Algorithms for real time magnetic field tracing and optimization Original Research Article

We describe algorithms for tracing vacuum magnetic field lines in complex geometries at interactive speeds (∼50,000 steps/s on a personal computer), and a post-processing perturbation method for optimization of magnetic surface properties. Algorithms include an efficient single evaluation predictor-corrector integrator, a rapidly converging, high precision evaluation of rotational transform, and a coil shape optimization algorithm. Results from a flexible multi-mesh interpolation based code BLINE are presented.