Non-inductive current drive experiments in JT-60U

Non-inductive current drive experiments by lower hybrid (LH) waves and neutral beams (NBs) in JT-60U are described with emphasis on current profile control. By phasings of LH multijunction launcher, the plasma internal inductance li was either increased by 0.04 or decreased by 0.13 from the ohmic value with 1.5 s, 3 MW LH waves. On the basis of this fundamental experiment, the internal inductance of the target plasma for NB injection was controlled by LH current drive shot by shot. We observed clear improvement in the energy confinement of the neutral beam heated plasma with the increase in li. Current profile control consistent with theory was also demonstrated by on-and off-axis tangential NBs. In addition, the profile of the plasma toroidal rotation was modified as inferred from the expected profile of NB momentum input. Combined full current drive of on-axis LH and off-axis NB current drives was also demonstrated.