Investigation of the coupling properties of the ion cyclotron fast wave under applied magnetic perturbations and MHD phenomena in ASDEX Upgrade
1 Max Planck Institute for Plasmaphysics, Boltzmannstraße 2, 85748 Garching bei München, Germany
2 Ludwig Maximillian University of Munich, Geschwister-Scholl-Platz 1, 80539 München, Germany
3 Applied Physics Department, University of Ghent, Sint-Pietersnieuwstraat 41, 9000 Ghent, Belgium
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Published online: 23 October 2017
The modulation of the ion cyclotron fast wave coupling to the plasma due to non-axisymmetric changes of the distance antenna-R-cutoff is studied. These changes can arise when magnetic perturbation (MP) fields are used, or when MHD activity is present. The application of MP fields can excite a low field side midplane plasma kink response that amplifies the vacuum perturbation field, leading to appreciable 3D plasma displacements. This effect is studied via NEMEC simulations. Rigid rotation of the MP field is found to produce a coherent antenna loading resistance modulation, suggesting an interplay between the non-axisymmetric magnetic field structure and the wave coupling properties. MHD modes are shown to introduce similar loading resistance oscillations, coherent with the mode rotation frequency. The case of a (2,1) mode is presented.
© The authors, published by EDP Sciences, 2017
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