THE MHD STABILITY OF A TWISTED FLUX TUBE PROMINENCE MODEL

The ideal MHD stability of the 2D twisted magnetic flux tube prominenc e model of Cartledge and Hood (1993) is investigated. The model includ es a temperature profile that varies from realistic prominence values up to typical coronal values. The prominence is considered to be of fi nite-width and finite height. The stability properties of the prominen ce models are studied by using a method that generates a separate nece ssary condition and a sufficient condition. These conditions give boun ds on the parameters that define marginal stability. In many cases the se bounds are quite close so that further, more detailed, stability ca lculations are not necessary. A number of parameter regimes are examin ed, corresponding to different profiles of the prominence temperatures , densities, and magnetic field shear. It is found that the model admi ts realistic stable and unstable loop lengths for observed prominence parameters when the axial magnetic field component does not vanish.