Effect of Scrape-Off-Layer Current on Reconstructed Tokamak Equilibrium
Abstract
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 -squared goodness-of-fit parameter is calculated for cases with and without scrape-off-layer current. The change in -squared is found to be minor when scrape-off-layer current is included however flux surfaces are shifted by up to 3 cm. 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.
Cite
@article{arxiv.1702.00076,
title = {Effect of Scrape-Off-Layer Current on Reconstructed Tokamak Equilibrium},
author = {J. R. King and S. E. Kruger and R. J. Groebner and J. D. Hanson and J. D. Hebert and E. D. Held and J. R. Jepson},
journal= {arXiv preprint arXiv:1702.00076},
year = {2017}
}
Comments
14 pages