Sensitivity of Equilibrium Reconstruction to Motional-Stark-effect Measurements
Authors: S. H. Batha, F. M. Levinton, S. P. Hirshman, et al.
The magnetic-field pitch-angle profile, gp(R) º arctan(Bpol/Btor), is measured on the Tokamak Fusion Test Reactor (TFTR) [Plasma Phys. Controlled Nucl. Fusion Res. 1, 51 (1987)] using a motional Stark effect (MSE) polarimeter. Measured pitch-angle profiles, along with kinetic profiles and external magnetic measurements, are used to compute a self-consistent equilibrium using the free-boundary Variational Moments Equilibrium Code vmec. Uncertainties in the q profile due to uncertainties in the gp(R), magnetic measurements, and kinetic measurements are quantified. Subsequent uncertainties in the vmec-calculated current-density and shear profiles are also quantified.