scholarly journals Relativistic Degeneracy Effect on Propagation of Arbitrary Amplitude Ion-Acoustic Solitons in Thomas-Fermi Plasmas

2010 ◽  
Vol 5 ◽  
pp. 045-045 ◽  
Author(s):  
Abdolrasoul ESFANDYARI-KALEJAHI ◽  
Massoud AKBARI-MOGHANJOUGHI ◽  
Ehsan SABERIAN
Keyword(s):  
Thomas Fermi ◽  
Relativistic Degeneracy ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Arbitrary Amplitude

Nonlinear structure of ion-acoustic solitary waves in a relativistic degenerate electron–positron–ion plasma

2011 ◽  
Vol 78 (2) ◽  
pp. 133-141 ◽  
Author(s):  
A. RASHEED ◽  
N. L. TSINTSADZE ◽  
G. MURTAZA ◽  
R. CHAUDHARY
Keyword(s):  
Solitary Waves ◽  
Acoustic Waves ◽  
Number Range ◽  
Thomas Fermi ◽  
Ion Plasma ◽  
Electron Positron ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic ◽  
Arbitrary Amplitude ◽  
Pseudo Potential

AbstractArbitrary amplitude and small amplitude ion-acoustic solitary waves (IASWs) have been investigated in a relativistic, collisionless, unmagnetized, and degenerate dense electron–positron–ion plasma. The arbitrary amplitude IASWs have been studied by using the Sagdeev-type pseudo-potential approach. Along with approximate solution, the exact amplitude solitary structure has also been studied numerically. The electrons and positrons are assumed to follow the corresponding Fermi distribution function and the ions are described by the hydrodynamic equations. A new dispersion relation for the ion-acoustic wave has been derived for the relativistic Thomas–Fermi plasma. An energy balance-like equation involving the Sagdeev-type pseudo-potential has been investigated and it has been shown that the concentration of plasma particles has significant effect on the permitted Mach number range of IASWs. Also, it has been pointed out that the only compressional supersonic IASWs can propagate in the relativistic Thomas–Fermi plasma. The present work would be helpful to understand the excitation of the nonlinear ion-acoustic waves in a degenerate plasma, such as in superdense white dwarfs and in the cores of massive planets.

Arbitrary-amplitude theory of ion-acoustic solitons in warm multi-fluid plasmas

1989 ◽  
Vol 41 (2) ◽  
pp. 341-353 ◽  
Author(s):  
S. Baboolal ◽  
R. Bharuthram ◽  
M. A. Hellberg
Keyword(s):  
Stationary Wave ◽  
Ion Concentration ◽  
Ion Temperature ◽  
Ion Plasma ◽  
Numerical Theory ◽  
Ion Acoustic ◽  
Wave Forms ◽  
Ion Acoustic Solitons ◽  
Arbitrary Amplitude ◽  
Ion Acoustic Soliton

A recently described numerical theory for obtaining the Sagdeev and real potential profiles of stationary wave forms in a plasma consisting of double-Maxwellian electrons and two or more species of warm ions is used for the study of solitons in such a plasma. The effects of ion temperature and light-ion concentration on rarefactive ion-acoustic soliton profiles in a double-ion plasma obtained with this large-amplitude theory are compared with those predicted from a Korteweg–de Vries equation. Application of the theory to the work of Nakamura and co-workers is discussed, and we draw attention to ion thermal effects.

Arbitrary amplitude ion acoustic solitons, double layers and supersolitons in a collisionless magnetized plasma consisting of non-thermal and isothermal electrons

2021 ◽  
Vol 76 (5) ◽  
pp. 455-468
Author(s):  
Sandip Dalui ◽  
Sankirtan Sardar ◽  
Anup Bandyopadhyay
Keyword(s):  
Magnetic Field ◽  
Double Layer ◽  
Static Magnetic Field ◽  
Negative Potential ◽  
Double Layers ◽  
Positive Potential ◽  
Solitary Structures ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Arbitrary Amplitude

