IAEA Fusion Energy Conference 2010

Proceedings of the 23rd IAEA Fusion Energy Conference
Daejeon, 11-16 October 2010

Organized by the International Atomic Energy Agency
and hosted by the Government of the Republic of Korea


(ITR/P1-25) ECRH Assisted Plasma Start-up with Toroidally Inclined Launch: Multi-Machine Comparison and Perspectives for ITER

J. Stober1), G.L. Jackson2), E. Ascasibar3), Y.S. Bae4), J. Bucalossi5), A. Cappa3), T. Casper6), M.H. Cho7), Y. Gribov6), G. Granucci8), K. Hanada9), J. Hobirk1), A.W. Hyatt2), S. Ide10), J.H. Jeong7), M. Joung4), T. Luce2), T. Lunt1), W. Namkung7), S.I. Park7), P.A. Politzer2), J. Schweinzer1), A.C.C. Sips11), the ASDEX Upgrade Team1), the TJ-II Team3) and the ITPA “Integrated Operations Scenarios” Topical Group members and experts
1) Max-Planck-Institut für Plasmaphysik, EURATOM-Association, Garching, Germany
2) General Atomics, San Diego, USA
3) Laboratorio Nacional de Fusion, Asociacion EURATOM/CIEMAT, Madrid, Spain
4) National Fusion Research Institute, Daejeon, Korea
5) Association Euratom-CEA, Cadarache, St. Paul-lez-Durance, France
6) ITER Organisation, St. Paul-lez-Durance, France
7) Pohang University of Science and Technology, Pohang, Korea
8) Associazione Euratom-ENEA sulla Fusione, IFP-CNR, Milano, Italy
9) RIAM, Kyushu University, Fukuoka, Japan
10) Japan Atomic Energy Agency, Naka, Japan
11) EFDA JET, Culham Science Centre, Abingdon, UK

Abstract.  ECRH assisted plasma break down is foreseen with full and half magnetic field in ITER. Therefore, the corresponding O1- and X2-schemes have been studied in present day devices with respect to pre-ionisation and breakdown assist. Earlier experiments, presented at the 2008 IAEA FEC, proved the feasability in principle. This contribution reports on common experiments studying the effect of toroidal inclination of the ECR beam, which is ≥20o in ITER. All devices could demonstrate successful breakdown assist also for this case, although the necessary power was up to 100% higher compared to perpendicular launch. Differences between the devices with regard to the required power and vertical field are discussed and analysed. In contrast to most of these experiments, ITER will build up loop voltage prior to the formation of the field null due to the strong shielding by the vessel. Possible consequences of this difference are discussed.

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