scholarly journals Effects of Boundary and Electron Inertia on the Ion Acoustic Wave in a Plasma: A Pseudopotential Approach

1998 ◽  
Vol 51 (1) ◽  
pp. 113 ◽  
Author(s):  
K. K. Mondal ◽  
S. N. Paul ◽  
A. Roy Chowdhury
Keyword(s):  
Acoustic Waves ◽  
Finite Geometry ◽  
Cylindrical Domain ◽  
Plasma Parameters ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Electron Inertia ◽  
Ion Acoustic ◽  
Pseudopotential Approach ◽  
Range Of Values

A pseudopotential approach is used to analyse the propagation of ion-acoustic waves in a plasma bounded by a cylindrical domain. The effect of the finite geometry is displayed both analytically and numerically. The phase velocity of the wave is determined and its variation is studied with respect to the plasma parameters. It is observed that the pseudopotential shows a wide variation of shape due to the imposition of a finite boundary condition. It is shown that if the other parameters are kept within a certain range of values, then the trapping of particles is favoured when the presence of the boundary is taken into account.

Freestreaming mode excited by a pulse

1986 ◽  
Vol 64 (7) ◽  
pp. 768-772
Author(s):  
Ludwig Schott
Keyword(s):  
Acoustic Waves ◽  
Voltage Pulse ◽  
Velocity Distribution Function ◽  
Density Perturbation ◽  
Zeroth Order ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Analytic Expressions ◽  
Applied Voltage Pulse

When a voltage pulse is applied to an exciter (probe or grid) immersed in a plasma, both an ion-acoustic wave and a freestreaming (ballistic) signal are excited. It is shown that the density perturbation produced by the freestreaming signal is independent of the shape of the applied-voltage pulse for times that are large compared with the temporal width of the pulse and at distances that are large compared with the size of the sheath at the exciter, but it depends on the second derivative of the zeroth-order velocity-distribution function. Analytic expressions that are valid for all times and positions are derived for a simple sheath model. Criteria are presented that enable the experimentalist to distinguish freestreaming modes from ion-acoustic waves.

Nonlinear interaction of slow Alfvén wave with ion acoustic wave and applications to space plasma

2013 ◽  
Vol 79 (5) ◽  
pp. 833-836 ◽  
Author(s):  
B. K. DAS ◽  
R. P. SHARMA ◽  
N. YADAV
Keyword(s):  
Acoustic Waves ◽  
Analytical Study ◽  
Pump Wave ◽  
Modulational Instability ◽  
Solar Wind Plasma ◽  
Alfven Wave ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Model Equations

AbstractThe paper is concerned with the analytical study of nonlinear coupling of slow Alfvén wave (SW) with ion acoustic waves (IAWs) in high-β and low-β plasmas. Here the pump wave (SW) number density gets perturbed in the presence of IAW. The model equations of IAW and SW turn out to be the modified Zakharov system of equations when the ponderomotive nonlinearities are incorporated in the IAW and SW dynamics. Growth rate of modulational instability has been calculated. The relevance of these investigations for solar wind plasma and solar coronal plasma has also been discussed.

Ion acoustic waves in expanding strongly coupled plasmas

2013 ◽  
Vol 79 (6) ◽  
pp. 1063-1066 ◽  
Author(s):  
J. T. MENDONÇA ◽  
N. SHUKLA ◽  
D. P. RESENDES ◽  
A. SERBETO
Keyword(s):  
Acoustic Waves ◽  
Temporal Change ◽  
Wave Mode ◽  
Mode Structure ◽  
Plasma Parameters ◽  
Ion Acoustic Waves ◽  
Strongly Coupled ◽  
Ultracold Plasmas ◽  
Ion Acoustic ◽  
Coupled Plasmas

AbstractWe consider the excitation and dispersion of ion acoustic waves in expanding ultracold plasmas, taking into account the influence of boundary conditions. A cylindrical plasma geometry is assumed. We show that temporal changes in the medium lead to a wave frequency shift, associated with an evolving radial and standing wave mode structure, and to the temporal change of the background plasma parameters. A non-collisional model for the cylindrical geometry is also proposed.

