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Alpha Particle Slowing-Down Characteristics and the Effect on MHD Instability Excitation at High-Density Operation Points in FFHRs

Hideaki MATSUURA, Osamu MITARAI¹⁾, Akio SAGARA²⁾ and Yasuyuki NAKAO

Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Fukuoka 819-0395, Japan

1)

Liberal Arts Education Center, Kumamoto Campus, Tokai University, 9-1-1 Toroku, Kumamoto 862-8652, Japan

2)

National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, 509-5292, Japan

(Received 6 December 2010 / Accepted 27 April 2011 / Published 12 July 2011)

Abstract

Alpha-particle slowing-down behaviors at low-temperature, high-density operation points in force-free helical reactors (FFHRs) are examined on the basis of a Fokker-Planck (FP) simulation that simultaneously consider the balance among generation, slowing down, and loss from the plasma in parallel with the density dependence of the Alfvén speed. An accurate treatment of the boundary velocity region between thermal and non-thermal components is shown to be important in evaluating the alpha particle population that can induce instability. In a typical high-density, low-temperature operation point in an FFHR, this population is reduced.

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

Keywords

alpha-particle velocity distribution function, Fokker-Planck equation, Alfvén eigenmode, MHD instability, force-free helical reactor (FFHR)

DOI: 10.1585/pfr.6.2405086

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References

• [1] N. Ohyabu et al., Phys. Rev. Let. 97, 055002 (2006).
• [2] O. Mitarai et al., Plasma Fusion Res. 2, 021 (2007).
• [3] A. Sagara et al., Fusion Eng. Des. 83, 1690 (2008).
• [4] O. Mitarai et al., Fusion Sci. Technol. 56, 1495 (2009).
• [5] S. Yamamoto et al., Nucl. Fusion 45, 326 (2005).
• [6] M.N. Rosenbluth et al., Phys. Rev. 107, 1 (1957).
• [7] S.T. Perkins and D.E. Cullen, Nucl. Sci. Eng. 20, 77 (1981).
• [8] H. Matsuura and Y. Nakao, Phys. Plasmas 13, 062507 (2006).
• [9] E. Bittoni et al., Nucl. Fusion 29, 931 (1980).
• [10] O. Mitarai et al., 23th IAEA FEC 2010, FTP/P6-19 (2010).
• [11] H. Matsuura and Y. Nakao, Phys. Plasmas 16, 042507 (2009).

This paper may be cited as follows:

Hideaki MATSUURA, Osamu MITARAI, Akio SAGARA and Yasuyuki NAKAO, Plasma Fusion Res. 6, 2405086 (2011).