The electron acoustic waves in plasmas with two kappa-distributed electrons at the same temperatures and immobile ions

Abstract

The linear electron acoustic waves propagating in plasmas with two kappa-distributed electrons and stationary ions are investigated. The temperatures of the two electrons are assumed to be same, but the kappa indices are not. It shows that if one kappa index is small enough and the other one is large enough, a weak damping regime of the electron acoustic waves exists. The dispersions and damping rates are numerically studied. The parameter spaces for the weakly damped electron acoustic waves are analyzed. Moreover, the electron acoustic waves in the present model are compared with those in other models, especially the plasmas with two-temperature electrons. At last, we perform Vlasov–Poisson simulations to verify the theory.

Kinetic theory of $\mathrm{sech}^2x$ electron holes and applications to Kappa-distributed plasmas

“…1 and 2. To verify our theory, we numerically calculate the self-consistent solution of the Poisson equation (38). The results are shown in Figs.…”

“…After approximating the second derivative with the central difference, Eq. (38) turns out to be a system of nonlinear equations which could be solved numerically by the is calculated from Eq. ( 33) and ∆ from Eq.…”

“…[26][27][28][29] The kappa distribution has been widely applied to study various physical phenomena in plasmas, for instance, electron firehose instabilities, 30,31 transport coefficients, [32][33][34] whistler instabilities, 35,36 and electron acoustic waves. 37,38 The purpose of this work is to investigate the general kinetic theory of sech 2 x EHs in weak amplitude limits and to study the physical properties of such EHs in kappa-distributed plasmas. To achieve the above goal, we organize the paper as follows.…”

“…. The potential (upper panel) and the electron number density (lower panel) solved from the self-consistent Poisson equation(38) for u = 0.65 and κ = 2. In the upper panel, the blue solid curve denotes the numerical solution of the potential.…”

Investigation of sheath properties in a warm plasma with two kappa-distributed electrons and monoenergetic electron beam

“…During the last decade, kappa distribution has been used by many authors for various research purposes such as occurrence and propagation of electron-acoustic and ion-acoustic waves, dust-ion-acoustic shock waves and electromagnetic cyclotron instabilities in plasma with two kappa-distributed electron species 13 – 22 . On the other hand, sheath formation in plasmas is one of the fundamental issues in plasma physics.…”