Browsing by Author "Mamun, A. A."

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Compressive and rarefactive ion-acoustic solitons in a magnetized quantum plasma
(Springer, 2016-04-06) Hosen, B.; Shah, M. G.; Hossen, M. R.; Mamun, A. A.
Compressive and rarefactive ion-acoustic solitary waves (IASWs) in a magnetized, collisionless, three-component, dense plasma system have been carried out. The plasma system is assumed to be composed of non-degenerate inertial ions, degenerate electrons and immobile positively charged heavy ions. The magnetized Korteweg-de Vries (K-dV) and modified K-dV (mK-dV) equations are derived by adopting reductive perturbation method to study the basic characteristics of IASWs. It is seen that the effects of degenerate pressure, number density of electrons, inertial ions, and positively charged static heavy ions significantly modify the fundamental features of IASWs. It is also found that the magnetic field (obliqueness) has a significant contribution on the characteristics of IASWs. The implication of our results in some space and laboratory plasma situations are concisely discussed. Full Text Link: https://doi.org/10.1140/epjp/i2016-16081-y
Cylindrical and Spherical Ion-Acoustic Shock Waves in a Relativistic Degenerate Multi-Ion Plasma
(Springer, 2014-07-24) Hossen, M. R.; Nahar, L.; Mamun, A. A.
A rigorous theoretical investigation has been made to study the existence and basic features of the ion-acoustic (IA) shock structures in an unmagnetized, collisionless multi-ion plasma system (containing degenerate electron fluids, inertial positively as well as negatively charged ions, and arbitrarily charged static heavy ions). This investigation is valid for both non-relativistic and ultra-relativistic limits. The reductive perturbation technique has been employed to derive the modified Burgers equation. The solution of this equation has been numerically examined to study the basic properties of shock structures. The basic features (speed, amplitude, width, etc.) of these electrostatic shock structures have been briefly discussed. The basic properties of the IA shock waves are found to be significantly modified by the effects of arbitrarily charged static heavy ions and the plasma particle number densities. The implications of our results in space and interstellar compact objects like white dwarfs, neutron stars, black holes, and so on have been briefly discussed. Full Tex Link: https://doi.org/10.1007/s13538-014-0242-6
Electrostatic Solitary Pulses in a Dusty Electronegative Magnetoplasma
(Pleiades Publishing, 2018-11-22) Banik, S.; Amina, M.; Ema, S. A.; Hossen, M. R.; Mamun, A. A.
The nonlinear characteristics of dust-electron-acoustic (DEA) waves in a dusty electronegative magneto plasma system consisting of nonextensive hot electrons, inertial cold electrons, positively charged static ions, and negatively charged immobile dust grains has been investigated. In this observation, the well-known reductive perturbation technique is employed to determine different types of nonlinear dynamical equations, namely, magnetized Korteweg–de Vries (KdV), magnetized modified KdV (mKdV), and magnetized Gardner equations. The stationary solitary wave and double layer solution of these three equations, which describe the characteristics of solitary waves and double layers of DEA waves, are obtained and numerically analyzed. It is noticed that various plasma parameters (viz., hot electron nonextensivity, positive ion-to-cold electron number density ratio, dust-to-cold electron number density ratio, etc.) significantly affect the basic properties of DEA solitary waves (DEASWs) and Gardner solitons (GSs). The prodigious results found from this theoretical investigation may be useful for researchers to investigate the nonlinear structures in various space and laboratory plasmas.
Electrostatic Solitary Structures in a Relativistic Degenerate Multispecies Plasma
(Springer, 2014-08-30) Hossen, M. R.; Mamun, A. A.
