[Table of Contents]

Plasma and Fusion Research

Volume 4, 027 (2009)

Regular Articles

Extension of Improved Particle and Energy Confinement Regime in the Core of LHD Plasma
Osamu KANEKO, Masayuki YOKOYAMA, Mikiro YOSHINUMA, Ken-ichi NAGAOKA, Katsumi IDA, Ryuichi SAKAMOTO, Tsuyoshi AKIYAMA, Naoko ASHIKAWA, Hirotaka CHIKARAISHI, Masahiko EMOTO, Hisamichi FUNABA, Pavel GONCHAROV, Motoshi GOTO, Takuya GOTO, Shinji HAMAGUCHI, Katsuji ICHIGUCHI, Takeshi IDO, Hiroe IGAMI, Katsunori IKEDA, Shinsaku IMAGAWA, Mitsutaka ISOBE, Kimitaka ITOH, Akifumi IWAMOTO, Ryutaro KANNO, Hiroshi KASAHARA, Naohiro KASUYA, Daiji KATO, Kazuo KAWAHATA, Masahiro KOBAYASHI, Shin KUBO, Ryuhei KUMAZAWA, Ryuji MAEKAWA, Suguru MASUZAKI, Toshiyuki MITO, Jun-ichi MIYAZAWA, Naoki MIZUGUCHI, Tomohiro MORISAKI, Shigeru MORITA, Gen MOTOJIMA, Sadatsugu MUTO, Takashi MUTOH, Yoshio NAGAYAMA, Noriyoshi NAKAJIMA, Yukio NAKAMURA, Hideya NAKANISHI, Kazumichi NARIHARA, Yoshiro NARUSHIMA, Kiyohiko NISHIMURA, Masaki NISHIURA, Tetsuhiro OBANA, Satoshi OHDACHI, Nobuyoshi OHYABU, Masaki OSAKABE, Tetsuo OZAKI, Byron J. PETERSON, Akio SAGARA, Kenji SAITO, Satoru SAKAKIBARA, Shinsuke SATAKE, Kuninori SATO, Tetsuo SEKI, Akihiro SHIMIZU, Takashi SHIMOZUMA, Mamoru SHOJI, Shigeru SUDO, Hideo SUGAMA, Chihiro SUZUKI, Yasuhiro SUZUKI, Hiromi TAKAHASHI, Kazuya TAKAHATA, Yasuhiko TAKEIRI, Hitoshi TAMURA, Naoki TAMURA, Kenji TANAKA, Shinichiro TODA, Kazuo TOI, Masayuki TOKITANI, Tokihiko TOKUZAWA, Katsuyoshi TSUMORI, Kiyomasa WATANABE, Ichihiro YAMADA, Hiroshi YAMADA, Osamu YAMAGISHI, Nagato YANAGI, Shinji YOSHIMURA, Yasuo YOSHIMURA and Akio KOMORI
National Institute for Fusion Science, Toki 509-5292 Japan
(Received 1 September 2008 / Accepted 23 April 2009 / Published 4 June 2009)

Abstract

Recent two major topics of Large Helical Device (LHD) towards fusion relevant conditions, high-density operation and high-ion-temperature operation, are reported. Super dense core plasma was obtained by the combination of repetitive hydrogen ice pellet injection and high power neutral beam injection (NBI) heating. A very peaked density profile with the highest central density of 1.1 × 1021 m-3 was produced showing that the particle transport was suppressed very well in the plasma core. The spatial density profile varies as the position of magnetic axis (Rax), and the steepest profile is obtained at Rax = 3.95 m. The highest central ion temperature of 5.6 keV was obtained in hydrogen plasma at electron density of 1.6 × 1019 m-3 by NBI, where a peaked ion-temperature profile with internal ion energy transport barrier was observed. The profile of electron temperature did not change much and was broad even when the ion temperature had a peaked profile. The central ion temperature is higher than the electron temperature, which is a new operation regime of LHD. High central ion temperature accompanied strong toroidal rotation and an extreme hollow profile of carbon ions (impurity hole). These steep temperature profiles were obtained so far at around Rax = 3.6 m. The compatibility between particle and energy confinement is a new issue of LHD to explore a new operation regime for attractive fusion reactor.

