0477077 - ÚFP 2018 RIV US eng J - Článek v odborném periodiku
Pitts, R.A. - Bardin, S. - Bazylev, B. - van den Berg, M.A. - Bunting, P. - Carpentier-Chouchana, S. - Coenen, J.W. - Corre, Y. - Dejarnac, Renaud - Escourbiac, F. - Gaspar, J. - Gunn, J. P. - Hirai, T. - Hong, S.-H. - Horáček, Jan - Iglesias, D. - Komm, Michael - Krieger, K. - Lasnier, C. - Matthews, G.F. - Morgan, T.W. - Panayotis, S. - Pestchanyi, S. - Podolník, Aleš - Nygren, R.E. - Rudakov, D.L. - De Temmerman, G. - Vondráček, Petr - Watkins, J.G.
Physics conclusions in support of ITER W divertor monoblock shaping.
Nuclear Materials and Energy. Roč. 12, August (2017), s. 60-74. E-ISSN 2352-1791.
[International Conference on Plasma Surface Interactions 2016, PSI2016 /22./. Roma, 30.05.2016-03.06.2016]
Institucionální podpora: RVO:61389021
Klíčová slova: ITER * Tungsten * Divertor * Shaping * Melting * MEMOS
Obor OECD: Fluids and plasma physics (including surface physics)
Web výsledku:
http://www.sciencedirect.com/science/article/pii/S2352179116302885
DOI: https://doi.org/10.1016/j.nme.2017.03.005

The key remaining physics design issue for the ITER tungsten (W) divertor is the question of monoblock (MB) front surface shaping in the high heat flux target areas of the actively cooled targets. Engineering tolerance specifications impose a challenging maximum radial step between toroidally adjacent MBs of 0.3 mm. Assuming optical projection of the parallel heat loads, magnetic shadowing of these edges is required if quasi-steady state melting is to be avoided under certain conditions during burning plasma operation and transiently during edge localized mode (ELM) or disruption induced power loading. An ex- periment on JET in 2013 designed to investigate the consequences of transient W edge melting on ITER, found significant deficits in the edge power loads expected on the basis of simple geometric arguments, throwing doubt on the understanding of edge loading at glancing field line angles. As a result, a coordi- nated multi-experiment and simulation effort was initiated via the International Tokamak Physics Activity (ITPA) and through ITER contracts, aimed at improving the physics basis supporting a MB shaping deci- sion from the point of view both of edge power loading and melt dynamics. This paper reports on the outcome of this activity, concluding first that the geometrical approximation for leading edge power load- ing on radially misaligned poloidal leading edges is indeed valid. On this basis, the behaviour of shaped and unshaped monoblock surfaces under stationary and transient loads, with and without melting, is compared in order to examine the consequences of melting, or power overload in context of the benefit, or not, of shaping. The paper concludes that MB top surface shaping is recommended to shadow poloidal gap edges in the high heat flux areas of the ITER divertor targets.

Trvalý link: http://hdl.handle.net/11104/0277166