The nonlinear propagation of cylindrical and spherical modified ion-acoustic (mIA) waves in an unmagnetized, collisionless, relativistic, degenerate multispecies plasma has been investigated theoretically. This plasma system is assumed to contain both relativistic degenerate electron and positron fluids, nonrelativistic degenerate positive and negative ions, and positively charged static heavy ions. The restoring force is provided by the degenerate pressures of the electrons and positrons, whereas the inertia is provided by the mass of positive and negative ions. The positively charged static heavy ions participate only in maintaining the quasi-neutrality condition at equilibrium. The nonplanar K-dV and mK-dV equations are derived by using reductive perturbation technique and numerically analyzed to identify the basic features (speed, amplitude, width, etc.) of mIA solitary structures. The basic characteristics of mIA solitary waves are found to be significantly modified by the effects of degenerate pressures of electron, positron, and ion fluids, their number densities, and various charge states of heavy ions. The implications of our results to dense plasmas in astrophysical compact objects (e.g., nonrotating white dwarfs, neutron stars, etc.) are briefly mentioned. Full Text Link: http://doi.org/10.1007/s13538-014-0254-2
Heavy Ion-Acoustic Solitary Waves and Double Layers in a Multi-Ion Plasma
(Springer, 2018-08-01) Shah, M. G.; Rahman, M. M.; Hossen, M. R.; Mamun, A. A.
The formation and propagation of small-amplitude heavy-ion-acoustic (HIA) solitary waves and double layers in an unmagnetized collisionless multicomponent plasma system consisting of superthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions are theoretically investigated. The reductive perturbation technique is employed to derive the modified Korteweg–de Vries (mKdV) and standard Gardner (SG) equations. The solitary wave (SW) solution of mKdV and SG equations, as well as double layers (DLs) solution of SG equation, is studied for analysis of higher order nonlinearity. It is found that the plasma system under consideration supports positive and negative potential Gardner solitons, but only positive potential mKdV solitons. In addition, it is shown that, the basic properties of HIA mKdV and Gardner solitons and DLs (viz. polarity, amplitude, width, and phase speed) are incomparably influenced by the adiabaticity effect of heavy ions and the superthermality effect of electrons. The relevance of the present findings to the system of space plasmas, as well as to the system of researchers interest, is specified. Full Text Link: https://doi.org/10.1134/S1063780X18090131
Heavy-Ion-Acoustic Solitary and Shock Waves in an Adiabatic Multi-Ion Plasma
(Springer, 2015-06-10) Hossen, M. A.; Rahman, M. M.; Hossen, M. R.; Mamun, A. A.
The standard reductive perturbation method has been employed to derive the Korteweg-deVries (K-dV) and Burgers (BG) equations to investigate the basic properties of heavy-ion-acoustic (HIA) waves in a plasma system which is supposed to be composed of nonthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions. The HIA solitary and shock structures are found to exist with either positive or negative potential. It is found that the effects of adiabaticity of inertial heavy ions, nonthermality of electrons, and number densities of plasma components significantly modify the basic properties of the HIA solitary and shock waves. The implications of our results may be helpful in understanding the electrostatic perturbations in various laboratory and astrophysical plasma environments. Full Text Link: https://doi.org/10.1007/s13538-015-0338-7
Instability Analysis of Positron-Acoustic Waves in a Magnetized Multi-Species Plasma
(IOP Science, 2016-07-20) Hossen, M. A.; Shah, M. G.; Hossen, M. R.; Mamun, A. A.
The nonlinear propagation of electrostatic excitations and their multi-dimensional instability in a magnetized, degenerate electron-positron-ion (EPI) plasma system (containing inertial cold positrons, relativistic degenerate electrons and hot positrons, and negatively charged immobile heavy ions) are theoretically investigated. The reductive perturbation method is employed to derive the Zakharov–Kuznetsov equation which admits a localized solitary wave solution for small but finite amplitude limit, and the multi-dimensional instability of the positron acoustic solitary waves (PASWs) is studied by the small-k perturbation expansion method. It is found that the basic characteristics (viz. phase speed, amplitude, width) of the PASWs are significantly affected by the degree of obliqueness, relativistic degeneracy, and plasma particle number densities. The instability criterion and its growth rate, which are depending on the magnetic field and the propagation directions of both the PASWs, and their perturbation modes are discussed. The present analysis can be helpful in understanding the nonlinear phenomenon in dense astrophysical as well as space plasma systems, especially in pulsar environments. Full Text Link: https://doi.org/10.1088/0253-6102/67/4/458
Ion-Acoustic Solitary Waves and Double Layers in a Magnetized Degenerate Quantum Plasma
(IEEE Xplore, 2017-11-09) Hosen, B.; Shah, M. G.; Hossen, M. R.; Mamun, A. A.
