Electron Temperature Fluctuations Associated with the Weakly Coherent Mode in the Edge of I-mode Plasmas

POSTER

Abstract

New measurements of electron temperature fluctuations associated with the weakly coherent mode (WCM) during improved mode, or I-mode plasmas at Alcator C-Mod are presented in this poster [A. E. White, et al. Nuclear Fusion, 51, 113005 (2011)]. The measurements are made with a 32-channel, high-resolution profile ECE radiometer. The WCM electron temperature fluctuations are localized to a 1 cm region inside the last closed flux surface. The WCM electron temperature fluctuation level is measured in several different I-mode discharges and is in the range 1-2\%, which is up to an order of magnitude smaller than the WCM density fluctuation level. The WCM edge fluctuations observed in I-mode are believed to play a role in increasing particle transport but not energy transport in the edge of I-mode plasmas. The large difference between normalized density and electron temperature fluctuation amplitudes provides new evidence that the WCM fluctuations can separately affect energy and particle transport.

*This work supported by the US Department of Energy under DE-FC02-99ER54512-CMOD.

Authors

  • A.E. White

    • Massachusetts Institute of Technology
  • P. Phillips

    • University of Texas, Austin
  • D.G. Whyte

    • Massachusetts Institute of Technology
  • A.E. Hubbard

    • Massachusetts Institute of Technology
  • C. Sung

    • Massachusetts Institute of Technology
  • J.W. Hughes

    • Massachusetts Institute of Technology
  • A. Dominguez

    • Massachusetts Institute of Technology
  • J. Terry

    • Massachusetts Institute of Technology
  • I. Cziegler

    • University of California, San Diego