Speaker
Manuel Garcia-Munoz
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/I5.013.pdf
Active Control of Alfvén Eigenmodes in Fusion Plasmas
M. Garcia-Munoz1, S. E. Sharapov2, E. Ascasibar3, A. Cappa3, L. Chen4,
J. Galdon-Quiroga1, J. M. García-Regaña3, J. Gonzalez-Martin1, W. W. Heidbrink5,
Ph. Lauber6, L. Sanchis-Sanchez1, P. Schneider6, J. Stober6, W. Suttrop6,
Y. Todo7, M. A. Van Zeeland8, F. Zonca9 and the AUG and MST1 Teams
1
Dept. of Atomic, Molecular and Nuclear Physics, Universidad de Sevilla, Sevilla, Spain,
2
CCFE, Culham Science Centre, Abingdon, UK, 3CIEMAT, Madrid, Spain, 4IFTS, Zhejiang
University, Hangzhou, China, 5Dept. of Physics and Astronomy, University of California,
Irvine, CA, USA, 6Max Planck Institut für Plasmaphysik, Garching, Germany,
7
National Institute for Fusion Science, Toki, Japan, 8General Atomics,
San Diego, CA, USA, 9ENEA, Frascati, Italy
Alfvén waves are magnetohydrodynamic fluctuations inherent to magnetized plasmas.
Gradients in the energetic particles’ distribution determine the resonant wave-particle energy
and momentum exchange. Burning plasmas in magnetically confined fusion devices are
prone to develop Alfvén Eigenmodes (AEs) that, if allowed to grow unabated, can cause an
important degradation of fusion performance through fast-ion redistribution. To obtain a
self-maintained burning plasma, fusion-born alpha particles must, however, be
well-confined. Recent breakthroughs in the diagnosis of the temporal evolution of the
energetic particles’ phase-space have allowed the identification of wave-particle interactions
that lead to a net fast-ion transport enabling the development of dedicated control techniques.
Several external actuators have shown their potential to mitigate or even suppress the AE
activity and associated fast-ion transport in tokamaks and stellarators. Most control
techniques aim at modifying the background kinetic and current profiles. Recent
experimental results have shown, however, that an active control of the fast-ion distribution,
i.e. AE drive directly, can be a robust and promising technique towards future burning
plasmas. Externally applied 3D fields and heating systems provide an excellent tool to tailor
the fast-ion distribution in phase-space, thus modifying their drive/damping through local
wave-particle interactions. Non-linear 3D hybrid kinetic-MHD simulations help to identify
the wave-particle resonances responsible for the observed AE drive/transport improving our
ability to develop robust control techniques for future burning plasmas. Recent experimental
and modelling results from a worldwide effort focused on addressing this important problem
will be presented. The prospects of each technique towards ITER will be discussed.
