Dynamics of pedestal rotation and ion temperature profile evolution in KSTAR

Pedestal rotation profiles are of great importance for ITER, in the multiple contexts of confinement enhancement, the source of intrinsic torque in H-mode, and their response to ELMs and to ELM suppression techniques. We report on findings from charge exchange spectroscopy, of toroidal rotation and profile structure and evolution in KSTAR H-mode pedestal plasmas. We emphasize pedestal rotation from charge exchange spectroscopy at the L to H transitions plays an essential role in determining transport which is related in rotation shear and stability which is affected by increased rotation with the high spatial resolution from charge exchange spectroscopy. The evident disparity between the width of the toroidal rotation pedestal and that of the ion temperature pedestal is interesting, since we usually expect that parallel shear flow instability could be a candidate in which the resulting momentum transport can make toroidal velocity profile broader. Magnetic perturbations make not only ELM disappeared but also toroidal rotation from the charge exchange spectroscopy decreased on KSTAR. Changes of the toroidal rotation profiles are observed from during ELM and ELM suppression. The pedestal top of the toroidal rotation during ELMy-H-mode is higher than that during suppression by RMPs. (author)