Magnetic field effects on the rayleigh-taylor instability in an inhomogeneous plasma

Abstract EN

The Rayleigh–Taylor (RT) instability is investigated analytically in an inhomogeneous plasma rotating uniformly in an external magnetic field.

For the case of two distinct densities separated by a sharp boundary, it is found that even when the heavier fluid is on top of the lighter fluid, there are still some stable modes in the presence of the magnetic field, which acts as a stabilizer.

In the case of a continuously varying density and for fast variations of the perturbation wavelength relative to the density variations in magnetized plasmas, RT instability does appear, with mode frequencies governed by the dispersion relation, where ρ0 is the equilibrium fluid density, ωc is the angular velocity, and k is the wave number of the perturbations.

The magnetic field still acts as a stabilizer up to a threshold value determined from the condition ω0 (k) = 0.