MHD BALLOONING STABILITY OF A SHEARED PLASMA SHEET

A three magnetic field component sheared plasma sheet equilibrium mode l is developed in the context of ideal magnetohydrodynamics (MHD). It is argued that MHD stability theory may be sufficiently correct for a thin sheet if the shear in the magnetic field is large enough. Using t he model magnetic held, the ballooning eigenvalue equation is solved f or several different values of equilibrium parameters. It is shown tha t for sufficiently large values of the shear parameter, the model is u nstable to symmetric ballooning modes with a growth rate on the order of one tenth the Alfven rate.