When RF power PLHH near the lower hybrid frequency is injected into the ohmically heated plasma in the WT-2 tokamak, the RF-driven current is generated (Irf~-12 kA) and the plasma (ne~-3 x 1012 cm-3)is sustained by this current without ohmic current during the injection of PLhh- The efficiency ofRF current drive is obtained as ITf=0.06PWH/ne R (kA, kW, 1013 cm-3, m),where R is the major radius. The current 7rf is carried by suprathermal electrons which interact resonantly with lower hybrid waves. A high frequency instability and associated relaxation oscillation are observed, which can be suppressed by a simultaneous injection of the electron cyclotron heating power.
ASJC Scopus subject areas
- Physics and Astronomy(all)