons or hot ions can lead to reduction in the amplitudes of the ion-and electron-acoustic solitons. However, the presence of hot electron and hot ion beams have no effect on the amplitudes of slow ion-acoustic modes. Possible application of this model to the electrostatic solitary waves (ESWs) observed in the plasma sheet boundary layer is discussed.
Soliton Collisions in the Ion Acoustic Plasma Equations  [PDF]
Yi Li,D. H. Sattinger
Physics , 1999, DOI: 10.1007/s000210050006
Abstract: Numerical experiments involving the interaction of two solitary waves of the ion acoustic plasma equations are described. An exact 2-soliton solution of the relevant KdV equation was fitted to the initial data, and good agreement was maintained throughout the entire interaction. The data demonstrates that the soliton interactions are virtually elastic
Modulational instability of ion-acoustic waves in a warm plasma
Modulational instability of ion—acoustic waves in a warm plasma

Xue Ju-Kui,Duan Wen-Shan,Lang He,

中国物理 B , 2002,
Abstract: Using the standard reductive perturbation technique, a nonlinear Schr?dinger equation is derived to study the modulational instability of finite-amplitude ion-acoustic waves in a non-magnetized warm plasma. It is found that the inclusion of ion temperature in the equation modifies the nature of the ion-acoustic wave stability and the soliton structures. The effects of ion plasma temperature on the modulational stability and ion-acoustic wave properties are investigated in detail.
One dimension PIC simulation of nonlinear ion-acoustic waves in plasma  [cached]
A Kargarian,MR Rouhani,H Hakimipajouh
Iranian Journal of Physics Research , 2011,
Abstract: In this paper with use of Particle in Cell (PIC) simulation method in one dimension the dynamic of ion acoustic soliton is studied. in this method the ions are monitored as particles and the electrons are assumed to be in thermal equilibrium. The dispersion relation of ion acoustic waves is investigated. The results are in good agreement with analytical results showing that in linear regime our code works correctly. Considering the solution of nonlinear KdV equation as initial perturbation, the propagation of ion acoustic soliton is studied. It is shown that the shape and the velocity of ion acoustic soliton is preserved during propagation through the plasma.
Ion thermal effects in oscillating multi-ion plasma sheath theory  [PDF]
J. Vranjes,B. P. Pandey,M. Y. Tanaka,S. Poedts
Physics , 2008, DOI: 10.1063/1.3036933
Abstract: The effects of ion temperature are discussed in a two-ion electron plasma and for a model applicable to the oscillating sheath theory that has recently been much in the focus of researchers. The differences between the fluid and kinetic models have been pointed out, as well as the differences between the approximative kinetic description (which involves the expansion of the plasma dispersion function), and the exact kinetic description. It is shown that the approximative kinetic description, first, can not describe the additional acoustic mode which naturally exists in the plasma with an additional ion population with a finite temperature, and, second, it yields an inaccurate Landau damping of the bulk ion acoustic mode. The reasons for these two failures are described. In addition to this, a fluid model is presented that is capable of capturing both of these features that are missing in the approximative kinetic description, i.e., two (fast and slow) ion acoustic modes, and the corresponding Landau damping of both modes.
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