Effects of Toroidal Rotation Sshear on Toroidicity-induced Alfven Eigenmodes in the National Spherical Torus Experiment

Podesta, M ; Fredrickson, E D ; Gorelenkov, N N ; LeBlanc, B P ; Heidbrink, W W ; Crocker, N A ; Kubota, S

关键词: NSTX DEVICE;    TOROIDAL CONFIGURATION;    ROTATION;    SHEAR;    ALFVEN WAVES;    KINETICS Alfven waves;    Wave Damping;    Tokamaks;    NSTX;    Spherical Torus;   

DOI  :  10.2172/988878
RP-ID  :  PPPL-4541
PID  :  OSTI ID: 988878
Others  :  TRN: US1007422

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

The effects of a sheared toroidal rotation on the dynamics of bursting Toroidicity-induced Alfven eigenmodes are investigated in neutral beam heated plasmas on the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40 557 (2000)]. The modes have a global character, extending over most of the minor radius. A toroidal rotation shear layer is measured at the location of maximum drive for the modes. Contrary to results from other devices, no clear evidence of increased damping is found. Instead, experiments with simultaneous neutral beam and radio-frequency auxiliary heating show a strong correlation between the dynamics of the modes and the instability drive. It is argued that kinetic effects involving changes in the mode drive and damping mechanisms other than rotation shear, such as continuum damping, are mostly responsible for the bursting dynamics of the modes.