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International audience; Heat flux deposition profiles, calculated from infrared imaging, are presented for JET and MAST cases in the presence of external magnetic perturbations. In L-mode, a clear splitting of the strike-point is observed and well reproduced by modelling based on field line tracing with no plasma magnetic response included (vacuum field approximation). In H-mode, in contrast, the splitting is not clearly observed in spite of being expected from vacuum field modelling. As illustrated by modelling results, screening effects could explain the absence of a clear splitting in H-mode. (C) 2010 Elsevier B.V. All rights reserved.Assoc EURATOM IPP CR, Inst Plasma Phys AS CR Vvi, Prague, Czech Republic.Max Planck Inst Plasma Phys, D-85748 Garching, Germany.Culham Sci Ctr, EURATOM CCFE Fus Assoc, Abingdon OX14 3DB, Oxon, England.Assoc Euratom Enea Fus, Consorzio RFX, I-35127 Padua, Italy.Asociac EURATOM CIEMAT, Lab Nacl Fus, Madrid, Spain.FOM Inst Plasma Phys Rijnhuizen, NL-3439 MN Nieuwegein, Netherlands.Ecole Polytech, CNRS, UMR 7648, LPTP, F-91128 Palaiseau, France.Forschungszentrum Julich, Assoc EURATOM FZJ, D-52425 Julich, Germany.TEC, EURATOM Belgian State Assoc, LPP ERM KMS, Brussels, Belgium.

In both JET and MAST, the Error Field Correction Coils (EFCCs) have been used recently in order to attempt to control Type I Edge Localised Modes (ELMs), which represent a major threat to the lifetime of plasma facing components in ITER. Using vacuum magnetic modelling it is suggested that the ELM mitigation observed at JET could be related to the stochastization of the magnetic field at the edge. Indeed, the onset of ELM mitigation is found to be correlated with a certain level of the Chirikov parameter profile. Initial MAST results are presented which show an effect of EFCCs on the ELMs, again compatible with edge stochastization according to the modelling. New coils dedicated to ELM control are ready for use on MAST this year and are presented here briefly.