[Table of Contents]

Plasma and Fusion Research

Volume 3, 050 (2008)

Regular Articles


Density Reconstruction Using a Multi-Channel Far-Infrared Laser Interferometer and Particle Transport Study of a Pellet-Injected Plasma on the LHD
Kenji TANAKA, Kazuo KAWAHATA, Tokihiko TOKUZAWA, Shigeki OKAJIMA1), Yasuhiko ITO, Katsunori MURAOKA1), Ryuichi SAKAMOTO, Kiyomasa WATANABE, Tomohiro MORISAKI, Hiroshi YAMADA and the LHD Experimental group
National Institute for Fusion Science, Toki 509-5292, Japan
1)
School of Engineering, Chubu University, Kasugai 487-8501, Japan
(Received 17 March 2008 / Accepted 16 June 2008 / Published 2 October 2008)

Abstract

Radial density profiles are obtained by applying the database slice and stuck density reconstruction technique to measured line-integrated densities, using multi-channel far-infrared laser interferometer installed on the Large Helical Device (LHD). A novel method that considers flux surfaces in the reconstruction process has been developed and applied successfully to a pellet-injected discharge in the LHD, enabling the identification of transient density peaking due to an inward pinch and enhanced diffusion in the edge region. The relationship between the change in particle transport and measured turbulence information obtained using reflectometry was also studied.


Keywords

multi-channel far-infrared interferometer, pellet injection, particle transport, convection velocity, diffusion coefficient, density peaking, Large Helical Device (LHD), reflectometry

DOI: 10.1585/pfr.3.050


References

  • [1] K. Kawahata, K. Tanaka, Y. Ito, A. Ejiri and S. Okajima, Rev. Sci. Instrum. 70, 707 (1999).
  • [2] Y. Ito, K. Haba, T. Tokuzawa and K. Kawahata, Fusion Eng. Des. 56-57, 965 (2001).
  • [3] T. Tokuzawa, K. Kawahata, K.Tanaka, Y. Ito, A. Ejiri and T. Simizu, Rev. Sci. Instrum. 72, 1103 (2001).
  • [4] H.K. Park, Plasma Phys. Control. Fusion 31, 2035 (1989).
  • [5] J.P.T. Koponen and O. Dumbrajs, Rev. Sci. Instrum. 68, 4038 (1997).
  • [6] I. Furuno et al., Plasma Phys. Control. Fusion 47, 46 (2005).
  • [7] S.P. Hirshman and J.C. Whitson, Phys. Fluids 26, 3553 (1983).
  • [8] T. Morisaki et al., J. Nucl. Mater. 313-316, 548-552 (2003).
  • [9] K. Narihara et al., Rev. Sci. Instrum. 72, 1122 (2001).
  • [10] K.W. Gentle et al., Plasma Phys. Control. Fusion 29, 1077 (1987).
  • [11] K. Tanaka et al., Nucl. Fusion 46, 110 (2006).
  • [12] K. Tanaka et al., Fusion Sci. Tech. 51, 97 (2007).
  • [13] J. O'Rourke et al., Plasma Phys. Control. Fusion 35, 585 (1993).
  • [14] H. Takenaga et al., Nucl. Fusion 35, 107 (1995).
  • [15] M. Shoji et al., J. Nucl. Mater. 337-339, 186 (2005).
  • [16] S. Murakami et al., Trans. Fusion Technol. 27, 256 (1995).
  • [17] H. Yamada, R. Sakamoto et al., Fusion Eng. Des. 49-50, 915-920 (2000).
  • [18] H. Takenaga, K. Tanaka, K. Muraoka et al., Nucl. Fusion 48, 075004 (2008).
  • [19] K. Tanaka, C. Michael, H. Takenaga, K. Muraoka et al., “Particle transport and fluctuation characteristics around the neoclassically optimized configuration in LHD,” submitted to Plasma Fusion Res.
  • [20] C. Angioni et al., Phys. Plasmas 10, 3225 (2003).
  • [21] O. Yamagishi et al., Phys. Plasmas 14, 012505 (2007).
  • [22] K. Tanaka et al., Rev. Sci. Instrum. 77, 10E912 (2006).
  • [23] J. Wesson, Tokamaks third edition (Clarendom Press, 2004).
  • [24] T.H. Watanabe et al., Nucl. Fusion 47, 1383 (2007).
  • [25] K. Tanaka et al., Plasma Phys. Control. Fusion 44, A231 (2002).
  • [26] K. Yamazaki, J. Plasma Fusion Res. 79, 739 (2003).
  • [27] T. Akiyama, K. Tanaka, L.N. Vyacheslavov, A. Sanin, T. Tokuzawa, Y. Ito, S. Tsuji-Iio, S. Okajima and K. Kawahata, Rev. Sci. Instrum. 74, 2695 (2003).
  • [28] K. Tanaka, L.N. Vyacheslavov, K. Kawahata, T. Tokuzawa and S. Okajima, Rev. Sci. Instrum. 75, 3429 (2004).
  • [29] K. Tanaka et al., Plasma Fusion Res. 2, S1033 (2007). (http://www.jspf.or.jp/PFR/PDF/pfr2007 02-S1033.pdf)
  • [30] N. Ohyabu et al., Phys. Rev. Lett. 97, 055002 (2006).
  • [31] K. Tanaka et al., J. Phys.: Conf. Ser. 123, 012020 (2008).

This paper may be cited as follows:

Kenji TANAKA, Kazuo KAWAHATA, Tokihiko TOKUZAWA, Shigeki OKAJIMA, Yasuhiko ITO, Katsunori MURAOKA, Ryuichi SAKAMOTO, Kiyomasa WATANABE, Tomohiro MORISAKI, Hiroshi YAMADA and the LHD Experimental group, Plasma Fusion Res. 3, 050 (2008).