1. Edge Turbulence Imaging in the Alcator C-Mod Tokamak
- Author
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null S.J. Zweben, null D.P. Stotler, null J.L. Terry, null B. LaBombard, null M. Greenwald, null M. Muterspaugh, null C.S. Pitcher, null the Alcator C-Mod Group, null K. Hallatschek, null R.J. Maqueda, null B. Rogers, null J.L. Lowrance, null V.J. Mastrocola, and null G.F. Renda
- Subjects
Physics ,Maxima and minima ,Tokamak ,Alcator C-Mod ,law ,Turbulence ,Plasma turbulence ,Nuclear fusion ,Plasma diagnostics ,Atomic physics ,Magnetic field ,law.invention - Abstract
The 2-D radial vs. poloidal structure of edge turbulence in the Alcator C-Mod tokamak [I.H. Hutchinson, R. Boivin, P.T. Bonoli et al., Nuclear Fusion 41(2001) 1391] was measured using fast cameras and compared with 3-D numerical simulations of edge plasma turbulence. The main diagnostic is Gas Puff Imaging (GPI), in which the visible D(subscript alpha) emission from a localized D(subscript 2) gas puff is viewed along a local magnetic field line. The observed D(subscript alpha) fluctuations have a typical radial and poloidal scale of approximately 1 cm, and often have strong local maxima (''blobs'') in the scrape-off layer. The motion of this 2-D structure motion has also been measured using an ultra-fast framing camera with 12 frames taken at 250,000 frames/sec. Numerical simulations produce turbulent structures with roughly similar spatial and temporal scales and transport levels as that observed in the experiment; however, some differences are also noted, perhaps requiring diagnostic improvement and/or additional physics in the numerical model.
- Published
- 2001
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