Linear and nonlinear obliquely propagating ion-acoustic waves in magnetized negative ion plasma with non-thermal electrons

2013 ◽  
Vol 79 (5) ◽  
pp. 893-908 ◽  
Author(s):  
M. K. MISHRA ◽  
S. K. JAIN
Keyword(s):  
Acoustic Waves ◽  
Kdv Equation ◽  
Negative Ions ◽  
Ion Concentration ◽  
Negative Ion ◽  
Slow Mode ◽  
Ion Temperature ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Ion Species

AbstractIon-acoustic solitons in magnetized low-β plasma consisting of warm adiabatic positive and negative ions and non-thermal electrons have been studied. The reductive perturbation method is used to derive the Korteweg–de Vries (KdV) equation for the system, which admits an obliquely propagating soliton solution. It is found that due to the presence of finite ion temperature there exist two modes of propagation, namely fast and slow ion-acoustic modes. In the case of slow-mode if the ratio of temperature to mass of positive ion species is lower (higher) than the negative ion species, then there exist compressive (rarefactive) ion-acoustic solitons. It is also found that in the case of slow mode, on increasing the non-thermal parameter (γ) the amplitude of the compressive (rarefactive) soliton decreases (increases). In fast ion-acoustic mode the nature and characteristics of solitons depend on negative ion concentration. Numerical investigation in case of fast mode reveals that on increasing γ, the amplitude of compressive (rarefactive) soliton increases (decreases). The width of solitons increases with an increase in non-thermal parameters in both the modes for compressive as well as rarefactive solitons. There exists a value of critical negative ion concentration (αc), at which both compressive and rarefactive ion-acoustic solitons appear as described by modified KdV soliton. The value of αc decreases with increase in γ.

Obliquely propagating ion-acoustic solitons in a multi-component magnetized plasma with negative ions

1994 ◽  
Vol 52 (3) ◽  
pp. 409-429 ◽  
Author(s):  
M. K. Mishra ◽  
R. S. Chhabra ◽  
S. R. Sharma
Keyword(s):  
Soliton Solution ◽  
Kdv Equation ◽  
Critical Concentration ◽  
Negative Ions ◽  
Magnetized Plasma ◽  
Negative Ion ◽  
Fast Mode ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Ion Species

Oblique propagation of ion-acoustic solitons in a magnetized low-β plasma consisting of warm positive and negative ion species along with hot electrons is studied. Using the reductive perturbation method, a KdV equation is derived for the system, which admits an obliquely propagating soliton solution. It is found that if the ions have finite temperatures then there exist two types of modes, namely slow and fast ion-acoustic modes. The parameter determining the nature of soliton (i.e. whether the system will support compressive or rarefactive solitons) is different for slow and fast modes. For the slow mode the parameter is the relative temperature of the two ion species, whereas for the fast mode it is the relative concentraion of the two ion species. For the fast mode it is found that there is a critical value of the negative-ion concentration below which only compressive solitons exist and above which rarefactive solitons exist. To discuss the soliton solution at the critical concentration, a modified KdV equation is derived. It is found that at the critical concentration of negative ions compressive and rarefactive solitons co-exist. The effects of temperature of different ion species, angle of obliqueness and magnetization on the characteristics of the solitons are discussed in detail.

Ion-acoustic solitons in magnetized multi-component plasmas including negative ions

1989 ◽  
Vol 41 (1) ◽  
pp. 139-155 ◽  
Author(s):  
K. P. Das ◽  
Frank Verheest
Keyword(s):  
Kdv Equation ◽  
Nonlinear Coefficient ◽  
Perturbation Expansion ◽  
Negative Ions ◽  
Magnetized Plasma ◽  
Three Dimensions ◽  
Negative Ion ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Ion Species

