The onset of the magnetic buoyancy instability in partially ionized plasmas

Institute for Astronomy and Astrophysics, University of Munich, Germany Centre of Interdisciplinary Plasma Science, Garching, Germany

Corresponding author: birk@usm.uni-muenchen.de

Received: 16 April 2002
Accepted: 4 June 2002

Abstract

The magnetic buoyancy instability greatly influences the transport of magnetic flux in a variety of astrophysical objects. In this paper the stability of magnetic flux layers against magnetic buoyancy perturbations is studied for the first time for partially ionized plasmas. Different to the pure magnetohydrodynamic case, the onset of unstable modes depends not only on the field gradient but also on the field strength. Momentum transfer between the ionized and neutral plasma components leads to stabilization of at least short wavelengths or even all buoyancy modes.