(IT/P1-29) Modelling of Edge Control by Ergodic Fields in DIII-D, JET and ITER

M. Becoulet1), E. Nardon1), G. Huysmans1), P. Thomas1), M. Lipa1), W. Zwingmann1), O. Czarny1), G. Agarici1), A. Saille1), J.-M. Verger1), R. Moyer2), T. Evans3), V. Chuyanov4), G. Federici4), Y. Gribov5), A. Polevoi5), G. Saibene6), G. Vayakis6), A. Portone6), A. Loarte6), V. Parail7), J. Hastie7), C. Gimblett7)
1)Association Euratom-CEA, CEA Cadarache, F-13108, St. Paul-lez-Durance, France
2)University of California, San Diego, La Jolla, CA 92093, USA
3)General Atomics, P.O. Box 85608, San Diego, CA 92186-5688, USA
4)ITER JWS Garching Co-center, Boltzmannstrasse2, 85748 Garching, Germany
5)ITER Naka JWS, 801-1 Mukouyama, Naka-shi,Ibaraki-ken, 311-0193 Japan
6) EFDA close Support Unit,2 Boltzmannstrasse,D-85748 Garching,Germany
7)Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon,OX143DB, U.K.

Abstract.  The present paper analyses possibilities of constructing coils systems in ITER and JET that are able to produce Resonant Magnetic Perturbation (RMP) spectra and edge ergodisation similar to the realistic experimental case of the total Type I ELMs suppression at high confinement in DIII-D. Due to the strong technical restrictions for the in-vessel implantation both in JET and ITER, external coil designs were considered initially. However, the large distance from the coils to plasma edge and rapid decay of the magnetic perturbation require much larger currents in ITER( 600kA) and JET( 400kA) compared to DIII-D ( 3kA) for typical H-mode scenarios at q95  3 and toroidal symmetry n=3. Moreover, the coils currents and central perturbations are almost prohibitively large for higher q95>4 scenarios. In-vessel coils closer to the plasma mounted on the blanket modules can be optimized for all ITER reference scenarios (q95=3-5) at 25kA. The non-linear MHD modelling of the self-consistent plasma response demonstrated plasma density transport due to drift generated in the presence of RMPs. The estimations of the screening of RMPs due to toroidal plasma rotation showed a strong decrease of the perturbation amplitude in the plasma centre in DIII-D, JET and ITER, but relatively weak effect in pedestal region depending on the plasma parameters.

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