Parameter dependence on the lower hybrid driven current in tokamaks

Uehara, Kazuya; Nagashima, Takashi*

An optimum efficiency and the current profile on the lower-hybrid driven current in tokamaks are estimated in half-experimental by the modified quasi-linear theory including the mode conversion effect, the accessibility condition and the non-linear effect of the parametric instability so as to predict the experimentally obtained flowing current. The spectrum gap is bridged by the gap parameter depending on the electron temperature and the rf power density. It is shown that for the JT-60 parameter an optimum N parallel of the rf wave must be less smaller for the higher electron temperature not to destroy the accessibility condition and the driving efficiency depends on the electron temperature. The survey is also performed for the LHCD of the ITER parameter.