The impact of equilibrium helical flows on the stability properties of low shear tokamak plasmas is assessed. The corrections due to such helical flow to the equilibrium profiles (mass density, pressure, Shafranov shift, magnetic fluxes) are computed by minimising order by order the generalised Grad-Shafranov equation. By applying the same minimisation procedure, a set of three coupled equations, suitable for the study of magnetohydrodynamic perturbations localised within core or edge transport barriers is derived in circular tokamak geometry. We apply these equations to modelling the impact of strong poloidal flow shear in the edge region caused by a radial electric field on the stability of edge infernal modes retaining vacuum effects. Due to the poloidal flow shearing, the effect of plasma rotation is not simply a Doppler shift of the eigenfrequency. Stabilisation is found even for weak flow amplitude.
Helical equilibrium magnetohydrodynamic flow effects on the stability properties of low-n ideal external-infernal modes in weak shear tokamak configurations
Brunetti, D.; Graves, J. P.; Lazzaro, E.; Mariani, A.; Nowak, S.; Cooper, W. A.; Wahlberg, C.
ID | 402899 |
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DOI | 10.1088/1361-6587/ab0f0b |
PRODUCT TYPE | Journal Article |
LAST UPDATE | 2022-04-13T16:11:32Z |
EU PROJECT | EUROfusion |
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TITLE | Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium |
FOUNDING PROGRAM | H2020 |