Analysis of fast-ion Dα data from the National Spherical Torus Experiment. (6th April 2016)

• Record Type: Journal Article
• Authors: Heidbrink, W.W.; Ruskov, E.; Liu, D.; Stagner, L.; Fredrickson, E.D.; Podestà, M.; Bortolon, A.
• Is Part Of: Nuclear fusion. Volume 56:Number 5(2016:May)
• Publication Date: 2016-04-06
• Subjects: Alfvén eigenmodes -- energetic particles -- spherical tokamak; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/5/056005
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Measured fast-ion D α (FIDA) data from an extensive NSTX database are compared to 'classical' predictions that neglect transport by instabilities. Even in the absence of appreciable MHD, in many cases, the profile peaks at smaller major radius and the profile is broader than the predictions. Abrupt large-amplitude MHD events flatten the FIDA profile, as do most toroidal Alfvén eigenmode (TAE) avalanche events. Generally, the onset of a long-lived mode also flattens the FIDA profile.