Stability ofn=1Kink Modes in Bean-Shaped Tokamaks

Abstract

Numerical studies show that by indenting the small-major-radius side of conventional finite-aspect-ratio tokamaks, significant improvements to the stability of pressuredriven ideal magnetohydrodynamic modes can be achieved. The internal $n=1\mathrm{}$ kink mode can be stabilized completely with quite modest indentation. In the presence of a nearby conducting wall, kink-ballooning mode stability is also improved, and accessibility to a second stable region at high plasma $\beta$ is possible.