Stability of Elevated-$q_{min}$ Steady-State Scenarios on DIII-D

Limits to high performance steady-state operation with $q_{min}$$>$1.4 and ${\beta_N\leq3.5}$ are identified and explained. Various $\beta_N$ and q-profile histories were produced while testing feedback control of these profiles. Ten pulses had no core MHD at $\beta_N$=3.4-3.5, with $q_{min}$=1.4-1.8, and $q_{95}$=5-5.8. These have predicted ideal-wall kink $\beta_N$ limits between 4 and 5. One pulse had an n=1 tearing mode (TM) at $\beta_N$=3.5 with no clear trigger. Five pulses developed n=1 TMs when $\beta_N$=2, $q_{min}$=2, and $q_{95}$=4.7. Stability calculations for these latter cases will be shown. In seven other shots, additional NBI power from sources with more normal injection was used, and these had off-axis fishbone (OAFB) modes at $\beta_N$=3.5. These sources produce more large-radius trapped ions whose precession can drive OAFB. Preliminary analysis suggests a threshold power or voltage exists. In some cases OAFB appear to trigger n=1 TMs. These studies seek to clarify the operational limits of a steady-state scenario for next step devices.