Detachment and Particle Exhaust via Impurity Seeding in DIII-D in 3D Fields

POSTER

Abstract

EMC3-EIRENE modeling of detachment in 3D scenarios with resonant magnetic perturbations applied shows that neon puffing (5-8% of ne,sep) is able to detach the ITER similar shape at DIII-D at comparatively lower separatrix impurity densities than nitrogen (10-15% of ne,sep). Simulations show impurity buildup on the low-field side at DIII-D on the shelf leading to far SOL detachment along the RMP lobes, and remaining semi-attached at the strike line near the lower pumping gap. Neutral pressure buildup is observed in the near SOL, for low main ion (D) densities (ne,sep=2e19 m-3) whereas full detachment is observed for higher separatrix densities (3e19 m-3) that still remain within the ELM suppression window. In order to efficiently pump out the extrinsic impurities prior to core contamination, it is necessary to identify global transport dynamics for seeded impurities (N, Ne) and fusion products (He) while also maintaining safe operational limits for the wall components. The data collected during this campaign are used to denote differences in particle transport shown in these simulations and those collected with coherent imaging spectroscopy, charge exchange recombination, neutral pressure measurements and helium beam measurements.

*This work was supported by DE-SC0020284, DE-FC02-04ER54698, DE-AC52-07NA27344 and DE-AC02-09CH11466.

Presenters

  • Xavier X Navarro Gonzalez

    • University of Wisconsin - Madison
    • University of Wisconsin-Madison

Authors

  • Xavier X Navarro Gonzalez

    • University of Wisconsin - Madison
    • University of Wisconsin-Madison
  • Aysia Demby

    • University of Wisconsin - Madison
  • Kole G Rakers

    • University of Wisconsin - Madison
  • Qiming Hu

    • Princeton University
    • Princeton Plasma Physics Laboratory (PPPL)
  • Huiqian Wang

    • General Atomics
  • Marcus G Burke

    • Lawrence Livermore National Laboratory
  • Colin Chrystal

    • General Atomics
  • Fenton Glass

    • General Atomics
  • Filippo Scotti

    • Lawrence Livermore National Laboratory
  • Heinke G Frerichs

    • University of Wisconsin - Madison
  • Oliver Schmitz

    • University of Wisconsin - Madison