[Table of Contents]

Plasma and Fusion Research

Volume 2, S1098 (2007)

Regular Articles

Present Status in the Development of 6 MeV Heavy Ion Beam Probe on LHD
Akihiro SHIMIZU, Takeshi IDO, Masaki NISHIURA, Haruhisa NAKANO, Ichihiro YAMADA, Kazumichi NARIHARA, Tsuyoshi AKIYAMA, Tokihiko TOKUZAWA, Kenji TANAKA, Kazuo KAWAHATA, Hiroe IGAMI, Yasuo YOSHIMURA, Takashi SHIMOZUMA, Shin KUBO, Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Katsuyoshi TSUMORI, Yasuhiko TAKEIRI, Osamu KANEKO, Shinji KATO, Mitsuhiro YOKOTA, Kiwamu TSUKADA, Hideki OGAWA, Akimitsu NISHIZAWA1), Yasuji HAMADA and LHD group
National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
1)
Tono Geoscience Center, Japan Atomic Energy Agency, Toki, Gifu 509-5102, Japan
(Received 13 December 2006 / Accepted 6 August 2007 / Published 20 November 2007)

Abstract

In order to measure the potential in Large Helical Device (LHD), we have been developing a heavy ion beam probe (HIBP). For probing beam, gold beam is used, which is accelerated by a tandem accelerator up to the energy of 6 MeV. The experiments for calibration of beam orbit were done, and experimental results were compared with orbit calculations. The experimental results coincided fairly with the calculation results. After the calibration of the beam orbit, the potential in plasma was tried to measure with the HIBP. The experimental data showed positive potential in a neutral beam heating phase on the condition of ne ∼ 5 × 1018 m-3, and the increase of potential was observed when the additional electron cyclotron heating was applied to this plasma. The time constant for this increase was about a few tens ms, which was larger than a theoretical expectation. In the spatial position of sample volume, we might have an ambiguity in this experiment.

Keywords

potential measurement, heavy ion beam probe (HIBP), Large Helical Device, tandem accelerator

DOI: 10.1585/pfr.2.S1098

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This paper may be cited as follows:

Akihiro SHIMIZU, Takeshi IDO, Masaki NISHIURA, Haruhisa NAKANO, Ichihiro YAMADA, Kazumichi NARIHARA, Tsuyoshi AKIYAMA, Tokihiko TOKUZAWA, Kenji TANAKA, Kazuo KAWAHATA, Hiroe IGAMI, Yasuo YOSHIMURA, Takashi SHIMOZUMA, Shin KUBO, Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Katsuyoshi TSUMORI, Yasuhiko TAKEIRI, Osamu KANEKO, Shinji KATO, Mitsuhiro YOKOTA, Kiwamu TSUKADA, Hideki OGAWA, Akimitsu NISHIZAWA, Yasuji HAMADA and LHD group, Plasma Fusion Res. 2, S1098 (2007).