[Table of Contents]

Plasma and Fusion Research

Volume 2, S1086 (2007)

Regular Articles


Effects of Ion Orbits Due to Potential Formation on Transverse Ion Transport in the Thermal Barrier Region of GAMMA10
H. SAIMARU, I. KATANUMA, Y. MIZOGUCHI, K. YASHIRO and T. CHO
Plasma Research Center, University of Tsukuba,1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8577, Japan
(Received 4 December 2006 / Accepted 1 March 2007 / Published 20 November 2007)

Abstract

Transverse ion loss in the thermal barrier region of the GAMMA10 tandem mirror is investigated with the mapping equations of ion drift orbits. The effects of a non-axisymmetric electrostatic potential in the thermal barrier are taken into account. The local stability of orbits and its diffusion are calculated numerically and these are compared with the results of A.B. Rechester and R.B. White [1]. It is found that there are two kinds of the transverse ion transport. One is chaotic ion orbits due to unstable ion drift, which cause cross-field ion diffusion. Another is the enhanced effects of ion radial step sizes on the transverse diffusion, because banana-like ion drift orbits appear due to the non-axisymmetric electrostatic potential formation.


Keywords

drift shear, fixed point, diffusion, stable region, tangent mapping

DOI: 10.1585/pfr.2.S1086


References

  • [1] A.B. Rechester and R.B. White, Phys. Rev. Lett. 44, 1586 (1980).
  • [2] K. Yatsu, T. Cho, M. Hirata, H. Hojo, M. Ichimura, K. Ishii et al., Nucl. Fusion 41, 613 (2001).
  • [3] I. Katanuma, H. Saimaru, Y. Tatematsu, T. Saito, K. Ishii, T. Cho et al., J. Plasma Fusion Res. SERIES 6, 461 (2004).
  • [4] H. Saimaru, I. Katanuma, Y. Sasagawa, T. Cho, Fusion Engineering and Design 81, 2801 (2006).
  • [5] A.J. Lichtenberg and M.A. Lieberman, Regular and Chaotic Dynamics (Springer-Verlag, Inc., New York, 1992) p.334.

This paper may be cited as follows:

H. SAIMARU, I. KATANUMA, Y. MIZOGUCHI, K. YASHIRO and T. CHO, Plasma Fusion Res. 2, S1086 (2007).