The frequencies of driven global eigenmodes of the Alfven wave have been measured on the PETULA Tokamak during experiments on Lower Hybrid Wave Current Drive (LHCD). Small but significant and reproducible shifts in their resonant frequencies were measured, which varied depending on the LHCD r.f. power. Explanations for these frequency changes are discussed.
Plasma Physics and Controlled Fusion,
Vol. 29, no. 11 (Nov 1987), pp. 1631-1636