skip to main content


Title: Effect of scrape-off-layer current on reconstructed tokamak equilibrium

Methods are described that extend fields from reconstructed equilibria to include scrape-off-layer current through extrapolated parametrized and experimental fits. The extrapolation includes both the effects of the toroidal-field and pressure gradients which produce scrape-off-layer current after recomputation of the Grad-Shafranov solution. To quantify the degree that inclusion of scrape-off-layer current modifies the equilibrium, the χ-squared goodness-of-fit parameter is calculated for cases with and without scrape-off-layer current. The change in χ-squared is found to be minor when scrape-off-layer current is included however flux surfaces are shifted by up to 3 cm. Here the impact on edge modes of these scrape-off-layer modifications is also found to be small and the importance of these methods to nonlinear computation is discussed.
ORCiD logo [1] ; ORCiD logo [1] ;  [2] ;  [3] ;  [3] ;  [4] ; ORCiD logo [4]
  1. Tech-X Corp., Boulder, CO (United States)
  2. General Atomics, San Diego, CA (United States)
  3. Auburn Univ., Auburn, AL (United States)
  4. Utah State Univ., Logan, UT (United States)
Publication Date:
Grant/Contract Number:
FC02-08ER54972; AC02-05CH11231; FC02-04ER54698; FC02-06ER54875; FG02-03ER54692
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 1; Journal ID: ISSN 1070-664X
American Institute of Physics (AIP)
Research Org:
Tech-X Corp., Boulder, CO (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Contributing Orgs:
General Atomics, San Diego, CA; Auburn University, Auburn, AL; Utah State University, Logan, UT
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Grad-Shafranov equilibrium; scrape-off-layer; macroscopic stability; peeling-balooning modes
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1361709