Session RP1 - Poster Session VIII.
POSTER session, Thursday afternoon, October 30
Fran Hill Southeast Exhibit Hall, ACC
An initial step toward developing an efficient equilibrium reconstruction code for three-dimensional (3D) plasmas has been taken. The 3D magnetics diagnostics codes V3RFUN and V3POST can be used to rapidly compute the expected magnetic signals in external loops arising from both external coil currents and internal stellarator plasma currents. The V3RFUN code is executed once initially (for a prescribed set of stellarator coils) to generate a database of diagnostic responses valid for arbitrary plasma currents. Then, the V3POST code is executed repeatedly from within the 3D optimization code STELLOPT to compute diagnostic signals arising from the MHD pressure and iota profiles. The optimizer determines the profiles which best match the measured external diagnostic signals. The relative computational efficiency of the V3POST evaluations renders this procedure numerically feasible and will provide a prototype for the eventual development of an optimized 3D reconstruction code (V3FIT). The prototype code will be used to examine numerical features of the reconstruction process - such as the level of convergence needed to estimate the signal gradients - which will guide the development of the optimized V3FIT code.