The properties of ion-acoustic (IA) solitary waves (SWs) and double layers (DLs) in a four-component magnetized degenerate quantum plasma system (containing nondegenerate inertial light ion, both nonrelativistically and ultrarelativistically degenerate electrons and positrons, and immobile heavy ion) are theoretically investigated by the reductive perturbation method. The Korteweg-de Vries (K-dV), the modified K-dV, and the Gardner equations are derived to examine the basic features (viz. amplitude, speed, and width) of IA SWs and DLs. It is found that the effects of the ultrarelativistically degenerate electrons and positrons, stationary heavy ion, external magnetic field (obliqueness), and so on, significantly modify the basic features of the IA SWs and DLs. The basic features and the underlying physics of IA SWs and DLs, which are relevant to some astrophysical compact objects including white dwarfs and neutron stars, are pinpointed. Full Text Link: http://doi.org/10.1109/TPS.2017.2766167
Korteweg-de Vries-Burgers equation in a multi-component magnetized plasma with nuclei of heavy elements
(Springer, 2016-12-29) Hosen, B.; Amina, M.; Mamun, A. A.; Hossen, M. R.
The nonlinear properties of ion-acoustic (IA) waves are investigated in a relativistically degenerate magnetized quantum plasma, whose constituents are non-degenerate inertial ions, degenerate electrons and immobile positively-charged heavy elements. For nonlinear studies, the well-known reductive perturbation technique is employed to derive the Korteweg-de Vries-Burger equation in the presence of relativistically degenerate electrons. Numerically, the amplitude, width, and phase speed are shown to be associated with the localized IA solitons, and shocks are shown to be significantly influenced by the various intrinsic parameters relevant to our model. The solitary and the shock wave properties have been to be influenced in the non-relativistic, as well as the ultrarelativistic, limits. The effects of the external magnetic field and the obliqueness are found to change the basic properties of IA waves significantly. The present analysis can be useful in understanding the collective process in dense astrophysical environments, like there of non-rotating white dwarfs, neutron stars, etc. Full Text Link: https://doi.org/10.3938/jkps.69.1762
Linear and nonlinear heavy ion-acoustic waves in a strongly coupled plasma
(American Institute of Physics (AIP), 2015-09-11) Ema, S. A.; Hossen, M. R.; Mamun, A. A.
A theoretical study on the propagation of linear and nonlinear heavy ion-acoustic (HIA) waves in an unmagnetized, collisionless, strongly coupled plasma system has been carried out. The plasma system is assumed to contain adiabatic positively charged inertial heavy ion fluids, nonextensive distributed electrons, and Maxwellian light ions. The normal mode analysis is used to study the linear behaviour. On the other hand, the well-known reductive perturbation technique is used to derive the nonlinear dynamical equations, namely, Burgers equation and Korteweg-de Vries (K-dV) equation. They are also numerically analyzed in order to investigate the basic features of shock and solitary waves. The adiabatic effects on the HIA shock and solitary waves propagating in such a strongly coupled plasma are taken into account. It has been observed that the roles of the adiabatic positively charged heavy ions, nonextensivity of electrons, and other plasma parameters arised in this investigation have significantly modified the basic features (viz., polarity, amplitude, width, etc.) of the HIA solitary/shock waves. The findings of our results obtained from this theoretical investigation may be useful in understanding the linear as well as nonlinear phenomena associated with the HIA waves both in space and laboratory plasmas. Full Text Link: https://doi.org/10.1063/1.4930265
Modeling of modified electron-acoustic solitary waves in a relativistic degenerate plasma
(Springer, 2015-01-06) Hossen, M. R.; Mamun, A. A.
