Tilting and shifting modes in a spheromak

Abstract

In the absence of a conducting wall, typical spheromak plasmas are unstable to tilting and/or shifting modes. The effects of the cross-sectional shape, aspect ratio, and the location of a conducting wall on the stability of these modes are investigated. A circular cross-section (b/a ~ 1) configuration with a flux hole δ = 0.5 (aspect ratio R/a = 2) will will be stabilized by an ellipsoidal wall of mean separation of 1.3 minor radii from the plasma.