Studies of ELM Heat Load, SOL Flow and Carbon Erosion from Existing Tokamak Experiments, and Projections for ITER
N. Asakura1), A. Loarte2), G. Porter3), V. Philipps4), B. Lipschultz5), A. Kallenbach6), G. Matthews7), G. Federici8), A. Kukushkin8), A. Mahdavi9), A.W. Leonard9), D. Whyte10), K. Itami1), H. Takenaga1), A.V. Chankin1), S. Higashijima1), T. Nakano1), A. Herrmann6), T. Eich6), B. LaBombard5)
1) Japan Atomic Energy Research Institute, Naka-machi, Naka-gun, Ibaraki 311-0193, Japan
2) EFDA CSU, Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München, Germany
3) Lawrence Livermore National Laboratory P.O.Box 808, Livermore, CA 94550, USA
4) Forschungszentrum Jülich, IPP, EURATOM-Association, D-52425 Jülich, Germany
5) MIT Plasma Science and Fusion Center, Cambridge, MA 02139, USA
6) Max-Planck-Institut für Plasma physik, D-85748 Garching bei München, Germany
7) Joint European Torus, Abingdon OX13 3EA, Oxon, United Kingdom
8) ITER International Team, Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München, Germany
9) General Atomics, P.O.Box 85606, San Diego, CA 92186-5608, USA
10) University of California at San Diego, San Diego, CA 92093, USA
Abstract.
Three important physics issues for the ITER divertor design and operation are summarized based on the experimental and numerical work from multi-machine database (JET, JT-60U, ASDEX Upgrade, DIII-D, Alcator C-Mod and TEXTOR). (i)The energy load associated with Type-I ELMs is of great concern for the lifetime of the ITER divertor target. In order to understand the physics base of the scaling models [1], the ELM heat and particle transport from the edge pedestal to the divertor is investigated. Convective transport during ELMs plays an important role in heat transport to the divertor. (ii)Determinat ion of the SOL flow pattern and the driving mechanism has progressed experimentally and numerically. Influences of the drift effects on the SOL and divertor plasma transport were discussed. (iii)Carbon erosion and redeposition are of great importance in particular for tritium retention via codeposition. Characteristics of chemical yield at two different deposited carbon surfaces, i.e. erosion- and redeposition-dominated areas, have been studied. Progress in the understanding of the chemical erosion is reviewed.