The modeling of a theoretical and numerical study on the nonlinear propagation of modified electron-acoustic (mEA) solitary waves has been carried out in an unmagnetized, collisionless, relativistic, degenerate quantum plasma (containing non-relativistic degenerate inertial cold electrons, both non-relativistic and ultra-relativistic degenerate hot electron and inertial positron fluids, and positively-charged static ions). A reductive perturbation technique is used to derive the planar and the nonplanar Korteweg-de Vries (K-dV) equations, which admit a localized wave solution for the solitary profile. The solitary wave’s characteristics are found to have been influenced significantly forin the non-relativistic and the ultra-relativistic limits. The mEA solitary waves are also found to have been significantly modified due to the effects of the degenerate pressure and the number densities of this dense plasma’s constituents. The properties of the planar K-dV solitary wave are quite different from those of the nonplanar K-dV solitary wave. The relevance of our results to astrophysical objects (like white dwarfs and neutron stars), which are of scientific interest, is briefly mentioned. Full Text Link: https://doi.org/10.3938/jkps.65.2045
Modeling of modified ion-acoustic shock waves in a relativistic electron degenerate multi-ion plasma for higher order nonlinearity
(Springer, 2015-04-11) Hossen, M. R.; Hossen, M. A.; Sultana, S.; Mamun, A. A.
A nonlinear propagation of modified ion-acoustic (mIA) shock waves in a relativistic degenerate plasma (containing inertial viscous positive and negative ion fluids, relativistic electron fluids, and negatively charged immobile heavy ions) has been investigated theoretically. The modified Burgers (mB) and further modified Burgers (FmB) equations have been derived by adopting reductive perturbation technique. The solutions of both mB and FmB equations have been numerically analyzed to characterize the basic features of mIA shock waves. The basic properties (speed, amplitude, width, etc.) of these electrostatic shock waves are found to be significantly modified by the effects of negatively charged static heavy ions and the plasma particle number densities. It is found that the properties of these shock waves obtained from this analysis are significantly different from those obtained from the analysis of standard Burgers equation. The implications of our results in space and interstellar compact objects like non-rotating white dwarfs, neutron stars, etc. are briefly discussed. Full Text Link: https://doi.org/10.1007/s10509-015-2278-7
Modified Ion-Acoustic Shock Waves and Double Layers in a Degenerate Electron-Positron-Ion Plasma in Presence of Heavy Negative Ions
(Springer, 2014-10-01) Hossen, M. A.; Hossen, M. R.; Mamun, A. A.
A general theory for nonlinear propagation of one dimensional modified ion-acoustic waves in an unmagnetized electron-positron-ion (e-p-i) degenerate plasma is investigated. This plasma system is assumed to contain relativistic electron and positron fluids, non-degenerate viscous positive ions, and negatively charged static heavy ions. The modified Burgers and Gardner equations have been derived by employing the reductive perturbation method and analyzed in order to identify the basic features (polarity, width, speed, etc.) of shock and double layer (DL) structures. It is observed that the basic features of these shock and DL structures obtained from this analysis are significantly different from those obtained from the analysis of standard Gardner or Burgers equations. The implications of these results in space and interstellar compact objects (viz. non-rotating white dwarfs, neutron stars, etc.) are also briefly mentioned. Full Text Link: https://doi.org/10.1007/s13538-014-0267-x
Nonlinear Dynamics in a Nonextensive Complex Plasma with Viscous Electron Fluids
(IOP Science, 2015-10-29) Hossen, M. R.; Ema, S. A.; Mamun, A. A.
