Abstract. The low voltage startup plasma has been studied in the HT-7 ( R = 1.22m, a = 0.27m) tokamak with Ion Cyclotron Range of Frequency (ICRF) wave and Lower Hybrid Wave (LHW) for pre-ionization. Successful low loop voltage startup experiment results had been obtained with ICRF (about 150kW) and LHW (about 200kW), for example, E 0.5V/m (with), E 2.5V/m (without). The ICRF and LHW assisted startup experiments on HT-7 have been successful in showing the positive effect on plasma pre-ionization and target plasma formation; reduction of the volt-second consumption during the period of the breakdown and the ramp-up; reduction of the loop voltage in the breakdown; and setting of a beneficial ramp-up rate for the whole superconducting tokamak.
IAEA 2001