[Table of Contents]

Plasma and Fusion Research

Volume 7, 1402152 (2012)

Regular Articles

Blob/Hole Generation in the Divertor Leg of the Large Helical Device
Hirohiko TANAKA, Noriyasu OHNO, Yoshiyuki TSUJI, Shin KAJITA1), Suguru MASUZAKI2), Masahiro KOBAYASHI2), Tomohiro MORISAKI2), Akio KOMORI2) and the LHD Experimental Group2)
Graduate School of Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
1)
EcoTopia Science Institute, Nagoya University, Nagoya, Aichi 464-8603, Japan
2)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 15 May 2012 / Accepted 20 September 2012 / Published 22 November 2012)

Abstract

We have analyzed ion saturation current fluctuation measured by a fast scanning Langmuir probe (FSP) in edge region of the Large Helical Device (LHD). Positive and negative spikes of the ion saturation current were observed in the private region and on the divertor leg, respectively. It was found that the boundary position between these regions corresponds to the low-field side (LFS) edge of the divertor leg where the gradient of the ion saturation current profile was the maximum. Such a positional relationship resembles that near the separatrix in the LFS in tokamaks, where blobs and holes are generated. Statistical analysis indicates similar fluctuation characteristics among different magnetic devices.

Keywords

blob, hole, cross-field transport, statistical analysis, LHD

DOI: 10.1585/pfr.7.1402152

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References

  • [1] J.A. Boedo, D.L. Rudakov, R.A. Moyer, G.R. McKee, R.J. Colchin, M.J. Schaffer, P.G. Stangeby, W.P. West, S.L. Allen, T.E. Evans, R.J. Fonck, E.M. Hollmann, S. Krasheninnikov, A.W. Leonard, W. Nevins, M.A. Mahdavi, G.D. Porter, G.R. Tynan, D.G. Whyte and X. Xu, Phys. Plasmas 10, 1670 (2003).
  • [2] G.S. Xu, V. Naulin, W. Fundamenski, C. Hidalgo, J.A. Alonso, C. Silva, B. Goncalves, A.H. Nielsen, J.J. Rasmussen, S.I. Krasheninnikov, B.N. Wan, M. Stamp and JET EFDA Contributors, Nucl. Fusion 49, 092002 (2009).
  • [3] J. Cheng, L.W. Yan, W.Y. Hong, K.J. Zhao, T. Lan, J. Qian, A.D. Liu, H.L. Zhao, Yi. Liu, Q.W. Yang, J.Q. Dong, X.R. Duan and Y. Liu, Plasma Phys. Control. Fusion 52, 055003 (2010).
  • [4] B. Nold, G.D. Conway, T. Happel, H.W. Müller, M. Ramisch, V. Rohde, U. Stroth and the ASDEX Upgrade Team, Plasma Phys. Control. Fusion 52, 065005 (2010).
  • [5] R.J. Maqueda, G.A. Wurden, S. Zweben, L. Roquemore, H. Kugel, D. Johnson, S. Kaye, S. Sabbagh and R. Maingi, Rev. Sci. Instrum. 72, 931 (2001).
  • [6] O. Grulke, J.L. Terry, B. Labombard and S.J. Zweben, Phys. Plasmas 13, 012306 (2006).
  • [7] J.L. Terry, S.J. Zweben, K. Hallatschek, B. LaBombard, R.J. Maqueda, B. Bai, C.J. Boswell, M. Greenwald, D. Kopon, W.M. Nevins, C.S. Pitcher, B.N. Rogers, D.P. Stotler and X.Q. Xu, Phys. Plasmas 10, 1739 (2003).
  • [8] G.S. Kirnev, V.P. Budaev, S.A. Grashin, L.N. Khimchenko and D.V. Sarytchev, Nucl. Fusion 45, 459 (2005).
  • [9] H. Tanaka, N. Ohno, N. Asakura, Y. Tsuji, H. Kawashima, S. Takamura, Y. Uesugi and the JT-60U Team, Nucl. Fusion 49, 065017 (2009).
  • [10] S.I. Krasheninnikov, Phys. Lett. A 283, 368 (2001).
  • [11] J.A. Boedo, D. Rudakov, R. Moyer, S. Krasheninnikov, D. Whyte, G. McKee, G. Tynan, M. Schaffer, P. Stangeby, P. West, S. West, S. Allen, T. Evans, R. Fonck, E. Hollmann, A. Leonard, A. Mahdavi, G. Porter, M. Tillack and G. Antar, Phys. Plasmas 8, 4826 (2001).
  • [12] G.S. Kirnev, V.P. Budaev, S.A. Grashin, E.V. Gerasimov and L.N. Khimchenko, Plasma Phys. Control. Fusion 46, 621 (2004).
  • [13] N. Ohno, S. Masuzaki, H. Miyoshi, S. Takamura, V.P. Budaev, T. Morisaki, N. Ohyabu and A. Komori, Contrib. Plasma Phys. 46, 692 (2006).
  • [14] J.M. Dewhurst, B. Hnat, N. Ohno, R.O. Dendy, S. Masuzaki, T. Morisaki and A. Komori, Plasma Phys. Control. Fusion 50, 095013 (2008).
  • [15] H. Tanaka, N. Ohno, Y. Tsuji, S. Kajita, S. Masuzaki, M. Kobayashi, T. Morisaki, H. Tsuchiya, A. Komori and the LHD Experimental Group, Phys. Plasmas 17, 102509 (2010).
  • [16] H. Tsuchiya, T. Morisaki, V. P. Budaev, A. Komori, H. Yamada and the LHD Experimental Group, Plasma Fusion Res. 5, S2078 (2010).
  • [17] S. Masuzaki, N. Ohno, V.P. Budaev, S. Sakakibara, T. Morisaki, M. Kobayashi, N. Ohyabu, A. Komori and the LHD Experimental Group, Proceedings of ITC/ISHW2007, Toki, Japan (2007).
  • [18] Y. Nakamura, M. Wakatani and K. Ichiguchi, J. Plasma Fusion Res. 69, 41 (1993).
  • [19] T. Morisaki, S. Sakakibara, K. Watanabe, H. Yamada, S. Masuzaki, N. Ohyabu, A. Komori, K. Yamazaki and O. Motojima, Contrib. Plasma Phys. 40, 266 (2000).
  • [20] S. Masuzaki, T. Morisaki, N. Ohyabu, A. Komori, H. Suzuki, N. Noda, Y. Kubota, R. Sakamoto, K. Narihara, K. Kawahata, K. Tanaka, T. Tokuzawa, S. Morita, M. Goto, M. Osakabe, T. Watanabe, Y. Matsumoto, O. Motojima and the LHD Experimental Group, Nucl. Fusion 42, 750 (2002).
  • [21] N. Ohno, V.P. Budaev, K. Furuta, H. Miyoshi and S. Takamura, Contrib. Plasma Phys. 44, 222 (2004).
  • [22] G.A. Antar, G. Counsell, Y. Yu, B. Labombard and P. Devynck, Phys. Plasmas 10, 419 (2003).

This paper may be cited as follows:

Hirohiko TANAKA, Noriyasu OHNO, Yoshiyuki TSUJI, Shin KAJITA, Suguru MASUZAKI, Masahiro KOBAYASHI, Tomohiro MORISAKI, Akio KOMORI and the LHD Experimental Group, Plasma Fusion Res. 7, 1402152 (2012).