TITLE:
Estimation of Ion Beam Trajectories for a Slot Aperture Accelerator of Long-Pulse Ion Source in Neutral Beam Injector
AUTHORS:
Doo-Hee Chang
KEYWORDS:
Long Pulse Ion Source; Slot Aperture Accelerator; EAST; Neutral Beam Injection; Ion Beam Trajectory; IGUN Code
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.3 No.2,
June
19,
2013
ABSTRACT:
A neutral beam injection (NBI) system has been developed and is
being tested for an Experimental Advanced Superconducting Tokamak (EAST)
device. The NBI system needs to be employed for an auxiliary heating and
current drive of EAST plasmas. The first long pulse ion source (LPIS-1) has
been installed in the neutral beam test bed (NBTB) system, and the performance
is being tested in the NBTB. The LPIS-1 consists of a magnetic bucket plasma
generator with multipole cusp-fields and a set of tetrode accelerators with
slit-type apertures (a transparency of 60%). The ion beam trajectories of the
accelerator column are estimated for the LPIS-1, including an original
structure, with the change of slit aperture distance, plasma grid shape, grid
gap distance, and voltage ratio between a plasma grid and a gradient grid using
the IGUN code. This kind of calculation for the ion beam trajectory may be
useful for the estimation of beam extraction characteristics and the direction
of accelerator upgrade or modification, prior to the experiments of ion beam
extraction.