NSTX H-mode measurement in conjunction with gyrocenter shift via FIReTIP system

POSTER

Abstract

The Far Infrared Tangential Interferometer/Polarimeter (FIReTIP) which spans the entire plasma is used to measure electron density fluctuations during the low confinement mode (L-mode) to high confinement mode (H-mode) transition on the National Spherical Tokamak Experiment (NSTX). The measured neutral density distribution and the radial electric field evolution are compared to the calculations based on the gyrocenter shift [K. C. Lee, \textit{Phys. Plasmas}\textbf{13}, 062505 (2006)].The statistical analysis of electron density fluctuations measured by the FIReTIP system including data from a newly installed additional channel will be reported. Also, the role of the neutral density gradient on the L to H transition associated with the radial electric field formation and turbulence suppression will be discussed.

Authors

  • M. Johnson

    University of California Davis

  • C.W. Domier

    University of California Davis, University of California at Davis

  • K.C. Lee

    University of California Davis

  • N.C. Luhmann, Jr.

    University of California at Davis, University of California Davis, UC at Davis

  • P.W. Ross

    Princeton Plasma Physics Laboratory

  • R.E. Bell

    Princeton University, Princeton Plasma Physics Laboratory, PPPL

  • H.K. Park

    Princeton University, Princeton Plasma Physics Laboratory