Keywords

helical system, density limit, internal diffusion barrier, internal transport barrier, plasma rotation, impurity hole

DOI: 10.1585/pfr.4.027

Full Text

PDF format (2.5Mbytes) PDF Download

References

  • [1] A. Iiyoshi et al., Fusion Technol. 17, 169 (1990).
  • [2] O. Motojima et al., Nucl. Fusion 47, S668 (2007).
  • [3] T. Mutoh et al., J. Plasma Fusion Res. 81, 229 (2005).
  • [4] T. Morisaki et al., Fusion Sci. Technol. 50, 216 (2006).
  • [5] K. Saito et al., J. Nucl. Mater. 363, 1323 (2007).
  • [6] K.Y. Watanabe et al., Nucl. Fusion 45, 1247 (2005).
  • [7] S. Sakakibara et al., Plasma Phys. Control. Fusion 44, A217 (2002).
  • [8] O. Kaneko et al., Phys. Plasmas 9, 2020 (2002).
  • [9] N. Ohyabu et al., Phys. Rev. Lett. 97, 05502 (2006).
  • [10] T. Morisaki et al., Phys. Plasmas 14, 056113 (2007).
  • [11] R. Sakamoto et al., Plasma Fusion Res. 2, 047 (2007).
  • [12] R. Sakamoto et al., Nucl. Fusion 41, 381 (2001).
  • [13] S. Sudo et al., Nucl. Fusion 30, 11 (1990).
  • [14] J. Miyazawa et al., Nucl. Fusion 48, 015003 (2008).
  • [15] S. Toda and K. Itoh, Plasma Fusion Res. 3, S1069 (2008).
  • [16] K. Ida et al., Phys. Rev. Lett. 86, 5297 (2001).
  • [17] T. Shimozuma et al., Plasma Phys. Control. Fusion 45, 1183 (2003).
  • [18] Y. Takeiri et al., Fusion Sci. Technol. 46, 106 (2004).
  • [19] M. Yokoyama et al., Nucl. Fusion 47, 1213 (2007).
  • [20] Y. Takeiri et al., Nucl. Fusion 47, 1078 (2007).
  • [21] S. Murakami et al., Fusion Sci. Technol. 46, 241 (2004).
  • [22] C.D. Beidler and W.D. D'haeseleer, Plasma Phys. Control. Fusion 37, 463 (1995).
  • [23] K. Ida et al., Nucl. Fusion 45, 391 (2005).
  • [24] M. Yoshinuma et al., EX/P5-1, 22nd IAEA Fusion Energy Conference, Geneva (2008), submitted to Nucl. Fusion.
  • [25] K. Tanaka et al., Fusion Sci. Technol. 51, 97 (2007).
  • [26] K. Ida et al., Phys. Plasmas 16, 056111 (2009).

This paper may be cited as follows:

Osamu KANEKO, Masayuki YOKOYAMA, Mikiro YOSHINUMA, Ken-ichi NAGAOKA, Katsumi IDA, Ryuichi SAKAMOTO, Tsuyoshi AKIYAMA, Naoko ASHIKAWA, Hirotaka CHIKARAISHI, Masahiko EMOTO, Hisamichi FUNABA, Pavel GONCHAROV, Motoshi GOTO, Takuya GOTO, Shinji HAMAGUCHI, Katsuji ICHIGUCHI, Takeshi IDO, Hiroe IGAMI, Katsunori IKEDA, Shinsaku IMAGAWA, Mitsutaka ISOBE, Kimitaka ITOH, Akifumi IWAMOTO, Ryutaro KANNO, Hiroshi KASAHARA, Naohiro KASUYA, Daiji KATO, Kazuo KAWAHATA, Masahiro KOBAYASHI, Shin KUBO, Ryuhei KUMAZAWA, Ryuji MAEKAWA, Suguru MASUZAKI, Toshiyuki MITO, Jun-ichi MIYAZAWA, Naoki MIZUGUCHI, Tomohiro MORISAKI, Shigeru MORITA, Gen MOTOJIMA, Sadatsugu MUTO, Takashi MUTOH, Yoshio NAGAYAMA, Noriyoshi NAKAJIMA, Yukio NAKAMURA, Hideya NAKANISHI, Kazumichi NARIHARA, Yoshiro NARUSHIMA, Kiyohiko NISHIMURA, Masaki NISHIURA, Tetsuhiro OBANA, Satoshi OHDACHI, Nobuyoshi OHYABU, Masaki OSAKABE, Tetsuo OZAKI, Byron J. PETERSON, Akio SAGARA, Kenji SAITO, Satoru SAKAKIBARA, Shinsuke SATAKE, Kuninori SATO, Tetsuo SEKI, Akihiro SHIMIZU, Takashi SHIMOZUMA, Mamoru SHOJI, Shigeru SUDO, Hideo SUGAMA, Chihiro SUZUKI, Yasuhiro SUZUKI, Hiromi TAKAHASHI, Kazuya TAKAHATA, Yasuhiko TAKEIRI, Hitoshi TAMURA, Naoki TAMURA, Kenji TANAKA, Shinichiro TODA, Kazuo TOI, Masayuki TOKITANI, Tokihiko TOKUZAWA, Katsuyoshi TSUMORI, Kiyomasa WATANABE, Ichihiro YAMADA, Hiroshi YAMADA, Osamu YAMAGISHI, Nagato YANAGI, Shinji YOSHIMURA, Yasuo YOSHIMURA and Akio KOMORI, Plasma Fusion Res. 4, 027 (2009).