Alpha particle-driven toroidal Alfvén eigenmodes in Tokamak Fusion Test Reactor deuterium–tritium plasmas: Theory and experiments

The toroidal Alfvén eigenmodes (TAE) in the Tokamak Fusion Test Reactor [K. Young et al., Plasma Phys. Controlled Fusion 26, 11 (1984)] deuterium–tritium plasmas are analyzed using the NOVA-K code [C. Z. Cheng, Phys. Rep. 211, 1 (1992)]. The theoretical results are compared with the experimental measurements in detail. In most cases, the theory agrees with the observations in terms of mode frequency, mode structure and mode stability. However, one mode with toroidal mode number n=2 is observed to be poloidally localized on the high field side of the magnetic axis with a mode frequency substantially below the TAE frequency.