Application of OEDGE to Transport Coefficient Extraction in \hbox{DIII-D} Joule Milestone Discharges

POSTER

Abstract

The OEDGE modeling code is used to extract estimates of radial transport coefficients from a series of \hbox{DIII-D} experiments designed to assess the divertor heat flux dependence on operational parameters. OEDGE is being used to analyse five ELMy \hbox{H-mode} discharges in which the plasma current was varied from \hbox{0.5 MA} to 1.48 MA while other parameters were held constant. Estimates of the effective experimental $\chi_\perp$ and $\rm D_\perp$ in the outer SOL for these discharges are determined. This process requires using experimental diagnostic data and onion-skin models (OSM) to reconstruct a plasma solution. Langmuir probe measurements of $n_{\rm e}$ and $T_{\rm e}$ and infrared measurements of target heat flux were used to determine input profiles of $n_{\rm e}$, $T_{\rm e}$ and $T_{\rm i}$ to be used in the plasma reconstruction. At the 5 mm outer midplane surface, typical extracted $\rm D_\perp$ values are 0.05 m$^2$/s while $\chi_\perp$ is 0.15 m$^2$/s. All discharges showed an increase of extracted $\chi_\perp$ with radius.

*Work supported in part by US DOE under DE-AC52-07NA27344, DE-FG02-07ER54917, DE-FC02-04ER54698, and DE-AC04-94AL85000.

Authors

  • J.A. Boedo

    • UCSD
  • J.D. Elder

    • U. Toronto
  • P.C. Stangeby

    • U. Toronto
  • C.J. Lasnier

    • LLNL
  • M.A. Makowski

    • LLNL
  • N.H. Brooks

    • General Atomics
  • A.W. Leonard

    • General Atomics
  • J.G. Watkins

    • SNL