(EX/P4-13) Studies of Dust Dynamics in High Temperature Plasmas

B.V. Kuteev1), B.V. Kuteev1), V.E. Fortov2), S.A. Kamneva1), L.N. Khimchenko1), V.I. Krauz1), S.V. Krylov1), Yu. V. Martynenko1), E.E. Mukhin3), G.T. Razdobarin3), O.F. Petrov2), T.S. Ramazanov4), V.A. Rozhansky5), V.Yu. Sergeev5), V.G. Skokov5), V.P. Smirnov1), S. V. Voskoboynikov5), A.M. Zhitlukhin6)
1) Nuclear Fusion Institute, Russian Research Centre “Kurchatov Institute”, Moscow, Russia
2) Institute of High Energy Densities, Joint Institute of High Temperatures, Moscow, Russia
3) A.F. Ioffe Physical Technical Institute, St. Petersburg, Russia
4) Al-Farabi Kazakh University, Almaty, Kazakhstan Republic
5) State Polytechnical University, St. Petersburg, Russia
6) TRINITI, Troitsk, Moscow Region, Russia

Abstract.  Dust generation and transport in apparatuses with high temperature plasmas create substantial problems on the way to fusion reactor with magnetic confinement [G. Federici, C. H. Skinner, J. N. Brooks, et al., Nucl. Fusion 41 (2001) 1967]. The dust influences likely upon operation regimes of the divertor and core plasmas. Accounting for strong requirements to tritium losses in fuel cycle, it is desirable to clarify in next future the role of dust in accumulation and transport of tritium in the reactor. In this paper the results of RosAtom Program ``Dust in high temperature plasmas” are summarized. The program has begun in Russia in 2004 and it has been supported by Kazakhstan activity in 2005. Experiments aimed at studying the dust generation in conditions corresponding to ELM and disruptions have been started using plasma guns and electron beam-plasma discharges. A new ablation regime characterized by generation of 10 μm dust particles was discovered in graphite pellet experiments on W7-AS stellarator. Studies of the Z-pinch stability with dust doped plasma are started in Kurchatov Institute. Dynamics of dust flows in gas discharges is investigated by IHED. Laser blow-off diagnostics of the films deposited on tokamak walls, including their thickness and atomic composition, is developed in Ioffe Institute. Surface and dust structure analysis is intensively developed on the basis of tunnel and atomic-force microscopy. Opportunities of Synchrotron Source of Kurchatov institute are used in analysis of films and dust composition and structure. A review of film/dust studies on tokamak T-10 is presented in [B.V. Kuteev, in Dust in Fusion Plasmas, Napa, California, April 5, 2005. http://maemail.ucsd.edu/dust/].First experiments with carbon dust injection into tokamak plasma showed that 2-10 μm dust at 300 m/s velocity penetrates 3-5 cm beyond the last closed magnetic surface. Thus it reaches plasma with the electron temperature up to 100 eV and the density about 1013 cm-3. The data obtained points out significant influence of radiative cooling on dust ablation. Dust penetration beyond the separatrix in reactor conditions seems possible.

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