GLOBAL SEARCHES OF HARTMANN-NUMBER-DEPENDENT STABILITY BOUNDARIES

A numerical technique is developed for searching for the stability bou ndary for a resistive, straight-cylinder, magnetohydrodynamic equilibr ium with spatially-dependent resistivity. For fixed aspect ratio, the boundary is a curve in the plane whose axes are Hartmann number and pi nch ratio (or reciprocal of the safety factor at the wall). The techni que is spectral and utilizes orthonormal eigenfunctions of the curl. N onlinear behavior above the stability boundary is computed for a parti cular profile, using a nonlinear version of the code.