Dynamics of turbulent transport in the scrape-off layer of the CASTOR tokamak

Journal Article · Sun Oct 15 04:00:00 EDT 2006 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2359721· OSTI ID:20860308

Devynck, P; Brotankova, J; Peleman, P; Spolaore, M; Figueiredo, H; Hron, M; Kirnev, G; Martines, E; Stockel, J; Van Oost, G; Weinzettl, V ^[1]

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1. Association EURATOM-CEA, CEA/DSM/DRFC Cadarache, 13108 Saint Paul Lez Durance (France) and Institute of Plasma Physics, Association EURATOM-IPP.CR, Prague (Czech Republic) and Department of Applied Physics, Ghent University, Ghent (Belgium) and Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, Padova (Italy)

In this paper, the propagation of turbulent events along radial and poloidal probe arrays in the scrape-off layer (SOL) of the tokamak CASTOR [M. Hron et al., Czech. J. Phys. 49, 181 (1999)] is observed using a novel correlation technique. The typical turbulent structures appear as dipoles on the floating potential signals and as positive bursts on the density. It is found that both dipoles and density bursts propagate over long radial distances in the SOL while propagating poloidally. A comparison of the measured velocities of the potential and density fluctuations shows that the density structures move radially faster than the potential ones. This allows us to understand how the density is convected by the turbulence. The density moves radially along the potential valleys created by the poloidal dipoles without modifying them. In the framework of an interchange turbulence, this property indicates that charge exchange collisions with neutrals in the SOL of CASTOR lead to a high viscosity that damps the zonal flows.

• OSTI ID: 20860308
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 13; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CASTOR TOKAMAK
CHARGE EXCHANGE
COMPARATIVE EVALUATIONS
CORRELATIONS
DIPOLES
ELECTRON COLLISIONS
FLUCTUATIONS
ION COLLISIONS
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA SCRAPE-OFF LAYER
PROBES
TURBULENCE
VISCOSITY