@article{8097,
  author = {J. Rasmussen and S. K. Nielsen and M. Stejner and J. Galdon-Quiroga and M. García-Muñoz and B. Geiger and A. S. Jacobsen and F. Jaulmes and S. B. Korsholm and N. Lazanyi and F. Leipold and F. Ryter and M. Salewski and M. Schubert and J. Stober and D. Wagner and ASDEX Upgrade Team and EUROfusion MST1 Team},
  title = {Collective Thomson scattering measurements of fast-ion transport due to sawtooth crashes in ASDEX Upgrade},
  abstract = {Sawtooth instabilities can modify heating and current-drive profiles and potentially increase fast-ion losses. Understanding how sawteeth redistribute fast ions as a function of sawtooth parameters and of fast-ion energy and pitch is hence a subject of particular interest for future fusion devices. Here we present the first collective Thomson scattering (CTS) measurements of sawtooth-induced redistribution of fast ions at ASDEX Upgrade. These also represent the first localized fast-ion measurements on the high-field side of this device. The results indicate fast-ion losses in the phase-space measurement volume of about 50% across sawtooth crashes, in good agreement with values predicted with the Kadomtsev sawtooth model implemented in TRANSP and with the sawtooth model in the EBdyna_go code. In contrast to the case of sawteeth, we observe no fast-ion redistribution in the presence of fishbone modes. We highlight how CTS measurements can discriminate between different sawtooth models, in particular when aided by multi-diagnostic velocity-space tomography, and briefly discuss our results in light of existing measurements from other fast-ion diagnostics.
},
  year = {2016},
  journal = {Nuclear Fusion},
  volume = {56},
  pages = {112014},
  url = {http://www.euro-fusionscipub.org/wp-content/uploads/eurofusion/WPMST1PR16_14817_submitted.pdf},
  doi = {10.1088/0029-5515/56/11/112014},
  language = {eng},
}