Blob-Filament characteristics in XGC1 simulations and implications for the SOL width

POSTER

Abstract

Blob-filament structures, formed due to plasma stratification, caused by strong turbulence near the separatrix, have been believed to be responsible for the convective transport at the SOL. Detachment of those coherent structures from the bulk can account for the intermittent nature of edge transport and their dynamics impact the heat flux width. The SOL width is a parameter of paramount importance in modern tokamaks as it controls the amount of power deposited at the divertor plates, directly affecting thus the viability of fusion. So far, studies of blobs have been confined to reduced fluid models and simplified geometries, leaving out important pieces of physics. Here, we analyze the results of simulations performed with the full-f, gyrokinetic code XGC1 which includes both turbulence and kinetic neoclassical effects in realistic divertor geometry. The blob contribution to the SOL width is estimated from examining the radial blob velocity and the parallel confinement time.

*We acknowledge computing resources on Titan at OLCF through the 2015 INCITE and the 2016 ALCC awards. Work supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-FG02-97ER54392.

Authors

  • Ioannis Keramidas Charidakos

    • University of Colorado, Boulder
  • J.R. Myra

    • Lodestar Research Corporation
    • Lodestar
  • Scott Parker

    • University of Colorado, Boulder, CO
    • University of Colorado, Boulder
    • University of Colorado
    • U. Colorado Boulder
    • University of Colorado at Boulder
  • S. Ku

    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Lab
    • PPPL
  • Jugal Chowdhury

    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Lab
  • R.M. Churchill

    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Lab
    • Princeton Plasma Phys Lab
    • PPPL
  • Robert Hager

    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Lab
    • PPPL
    • Princeton University
  • C.S. Chang

    • Princeton Plasma Physics Laboratory
    • Princeton Plasma Physics Lab
    • PPPL
    • Princeton University