The toroidal plasma current is started up by rf power alone and is ramped up to above 20 kA in a low density plasma. The fraction ε
R of injected LHW power is converted into poloidal magnetic field energy and its maximum value is about 5 %. For high density cases, a quasi-steady state discharge is obtained and the figure of merit η
CD for steady current drive by LHW is about 0.04 × 10
19 (A·m
-2/W). The direct loss of fast electrons from the plasma is very large and results in the low ε
R and η
CD in our experiments.
抄録全体を表示