Heating and Current Drive by N-NBI in JT-60U and LHD

Two pilot facilities of advanced negative-ion-based neutral beam injection heating system have been working successfully on the JT-60U tokamak and the LHD heliotron in Japan. These were the first applications of negative-ion technology to the production of high current neutral beam for plasma heating as well as current drive. High energy deuterium beam of 400 keV (5.8 MW) was injected in JT-60U for efficient current drive, and high power hydrogen beam of 9.0 MW (160 keV) was injected in LHD producing high performance plasmas. These results demonstrate the feasibility of negative ion beam system for future fusion reactors such as ITER.