Ion-acoustic waves in finite geometry

1983 ◽  
Vol 26 (4) ◽  
pp. 953 ◽  
Author(s):  
R. V. Jensen
Keyword(s):  
Acoustic Waves ◽  
Finite Geometry ◽  
Ion Acoustic Waves ◽  
Ion Acoustic

scholarly journals Effect of Negative Ions on the Instability of Ion-acoustic Waves in a Relativistic Plasma

1997 ◽  
Vol 50 (2) ◽  
pp. 319 ◽  
Author(s):  
K. K. Mondal ◽  
S. N. Paul ◽  
A. Roychowdhury
Keyword(s):  
Dispersion Relation ◽  
Acoustic Wave ◽  
Acoustic Waves ◽  
Negative Ions ◽  
Ion Concentration ◽  
Negative Ion ◽  
Relativistic Velocity ◽  
Ion Acoustic Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic

The dispersion relation of an ion-acoustic wave propagating through a collisionless, unmagnetised plasma, having warm isothermal electrons and cold positive and negative ions has been derived. It is seen that the ion-acoustic wave will be unstable in the presence of streaming of ions. Instability of the wave is graphically analysed for the plasma having (H+, O¯) ions, (H+, O2¯) ions, (H+, SF5¯) ions, (He+, Cl¯) ions and (Ar+, O¯) ions with different negative ion concentration and relativistic velocity.

scholarly journals Nonlinear Waveforms for Ion-Acoustic Waves in Weakly Relativistic Plasma of Warm Ion-Fluid and Isothermal Electrons

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
S. A. El-Wakil ◽  
Essam M. Abulwafa ◽  
E. K. El-Shewy ◽  
H. G. Abdelwahed ◽  
Hamdi M. Abd-El-Hamid
Keyword(s):  
Acoustic Waves ◽  
Kdv Equation ◽  
Algebraic Method ◽  
Finite Amplitude ◽  
Reductive Perturbation Method ◽  
Relativistic Plasma ◽  
Plasma Parameters ◽  
Ion Acoustic Waves ◽  
Ion Acoustic ◽  
Weakly Relativistic Plasma

The reductive perturbation method has been employed to derive the Korteweg-de Vries (KdV) equation for small- but finite-amplitude electrostatic ion-acoustic waves in weakly relativistic plasma consisting of warm ions and isothermal electrons. An algebraic method with computerized symbolic computation is applied in obtaining a series of exact solutions of the KdV equation. Numerical studies have been made using plasma parameters which reveal different solutions, that is, bell-shaped solitary pulses, rational pulses, and solutions with singularity at finite points, which called “blowup” solutions in addition to the propagation of an explosive pulses. The weakly relativistic effect is found to significantly change the basic properties (namely, the amplitude and the width) of the ion-acoustic waves. The result of the present investigation may be applicable to some plasma environments, such as ionosphere region.

scholarly journals Generation of Low-Frequency Kinetic Waves at the Footpoints of Pre-Flare Coronal Loops

Solar Physics ◽  
2020 ◽  
Vol 295 (12) ◽  
Author(s):  
Alexandr Kryshtal ◽  
Anna Voitsekhovska ◽  
Oleg Cheremnykh ◽  
Istvan Ballai ◽  
Gary Verth ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Low Frequency ◽  
Small Scale ◽  
Plasma Parameters ◽  
Ion Acoustic Waves ◽  
Frequency Wave ◽  
Electric And Magnetic Fields ◽  
Ion Acoustic ◽  
Flare Process ◽  
Semi Empirical

AbstractIn this study we discuss the excitation of low-frequency plasma waves in the lower-middle chromosphere region of loop footpoints for the case when the plasma can be considered to be in a pre-flare state. It is shown that among the well-known semi-empirical models of the solar atmosphere, only the VAL (F) model together with a particular set of basic plasma parameters and amplitudes of the electric and magnetic fields supports generation of low-frequency wave instability. Our results show that it is possible to predict the onset of the flare process in the active region by using the interaction of kinetic Alfvén and kinetic ion-acoustic waves, which are solutions of the derived dispersion equation. The VAL (F) model allows situations when the main source of the aforementioned instability can be a sub-Dreicer electric field and drift plasma movements due to presence of spatial inhomogeneities. We also show that the generation of kinetic Alfvén and kinetic ion-acoustic waves can occur both, in plasma with a purely Coulomb conductivity and in the presence of small-scale Bernstein turbulence. The excitation of the small amplitude kinetic waves due to the development of low threshold instability in plasma with relatively low values of the magnetic field strength is also discussed.

scholarly journals Solar Type I Radio Bursts: An Ion-Acoustic Wave Model

1980 ◽  
Vol 86 ◽  
pp. 251-254
Author(s):  
A. O. Benz ◽  
D. G. Wentzel
Keyword(s):  
Acoustic Waves ◽  
Wave Model ◽  
Type I ◽  
Radio Bursts ◽  
Ion Acoustic Waves ◽  
Langmuir Waves ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Solar Type ◽  
Astronomy And Astrophysics

(paper submitted to Astronomy and Astrophysics)We propose a model for type I emission based on scattering of Langmuir waves by ion acoustic waves, which are associated with the evolution of the associated active region on the Sun.

Sign in / Sign up

Export Citation Format

Share Document