Driven current and plasma property during LHCD in the HT-6B tokamak

LHCD experiments have been successfully carried out in tokamaks since 1980's. In IPP Hefei there is a LHCD project including a 100 kw power level experiment on HT-6B tokamak, a 500 kW experiment on HT-6M tokamak and a 1 MW Program on the HT-7 tokamak which is a superconductive machine under construction. The experiment on HT-6B has been carried on for a year. The microwave source consists of a magnetron with 100 kW output power, 2.45 GHz frequency and pulse length 100 mSec and a multijunction antenna composed by 8 subwaveguides. LHCD experiment has been performed under the conditions of with or without inductive DC electrical field. The dependence of the coupling between the launcher and the plasma to the operation parameters, such as Bt, Ne, plasma displacement, was obtained. The driven fast electrons were measured. The efficiency of LHCD was obtained. The MHD instabilities including sawtooth oscillations changed during LHCD and the amplification or suppression of the modes depended on the conditions of LHCD. 3 refs, 12 figs