Excitation and Formation Conditions of Monotonic Shock Waves in Magnetized Plasmas with Superthermality Distributed Electrons

Abstract

Nonlinear excitation and the properties of ion-acoustic shock waves (IASWs) in a magnetoplasma model composed of viscous ions with two-temperature superthermality distributed electrons are studied by employing the well-known reductive perturbation analysis to obtain a nonlinear Zakharov-Kuznetsov-Burgers equation (ZKBE), which admits the excitation of nonlinear IASWs in superthermal plasmas. Applying the tanh method, we discuss the solutions of the ZKBE. The asymptotic behavior and the stability of the analytical shock wave solution are studied. In general, nonlinear ion-acoustic disturbances are found analytically to exhibit only monotonic shock structures in the proposed model. For different situations, the effects of the dispersion and the dissipation coefficients on the profiles of the shock structures are discussed. The findings here demonstrate that the effective features of nonlinear IASWs depend strongly on the dispersion and the dissipation coefficients, which include physical parameters such as the superthermality of cold electrons, the cold superthermal electron-to-ion number density ratio, the ion kinematic viscosity and the ion cyclotron frequency. The current work may be helpful for an advanced comprehension of the physical nature of shock waves in astrophysical plasma situations.