Highlights from the Asia Pacific Region

2013 ◽  
Vol 02 (01) ◽  
pp. 15-25 ◽  
Author(s):  
APPN Editorial Office
Keyword(s):  
Kdv Equation ◽  
Critical Density ◽  
Negative Ions ◽  
Mkdv Equation ◽  
Asia Pacific ◽  
Asia Pacific Region ◽  
Ion Acoustic Wave ◽  
Multicomponent Plasma ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons

It is well known that multicomponent plasma with negative ions supports a number of wave modes such as ion-acoustic solitons described by the Kortewege-de Vries (KdV) equation, modified KdV solitons at critical density of negative ions and ion-acoustic envelop solitons described by nonlinear Schrödinger equation (NLSE). The NLSE which is equivalent to the mKdV equation is applicable in describing evolution of ion-acoustic wave in plasma at critical density of negative ions which becomes modulationaly unstable when the nonlinear co-efficient is negative.

scholarly journals Ion Acoustic Peregrine Soliton Under Enhanced Dissipation

2021 ◽  
Vol 8 ◽  
Author(s):  
Pallabi Pathak
Keyword(s):  
Acoustic Wave ◽  
Negative Ions ◽  
Landau Damping ◽  
Ion Acoustic Wave ◽  
Multicomponent Plasma ◽  
Plasma Device ◽  
Ion Acoustic ◽  
Damping Rate ◽  
Double Plasma Device ◽  
Spatial Damping

The effect of enhanced Landau damping on the evolution of ion acoustic Peregrine soliton in multicomponent plasma with negative ions has been investigated. The experiment is performed in a multidipole double plasma device. To enhance the ion Landau damping, the temperature of the ions is increased by applying a continuous sinusoidal signal of frequency close to the ion plasma frequency ∼1 MHz to the separation grid. The spatial damping rate of the ion acoustic wave is measured by interferometry. The damping rate of ion acoustic wave increases with the increase in voltage of the applied signal. At a higher damping rate, the Peregrine soliton ceases to show its characteristics leaving behind a continuous envelope.

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.

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.

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.

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

1986 ◽  
Vol 36 (2) ◽  
pp. 301-312 ◽  
Author(s):  
S. G. Tagare
Keyword(s):  
Acoustic Wave ◽  
Vries Equation ◽  
Collisionless Plasma ◽  
Negative Ions ◽  
Ion Temperature ◽  
Ion Acoustic Wave ◽  
Basic Set ◽  
Ion Acoustic ◽  
De Vries ◽  
Ion Acoustic Solitons

Ion-acoustic solitons in a collisionless plasma with adiabatic positive and negative ions with equal ion temperature and isothermal electrons are studied by using the reductive perturbation method. The basic set of fluid equations is reduced for the fast ion-acoustic wave to the Korteweg–de Vries and modified Korteweg–de Vries equation and for the slow ion-acoustic wave to the Korteweg–de Vries equation. Stationary solutions of these equations are obtained and the effect of ion temperature on fast and slow ion-acoustic solitons is investigated.

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.

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