Measurement of sawtooth induced fast ion transport on DIII-D with a suite of imaging energetic particle diagnostics

Transport of neutral beam generated fast ions in the presence of sawtooth crashes is investigated experimentally at the DIII-D with a suite of newly developed imaging energetic particle diagnostics, which includes two Imaging Neutral Particle Analyzers (INPAs) and one Imaging Fast-Ion D-Alpha (IFIDA) diagnostic. The INPAs and IFIDA measure fast ions that charge exchange with injected beam neutrals and thus provide the local fast-ion distribution. The two INPAs are sensitive to passing and trapped fast ions with energy > 20 keV. The IFIDA integrates fast-ion density in the energy range of 40-80 keV and provides a spatial profile of passing fast-ion density with high spatial resolution. The INPA and IFIDA images before and after sawteeth show that high energy (E>40 KeV) passing fast ions are strongly redistributed from the core to the region outside of the q=1 surface, and the central fast ion density can be reduced by ~30%. Lower energy (E<40 keV) passing fast ions have a similar trend, but the relative change is <10%. The trapped particles in all energies are weakly affected, and a few percent increase of trapped particles in the region just outside the q=1 surface is observed. Tomographic inversion of the fast-ion distribution as well as the comparison with different sawtooth models will be presented.