17th Technical Meeting on Energetic Particles and Theory of Plasma Instabilities in Magnetic Confinement Fusion

Measurements of Alfven Eigenmode stability in JET D and T plasmas

9 Dec 2021, 16:10

20m

Virtual Event

Oral Collective Phenomena Collective Phenomena (Alfven and Low Frequency Modes)

Speaker

Dr Roy Tinguely (MIT PSFC)

Description

We present recent measurements and analyses of Alfven Eigenmode (AE) stability in JET D and T plasmas. Stable AEs are resonantly excited by an array of eight in-vessel, toroidally-spaced antennas with independent power and phasing. Databases of stable AE frequencies, net damping rates $\gamma <0$, and toroidal mode numbers have been assembled for various isotope mixes, and trends are explored. In addition, we highlight two distinct cases when radiative and collisional damping dominate the experimentally measured damping rates, confirmed by MHD modeling. Unstable AEs – including low frequency BAEs to high frequency EAEs – from approximately 2000 plasmas have been compiled into a database; trends in the saturation amplitudes, growth rates $\gamma >0$, and poloidal/toroidal mode numbers are investigated. Finally, we hope to show preliminary results from JET’s DT campaign, from which the contribution of alpha drive to AE stability could be assessed.

Presentation materials

Tinguely_IAEA-EP2021_slides_211209_toShare.pdf