Beam acceleration test in negative-ion based NBI system for JT-60U
Beam extraction and acceleration test in the Negative Ion Based Neutral Beam Injector for JT-60U has been started using one ion source that is designed to produce a 500 keV, 22 A D{sup {minus}} ion beam. Deuterium negative ions are produced in a cesium-seeded semi-cylindrical plasma generator and accelerated by a multi-aperture three-stage electrostatic accelerator. In the preliminary experiment of beam acceleration, the D{sup {minus}} ion beam of 13.5 A was successfully accelerated to 400 keV for a pulse duration of 0.12 s. The negative ion beam power was 5.4 MW. The operating gas pressure in the plasma generator was as low as 0.22 Pa. The highest energy beam of 460 keV, 2.4 A, 0.44 s was also obtained. The ratio of extracted electron current to extracted negative ion current is estimated Ie/I{sub D{sup {minus}}}{lt}1. It was confirmed that the electron leak from the extractor to the accelerator is suppressed efficiently by the effects of biassing, electron trapping gap and magnetic field. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 451329
- Report Number(s):
- CONF-9510304-; ISSN 0094-243X; TRN: 97:005659
- Journal Information:
- AIP Conference Proceedings, Vol. 380, Issue 1; Conference: Joint meeting of the 7. international symposium on the production and neutralization of negative ions and beams and the 6. European workshop on the production and application of light negative ions, Upton, NY (United States), 23-27 Oct 1995; Other Information: PBD: Jul 1996
- Country of Publication:
- United States
- Language:
- English
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