Investigation of edge ExB sheared flow development in the TJ-II stellarator

POSTER

Abstract

Experiments carried out by means of Langmuir probes in the TJ-II stellarator have shown that above a plasma density threshold the level of turbulence decreases with a concomitant development of ExB perpendicular sheared flow (i.e. naturally occurring shear layer). The effect of density on sheared flows has been observed in different plasma magnetic configurations and regimes [1, 2]. The reversal in the ExB rotation has been 2-D visualized using Ultra Fast Speed cameras. Estimated velocity of observed blobs, rotating predominantly in the perpendicular direction, is in the range of 10$^{3}$--10$^{4}$ m/s. Heavy Ion Beam Probe and reflectometry measurements also show a strong dependence of edge radial electric fields and plasma rotation with plasma density. [1] C. Hidalgo et al., Phys. Rev. E 70 (2004) 067402. [2] M.A. Pedrosa et al., Plasma Phys. Control. Fusion 47 (2005) 777.

Authors

  • M. Angeles Pedrosa

    • Laboratorio Nacional de Fusion, Spain

  • Arturo Alonso

  • Eduardo Calder\'{o}n

    • Laboratorio Nacional de Fusion, Spain

  • Alexander A. Chmyga

  • Nicolai B. Dreval

    • Institute of Plasma Physics, Ukraine

  • Leonid Eliseev

    • Institute of Nuclear Fusion, Russia

  • Teresa Estrada

  • Carlos Hidalgo

    • Laboratorio Nacional de Fusion, Spain
    • CIEMAT

  • Ludmila Krupnik

    • Institute of Plasma Physics, Ukraine

  • Alexander V. Melnikov

    • Institute of Nuclear Fusion, Russia

  • Roberto Octavio Orozco

  • Jose Luis de Pablos

    • Laboratorio Nacional de Fusion, Spain

  • S. Zweben

    • Princeton Plasma Physics Laboratory, Princeton, NJ, USA
    • Princeton Plasma Physics Laboratory, USA
    • Princeton University
    • PPPL