Onion-skin method (OSM) analysis of DIII-D edge measurements

Abstract OSM analysis provides, in principle a method for establishing the 2-D edge `fields' of n e , T e , T i , etc., which is the prerequisite for analyzing the physics processes occurring in the edge, including impurity behavior. In order to further test this method, an OSM analysis of an extensive edge database for an L-mode DIII-D discharge has been carried out, the first part of which is reported here. Consistency of the OSM results with Langmuir probe, Dα, and edge Thomson scattering measurements encourages further development of the method.