Empirical Inference of fast ion transport using Electron Cyclotron Emission temperature fluctuations

POSTER

Abstract

Experimental fast ion transport by Alfven Eigenmodes is found to be accurately described by an empirical diffusion estimate from normalized temperature fluctuations at the DIII-D tokamak. These temperature fluctuations are extracted from 2nd harmonic X-mode electron cyclotron emission by the Electron Cyclotron Emission Radiatiometry (ECE) system, which allows for routine local normalized temperature fluctuation measurements in the range of 20-250 kHz across the tokamak outboard midplane. It is found empirically that the total normalized ECE electron temperature fluctuation profiles can be converted into a spatial and temporally varying anomalous diffusion profile using a constant multiplicative factor for unit conversion. These ECE inferred fast ion diffusion estimates, coupled with TRANSP/NUBEAM simulations, predict neutron rates in agreement with experimental measurements within 10-20%. Higher order validation tests using experimental Fast Ion Deuterium Alpha (FIDA) emission profiles are ongoing, seeking to further validate these empirical Alfven eigenmode based transport estimates. A database of empirically inferred diffusion profiles is being constructed to test predictions from the reduced fast ion transport models TGLF-EP+ALPHA and RBQ.

*This work was supported by the US Department of Energy under Awards No. DE-FC02-04ER54698, DE-FG02-97ER54415, DE-SC0020337, DE-AC02-09CH11466, DE-SC0020287, DE-SC0024399, DE-SC0014664, and DE-FG02-08ER54999.

Presenters

  • Kyle Callahan

    • Oak Ridge Institute for Science and Education
    • University of California, Los Angeles

Authors

  • Kyle Callahan

    • Oak Ridge Institute for Science and Education
    • University of California, Los Angeles

  • Michael A Van Zeeland

    • General Atomics

  • William Walter Heidbrink

    • University of California, Irvine

  • Max E Austin

    • University of Texas at Austin
    • University of Texas Austin

  • Xiaodi Du

    • General Atomics

  • Tommaso Barberis

    • Princeton Plasma Physics Laboratory (PPPL)
    • PPPL

  • Vinicius N Duarte

    • Princeton Plasma Physics Laboratory (PPPL)

  • Nikolai N Gorelenkov

    • Princeton Plasma Physics Laboratory (PPPL)

  • Lothar W Schmitz

    • University of California, Los Angeles

  • Christopher G Holland

    • University of California, San Diego

  • Joseph T McClenaghan

    • General Atomics

  • Eric M. Bass

    • University of California, San Diego

  • Alessandro Bortolon

    • Princeton Plasma Physics Laboratory (PPPL)

  • Zheng Yan

    • University of Wisconsin - Madison
    • University of Wisconsin Madison