Novel Alfv\'{e}n eigenmode structure measurements in NSTX via reflectometry

Novel measurements of toroidicity-induced (TAE), global (GAE) and compressional (CAE) Alfv\'{e}n eigenmode structure have been obtained in NSTX with a recently upgraded 16 channel array of fixed frequency quadrature reflectometers. Measurements of TAE ($\sim $ 50 kHz $<$ f $< \quad \sim $ 150 kHz) phase show significant radial variation in the midplane, indicating radial propagation. This distinctly contrasts with expectation from ideal MHD since the plasma is up-down symmetric. The structure of GAEs and CAEs (f $< \quad \sim $ 400 kHz) have been obtained for the first time in the core of NSTX high power beam-heated H-mode plasmas. The GAEs have core-peaked, broad radial structure, while the CAEs are strongly core-localized, with substantially higher amplitude. GAEs, which are observed to correlate with enhanced thermal electron transport in such plasmas [D Stutman, PRL 102 115002 (2009)], are hypothesized to be the cause due to their core localization and capacity to resonantly modify electron orbits. The observed CAE structures indicate they must also be considered.