A bump-on-tail model for Alfvén eigenmodes in toroidal plasmas
2015 (English)Conference paper (Other academic)
Presented is a numerical model for solving the nonlinear dynamics of Alfvén eigenmodes and energetic ions self-consistently. The model is an extension of a previous bump-on-tail model [1,2], taking into account particle orbits and wave fields in realistic toroidal geometries. The model can be used in conjunction with an orbit averaged Monte Carlo code that handles heating and current drive (similar to e.g. the SELFO code), which enables modeling of the effects of MHD activity on plasma heating. For rapid particle tracing, the unperturbed guiding center orbits are described with canonical action-angle coordinates , and the perturbed Hamiltonian for wave-particle interaction is included as Fourier components in the same angles . This allows the numerical integrator to take time steps over several transit periods, which efficiently resolves the relevant time scales for nonlinear wave-particle dynamics. The wave field is modeled by a static eigenfunction and a dynamic complex amplitude driven by the interactions with resonant and non-resonant particles.
 E. Tholerus, T. Hellsten and T. Johnson, Phys. Plasmas 22, 082106 (2015)
 S. Tholerus, T. Hellsten and T. Johnson, J. Phys.: Conf. Ser. 561, 012019 (2014)
 A. N. Kaufman, Phys. Fluids 15, 1063 (1972)
 H. L. Berk, B. N. Breizman and M. S. Pekker, Nucl. Fusion 35, 1713 (1995)
Place, publisher, year, edition, pages
International Atomic Energy Agency, 2015.
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-192940OAI: oai:DiVA.org:kth-192940DiVA: diva2:973934
14th IAEA Technical Meeting on “Energetic Particles in Magnetic Confinement Systems”, Vienna, Austria, September 1 - 4, 2015
FunderSwedish Research Council, 621-2011-5387
QC 201609272016-09-232016-09-232016-09-27Bibliographically approved