Influence of plasma inhomogeneity with allowance for bremsstrahlung on absorption of an Alfvén wave by a dissipative plasma

The paper investigates a mathematical model of the absorption of an Alfvén wave in an inhomogeneous incompressible dissipative plasma using the equations of two-fluid electromagnetic hydrodynamics. It is shown that a consequence of taking into account bremsstrahlung is the finiteness of the penetration depth of the Alfvén wave into an inhomogeneous plasma and a steady quasi-stationary regime of the Alfvén wave absorption. Density inhomogeneities of two types are considered – hump and hollows, which are distributed according to the Gaussian law. The dependences on the value of the hump of the penetration depth of the Alfvén wave into the inhomogeneous plasma and the maximum temperatures of electrons and ions are obtained. The study showed that an increase in the amplitude of the incident wave leads to an increase in the maximum values of the electron and ion temperatures, as well as the depth of penetration of the Alfvén wave into an inhomogeneous dissipative plasma.

Depression and Excitation of Buneman’s Instability in Two Ions Species Magnetized Dusty Plasma

In this research, theoretical method was used to examine the excitation and depression state for two-stream Buneman’s instability (BI) when we assumed an inhomogeneous, anisotropic, multi ions species with the presence of dust grains in plasma. The plasma also studied at different temperatures state. The diffusion equation was also derived and solved in one dimension for the Buneman’s instabilities that arise in such a situation within plasma. We develop the single-ion theory into a multiple-ion-species theory. This study concluded that: degree of plasma inhomogeneity, electron to ions temperature ratio, multi ions species and dust grains which have thermal velocity play a very important role in the depression and excitation of instability such Buneman’s instability.

Turbulence and Plasma Inhomogeneity Observed by Swarm Constellation

<p>The ionospheric environment is a complex system where dynamic phenomena, such as turbulence (fluid and magnetohydrodynamics) and plasma instabilities generally occur as a consequence of the coupling processes among solar wind, magnetosphere and ionosphere. It has been suggested that the turbulent character of the ionospheric plasma density also enters into the formation and dynamics of ionospheric inhomogeneities and irregularities, which essentially characterize the active equatorial, mid-latitude and polar regions. The ionospheric turbulence indirectly plays an important role also in the framework of space weather when due to the arrival of solar perturbations the plasma, the energetic particle distributions, the electric and magnetic fields within the magnetosphere and ionosphere are deeply modified thus paving the way for an increase in the ionospheric turbulence. Recent findings within the ESA funded project “Characterization of IoNospheric TurbulENce level by Swarm constellation (INTENS)” permitted us to investigate the role played by the turbulence on scales from hundreds of kilometers to a few kilometers in generating multi-scale plasma structures and inhomogeneities in the ionospheric environment at different latitudes. This presentation reports on the most promising results of the INTENS project regarding the investigation of turbulence and plasma conditions in the topside ionosphere using Swarm data.</p>

A drift of Langmuir waves in a magnetized inhomogeneous plasma

The concept of informativeness of nonlinear plasma physics scenarios is explained. Natural ideas of developing highly informative models of plasma kinetics are spelled out. They are applied to develop a formula that governs the drift of long Langmuir waves in spatial positions and wave vectors in a magnetized plasma due to the plasma inhomogeneity. Together with previous findings (Erofeev, Phys. Plasmas, vol. 22, 2015, 092302), the formula evidences the need for an intelligent generalization of the notion of wave energy density from usual homogeneous plasmas to inhomogeneous ones.