A study is made of ion-acoustic solitons in a low-β magnetized plasma consisting of any number of adiabatic positive and negative ion species in addition to the presence of isothermal electrons. A KdV equation in three dimensions or KdV-ZK equation is derived. This equation admits comprehensive or rarefactive solitons propagating in any oblique direction with respect to the direction of the external magnetic field, depending on the density of the negative ion species. When the nonlinear coefficient of this equation vanishes, the nonlinear ion-acoustic wave is described by a modified KdV equation in three dimensions. This equation is also derived and its solitary-wave solutions are discussed. Both compressive and rarefactive solitons are possible. Finally, the three-dimensional stability of these solitons is investigated by the small-k perturbation expansion method of Rowlands and Infeld. Stability criteria and growth rates of instabilities are derived.

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 Effect of ion temperature on ion-acoustic solitons in a two-ion warm plasma with adiabatic positive and negative ions and isothermal electrons

1987 ◽  
Vol 37 (2) ◽  
pp. 322-322 ◽  
Author(s):  
S. G. Tagare
Keyword(s):  
Nonlinear Term ◽  
Kdv Equation ◽  
Negative Ions ◽  
Ion Temperature ◽  
Correct Version ◽  
Modified Kdv Equation ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Warm Plasma ◽  
Image Position

In the above mentioned paper, table 1 is incorrect and the correct version is given below. Thus the result which was there obtained, namely that the coefficient of the nonlinear term of the modified KdV equation becomes negative, is not correct and, in fact, the coefficient is always positive.

Oblique collision of plane ion acoustic solitons in a multicomponent plasma with negative ions

1999 ◽  
Vol 61 (1) ◽  
pp. 151-159 ◽  
Author(s):  
H. BAILUNG ◽  
Y. NAKAMURA
Keyword(s):  
Negative Ions ◽  
Resonant Interaction ◽  
Ion Concentration ◽  
Negative Ion ◽  
Oblique Collision ◽  
Resonance Amplitude ◽  
Multicomponent Plasma ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Experimental Findings

The resonant interaction of compressive and rarefactive ion acoustic solitons is studied experimentally in a multicomponent plasma containing additional negative-ion species. With increasing concentration of negative ions, the resonance amplitude increases for compressive ion acoustic solitons when the angle of collision is fixed. When the negative-ion concentration is larger than a critical value, the rarefactive ion acoustic solitons undergo resonant interaction for a lower resonance amplitude. Theoretical predictions of the Korteweg–de Vries equation agree with experimental findings.

scholarly journals Dynamics of modulationally unstable ion-acoustic wavepackets in plasmas with negative ions

2008 ◽  
Vol 74 (5) ◽  
pp. 639-656 ◽  
Author(s):  
MICHAEL S. RUDERMAN ◽  
TATYANA TALIPOVA ◽  
EFIM PELINOVSKY
Keyword(s):  
Nonlinear Theory ◽  
Acoustic Waves ◽  
Modulational Instability ◽  
Negative Ions ◽  
Ion Concentration ◽  
Negative Ion ◽  
Gardner Equation ◽  
Weakly Nonlinear ◽  
Weakly Nonlinear Theory ◽  
Ion Acoustic

AbstractIn this paper we study the propagation of nonlinear ion-acoustic waves in plasmas with negative ions. The Gardner equation governing these waves in plasmas with the negative ion concentration close to critical is derived. The weakly nonlinear theory of modulational instability based on the use of the nonlinear Schrödinger equation is discussed. The investigation of the nonlinear dynamics of modulationally unstable quasi-harmonic wavepackets is carried out by the numerical solution of the Gardner equation. The results are compared with the predictions of the weakly nonlinear theory.

