Characterization of 3-strap antennas in ASDEX Upgrade
1 Max-Planck-Institut für Plasmaphysik, Boltzmannstr.2, 85748 Garching, Germany
2 IRFM, CEA Cadarache, 13108 Saint Paul lez Durance, France
3 IJL UMR 7198, U. de Lorraine P2M, Fac. Des Sciences, BP 70239, F-54506 Vandœuvre Cedex, France
4 Politecnico di Torino, Torino, Italy
5 Technische Universität München, Boltzmannstr. 15, 85748 Garching, Germany
6 Applied Physics Department, University of Ghent, B-9000 Ghent, Belgium
* Corresponding author: email@example.com author
Published online: 23 October 2017
The response of the local RF current measured at limiters of 3-strap ICRF antenna to variations of power balance and phasing at fICRF=30MHz agrees qualitatively well with EM calculations by TOPICA and RAPLICASOL codes. Measurements of tungsten sputtering yield and DC current at the limiters correlate strongly with the local RF current. In contrast to findings for the 2-strap antennas, values of DC current are predominantly positive, and negative only for some locations and feeding parameters. Explanations can involve more physical mechanisms than only parallel sheath dynamics.
© The authors, published by EDP Sciences, 2017
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