Erlangen 2018 – scientific programme

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P: Fachverband Plasmaphysik

P 26: Magnetic Confinement II - Helmholtz Graduate School V

P 26.5: Talk

Thursday, March 8, 2018, 15:40–16:05, A 0.112

New insights into fast ion induced turbulence stabilization — •Alessandro Di Siena, Tobias Goerler, Hauke Doerk, Emanuele Poli, and Roberto Bilato — Max Planck Institute for Plasma Physics, Boltzmannstr.2, 85748 Garching, Germany

The beneficial effect of fast ions on plasma turbulence has been observed in several experimental discharges and in different tokamak devices, e.g. ASDEX Upgrade and JET. Such energetic particles, usually created by auxiliary heating systems such as external neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH) may strongly suppress plasma turbulence, possibly increasing the performance of future fusion reactors. Although, these findings have been reproduced in numerical gyrokinetic simulations the physics of the significant fast ion stabilisation is still mostly unknown and usually highlighted as nonlinear electromagnetic stabilisation. In the contribution at hand, a wave-energetic particle resonance stabilising mechanisms is presented with both gyrokinetic GENE simulations and a reduced Vlasov-Poisson theoretical model. Key parameters controlling the role of the fast ions are identified and various ways of optimising their beneficial impact are explored. Experimental evidences of this effect are shown and ITER extrapolations are drawn.