MHD Spectroscopy of Fusion Plasmas by ECE-Imaging of Reversed-Shear Alfv\'en Eigenmodes
POSTER
Abstract
The spatial electron temperature data acquired using the electron cyclotron emission imaging (ECEI) diagnostic on \hbox{DIII-D} was used to detect and study the spatial structure of Alfv\'en eigenmodes present in reversed-shear plasmas. The $q$-profile and magnetic field topology of the plasma are deduced from the spatial mode structure and compared with measurements made using the motional Stark effect diagnostic. These results are compared with calculations of the RSAE mode structure obtained using the Nova, TAEFL, Gyro, GTC, and M3D codes with measured plasma profiles as input. The implications for MHD spectroscopy are discussed.
*Work supported in part by the US Department of Energy under DE-FG03-89ER51116 and DE-AC02-09CH11466 and the National Undergraduate Fellowship in Fusion Science and Engineering.