Influence of the electronic mass on the Rayleigh-Taylor instability
In this thesis we present an analytical formulation of Rayleigh-Taylor instability in magnetized plasmas using a modified expression of Ohm’s law, which includes an electron-mass dependent term. For this, first, the Rayleigh-Taylor instability is addressed in a classic fluid of hydrodynamics and in an ideal plasma magnetically confined. In order to describe satisfactorily the dissipative processes at sufficiently high rates and, therefore, the generalized Ohm’s law will be addressed taking into account the inertia of the electronic mass. Then, with this approach, a formulation of Rayleigh-Taylor instability is developed in a viscousresistive plasma slab under the action of a shear magnetic field and a current density. In the neighborhood of the rational surface, the density of restorative force approximates of the density of gravitational force. In this region, when the viscous effects are negligible, it is shown that the viscous-resistive layer is provided by the resistive layer. However, when the viscous effects become important, it is verified that the viscous-resistive boundary layer is given by the geometric mean of the resistive and viscous boundary layers. Thus, a dispersion ratio for the growth rate of the perturbative modes is obtained in terms of the viscous-resistive layer. Finally, the scale of the temporal growth rate of Rayleigh-Taylor instability with plasma resistivity, fluid viscosity and electron density is presented and discussed.