Momentum Confinement on DIII-D with Low Net Neutral Beam Torque

Momentum confinement was investigated in ELMing H-mode plasmas with elevated q$_{min}$. Torque scans were performed at constant $\beta_{{\rm N}}$, and the rotation profile was measured using charge exchange recombination (CER) spectroscopy. Studies of the mechanical angular momentum in the plasma show a non-uniform response to the applied neutral beam torque, resulting in a torque dependence of the momentum confinement time. Under nominally balanced neutral beam injection, the plasma maintains a significant rotation in the same direction as the plasma current (co-rotation). The intrinsic rotation can be understood as being due to an offset in the applied torque (i.e. an ``anomalous torque''). Analysis including the effect of anomalous fast ion diffusion shows that the anomalous torque appears to have a magnitude comparable to one neutral beam source, with the torque peaked at the edge of the plasma. Meaningful studies of momentum confinement must account for this intrinsic rotation/anomalous torque.