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