Ideal MHD stability calculations for compact stellarators

Stability results for high-n ideal local pressure-driven instabilities (ballooning and interchange: modes) are calculated from the COBRA and TERPSICHORE codes and compared for several low aspect ratio stellarators. Such a comparison is important because of the predominant roles that these codes are playing in the design of compact stellarators at several laboratories around the world. The code development required to reach the levels of convergence and accuracy needed for reliable operation at low aspect ratios is also described. (C) 2001 Elsevier Science B.V. All rights reserved.