Abstract
MHD-instability properties of the solar prominence model of Low (1981) assuming a nonuniform magnetic field along the prominence axis (Bx) are investigated. We used a two-dimensional formalism based on the Energy Principle of ideal MHD (Bernstein et al. 1958). Different functional forms for Bx(A), where A is the axial component of the vector potential are considered. Observed parameter ranges as well as several cases outside these ranges are taken into account. For weak and moderate Bx, Low's model can also explain the reported short-period horizontal oscIllations with periods up to 7 minutes. Such oscillations are mainly sustained by the Lorentz force. Large intensities of Bx can produce the onset of a severe instability which could be possibly identified with a macroscopic drift instability. For values of the parameters outside the observed range, Bx causes a slight weakening of the instability with respect to the case with a vanishing Bx, however a considerable enlargement of the stability region is not achieved.
