Lq. Hu et al., Beam divergence and power loading on the beamline components of the negative-ion based NBI system for JT-60U, FUSION ENG, 54(2), 2001, pp. 321-330
In JT-60U, a high-energy neutral beam injection (NBI) program using negativ
e-ion based NBI (N-NBI) for non-inductive current drive and core plasma hea
ting studies in high-density plasma has progressed. The target performance
of the N-NBI is a neutral beam injection power of 10 MW for 10 s at 500 keV
. A neutral beam power of 5.2 MW at 350 keV with deuterium has already been
injected into JT-60U plasma. The beam divergence and power loading onto th
e beamline components are two important items to evaluate beam performance.
The beam divergence, estimated roughly from heat loads at the beam drift d
uct in beam injection experiments into JT-60U plasma, was around 4 mrad for
the horizontal direction and 6 mrad for the vertical direction, which were
close to the design values of 5 mrad. The power loading on beamline compon
ents were reasonable as compared with the design value. (C) 2001 Elsevier S
cience B.V. All rights reserved.