Blob structure and motion in the edge and SOL of NSTX. (28th January 2016)

• Record Type: Journal Article
• Authors: Zweben, S J; Myra, J R; Davis, W M; D'Ippolito, D A; Gray, T K; Kaye, S M; LeBlanc, B P; Maqueda, R J; Russell, D A; Stotler, D P
• Other Names: collab.
• Is Part Of: Plasma physics and controlled fusion. Volume 58:Number 4(2016:Apr.)
• Publication Date: 2016-01-28
• Subjects: tokamak -- turbulence -- edge; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/0741-3335/58/4/044007
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: The structure and motion of discrete plasma blobs (a.k.a. filaments) in the edge and scrape-off layer of NSTX is studied for representative Ohmic and H-mode discharges. Individual blobs were tracked in the 2D radial versus poloidal plane using data from the gas puff imaging diagnostic taken at 400 000 frames s −1 . A database of blob amplitude, size, ellipticity, tilt, and velocity was obtained for ~45 000 individual blobs. Empirical relationships between various properties are described, e.g. blob speed versus amplitude and blob tilt versus ellipticity. The blob velocities are also compared with analytic models.