Measurements of plasma rotation in tokamak LT-3

Rotation of the plasma in LT-3 has been measured from the Doppler shift of lines emitted by ionized oxygen impurities. In stable discharges, toroidal rotation of the ions in the direction of the discharge current was measured at velocities of up to 5 km · s −1 , while poloidal rotation was observed in the electron diamagnetic drift direction, reaching linear velocities of 1.6 km · s −1 at a minor radius of 5 cm. In unstable discharges, the plasma rotation collapses at the disruptions, and then re-appears as the magnetic surfaces are reformed.