International Journal of

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The behavior of linear and nonlinear dust acoustic waves (DAWs) in an unmagnetized plasma including inertialess electrons and positrons, ions, and mobile positive/negative dust grains are studied. Reductive perturbation method is employed for small and finite amplitude DAWs. To investigate the solitary waves, the Korteweg–de Vries (KdV) equation is derived and the solution is presented. By numerical analysis, it is found that the soliton structure of the dust acoustic wave depends upon plasma parameters like electron to ion Fermi temperature ratio, s, dust to ion temperature ratio d and quantum diffraction parameter H.

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The propagation of arbitrary amplitude dust ion acoustic waves (DIAWs) in a magnetized collisional dusty plasma including hot electrons, with kappa velocity distribution for electrons, warm ions and dust particles has been studied. In the presence of immobile massive dust particulates, DIAWs have been investigated through the Sagdeev pseudo-potential method. It is demonstrated that the amplitude and width of the pseudo-potential are increased with the ion density and also with Directional cosines. It is shown that the behaviors of the amplitude and the width of the wave in terms of all of plasma parameters is similar to the our recently work, and the spectral index has a little effect on the wave.

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In this paper, we have simulated the excitation of wake fields in the interaction of an intensive laser pulses having Half-Sine and Gaussian time envelopes with a fully ionized cold plasma using particle in cell (PIC) method. We investigated the dependency of wake filed amplitude to different laser and plasma parameters such as laser wavelength, pulse duration and electron number density. In addition, the effect of employing a longitudinal magnetic field on the intensity of wake field is studied. It has been seen that the wake field intensity is enhanced in the presence of a magnetic field for both Half-Sine and Gaussian shape pulses. Our aim has been finding optimum values of different parameters for which higher accelerating wake electric fields can be obtained.

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In this article, linear and nonlinear dust ion acoustic (DIA) waves are studied in a magnetized quantum dusty plasma which consists of inertialess electrons and positrons, cold ions and negatively charged dust grains. For this purpose, quantum Hydrodynamic model (QHD) and reductive perturbation method are employed. To investigate linear and nonlinear waves, dispersion relation and a quantum Zakharov-Kuznetsov (ZK) equation are derived respectively. A stationary solution of the ZK equation is obtained to investigate the effects of plasma parameters on the amplitude of the solitons.
 

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In this paper, the interaction of Gaussian laser beam with under-dense plasma by taking the weakly relativistic ponderomotive nonlinearity has been investigated. For this purpose, the effect of the linear plasma electron temperature and upward exponential electron density profile on the laser propagation has been studied. The nonlinear second-order differential equation of the dimensionless beam-width parameter, f, on the distance of propagation, h, is derived by following WKB and paraxial approximation and solved numerically for the several initial electron temperatures. It is found that, the electron temperature ramp combined with upward ramp density profile would be caused stronger self-focusing where the beam width oscilates with less amplitude and smaller spot size. This could lead to further penetration of the laser beam inside the plasma by reducing the effects of diffraction.

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Propagation of ion acoustic solitary waves (IASWs) in electronegative plasma containing positive and negative ions, trapped and non-thermal electrons are investigated. Using the Sagdeev pseudopotential method and investigation of the energy integral, the existence of propagation regions for these waves is analyzed. It is shown that the Mach number, positive and negative ions densities ratio and the trapping parameter can lead to change the pseudopotential amplitude and also it is shown that the lower limit of the Mach number increases with the density and mass ratios of positive and negative ions, but the upper limit of the Mach number does not depend on the densities ratio. The results show that for this kind plasma, there is only compressive IASW. This research will be helpful in understanding of physical phenomena concerned in plasmas in which the effects of trapped electrons control the dynamics of wave.