The effect of κ-distributed trapped electrons on fully nonlinear electrostatic solitary waves in an electron–positron-relativistic ion plasma

Abstract

Based on the hydrodynamic model, the existence and propagation features of fully nonlinear electrostatic solitary waves in an unmagnetized, collisionless, homogenous three-component plasma have been investigated. The plasma containing cold relativistic ions, Boltzmann positrons, and trapped electrons modelled by κ-trapped distribution function. Employing the pseudo-potential method, the Sagdeev pseudo-potential and the first integral energy equation for the system as a function of the electrostatic potential (disturbance) have been derived. The influence of the relevant plasma configurations including the propagation pulse velocity, the superthermality index, the characteristic trapping parameter, the relativistic strength parameter, the positron density ratio, and the positron temperature ratio, on the properties of electrostatic solitary pulse profile has been determined. The results of our study may be helpful in better interpretation of the existence of localized structures in astrophysical and space plasmas as well as in laboratory plasmas, where the positron-ion plasmas with nonthermal trapped electrons can exist.

Nonlinear particle trapping by coherent waves in thermal and nonthermal plasmas

“…The spacecraft observations unveiled that kappa (κ) distribution represents a more realistic picture, and the assumption of space plasma being in the state of thermal equilibrium is absurd. The index κ (the distribution function spectral index), for which the kappa distribution is called, is the strength of distribution [25]. Various studies have provided theoretical backing to develop plasma theories and simulations based on kappa distribution [26][27][28][29].…”