[Table of Contents]

Plasma and Fusion Research

Volume 3, S1057 (2008)

Regular Articles

Parametric Dependence of the Perpendicular Velocity Shear Layer Formation in TJ-II Plasmas
Luis GUIMARAIS, Teresa ESTRADA1), Enrique ASCASIBAR1), María E. MANSO, Luis CUPIDO, Tim HAPPEL1), Emilio BLANCO1), Francisco CASTEJON, Rubén Jimenez-GOMEZ1), María A. PEDROSA1), Carlos HIDALGO1), Ignacio PASTOR1) and Antonio Lopez-FRAGUAS1)
As. Euratom-IST, CFN, Instituto Superior Técnico, Lisbon, Portugal
Laboratorio Nacional de Fusión. As. Euratom-CIEMAT, Madrid, Spain
(Received 16 November 2007 / Accepted 29 February 2008 / Published 4 August 2008)


In TJ-II plasmas, the perpendicular rotation velocity of the turbulence changes from positive to negative (from ion to electron diamagnetic direction) inside the Last Closed Magnetic Surface (LCMS) when the line-averaged plasma density exceeds some critical value, this change being dominated by the inversion in the radial electric field. In this work we study the parameters that control the inversion in the perpendicular rotation. A parametric dependence of the critical density has been obtained studying plasmas confined in different magnetic configurations (different rotational transform and/or plasma volume) and heated with different ECH power levels. The studied data set shows a positive exponential dependence on heating power and a negative one on plasma radius, while the dependence on rotational transform has low statistical meaning. Besides, analysis of local plasma parameters points to plasma collisionality as the parameter that controls the inversion of the perpendicular rotation velocity of the turbulence.


radial electric field, perpendicular rotation, turbulence, reflectometry, stellarator

DOI: 10.1585/pfr.3.S1057


  • [1] C. Hidalgo, M.A. Pedrosa, L. García and A. Ware, Phys. Rev. E 70, 067402 (2004).
  • [2] M.A. Pedrosa, C. Hidalgo, E. Calderón, T. Estrada, A. Fernández, J. Herranz, I. Pastor and the TJ-II team, Plasma Phys. Control. Fusion 47, 777 (2005).
  • [3] J.A. Alonso, S.J. Zweben, P. Carvalho et al., Plasma Phys. Control. Fusion 48, B465 (2006).
  • [4] T. Estrada, E. Blanco, L. Cupido, M.E. Manso and J. Sánchez, Nucl. Fusion 46, S792 (2006).
  • [5] B.A. Carreras, L. García, M.A. Pedrosa and C. Hidalgo, Phys. Plasmas 13, 122509 (2006).
  • [6] A.V. Melnikov, J.A. Alonso, E. Ascasíbar et al., Fusion Sci. Tech. 51, 31 (2007).
  • [7] J. Herranz, I. Pastor, F. Castejón et al., Phys. Rev. Lett. 85, 4715 (2000).
  • [8] J.M. Fontdecaba et al., Fusion Sci. Tech. 46, 271 (2004).
  • [9] E. Ascasíbar, T. Estrada, F. Castejón, A. López-Fraguas, I. Pastor, J. Sánchez, U. Stroth, J. Qin and TJ-II team, Nucl. Fusion 45, 276 (2005).
  • [10] L. Cupido, J. Sánchez and T. Estrada, Rev. Sci. Instrum. 75, 3865 (2004).
  • [11] G.D. Conway, C. Angioni, R. Dux et al., Nuclear Fusion 46, S799 (2006).
  • [12] M. Hirsch, E. Holzhauer, J. Baldzuhn, B. Kurzan and B. Scott, Plasma Phys. Control. Fusion 43, 1641 (2001).
  • [13] M.A. Pedrosa, C. Hidalgo, E. Calderón, J.A. Alonso, R.O. Orozco, J.L. de Pablos and TJ-II team, Czech. J. Phys. 55, 1579 (2005).
  • [14] M.A. Pedrosa, C. Alejaldre, J.A. Alonso et al., EX/P 6-21 IAEA (2004).
  • [15] V.I. Vargas, D. López-Bruna, J.M. Reynolds, T. Estrada and J. Guasp, 34th EPS Conference on Plasma Physics, Warsaw, Poland (2007).
  • [16] K. Ida, M. Yoshinuma and M. Yokoyama et al., Nucl. Fusion 45, 391 (2005).
  • [17] T. Happel, T. Estrada, L. Cupido, E. Blanco, M.A. Pedrosa and R. Jiménez-Gómez, 8th International Reflectometry Workshop, St. Petersburg, Russia (2007).
  • [18] V. Tribaldos, Phys. Plasmas 8, 1229 (2001).
  • [19] V. Tribaldos and J. Guasp, Plasma Phys. Control. Fusion 47, 545 (2005).
  • [20] F. Castejón, L.A. Fernández, J. Guasp, V. Martín-Mayor, A. Tarancón and J.L. Velasco, Plasma Phys. Control. Fusion 49, 753 (2007).

This paper may be cited as follows:

Luis GUIMARAIS, Teresa ESTRADA, Enrique ASCASIBAR, María E. MANSO, Luis CUPIDO, Tim HAPPEL, Emilio BLANCO, Francisco CASTEJON, Rubén Jimenez-GOMEZ, María A. PEDROSA, Carlos HIDALGO, Ignacio PASTOR and Antonio Lopez-FRAGUAS, Plasma Fusion Res. 3, S1057 (2008).