Find in Library

Negative triangularity (NT) experiments in DIII-D point to an emergent reactor scenario free of sawteeth, endowed with benign, nondisruptive n = 2 tearing modes, which experience q _min $ \geqslant $ 1 similar to the positive triangularity hybrid scenario. Plasmas exhibiting this behavior attain ${\beta _{\text{N}}} > 3$ , high enough to reconsider long held views of NT stability. Ideal MHD and tearing stability analysis of well-diagnosed equilibrium reconstructions of experimental hybrid-like plasmas predict that among shape parameters, MHD stability limits are only sensitive to average triangularity. Operation is predicted to be possible at ${\beta _{\text{N}}}$ relevant to upcoming tokamaks and commercial NT reactors.