Negative-ion based NBI system for JT-60U

Abstract

A 500 keV negative-ion based NBI system is under construction for NB current drive and plasma core heating in high density plasmas in JT-60U. Part of the beamline and the high voltage power supply required for a verification test of an ion source have completed in March 1995. After having done a high potential test of the power supply, the negative-ion generation and acceleration tests have started in June 1995 aiming at deuterium beams of 500 keV, 22 A. In initial experiment, deuterium negative-ion beams of 410 keV, 6.1 A (2.5 MW) for 0.2 sec, so far, have been achieved. This is the world highest D/sup -/ current and negative ion beam power. The construction of the total system will be completed by the beginning of 1996, and the beam injection will start in March 1996.