MEASUREMENTS OF ELECTRON DYNAMICS DURING LOWER-HYBRID CURRENT DRIVE

The method of oblique-incidence electron cyclotron wave transmission i s studied in a lower hybrid driven tokamak plasma. Cyclotron wave tran smission measures the asymmetry in the suprathermal electron parallel- momentum distribution which may be integrated to obtain a measure of t he suprathermal electron current. Questions of resolution, sensitivity , and technique am addressed experimentally. The results indicate that cyclotron wave transmission is well suited for studies of electron ve locity-space phenomena and may be used to detect small perturbations i n the suprathermal current.