[Table of Contents]

Plasma and Fusion Research

Volume 2, S1051 (2007)

Regular Articles

Simultaneous Measurements of Proton Ratio and Beam Divergence of Positive-Ion-Based Neutral Beam in the Large Helical Device
Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Yasuhiko TAKEIRI, Yoshihide OKA, Katsuyoshi TSUMORI, Osamu KANEKO and LHD experimental group
National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
(Received 11 December 2006 / Accepted 18 April 2007 / Published 20 November 2007)

Abstract

A spectroscopy system was installed on the diagnostic neutral beam injector in LHD. The Hα lines spectrum emitted by full, half and one-third energy component are clearly observed, and the proton ratio and the beam divergence were estimated by the line intensity and the line width, respectively. The proton ratio of 85∼90 % is achieved in high arc power discharge. The beam divergence of them shows their minimum with the same perveance. It was experimentally confirmed that the spectroscopy system is useful for the monitor of the proton ratio and the divergence of the beam.

Keywords

diagnostic neutral beam, proton ratio, beam divergence, positive-ion-based neutral beam injector, beam emission

DOI: 10.1585/pfr.2.S1051

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References

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This paper may be cited as follows:

Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Yasuhiko TAKEIRI, Yoshihide OKA, Katsuyoshi TSUMORI, Osamu KANEKO and LHD experimental group, Plasma Fusion Res. 2, S1051 (2007).