The effects of twisted magnetic field on coronal loops oscillations and dissipation

Abstract

The standing MHD modes in a zero-$\beta$ cylindrical magnetic flux tube modelled as a straight core surrounded by a magnetically twisted annulus, both embedded in a straight ambient external field is considered. The dispersion relation for the fast MHD waves is derived and solved numerically to obtain the frequencies of both the kink ($m=1$), and fluting ($m=2,3$) waves. Damping rates due to both viscous and resistive dissipations in presence of the twisted magnetic field is derived and solved numerically for both the kink and fluting waves.

13 pages, 11 figures

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