Sheared Magnetic Field and Kelvin-Helmholtz Instability

Abstract

We studied the evolution of the Kelvin Helmholtz Instability (KHI) in the context of plasma flows and jets stability. We focused on the presence of a magnetic field reversal along the interface of the jet with the ambient medium. The aim of the work is to compare this case with the known results from the uniform magnetic field case. Indeed, we performed magnetohydrodynamic simulations of a single shear layer and of a jet in slab geometry. In the single shear layer simulations we found significant differences in the growth rates and the behavior of the instability. In particular, the KHI presented higher growth rates and a more unstable nature in the regime of high magnetic fields. In the slab jet simulations, the magnetic field is amplified around the jet even for supersonic Mach numbers, contrary to previous believe.