Impact of rotation and ion diamagnetic dxc vmrift on MHD stability at edge pedestal in quiescent H-mode plasmas. (31st July 2020)

• Record Type: Journal Article
• Authors: Aiba, N.; Chen, X.; Osborne, T.H.; Honda, M.; Burrell, K.H.; Snyder, P.B.
• Is Part Of: Nuclear fusion. Volume 60:Number 9(2020)
• Publication Date: 2020-07-31
• Subjects: QH-mode -- plasma rotation -- ion diamagnetic drift -- MHD stability; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/1741-4326/ab8c66
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: MHD stability at edge pedestal in a QH-mode plasma in DIII-D was analyzed by taking into account plasma rotation and ion diamagnetic drift effects. We have found that the coupled rotation and ion diamagnetic drift effects can stabilize a kink/peeling mode in the QH-mode plasma rotating in the direction counter to the plasma current, although it has been recognized the rotation alone destabilizes the mode regardless of its direction. The physics mechanism responsible for the stabilization was identified as reduction of the destabilizing effect by dynamic pressure through the coupling between the rotation and the ion diamagnetic drift. The coupling effect can be harnessed to both stabilize and destabilize the kink/peeling mode by switching the rotation direction, the trend which could be the reason that the QH-mode plasmas in DIII-D favor toroidal rotation counter to the plasma current direction.