Experimental investigation of geodesic acoustic modes on JET using Doppler backscattering. (19th August 2016)

• Record Type: Journal Article
• Authors: Silva, C.; Hillesheim, J.C.; Hidalgo, C.; Belonohy, E.; Delabie, E.; Gil, L.; Maggi, C.F.; Meneses, L.; Solano, E.; Tsalas, M.
• Other Names: collab.
• Is Part Of: Nuclear fusion. Volume 56:Number 10(2016:Oct.)
• Publication Date: 2016-08-19
• Subjects: edge turbulence -- GAMs -- Doppler backscattering; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/10/106026
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Geodesic acoustic modes (GAMs) have been investigated in JET ohmic discharges using mainly Doppler backscattering. Characteristics and scaling properties of the GAM are studied. Time and spatial resolved measurements of the perpendicular velocity indicate that GAMs are located in a narrow layer at the edge density gradient region with amplitude corresponding to about 50% of the mean local perpendicular velocity. GAMs on JET appear to be regulated by the turbulence drive rather than by their damping rate. It is also shown that the GAM amplitude is ~20% larger in deuterium than in hydrogen plasmas.