[Table of Contents]

Plasma and Fusion Research

Volume 3, S1044 (2008)

Regular Articles

A Systematic Study of Impurity Ion Poloidal Rotation and Temperature Profiles Using CXRS in the TJ-II Stellarator
Jose M. CARMONA, Kieran J. MCCARTHY, Victor TRIBALDOS and Maria A. OCHANDO
Laboratorio Nacional de Fusión, EURATOM-CIEMAT, E-28040 Madrid, Spain
(Received 17 November 2007 / Accepted 5 February 2008 / Published 4 August 2008)

Abstract

A concise systematic study of impurity parameter profiles (impurity ion temperatures and poloidal velocities) measured under different plasma conditions has been carried out in the TJ-II stellarator using an active spectroscopic diagnostic system covering a large section of the central plasma minor radius, from r/a = 0.3 to 0.85, with high spatial resolution. For this, plasmas using hydrogen as the working gas were created and maintained using electron cyclotron resonance heating (from 400 to 500 kW) and line-averaged densities between 0.4 and 0.9 × 1019 m-3 were achieved. In the first instance, it is noted that ion temperature profiles tend to be flat across the accessible plasma radius, whilst a transition in the poloidal velocity from the ion to the electron diamagnetic direction is observed with increasing density. At the same time, the shear point for impurity velocity is seen to propagate outwards towards the plasma edge. Similarly, at a fixed density, a similar tendency is observed when raising the injected heating power. These results together with the behaviour of the impurity temperatures for the same conditions, suggest that collision frequency νEb/e ∼ neTe-3/2 can be considered as an important controlparameter of plasma dynamics.

Keywords

charge exchange, spectroscopy, ion temperature, poloidal rotation, TJ-II

DOI: 10.1585/pfr.3.S1044

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References

  • [1] H. Ehmler et al., Plasma Phys. Control. Fusion 45, 53 (2003).
  • [2] S. Gangadhara et al., Rev. Sci. Instrum. 77, 10F109 (2006).
  • [3] R.C. Isler, Plasma Phys. Control. Fusion 36, 171 (1994).
  • [4] K. Ida et al., Rev. Sci. Instrum. 71, 2360 (2000).
  • [5] E. Ascasíbar et al., Fusion Eng. Des. 56-57, 145 (2001).
  • [6] G.F. Abdrashitov et al., Rev. Sci. Instrum. 72, 34 (2001).
  • [7] R.E. Bell et al., Rev. Sci. Instrum. 75, 4158 (2004).
  • [8] A.S. Stringanov et al,. Tables of Spectral Lines of Neutral and Ionized Atoms, IFI/Plenum, New York, 1968.
  • [9] J.M. Carmona et al., to be published.
  • [10] R.J. Fonck, Phys. Rev. A 29, 3288 (1984).
  • [11] R. Balbín et al., Proc.15th Inter. Stellarator Workshop, Madrid(2005), http://www-fusion.ciemat.es/SW2005/
  • [12] K.J. McCarthy et al., Europhys. Lett. 63, 49 (2003).
  • [13] B. Zurro et al., Fusion Sci. Technol. 50, 419 (2006).
  • [14] C. Hidalgo et al., Phys. Rev. E 70, 067402 (2004).
  • [15] R. Burhenn et al., Fusion Sci. Technol. 46,115 (2006).
  • [16] J. Guasp et al., Fusion Technol. 35, 32 (1999) .
  • [17] A. Fernández et al., Fusion Sci. Technol. 46, 335 (2004).

This paper may be cited as follows:

Jose M. CARMONA, Kieran J. MCCARTHY, Victor TRIBALDOS and Maria A. OCHANDO, Plasma Fusion Res. 3, S1044 (2008).