Effects of Er/RBθ profiles on transport reduction in DIII-D and TFTR

A possible relation between the ExB flow curvature and the reduction of electron thermal diffusivity is discussed. We show that unlike the ExB flow shear, the ExB flow curvature has no universal effects on the evolution of the two-point correlation function. Since various instabilities respond differently to the ExB flow curvature, we can gain useful insights into the nature of the ambient turbulence responsible for the electron thermal transport by examining the Er/RBθ profiles. Initial results from DIII-D and TFTR are discussed. (author)