A diffusive empirical fast ion transport model using electron temperature fluctuation data

A novel data-driven method for inferring magneto-hydrodynamic-induced diffusive fast ion transport using normalized electron cyclotron emission temperature fluctuation measurements is reported. The model developed is found to reproduce experimental measurements from three levels of fast ion diagnostics for a single discharge at the DIII-D tokamak with strong Alfvén Eigenmode activity: the volumetric neutron rate, spatially resolved fast ion D−α spectra, and phase space resolved imaging neutral particle analyzer. The application of this method to a database of more than 30 DIII-D discharges finds the predicted neutron rates and stored energies agree with experiment with an accuracy of 12.5% and 8.5%, respectively, for shots with dominantly Alfvén Eigenmode based activity, and irregular agreement in the presence of strong tearing and kink mode activity.