Cylindrical ion-acoustic waves in a warm multicomponent plasma

2000 ◽  
Vol 63 (4) ◽  
pp. 343-353 ◽  
Author(s):  
S. K. EL-LABANY ◽  
S. A. EL-WARRAKI ◽  
W. M. MOSLEM
Keyword(s):  
Perturbation Theory ◽  
Acoustic Waves ◽  
Vries Equation ◽  
Negative Ions ◽  
Ion Acoustic Waves ◽  
Multicomponent Plasma ◽  
Reductive Perturbation ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Warm Plasma

Cylindrical ion-acoustic solitons are investigated in a warm plasma with negative ions and multiple-temperature electrons through the derivation of a cylindrical Korteweg–de Vries equation using a reductive perturbation theory. The results are compared with those for the corresponding planar solitons.

Ion-acoustic waves in a degenerate multicomponent magnetoplasma

2012 ◽  
Vol 79 (2) ◽  
pp. 163-168 ◽  
Author(s):  
U. M. ABDELSALAM ◽  
M. M. SELIM
Keyword(s):  
Solitary Waves ◽  
Acoustic Waves ◽  
Three Dimensional ◽  
Negative Ions ◽  
Expansion Method ◽  
Reductive Perturbation Method ◽  
Negative Ion ◽  
Zk Equation ◽  
Ion Acoustic ◽  
Astrophysical Objects

AbstractThe hydrodynamic equations of positive and negative ions, degenerate electrons, and the Poisson equation are used along with the reductive perturbation method to derive the three-dimensional Zakharov–Kuznetsov (ZK) equation. The G′/G-expansion method is used to obtain a new class of solutions for the ZK equation. At certain condition, these solutions can describe the solitary waves that propagate in our plasma. The effects of negative ion concentrations, the positive/negative ion cyclotron frequency, as well as positive-to-negative ion mass ratio on solitary pulses are examined. Finally, the present study might be helpful to understand the propagation of nonlinear ion-acoustic solitary waves in a dense plasma, such as in astrophysical objects.

scholarly journals Experiments on ion-acoustic rarefactive solitons in a multi-component plasma with negative ions

1985 ◽  
Vol 33 (2) ◽  
pp. 237-248 ◽  
Author(s):  
Y. Nakamura ◽  
J. L. Ferreira ◽  
G. O. Ludwig
Keyword(s):  
Vries Equation ◽  
Critical Concentration ◽  
Negative Ions ◽  
Finite Amplitude ◽  
Ion Temperature ◽  
Ion Acoustic ◽  
De Vries ◽  
Component Plasma ◽  
Ion Acoustic Solitons

Ion-acoustic solitons in a three-component plasma which consists of electrons and positive and negative ions have been investigated experimentally. When the concentration of negative ions is smaller than a certain value, positive or compressive solitons are observed. At the critical concentration, a broad pulse of small but finite amplitude propagates without changing its shape. When the concentration is larger than this value, negative or rarefactive solitons are excited. The velocity and the width of these solitons are measured and compared with predictions of the Korteweg-de Vries equation which takes the negative ions and the ion temperature into consideration. Head-on and overtaking collisions of the rarefactive solitons have been observed to show that the solitons are not affected by these collisions.

Propagation of nonlinear electrostatic drift solitary waves in a collisionless plasma consisting of two ion species

1977 ◽  
Vol 55 (10) ◽  
pp. 861-865
Author(s):  
S. G. Tagare
Keyword(s):  
Solitary Wave ◽  
Solitary Waves ◽  
Collisionless Plasma ◽  
Argon Plasma ◽  
Negative Ions ◽  
Ionic Species ◽  
Ion Concentration ◽  
Negative Ion ◽  
Light Ions ◽  
Ion Species

A modified two-dimensional Korteweg – de Vries equation for a collisionless plasma consisting of two distinct ionic species and isothermal electrons has been derived. The effect of concentration of light ions on the amplitude and the width of the drift solitary wave is examined for an argon plasma and a helium plasma with hydrogen ion impurities. Similarly the effect of concentration of negative ions on the amplitude of the drift solitary wave is examined and it is shown that when negative ions are present one gets the usual compressive drift solitary waves with positive amplitude as well as rarefactive drift solitary waves with negative amplitude depending on the negative ion concentration.

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