On the generation of envelope solitons in the presence of excess superthermal electrons and positrons

Abstract

A theoretical model is presented to investigate the existence, formation, and possible realization of nonlinear envelope ion acoustic solitary waves which accompany collisionless electron-positron-ion plasmas with high-energy electrons and positrons (represented by kappa distribution). By employing the reductive perturbation method, the hydrodynamic model and the Poisson equation are reduced to nonlinear Schrödinger equation. The effects of the superthermal parameters, as well as ion-to-electron temperature ratio on the propagation and stability of the envelope solitary waves are examined. The superthermal parameters (ion-to-electron temperature ratio) give rise to instability (stability) of the solitary excitations, since the instability window is strongly modified. Finally, the present results should elucidate the excitation of the nonlinear ion-acoustic solitary wave packets in superthermal electron-positron-ion plasmas, particularly in interstellar medium.

Nonplanar dust ion-acoustic solitary and shock excitations in electronegative plasmas with trapped electrons

“…Recently, Mamun et al (2009aMamun et al ( , 2009b have investigated the properties of solitary waves and double layers in an electronegative dusty plasma in a planar geometry, and compared the results with experiment of Ghim and Hershkowitz (2009). Many authors have been investigated the nonlinear wave behavior in multicomponent plasmas (see e.g., El-Labany et al 2008Kalita and Barman 2010;Shalaby et al 2010;Tribeche and Benzekka 2011;Alinejad 2011;El-Shewy et al 2011;Pakzad 2011;Sabry et al 2011;Elwakil et al 2011). However, to the authors' knowledge, the study of nonplanar three-dimensional pulses (solitary and shock pulses) in multicomponent (positive-negative) trapped plasmas with stationary positively/negatively charged dust impurities has not been examined so far, which is the aim of the present work.…”

Large Amplitude Dust-acoustic Solitons in a Plasma Consisting of Superthermal Electron-positron Pairs and Dust Particulates

“…However, with more and more empirical data becoming available from space plasma systems, it is realized that in such systems, the particle distribution significantly deviates from the Maxwellian distribution [26][27][28] due to the presence of superthermal particles having high energy tails [29]. These superthermal particles can be described bydistribution rather than Maxwellian [30][31][32][33][34][35][36][37][38]. The Lorentzian (or Kappa) distribution has been widely used for conventional plasmas (not for a dust component).…”

“…The parameter determines the high energy power law index (which approaches to Maxwellian distribution for ) [40]. The distribution function was argued to provide a much better fit to existing observations than the Maxwellian [29][30][31][32][33][34][35][36][37][38][39][40][41]. The kappa distribution function applications include; for instance, the interpolation of observations in the Earth's foreshock with 3 < e < 6 [42,43] and the solar wind models with coronal electrons with 2 < e < 6 [42,44].…”

Effect of the presence of excess superthermal hot electrons on electron-acoustic solitary waves in auroral zone plasma

“…Superthermal particles may arise due to the effect of external forces acting on the space environment plasmas or to wave-particle interaction. Plasmas with an excess of superthermal nonMaxwellian electrons are generally characterized by a long tail in the high energy region (Mendis and Rosenberg 1994;Leubner and Schupfer 2002;Hellberg and Mace 2002;Tribeche and Boubakour 2009;Gill et al 2010;Sabry et al 2011). Younsi and Tribeche (2010), studied the problem of arbitrary amplitude (EAWs) in a plasma having cold fluid electrons, hot superthermal electrons and stationary ions.…”