Full Paper
Contents  Return  Previous Page  Next Page  Index

Return To: Session EX/P5 - C-Mod, TCV, TEXTOR, RFX, GOL,
Prev Page: (EX/P5-09) Dynamic Effects of Rotating Helical Magnetic Field
Next Page: (EX/P5-11) Control of the Sawtooth Instability by Electron

(EX/P5-10) Experimental/Theoretical Comparisons of the Turbulence in the Scrape-Off-Layers of Alacator C-Mod, DIII-D, and NSTX

J.L. Terry1), S.J. Zweben2), D.L. Rudakov3), J.A. Boedo3), K. Hallatschek4), R.J. Maqueda5), R.A. Moyer3), B. Bai1), C.J. Boswell1), M. Greenwald1), S. Krasheninnikov3), B. LaBombard1), D. Kopon1), A.W. Leonard6), M.A. Mahdavi6), G.R. McKee7), W.M. Nevins8), B.N. Rogers9), P.C. Stangeby10), D. Stotler2), J.G. Watkins11), W.P. West6), D.G. Whyte3), X.Q. Xu8)
1) Massachusetts Institute of Technology, Cambridge, USA
2) Princeton Plasma Physics Laboratory, Princeton, NJ, USA
3) University of California, San Diego, CA, USA
4) Max Planck Institute of Plasma Physics, Garching, Germany
5) Los Alamos National Laboratories, Los Alamos, NM, USA
6) General Atomics, San Diego, CA, USA
7) University of Wisconsin, Madison, WI, USA
8) Lawrence Livermore Laboratory, Livermore, CA, USA
9) Dartmouth University, Hanover, NH, USA
10) University of Toronto, Institute for Aerospace Studies, Toronto, Canada
11) Sandia National Laboratories, Albuquerque, NM, USA

Abstract.  The intermittent turbulent transport in the Scrape-Off Layers of Alcator C-Mod, DIII-D, and NSTX is studied experimentally. In C-Mod and NSTX the turbulence is imaged with a very high density of spatial measurements. The 2D structure and dynamics of emission from a localized gas puff are observed, and intermittent features (also sometimes called ``blobs'') are typically seen. The intermittent features are often born near the separatrix and propagate predominately outward and poloidally. Qualitatively similar features (but with a larger size-scale) are also seen in the NSTX SOL. On DIII-D the edge turbulence is imaged using BES, and similar intermittent features are seen. Also the fluctuating components of density, temperature and poloidal electric field are simultaneously measured using a reciprocating Langmuir probe array. The density and temperature fluctuations have strongly non-Gaussian statistics, and events with amplitudes above 10 times the mean level are responsible for large fractions of the net particle and heat transport. The experimental observations from C-Mod are compared with numerical simulations of electromagnetic turbulence in a 3D flux tube at the plasma edge.

Read the full paper in PDF format.

IAEA 2003