Cylindrical and spherical dust-electron-acoustic (DEA) shock waves and double layers in an unmagnetized, collisionless, complex or dusty plasma system are carried out. The plasma system is assumed to be composed of inertial and viscous cold electron fluids, nonextensive distributed hot electrons, Maxwellian ions, and negatively charged stationary dust grains. The standard reductive perturbation technique is used to derive the nonlinear dynamical equations, that is, the nonplanar Burgers equation and the nonplanar further Burgers equation. They are also numerically analyzed to investigate the basic features of shock waves and double layers (DLs). It is observed that the roles of the viscous cold electron fluids, nonextensivity of hot electrons, and other plasma parameters in this investigation have significantly modified the basic features (such as, polarity, amplitude and width) of the nonplanar DEA shock waves and DLs. It is also observed that the strength of the shock is maximal for the spherical geometry, intermediate for cylindrical geometry, while it is minimal for the planar geometry. The findings of our results obtained from this theoretical investigation may be useful in understanding the nonlinear phenomena associated with the nonplanar DEA waves in both space and laboratory plasmas. Full Text Link: https://doi.org/10.1088/0256-307X/33/6/065203
Nonlinear Dynamics in Strongly Coupled Quantum Plasma
(High Temperature, Springer, 2020-02-12) Hossen, M. R.; Ema, S. A.; Mamun, A. A.
The properties of cylindrical and spherical modified ion-acoustic waves in a strongly coupled plasma (containing strongly correlated non-relativistic ions, weakly correlated relativistic (both non-relativistic and ultra-relativistic) electron and positron fluids, and positively charged static heavy ions) are investigated theoretically. The restoring force is provided by the degenerate pressure of the electron and positron fluids, whereas the inertia is provided by the mass of ions. The positively charged static heavy ions participate only in maintaining the quasi-neutrality condition at equilibrium. By using reductive perturbation method, we have derived modified Burgers and Korteweg–de Vries equations. Their shock and solitary wave solutions are also numerically analyzed to understand the localized electrostatic disturbances. The basic features of modified ion-acoustic shock and solitary waves are found to be significantly modified by the effects of degenerate pressure of electrons, positrons, and ion fluids, their number densities, and various charge states of heavy ions. It is also observed that the amplitude of these shock and solitary profiles are maximum for spherical geometry, intermediate for cylindrical geometry, and minimum for planar geometry. The present analysis can be helpful for understanding different degenerate and relativistic phenomena in dense astrophysical environments as well as laboratory plasma systems.
Nonlinear heavy-ion-acoustic waves in an adiabatic collisionless Bi-ion plasma
(Springer, 2017-03-07) Hossen, M. A.; Rahman, M. M.; Hossen, M. R.; Mamun, A. A.
The basic properties of heavy-ion-acoustic (HIA) waves have been investigated in a collisionless plasma system which is supposed to be composed of nonthermal electrons, Boltzmann distributed light ions, and adiabatic positively charged inertial heavy ions. The Kortewg-de Vries and Burgers equations are derived in nonplanar (cylindrical and spherical) geometry by employing the standard reductive perturbation method for studying the basic features (viz. amplitude, phase speed, etc.) of HIA solitary and shock waves, which are associated with either positive or negative potential. It is found that the effects of nonplanar geometry, adiabaticity of positively charged inertial heavy ions, the presence of nonthermal (Cairns distributed) electrons, and number densities of the plasma components significantly modify the basic features of nonplanar HIA waves. It has been observed that the properties of solitary and shock waves associated with HIA waves in a nonplanar geometry differ from those in a planar geometry. The implications of our results may be helpful in understanding the electrostatic perturbations in various laboratory and astrophysical plasma environments. Full Text Link: https://doi.org/10.1134/S1063780X17040043
Nonlinear ion modes in a strongly coupled plasma in the presence of nonthermal ion fluids and polarization force
(Springer, 2016-05-14) Ema, S. A.; Hossen, M. R.; Mamun, A. A.
