Edge and SOL turbulence and blob variations over a large database in NSTX. (3rd September 2015)

• Record Type: Journal Article
• Authors: Zweben, S.J.; Davis, W.M.; Kaye, S.M.; Myra, J.R.; Bell, R.E.; LeBlanc, B.P.; Maqueda, R.J.; Munsat, T.; Sabbagh, S.A.; Sechrest, Y.; Stotler, D.P.
• Other Names: collab.
• Is Part Of: Nuclear fusion. Volume 55:Number 9(2015:Sep.)
• Publication Date: 2015-09-03
• Subjects: tokamak -- turbulence -- edge -- scrape-off-layer; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/55/9/093035
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: This paper describes the range of variations in edge and SOL turbulence observed using a gas puff imaging (GPI) diagnostic in NSTX discharges. The database consists of 140 shots including Ohmic, L-mode, and H-mode plasmas measured during steady-state conditions (e.g. without ELMs). Turbulence quantities were evaluated using both cross-correlation analysis and blob tracking. Relative fluctuation levels varied from –1.0, correlation times were –40 μ s, correlation lengths were –10 cm, and turbulence velocities were km s −1 and km s −1 outwards. These variations were evaluated with respect to both the global and local edge plasma parameters, and compared with simplified theoretical models.