title: Operating characteristics of a new ion source for KSTAR neutral beam injection system.
abstract: A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.
authors.affiliation: Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Tae-Seong
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Doo-Hee
authors.initials: DH
authors.lastname: Chang
authors.affiliation: Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Kwang Won
authors.initials: KW
authors.lastname: Lee
authors.affiliation: Department of Nuclear Fusion Engineering Development, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea.
authors.forename: Sang-Ryul
authors.initials: SR
authors.lastname: In