Analysis of Pedestal Transport

POSTER

Abstract

To clarify plasma transport properties in the pedestal, we have undertaken an H-mode Edge Pedestal (HEP) Benchmarking Exercise (BE) for a single DIII-D pedestal. Codes used include 1.5D interpretive (ONETWO, WMS), 1.5D predictive (ASTRA) and 2D (SOLPS, UEDGE) codes. The particular DIII-D discharge considered is 98889, which has a typical low density H-mode pedestal. Transport properties are analyzed in near transport equilibrium between Type I ELMs. Both 2D and 1.5D transport properties are obtained and compared. Inferred radial diffusivities are smallest near the midpoint of the pedestal, about $0.1 - 0.3$ m$^2$/s for electron and ion heat but 10 times smaller for net particle transport. The small effective particle diffusivity could be the result of an inward particle pinch nearly balancing a diffusive outward radial particle flux. These and other pedestal plasma transport properties will be discussed.

*Work supported by US DOE under DE-FG02-92ER54139, DE-FG02-08ER54999, DE-FC02-04ER54698, DE-AC05-00OR22725, DE-FG02-92ER54141, DE-AC52-07NA27344 and DE-FG02-00ER54538.

Authors

  • J.D. Callen

    • University of Wisconsin
    • U. Wisconsin-Madison
    • Department of Engineering Physics, University of Wisconsin-Madison

  • R.J. Groebner

    • General Atomics

  • T.H. Osborne

    • General Atomics
    • GA

  • J.M. Canik

    • ORNL

  • L.W. Owen

    • ORNL

  • A. Pankin

    • Lehigh University

  • T. Rafig

    • Lehigh University

  • T.D. Rognlien

    • LLNL

  • W.M. Stacey

    • Georgia Tech.