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Title: Modeling ExB drift transport in conceptual slot divertor configurations

Journal Article · · Contributions to Plasma Physics
 [1];  [2];  [2];  [2];  [2]
  1. Univ. of Washington, Seattle, WA (United States)
  2. General Atomics, San Diego, CA (United States)

At DIII-D, a slot divertor concept, called small-angle-slot (SAS), is under development, aiming to enable detachment at relatively low plasma edge density. We report on simulations using the SOLPS-ITER two-dimensional edge code to examine the performance of conceptual “SAS 2” slot configurations. The focus of the analysis is on E × B drift effects on upstream density at detachment (UDD), with detachment marked by electron temperature Te ≤ 3 eV at the outer strike point (OSP). With toroidal field such that radial E × B drift carries particles from the OSP towards the private flux region (PFR), placing the OSP near the inner slot wall gives ≈20% lower UDD than having the OSP near the outer wall. The inner wall effectively traps the radial E × B drift flux, resulting in low Te and associated radial electric field in the PFR, and thus small losses from the slot to the inner target via poloidal E × B drift flux. With toroidal field reversed such that radial E × B drift is reversed, OSP placement near the inner wall gives ≈10% lower UDD than OSP placement near the outer wall. Although radial E × B flux is from the OSP towards the outer wall, this flux largely escapes the slot, raising the UDD. Finally, a change in the slot shaping is suggested with the goal of eliminating such E × B-driven particle losses from the slot.

Research Organization:
Univ. of Washington, Seattle, WA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Technology Utilization (EE-34); USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Grant/Contract Number:
SC0019473; FC02-04ER54698
OSTI ID:
1601921
Alternate ID(s):
OSTI ID: 1599915
Journal Information:
Contributions to Plasma Physics, Vol. 60, Issue 5-6; Conference: Plasma Edge Theory Workshop, San Diego, CA (United States), Aug. 19-21, 2019; ISSN 0863-1042
Publisher:
WileyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

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