Observations of impurity toroidal totation suppression with ITB formation in ICRF and ohmic H mode Alcator C-Mod plasmas

摘要

Co-current central impurity toroidal rotation has been observed in AlcatorC-Mod plasmas with on-axis ICRF heating. The rotation velocity increases with plasma stored energy and decreases with plasma current. Very similar behaviour has been seen during ohmic H modes, witch suggests that the rotation, generated in the absence of an external momentum source, is not mainly an ICRF effect.