Modelling of plasma response to resonant magnetic perturbations and its influence on divertor strike points(IAEA24th.)

0397689 - ÚFP 2014 RIV US eng O - Others
Cahyna, Pavel - Liu, Y.Q. - Nardon, E. - Kirk, A. - Peterka, Matěj - Harrison, J.R. - Thornton, A. - Chapman, I. - Pánek, Radomír - Schmitz, O.
Modelling of plasma response to resonant magnetic perturbations and its influence on divertor strike points(IAEA24th.).
2013
R&D Projects: GA ČR GAP205/11/2341
Institutional support: RVO:61389021
Keywords : Magnetohydrodynamics * tokamak * divertor * magnetic perturbation
Subject RIV: BL - Plasma and Gas Discharge Physics
http://www-naweb.iaea.org/napc/physics/FEC/FEC2012/papers/577_THP427.pdf

Resonant magnetic perturbations for ELM mitigation in tokamaks can be modified by the plasma response and indeed strong screening of the applied perturbation is in some cases predicted by simulations. In this contribution we use the spiralling patterns (footprints) appearing on the divertor to reveal information about the plasma response. We use two theoretical tools for investigation of the impact of plasma response on footprints: a simple model of the assumed screening currents, and the MHD code MARS-F. MARS-F predicts a more significant reduction of footprints in odd parity than in even parity, explaining the results obtained on MAST. In the MAST experiments the footprints are correlated with the density pump-out, but appear later. Their sudden appearance is incompatible with the vacuum perturbation field approximation and can be explained by a decay of the plasma screening (the event of perturbation penetration).
Permanent Link: http://hdl.handle.net/11104/0225317