Construction of negative-ion based NBI for JT-60U

Kawai, Mikito; Akino, Noboru; Ebisawa, Noboru; Honda, Atsushi; Ito, Takao; Kazawa, Minoru; Kuriyama, Masaaki; Mogaki, Kazuhiko; Oga, Tokumichi; Ohara, Hiroshi; Okumura, Yoshikazu; Sato, Fujio*; Usui, Katsutomi; Yamamoto, Masahiro; Watanabe, Kazuhiro

The world's first negative-ion based neutral beam injector(N-NBI) system has been developed for studies of non-inductive current drive and plasma core heating with high energy neutral beam injection in higher density plasma. Construction of the N-NBI system for JT-60U was completed in March 1996. The system is composed of a beamline with two ion souces, a set of ion source power supllies, control system and auxiliary sub-system such as cooling water, refrigeration and vaccum system. In July 2001, deuterium neutral beam injection of 400keV and 5.8MW into JT-60U plasma was achieved. In order to increase both beam power and energy we have to go on more improvement of the N-NBI.