The nonlinear propagation of ion-acoustic (IA) waves in a strongly coupled plasma system containing Maxwellian electrons and nonthermal ions has been theoretically and numerically investigated. The well-known reductive perturbation technique is used to derive both the Burgers and Korteweg−de Vries (KdV) equations. Their shock and solitary wave solutions have also been numerically analyzed in understanding localized electrostatic disturbances. It has been observed that the basic features (viz. polarity, amplitude, width, etc.) of IA waves are significantly modified by the effect of polarization force and other plasma parameters (e.g., the electron-to-ion number density ratio and ion-to-electron temperature ratio). This is a unique finding among all theoretical investigations made before, whose probable implications are discussed in this investigation. The implications of the results obtained from this investigation may be useful in understanding the wave propagation in both space and laboratory plasmas. Full Text Link: https://doi.org/10.1134/S1063780X16040048
Nonlinear propagation of positron-acoustic waves in a four component space plasma
(Cambridge University Press, 2015-08-04) Shah, M. G.; Hossen, M. R.; Mamun, A. A.
The nonlinear propagation of positron-acoustic waves (PAWs) in an unmagnetized, collisionless, four component, dense plasma system (containing non-relativistic inertial cold positrons, relativistic degenerate electron and hot positron fluids as well as positively charged immobile ions) has been investigated theoretically. The Korteweg–de Vries (K–dV), modified K–dV (mK–dV) and further mK–dV (fmK–dV) equations have been derived by using reductive perturbation technique. Their solitary wave solutions have been numerically analysed in order to understand the localized electrostatic disturbances. It is observed that the relativistic effect plays a pivotal role on the propagation of positron-acoustic solitary waves (PASW). It is also observed that the effects of degenerate pressure and the number density of inertial cold positrons, hot positrons, electrons and positively charged static ions significantly modify the fundamental features of PASW. The basic features and the underlying physics of PASW, which are relevant to some astrophysical compact objects (such as white dwarfs, neutron stars etc.), are concisely discussed. Full Text Link: https://doi.org/10.1017/S0022377815001014
Nonplanar ion-acoustic shock waves in degenerate plasmas with positively charged heavy ions
(Elsevier, 2014-08-12) Hossen, M. R.; Nahar, L.; Sultana, S.; Mamun, A. A.
The theoretical and numerical study on the nonlinear propagation of heavy-ion-acoustic (HIA) shock waves has been carried out in an unmagnetized, collisionless dense plasma system (containing degenerate electron and inertial light ion fluids, and positively charged static heavy ions). The normal mode analyse is used to investigate the linear wave properties. Reductive perturbation technique is used to derive the Burgers equation which admits a localized wave solution for the shock profile. It is seen that the shock wave characteristics have been influenced significantly for the non-relativistic as well as for the ultra-relativistic limits. It has also been found that the effect of degenerate pressure and number density of electron and inertial light ion fluids, and positively charged static heavy ions significantly modify the basic features (speed, amplitude, width, etc.) of HIA shock waves. The relevance of our results in astrophysical objects (like white dwarfs and neutron stars), which are of scientific interest, is briefly discussed. Full Text Link: https://doi.org/10.1016/j.hedp.2014.08.001
Nonplanar Positron-Acoustic Shock Waves in Astrophysical Plasmas
(Springer, 2015-02-18) Shah, M. G.; Hossen, M. R.; Mamun, A. A.
The problem of nonlinear positron-acoustic shock waves (PASWs) in an unmagnetized, collisionless, dense plasma system (containing non-relativistic cold positrons, both non-relativistic and ultra-relativistic degenerate electrons, and hot positron fluids and positively charged static ions) is addressed. The combined effects of the non-relativistic and ultra-relativistic degenerate electron and hot positron fluids are organized in the study of the PASWs. By using the reductive perturbation method, modified Burgers equation is derived and numerically analyzed. For the non-relativistic limits in like manner for the ultra-relativistic limits, it is seen that the shock wave characteristics are modified significantly. The effects of kinematic viscosity, degenerate pressure, nonplanar geometries, and plasma particle number densities on the properties of PASWs are numerically analyzed. As time goes, PASWs propagating in cylindrical and spherical geometry are deformed. The fundamental features and the underlying physics of PASWs, which are concerned to some astrophysical compact objects (viz. neutron stars, white dwarfs, etc.), are concisely mentioned. Full Text Link: https://doi.org/10.1007/s13538-015-0304-4