Fishbone-induced fast-ion transport in NSTX

Fast-ions from neutral beams excite bursts of large amplitude (\textit{$\delta $n}/$n \quad \sim $ 1{\%}) fishbones -- low $f$ ($\sim $ 25 kHz) global modes -- in NSTX. The bursts correlate with significant fast-ion loss, indicated by large ( $>$ $\sim $ 10{\%} ) drops in neutron flux. The role of fishbones in the loss is probed via theoretical tools, measurement and modeling. The radial structure of the fishbone density perturbation -- measured with 5 fixed-frequency reflectometers -- has been compared to the modeled reflectometer response to eigenmodes found by the NOVA-K ideal stability code. Ideally unstable internal kinks, expected to have structure similar to fishbones, were considered. The best match will be used with the ORBIT guiding-center code to estimate fast-ion redistribution and loss using an intial distribution from the TRANSP Monte Carlo beam deposition code. The perturbation to the population will be compared with measured changes in the flux and spectrum of energetic neutrals via modeling.