Plasma and Fusion Research

Volume 5, S1015 (2010)

Regular Articles

Potential Measurement with the 6-MeV Heavy Ion Beam Probe of LHD

Akihiro SHIMIZU, Takeshi IDO, Masaki NISHIURA, Shigetoshi NAKAMURA¹⁾, Harushisa NAKANO, Shinsuke OHSHIMA²⁾, Akimitsu NISHIZAWA, Masayuki YOKOYAMA, Yasuo YOSHIMURA, Shin KUBO, Takashi SHIMOZUMA, Hiroe IGAMI, Hiromi TAKAHASHI, Naoki TAMURA, Ichihiro YAMADA, Takashi MINAMI, Kazumichi NARIHARA, Tsuyoshi AKIYAMA, Tokihiko TOKUZAWA, Kenji TANAKA, Kazuo KAWAHATA, Kazuo TOI, Mitsutaka ISOBE, Fumitake WATANABE, Kunihiro OGAWA¹⁾, Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Katsuyoshi TSUMORI, Yasuhiko TAKEIRI, Osamu KANEKO, Shinji KATO, Mitsuhiro YOKOTA, Yasuji HAMADA and LHD Group

: National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292, Japan
1): Department of Energy Science and Engineering, Nagoya University, Nagoya 464-8603, Japan
2): Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan

(Received 3 February 2009 / Accepted 9 September 2009 / Published 26 March 2010)

Abstract

The potential in the plasma core of the Large Helical Device (LHD) was measured with the 6 MeV Heavy Ion Beam Probe (HIBP). The radial profile of the potential in the region where the normalized minor radius, ρ, is less than 0.5 was measured and the electric field obtained from the fitting function of the experimental data was compared with that calculated from neoclassical ambipolarity. The experimental results coincide well with the theoretical calculations. Negative pulses were observed in the potential signal in the inward shifted magnetic configuration. The time constants of these pulses were less than the energy confinement time. Potential fluctuations of the coherent modes were also observed, and one of their frequencies coincided with the geodesic acoustic mode (GAM). In this report, the present status of potential measurements with the HIBP system in LHD is described.

Keywords

Large Helical Device, heavy ion beam probe, potential, tandem accelerator, tandem analyzer

DOI: 10.1585/pfr.5.S1015

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References

[1] R.J. Groebner, K.H. Burrell, R.P. Seraydarian et al., Phys. Rev. Lett. 64, 3015 (1990).
[2] K. Ida, S. Hidekuma, Y. Miura, T. Fujita, M. Mori, K. Hoshino, N. Suzuki, T. Yamauchi et al., Phys. Rev. Lett. 65, 1364 (1990).
[3] T. Ido, K. Kamiya, Y. Miura, Y. Hamada, A. Nishizawa and Y. Kawasumi, Phys. Rev. Lett. 88, 055006 (2002).
[4] A. Fujisawa, H. Iguchi, T. Minami, Y. Yoshimura, H. Sanuki, K. Itoh, S. Lee, K. Tanaka et al., Phys. Rev. Lett. 82, 2669 (1999).
[5] A. Fujisawa, H. Iguchi, T. Minami, Y. Yoshimura, K. tanaka, K. Itoh, H. Sanuki, S. Lee, M. Kojima, S.-I. Itoh, M. Yokoyama, S. Kado, S. Okamura, R. Akiyama, K. Ida et al., Phys. Plasmas 7, 4152 (2000).
[6] T. Estrada, A. Alonso, A.A. Chmyga, N. Dreval, L. Eliseev, C. Hidalgo, A.D. Komarov, A.S. Kozachok et al., Plasma Phys. Control. Fusion 47, L57 (2005).
[7] K.H. Burrell, Phys. Plasmas 4, 1499 (1997).
[8] T.P. Crowley et al., IEEE Trans. Plasma Sci. 22, 291 (1994).
[9] T. Ido, A. Shimizu, M. Nishiura, A. Nishizawa, S. Katoh, K. Tsukada, M. Yokota, H. Ogawa, T. Inoue, Y. Hamada et al., Rev. Sci. Instrum. 77, 10F523 (2006).
[10] A. Shimizu, T. Ido, M. Nishiura, H. Nakano, I. Yamada, K. Narihara, T, Akiyama, T. Tokuzawa, K. Tanaka et al., J. Plasma Fusion Res. 2, S1098 (2007).
[11] M. Nishiura, T. Ido, A. Shimizu, S. Kato, K. Tsukada, A. Nishizawa, Y. Hamada, Y. Matsumoto et al., Rev. Sci. Instrum. 77, 03A537 (2006).
[12] T. Ido, A. Shimizu, M. Nishiura, Y. Hamada, S. Kato, A. Nishizawa and H. Nakano, J. Plasma Fusion Res. 2, S1100 (2007).
[13] G.A. Proca and T.S. Green, Rev. Sci. Instrum. 41, 1778 (1970).
[14] Y. Hamada, A. Fujisawa, H. Iguchi, A. Nishizawa and Y. Kawasumi, Rev. Sci. Instrum. 68, 2020 (1997).
[15] C.D. Beidler, W.D. D'haeseleer, Plasma Phys. Control. Fusion 37, 463 (1995).
[16] A. Fujisawa, H. Iguchi, H. Idei, S. Kubo, K. Matsuoka, S. Okamura, K. Tanaka, T. Minami, S. Ohdachi, S. Morita, H. Zushi et al., Phys. Rev. Lett. 81, 2256 (1998).
[17] A. Fujisawa, H. Iguchi, T. Minami, Y. Yoshimura, K. Tanaka, K. Itoh, H. Sanuki, S. Lee, M. Kojima, S.-I. Itoh et al., Phys. Plasmas 7, 4152 (2000).
[18] N. Winsor, J.L. Johnson and J.M. Dowson, Phys. Fluids 11, 2448 (1968).
[19] P.H. Diamond, S.-I. Itoh, K. Itoh and T.S. Hahm, Plasma Phys. Control. Fusion 47, R35 (2005).
[20] T. Ido, A. Shimizu, M. Nishiura, H. Nakano, S. Ohshima, S. Kato, Y. Hamada, Y. Yoshimura, S. Kubo, T. Shimozuma, H. Igami, H. Takahashi, K. Toi et al., Rev. Sci. Instrum. 79, 10F318 (2008).

This paper may be cited as follows:

Akihiro SHIMIZU, Takeshi IDO, Masaki NISHIURA, Shigetoshi NAKAMURA, Harushisa NAKANO, Shinsuke OHSHIMA, Akimitsu NISHIZAWA, Masayuki YOKOYAMA, Yasuo YOSHIMURA, Shin KUBO, Takashi SHIMOZUMA, Hiroe IGAMI, Hiromi TAKAHASHI, Naoki TAMURA, Ichihiro YAMADA, Takashi MINAMI, Kazumichi NARIHARA, Tsuyoshi AKIYAMA, Tokihiko TOKUZAWA, Kenji TANAKA, Kazuo KAWAHATA, Kazuo TOI, Mitsutaka ISOBE, Fumitake WATANABE, Kunihiro OGAWA, Kenichi NAGAOKA, Katsunori IKEDA, Masaki OSAKABE, Katsuyoshi TSUMORI, Yasuhiko TAKEIRI, Osamu KANEKO, Shinji KATO, Mitsuhiro YOKOTA, Yasuji HAMADA and LHD Group, Plasma Fusion Res. 5, S1015 (2010).