Higher-order contributions to ion-acoustic solitary waves in a warm multicomponent plasma with an electron beam

2000 ◽  
Vol 63 (2) ◽  
pp. 139-155 ◽  
Author(s):  
W. M. MOSLEM
Keyword(s):  
Electron Beam ◽  
Solitary Waves ◽  
Kdv Equation ◽  
Negative Ions ◽  
Type Equation ◽  
Higher Order ◽  
Second Order ◽  
Negative Ion ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic

Higher-order contributions in reductive perturbation theory are studied for small- but finite-amplitude ion-acoustic solitary waves in a warm plasma with negative-ion, positron and electron constituents traversed by a warm electron beam (with different temperatures and pressures). The basic set of fluid equations are reduced to a Korteweg–de Vries (KdV) equation for the first-order perturbed potential and a linear inhomogeneous KdV-type equation for the second-order perturbed potential. At the critical negative-ion density, the coefficient of the nonlinear term in the KdV equation vanishes. A new set of stretched coordinates is then used to derive a modified KdV equation and a linear inhomogeneous modified KdV-type equation at the critical density of negative ions for the second-order perturbed potential. Stationary solutions of the coupled equations, for both cases, are obtained using a renormalization method.

Higher-Order Nonlinear Effects on Wave Structures in a Multispecies Plasma with Nonisothermal Electrons

2010 ◽  
Vol 65 (4) ◽  
pp. 315-328 ◽  
Author(s):  
Tarsem Singh Gill ◽  
Parveen Bala ◽  
Harvinder Kaur
Keyword(s):  
Solitary Waves ◽  
Kdv Equation ◽  
Negative Ions ◽  
Nonlinear Effects ◽  
Higher Order ◽  
Relative Temperature ◽  
Generalized Kdv Equation ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic ◽  
Fast Ion

In the present investigation, we have studied ion-acoustic solitary waves in a plasma consisting of warm positive and negative ions and nonisothermal electron distribution. We have used reductive perturbation theory (RPT) and derived a dispersion relation which supports only two ion-acoustic modes, viz. slow and fast. The expression for phase velocities of these modes is observed to be a function of parameters like nonisothermality, charge and mass ratio, and relative temperature of ions. A modified Korteweg-de Vries (KdV) equation with a (1+1/2) nonlinearity, also known as Schamel-mKdV model, is derived. RPT is further extended to include the contribution of higher-order terms. The results of numerical computation for such contributions are shown in the form of graphs in different parameter regimes for both, slow and fast ion-acoustic solitary waves having several interesting features. For the departure from the isothermally distributed electrons, a generalized KdV equation is derived and solved. It is observed that both rarefactive and compressive solitons exist for the isothermal case. However, nonisothermality supports only the compressive type of solitons in the given parameter regime.

Effect of Concentration of Negative Ion and Temperature of both Ions on Amplitude and Width for Non-Thermal Plasma

2015 ◽  
Vol 54 ◽  
pp. 166-183
Author(s):  
Sankar Chattopadhyay
Keyword(s):  
Solitary Waves ◽  
Thermal Plasma ◽  
Negative Ions ◽  
Second Order ◽  
Negative Ion ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic ◽  
Non Thermal Plasma ◽  
Unmagnetized Plasma

In an unbounded, collisionless and unmagnetized plasma consisting of positive and negative ions together with non-thermal electrons, first and second order amplitudes and widths of the ion-acoustic solitary waves are discussed here properly along with the effect of the concentration of negative ion and temperature of both positive and negative ions.

Nonlinear wave propagation of large amplitude ion-acoustic solitary waves in negative ion plasmas with superthermal electrons

2013 ◽  
Vol 79 (5) ◽  
pp. 613-621 ◽  
Author(s):  
S. K. EL-LABANY ◽  
R. SABRY ◽  
E. F. EL-SHAMY ◽  
D. M. KHEDR
Keyword(s):  
Solitary Waves ◽  
Large Amplitude ◽  
Negative Ions ◽  
High Energy ◽  
Negative Ion ◽  
Energetic Electrons ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic ◽  
Negative Ion Plasmas ◽  
Arbitrary Amplitude

AbstractInvestigation of arbitrary amplitude nonlinear ion-acoustic solitary waves which accompany collisionless positive–negative ion plasmas with high-energy electrons (represented by kappa distribution) is presented. Arbitrary amplitude solitary waves are investigated by deriving an energy-integral equation involving a Sagdeev-like pseudopotential. The existence regions of solitary pulses are, defined precisely, modified by the superthermality of energetic electrons. Furthermore, numerical calculations reveal that both compressive and rarefactive pulses may exist for negative ion mass groups in Titan's atmosphere. The superthermality of energetic electrons are found to modify the existence domains of large amplitude ion-acoustic waves in Titan's atmosphere. The dependence of solitary excitation characteristics on the superthermal parameter, the negative ion concentration, the positive-to-negative ions mass ratio, and the Mach number have been investigated. The present study might be helpful to understand the excitation of fully nonlinear ion-acoustic solitary pulses that may appear in the interplanetary medium and/or in the astrophysical plasmas in general.

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.

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.

Dust ion-acoustic solitary waves in a dusty plasma with positive and negative ions

2008 ◽  
Vol 15 (6) ◽  
pp. 063701 ◽  
Author(s):  
F. Sayed ◽  
M. M. Haider ◽  
A. A. Mamun ◽  
P. K. Shukla ◽  
B. Eliasson ◽  
...  
Keyword(s):  
Dusty Plasma ◽  
Solitary Waves ◽  
Negative Ions ◽  
Ion Acoustic Solitary Waves ◽  
Ion Acoustic
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