Abstract
Fast-ion driven Alfvén waves with frequency close to the ion cyclotron frequency (f=0.58fci) excited by energetic ions from a neutral beam are stabilized via a controlled energetic ion density ramp for the first time in a fusion research plasma. The scaling of wave amplitude with injection rate is consistent with theory for single mode collisional saturation near marginal stability. The wave is identified as a shear-polarized global Alfvén eigenmode excited by Doppler-shifted cyclotron resonance with fast ions with sub-Alfvénic energetic ions, a first in fusion research plasmas.
Original language | English |
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Article number | 155001 |
Journal | Physical Review Letters |
Volume | 126 |
Issue number | 15 |
DOIs | |
State | Published - Apr 16 2021 |
Externally published | Yes |