Study of nonlinear wave processes in plasmas using the formalism of a special Lorentz transformation for a space-independent frame.
In questo lavoro si studia la instabilità gravitazionale di un fluido comprimibile, elettroconduttore, descritto dalle equazioni della magnetofluidodinamica in presenza delle correnti di Hall e di ion slip. Si determina la condizione per la instabilità relativa ad una classe di perturbazioni assialsimmetriche.
In this paper we extend to Plasma Mechanics the study of the hydrodynamic steady motions in which the streamlines are circular helixes. The plasma is described by the magnetofïuiddynamic equations with the Hall effect. Velocity and magnetic fields (and, in correspondence, the pressure field) that make such motions possible are determined. So a class of exact solutions of the magnetofïuiddynamic equations with the Hall effect is pointed out.
This paper studies the magnetodynamic equilibrium of a radiative, infinitely conducting plasma, undergoing both a rotation motion around a symmetry axis and a motion in the meridian plans. It is assumed that on plasma acts its own gravitation. In the first nota the plasma is considered incompressible; for such a plasma the approximation of a perfect gas is valid.
This paper studies the magnetodynamic equilibrium of a radiative, infinitely conducting plasma, undergoing both a rotation motion around a symmetry axis and a motion in the meridian plans. It is assumed that on plasma acts its own gravitation. In the second note the plasma is supposed to be polytropic and compressible. The stability criterion of such a splasma is also obtained.
The Euler-Poisson system is a fundamental two-fluid model to describe the dynamics of the plasma consisting of compressible electrons and a uniform ion background. In the 3D case Guo [7] first constructed a global smooth irrotational solution by using the dispersive Klein-Gordon effect. It has been conjectured that same results should hold in the two-dimensional case. In our recent work [13], we proved the existence of a family of smooth solutions by constructing the wave operators for the 2D system....
We study the theoretical and numerical coupling of two hyperbolic systems of conservation laws at a fixed interface. As already proven in the scalar case, the coupling preserves in a weak sense the continuity of the solution at the interface without imposing the overall conservativity of the coupled model. We develop a detailed analysis of the coupling in the linear case. In the nonlinear case, we either use a linearized approach or a coupling method based on the solution of a Riemann problem. We...
We study the theoretical and numerical coupling of two hyperbolic systems of conservation laws at a fixed interface. As already proven in the scalar case, the coupling preserves in a weak sense the continuity of the solution at the interface without imposing the overall conservativity of the coupled model. We develop a detailed analysis of the coupling in the linear case. In the nonlinear case, we either use a linearized approach or a coupling method based on the solution of a Riemann problem....
In this paper, we study a Zakharov system coupled to an electron diffusion equation in order to describe laser-plasma interactions. Starting from the Vlasov-Maxwell system, we derive a nonlinear Schrödinger like system which takes into account the energy exchanged between the plasma waves and the electrons via Landau damping. Two existence theorems are established in a subsonic regime. Using a time-splitting, spectral discretizations for the Zakharov system and a finite difference scheme for the...
In this paper, we study a Zakharov system coupled to an electron diffusion equation in order to describe laser-plasma interactions. Starting from the Vlasov-Maxwell system, we derive a nonlinear Schrödinger like system which takes into account the energy exchanged between the plasma waves and the electrons via Landau damping. Two existence theorems are established in a subsonic regime. Using a time-splitting, spectral discretizations for the Zakharov system and a finite difference scheme for...