Abstract Using Sagdeev pseudo-potential technique, we have studied the arbitrary amplitude ion acoustic solitons, double layers and supersolitons in a collisionless plasma consisting of adiabatic warm ions, non-thermal hot electrons and isothermal cold electrons immersed in an external uniform static magnetic field. We have used the phase portraits of the dynamical system describing the non-linear behaviour of ion acoustic waves to confirm the existence of different solitary structures. We have found that the system supports (a) positive potential solitons, (b) negative potential solitons, (c) coexistence of both positive and negative potential solitons, (d) negative potential double layers, (e) negative potential supersolitons and (f) positive potential supersolitons. Again, we have seen that the amplitude of the positive potential solitons decreases or increases with increasing n ch according to whether 0 < n c h < n c h ( c ) $0{< }{n}_{ch}{< }{n}_{ch}^{\left(c\right)}$ or n c h ( c ) < n c h ≤ 1 ${n}_{ch}^{\left(c\right)}{< }{n}_{ch}\le 1$ , where n c h ${n}_{ch}$ is the ratio of isothermal cold and non-thermal hot electron number densities, and n c h ( c ) ${n}_{ch}^{\left(c\right)}$ is a critical value of n ch . Also, we have seen that the amplitude of the positive potential solitons decreases with increasing β e , where β e is the non-thermal parameter. We have also investigated the transition of different negative potential solitary structures: negative potential soliton (before the formation of negative potential double layer) → negative potential double layer → negative potential supersoliton → negative potential soliton (after the formation of negative potential double layer) by considering the variation of θ only, where θ is angle between the direction of the external uniform static magnetic field and the direction of propagation of the ion acoustic wave.

Cut-off conditions and existence domains for large-amplitude ion-acoustic solitons and double layers in fluid plasmas

1990 ◽  
Vol 44 (1) ◽  
pp. 1-23 ◽  
Author(s):  
S. Baboolal ◽  
R. Bharuthram ◽  
M. A. Hellberg
Keyword(s):  
Negative Ion ◽  
Double Layers ◽  
Sagdeev Potential ◽  
Ion Acoustic ◽  
Negative Ion Plasmas ◽  
Ion Acoustic Solitons ◽  
Arbitrary Amplitude ◽  
Ion Species ◽  
Positive Ion

It is shown how existence domains for arbitrary-amplitude ion-acoustic solitons and double layers are determined numerically by cut-off conditions on the corresponding Sagdeev potential. A two-electron-temperature model is considered, and in positive-ion plasmas the cut-off conditions are given in terms of the electron parameters, while for negative-ion plasmas such conditions are described in terms of parameters characterizing the role of the negative ion species.

Oblique ion acoustic excitations in an ultra-relativistic degenerate dense magnetoplasma

2017 ◽  
Vol 95 (7) ◽  
pp. 655-661 ◽  
Author(s):  
Ata-ur Rahman ◽  
A. Qamar ◽  
S. Naseer ◽  
S.N. Naeem
Keyword(s):  
Acoustic Waves ◽  
Nonlinear Propagation ◽  
Physical Parameters ◽  
Ion Acoustic Waves ◽  
Linear Dispersion ◽  
Ion Acoustic ◽  
Ion Acoustic Solitons ◽  
Arbitrary Amplitude ◽  
Pseudopotential Approach ◽  
Acoustic Excitations

The linear and nonlinear propagation of ion acoustic waves is considered in a degenerate magnetoplasma, composed of relativistic degenerate electrons and an inertial ion fluid. A linear dispersion relation is derived in the linear approximation. The Sagdeev pseudopotential approach is used to investigate the properties of arbitrary amplitude, obliquely propagating ion acoustic solitary waves. The expression for the lower and upper Mach numbers for the existence of magnetized ion acoustic solitons has also been derived. The significant influence on the properties of soliton structures of relevant physical parameters, such as the plasma number density, the obliqueness (the angle between soliton propagation direction and magnetic field), and the soliton speed is also investigated. At the end, analytical results are supplemented through numerical analysis by using typical representative parameters consistent with degenerate and ultra-relativistic magnetoplasmas of astrophysical regimes.

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