Development of the JT‐60SA Neutral Beam Injectors

This paper describes the development of the neutral beam (NB) systems on JT-60SA, where 30-34 MW D-0 beams are required to be injected for 100 s. A 30 s operation of the NB injectors suggests that existing beamline components and positive ion sources on JT-60U can be reused without the modifications on JT-60 SA. The JT-60 negative ion source was modified to improve the voltage holding capability, which leads to a successful acceleration of 2.8 A H- ion beam up to 500 keV of the rated acceleration energy for JT-60SA.