High power beam operation with the negative-ion based NBI for JT-60U

The negative-ion based NBI for JT-60U has been making efforts to increase beam power and beam energy since the operation started in March 1996. The NBI system has already operated negative ion beams of 14.3 A at 380 keV with deuterium and 18.4 A at 350 keV with hydrogen. In the beam injection into JT-60U, a deuterium neutral beam power of 3.6 MW at 350 keV has been injected for 0.9 sec, and plasma reactions against the high energy beam injection with the N-NBI have been confirmed to be in agreement with a theoretical prediction.