Session KP01 - Poster Session III.
POSTER session, Tuesday afternoon, March 23
Exhibit Hall, GWCC
The NESCOIL code [P. Merkel, Nucl. Fusion 27, 867 (1987)] can be used to determine both current sheets and discrete coils which can approximately match a prescribed distribution of | B |^2 on a plasma/vacuum interface, subject to the constraint B \cdot n = 0 (where n is the surface normal). The optimization of the coils in three dimensions is done by discretizing them into many connected filaments which are varied to match various physics and engineering constraints. This process is both time consuming and overly restrictive, since the coil topology is frozen-in and determining by the initial set of filaments. We describe a new optimization technique, in which the rapid (current-sheet) version of NESCOIL is embedded in a Levenberg-Marquardt numerical optimizer. This technique permits coil topology changes and can be used to find coils which satisfy engineering criteria of interest (current density limits, field on coil, coil-to-plasma separations, coil complexity and curvature). Application of this procedure to designing coils for the NCSX will be described.