EXPERIMENTAL-OBSERVATION OF RF DRIVEN PLASMA-FLOW IN THE PHAEDRUS-T TOKAMAK

We have observed frequency shifts of the 2/1 tearing mode in a tokamak that are consistent with injecting momentum with low frequency rf wav es. The 2/1 frequency increased for current drive antenna phasing, dec reased for anticurrent drive phasing, and was linear with rf power and driven current. The change in the toroidal velocities derived from th e frequency shifts and the calculated rf momentum is consistent. The f requency change also increased with magnetic field, independent of ant enna phasing. This is the first demonstration of modifying the 2/1 fre quency through rf momentum input.