Correlation ECE and Doppler Backscattering Diagnostics for Alcator C-Mod

POSTER

Abstract

A Correlation Electron Cyclotron Emission (CECE) diagnostic and an X-mode reflectometer system are being developed to measure long wavelength ($k_{\theta}\rho_s$) core electron temperature fluctuations and density fluctuations, respectively, at Alcator C-Mod. These new diagnostics will allow for detailed two-field core turbulence measurements and validation studies. Adjustable optics will allow the reflectometer to be configured as a Doppler backscattering system. Global, nonlinear gyrokinetic turbulence simulations (GYRO) and synthetic diagnostics are used to model the diagnostics' expected responses to turbulence in a variety of operating regimes. The challenges associated with the high frequency systems required for core turbulence studies at C-Mod and the feasibility of combining these complementary diagnostics into a single transmission system will be assessed. Accessibility limits, expected wavenumber sensitivity and waveguide/antennae configurations are discussed.

*Supported by the US Department of Energy under DE-FC02-99ER54512.

Authors

  • C. Burns

    • MIT PSFC
  • A. Hubbard

    • MIT PSFC
  • P. Phillips

    • University of Texas, Austin
  • J. Irby

  • M. Greenwald

    • MIT PSFC
  • D.R. Mikkelsen

    • PPPL
  • N.T. Howard

    • MIT PSFC