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Energetic negative ion source for fusion at NIFS (invited)

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.1146854· OSTI ID:279527
; ; ; ; ; ; ;  [1];  [2]; ;  [3]
  1. National Institute for Fusion Science, Nagoya 464-01 (Japan)
  2. Department of Electrical Engineering, Faculty of Engineering, Tohoku University, Aoba, Sendai, 980-77 (Japan)
  3. The Graduate University for Advanced Studies, Oroshi-cho, Toki-shi, Gifu, 509-02 (Japan)
Large high current hydrogen negative ion sources have been developed for the negative ion based neutral beam injector of the Large Helical Device (LHD) at NIFS. The prototype of the negative ion source is required to deliver a negative ion beam of 45 A at the beam energy of 125 keV. The optimization of 1/3 scale ion sources which are multicusp ion source with a rod and an external magnetic filter, respectively, has been investigated for the operation parameter of the plasma source. A total H{sup {minus}} current of 16 A is extracted at an operating pressure of 0.9{endash}0.45 Pa with Cs seeding operation. Negative hydrogen ion current is proportional to the input arc power and a beam current density of 45 mA/cm{sup 2} is attained. The beam extraction and acceleration characteristics are studied for a single-stage and a two-stage acceleration electrode. A beam divergence angle of 5 mrad is obtained. The results of research and development of a hydrogen negative ion source at NIFS will be reviewed. {copyright} {ital 1996 American Institute of Physics.}
OSTI ID:
279527
Journal Information:
Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 3 Vol. 67; ISSN 0034-6748; ISSN RSINAK
Country of Publication:
United States
Language:
English