Magnetic perturbation experiments on MAST L- and H-mode plasmas using internal coils

0366888 - ÚFP 2012 RIV GB eng J - Journal Article
Kirk, A. - Liu, Y.Q. - Nardon, E. - Tamain, P. - Cahyna, Pavel - Chapman, I. - Denner, P. - Meyer, H. - Mordijck, S. - Temple, D.
Magnetic perturbation experiments on MAST L- and H-mode plasmas using internal coils.
Plasma Physics and Controlled Fusion. Roč. 53, č. 6 (2011), 065011-065011. ISSN 0741-3335. E-ISSN 1361-6587
R&D Projects: GA ČR GAP205/11/2341
Institutional research plan: CEZ:AV0Z20430508
Keywords : Resonant magnetic perturbations * L-H transition * spherical tokamaks * edge localized modes
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 2.425, year: 2011
http://dx.doi.org/10.1088/0741-3335/53/6/065011

Experiments have been performed on MAST using internal (n = 3) resonant magnetic perturbation (RMP) coils. The application of the RMPs to L-mode discharges has shown a clear density pump-out when the field line pitch angle at the low-field side of the plasma is sufficiently well aligned with the applied field. The application of the RMPs before the L–H transition increases the power required to achieve H-mode by at least 30%. In type I ELMing H-mode discharges, at a particular value of q95, the ELM frequency can be increased by a factor of 5 by the application of the RMPs. This effect on the ELMs and the L-mode density pump-out is not correlated with the width of the region for which the Chirikov parameter, calculated using the vacuum field, is greater than 1 but may be correlated with the size of the resonant component of the applied field in the pedestal region or with the location of the peak plasma displacement when the plasma response is taken into account.
Permanent Link: http://hdl.handle.net/11104/0201723