Modeling the dynamics of toroidal Alfvén eigenmodes
2013 (English)Conference paper (Other academic)
A model describing nonlinear dynamics of a single Alfvén eigenmode excited by an inverted energy distribution of energetic ions is presented, suitable for drift orbit averaged Monte Carlo codes. The nonlinear dynamics of the wave mode is modeled with a complex wave amplitude, and is characterized by the formation of coherent structures in phase space, caused by wave-particle interaction. The transition to a quasilinear regime is modeled with a phenomenological decorrelation of the wave-particle phase. As the decorrelation is increased the coherent phase-space structures diminishes, and frequency chirping events in the marginal stability region is limited. The strength of the decorrelation modifies the saturation level and saturation time of the eigenmode amplitude.
Place, publisher, year, edition, pages
International Atomic Energy Agency, 2013.
Monte Carlo model, wave-particle interactions, bump-on-tail instabilities, toroidal Alfvén eigenmodes, nonlinear dynamics
Fusion, Plasma and Space Physics
Research subject Physics
IdentifiersURN: urn:nbn:se:kth:diva-161926OAI: oai:DiVA.org:kth-161926DiVA: diva2:796614
13th IAEA Technical Meeting on “Energetic Particles in Magnetic Confinement Systems”, Beijing, China, September 17 - 20, 2013
QC 201503192015-03-192015-03-192016-09-27Bibliographically approved