Visible Imaging of Edge Turbulence in NSTX
Authors: S. Zweben, R. Maqueda, K. Hill, D. Johnson, S. Kaye, H. Kugel, F. Levinton, R. Maingi, L. Roquemore, S. Sabbagh, and G. Wurden
Date of PPPL Report: June 2000
Presented at: the 27th European Physical Society's (EPS) Conference on Controlled Fusion and Plasma Physics, June 12-16, 2000, Budapest, Hungary. A "Provisional Collection of Submitted Contributions" can be found at the following web site: http://www.eps2000.kfki.hu (active as of August 16, 2000). Papers are in PDF format.
Edge plasma turbulence in tokamaks and stellarators is believed to cause the radial heat and particle flux across the separatrix and into the scrape-off-layers of these devices. This paper describes initial measurements of 2-D space-time structure of the edge density turbulence made using a visible imaging diagnostic in the National Spherical Torus Experiment (NSTX). The structure of the edge turbulence is most clearly visible using a method of "gas puff imaging" to locally illuminate the edge density turbulence.