Title: Interpretative SOL modeling throughout multiple ELM cycles in DIII-D

Abstract

Coupling between the UEDGE (edge fluid model), GINGRED (grid generation) and CAKE (equilibrium reconstruction) codes opens the door for automated interpretative scrape-off-layer (SOL) analysis over entire discharges, providing information that is essential in efforts to couple the SOL to core transport codes. In this work, we utilize new developments in the autoUEDGE code [Izacard, O. et al., 60th Annual Meeting of the APS Division of Plasma Physics 53, 11 (2018)] to investigate the behavior of the DIII-D SOL during the temporal evolution of an edge-localized mode (ELM) cycle. Modeled temperature and density profiles in UEDGE are automatically matched to experimental measurements by iteratively and self-consistently adjusting transport coefficient profiles in the plasma edge. This analysis is completed over multiple ELM cycles of a well-diagnosed discharge with long (~100 ms) inter-ELM periods. Directly after the ELM crash, a short period of high-density, low-temperature conditions is observed in Langmuir probe measurements at the outer divertor. This regime is associated with enhanced Dα emission and incident particle flux, suggesting that the divertor enters a period of high recycling after an ELM crash. After about ~25 ms, divertor conditions return to their pre-ELM conditions and remain there for several tens of milliseconds. Using themore » autoUEDGE code, the SOL is modeled as a function of ELM cycle using upstream profiles as input. Here, the 2D modeling successfully reproduces both divertor Thomson scattering measurements and the experimentally observed divertor dynamics. Though the recycling is kept fixed throughout the modeling, changes in particle fluxes are consistent with local experimental recycling changes induced by ELMs. Agreement between modeling and observation suggests a strong link between upstream profiles and the high-recycling divertor conditions directly following large type-I ELMs.« less

Authors:

Nelson, A. O. ;

• Search DOE PAGES for author "Nelson, A. O."
• Search DOE PAGES for ORCID "0000-0002-9612-1936"

Xing, Z. A. ;

• Search DOE PAGES for author "Xing, Z. A."
• Search DOE PAGES for ORCID "0000-0003-3887-0792"

Izacard, O.; Laggner, F. M. ;

• Search DOE PAGES for author "Laggner, F. M."
• Search DOE PAGES for ORCID "0000-0003-1601-2973"

Kolemen, E.

• Search DOE PAGES for author "Kolemen, E."
• Search DOE PAGES for ORCID "0000-0003-4212-3247"

Publication Date:

Mon Mar 01 00:00:00 EST 2021

Research Org.:

General Atomics, San Diego, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Fusion Energy Sciences (FES)

OSTI Identifier:

1745065

Alternate Identifier(s):

OSTI ID: 1737550

Grant/Contract Number:  

FC02-04ER54698; AC02-09CH11466; SC0015480; SC0015878

Resource Type:

Published Article

Journal Name:

Nuclear Materials and Energy

Additional Journal Information:

Journal Name: Nuclear Materials and Energy Journal Volume: 26 Journal Issue: C; Journal ID: ISSN 2352-1791

Publisher:

Elsevier

Country of Publication:

Netherlands

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY; UEDGE; SOL; ELMs; integrated modeling