Spatial Damping of Kink MHD Waves in the Presence of Magnetic Twist and Plasma Flow

Abstract

Propagating kink magnetohydrodynamic waves in magnetic flux tubes with incompressible plasma have been studied. The plasma has been assumed to flow along the magnetic field lines, and the magnetic field lines have been assumed to be twisted. Both the flow and the magnetic twist reduce the symmetry of the dispersion curves of the kink waves. The magnetic twist modifies the the properties of the forward and backward waves with positive and negative azimuthal wavenumbers, which are under Kelvin–Helmholtz instability due to plasma flow, in different manners. The effect of the magnetic twist on the spatial resonant damping of kink waves depends on the direction of the propagation and azimuthal wavenumber of the wave, and also on the direction of the plasma flow. Our conclusion is that the magnetic twist modifies the properties of the propagating kink waves depending on the wavenumbers of the wave and the direction of the plasma flow.