Comparison of Edge Turbulence Imaging at Two Different Poloidal Locations in the Scrape-off Layer of Alcator C-Mod

Technical Report · Fri Mar 29 04:00:00 EDT 2013

DOI:https://doi.org/10.2172/1072360· OSTI ID:1072360

Zweben, S. J. ^[1]; Terry, J. L. ^[2]; Agostini, M. ^[3]; Davis, W. M. ^[1]; Diallo, A. ^[1]; Ellis, R. A. ^[1]; Golfinopoulos, T. ^[2]; Grulke, O. ^[4]; Hughes, J. W. ^[2]; LaBombard, B. ^[2]; Landreman, M. ^[2]; Myra, J. R. ^[5]; Pace, D. C. ^[6]; Stotler, D. P. ^[1]

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1. Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
3. European Atomic Energy Community (Euratom), Ispra (Italy)
4. Max Planck Institute for Plasma Physics, Greifswald (Germany)
5. Lodestar Research Corp., Boulder, CO (United States)
6. General Atomics, San Diego, CA (United States)

This paper describes 2-D imaging measurements of plasma turbulence made in the scrape-off layer of the Alcator C-Mod tokamak simultaneously at two different poloidal locations, one near the outer midplane and the other near the divertor X-point region. These images were made with radial and poloidal resolution using two gas puff imaging (GPI) diagnostics, which were not directly connected along a B field line. The turbulence correlation structure has a significantly different tilt angle with respect to the local flux surfaces for the midplane and X-regions, and a slightly different ellipticity and size. The time-averaged turbulence velocities can be different in the midplane and Xregions, even within the same flux surface in the same shot, and in most cases the fluctuations in poloidal velocity in these two regions were not correlated. These structures are partially consistent with a magnetic flux tube mapping model, and the velocities are compared with various poloidal flow models.

• Research Organization: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
• Sponsoring Organization: USDOE Office of International Affairs (IA), Climate Change Policy and Technology
• OSTI ID: 1072360
• Report Number(s): PPPL--4864
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Scrape-off Layer (SOL)
Tokamaks
Turbulence