Title: 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
$\chi$-squared goodness-of-fit parameter is calculated for cases with and
without scrape-off-layer current. The change in $\chi$-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.