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Observation of Cross-Field Transport of Pellet Plasmoid in LHD

Ryuichi SAKAMOTO and Hiroshi YAMADA

National Institute for Fusion Science, Toki, Gifu 509-5292, Japan

(Received 8 March 2011 / Accepted 29 May 2011 / Published 24 June 2011)

Abstract

A three-dimensional observation of the solid hydrogen pellet ablation has been performed by using a fast stereo imaging camera to investigate the pellet ablation dynamics. The initial velocity component of the injected pellet is maintained during ablation in a hot plasma, and the pellet penetrates to the core plasma. On the other hand, it has been observed that part of high density pellet plasmoid, which is formed around the pellet substance by ablating hydrogen pellet, intermittently breaks away from the pellet ablating position and the breakaway plasmoid is transported across a confinement field. The breakaway plasmoid recurrently develops at the rate of about 100 times per millisecond and it is non-diffusively transported approximately 0.1 m during its several 10 µs lifetime in the opposite direction to the pellet motion, namely, toward the low magnetic field side. This observation gives a reasonable explanation for the difference between the pellet ablation position and the effective particle deposition profile.

Copyright (c) 2011 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

pellet, fueling, ablation, plasmoid, non-diffusive transport

DOI: 10.1585/pfr.6.1402085

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References

• [1] S.L. Milora et al., Nucl. Fusion 35, 657 (1995).
• [2] B. Pégourié et al., Plasma Phys. Control. Fusion 49, R87 (2007).
• [3] L.R. Baylor et al., Nucl. Fusion 37, 445 (1997).
• [4] P.T. Lang et al., Phys. Rev. Lett. 79, 1487 (1997).
• [5] L.R. Baylor et al., Fusion Technol. 34, 425 (1998).
• [6] V.A. Rozhansky et al., Plasma Phys. Control. Fusion 37, 399 (1995).
• [7] P.B. Parks et al., Phys. Plasmas 7, 1968 (2000).
• [8] B. Pégourié et al., Nucl. Fusion 47, 44 (2007).
• [9] L.R. Baylor et al., Nucl. Fusion 47, 443 (2007).
• [10] R.D. Durst et al., Nucl. Fusion 30, 3 (1990).
• [11] J. de Kloe et al., Phys. Rev. Lett. 82, 2685 (1999).
• [12] H.W. Müller et al., Phys. Rev. Lett. 83, 2199 (1999).
• [13] R. Sakamoto et al., Rev. Sci. Instrum. 76, 103502 (2005).
• [14] R. Hartley and A. Zisserman, Multiple View Geometry in Computer Vision, Second edition (Cambridge University Press, 2003).
• [15] R. Sakamoto et al., Nucl. Fusion 44, 624 (2004).
• [16] Y. Nakamura et al., Nucl. Fusion 26, 907 (1986).
• [17] P.B. Parks and R.J. Turnbull, Phys. Fluids 21, 1735 (1978).
• [18] M. Hoshino et al., Plasma Fusion Res. 1, 033 (2006).

This paper may be cited as follows:

Ryuichi SAKAMOTO and Hiroshi YAMADA, Plasma Fusion Res. 6, 1402085 (2011).