Publications

Direct construction of optimized stellarator shapes. I. Theory in cylindrical coordinates
Journal ArticleThe confinement of guiding center trajectories in a stellarator is determined by the variation of the magnetic field strength B in Boozer coordinates (r,θ,φ), but B(r,θ,φ) depends on the flux surface shape in a complicated way. Here we derive equations relating B(r,θ,φ) in Boozer coordinates and the rotational transform to the shape of flux...

Direct construction of optimized stellarator shapes. II. Numerical quasisymmetric solutions
Journal ArticleQuasisymmetric stellarators are appealing intellectually and as fusion reactor candidates since the guiding center particle trajectories and neoclassical transport are isomorphic to those in a tokamak, implying good confinement. Previously, quasisymmetric magnetic fields have been identified by applying blackbox optimization algorithms to...

Optimized quasisymmetric stellarators are consistent with the GarrenBoozer construction
Journal ArticleMost quasisymmetric stellarators to date have been designed by numerically optimizing the plasma boundary shape to minimize symmetrybreaking Fourier modes of the magnetic field strength B. At high aspect ratio, a faster approach is to directly construct the plasma shape from the equations of quasisymmetry near the magnetic axis derived by...

Taylor States in Stellarators: A Fast Highorder Boundary Integral Solver
Journal ArticleWe present a boundary integral equation solver for computing Taylor relaxed states in nonaxisymmetric solid and shelllike toroidal geometries. The computation of Taylor states in these geometries is a key element for the calculation of stepped pressure stellarator equilibria. The integral representation of the magnetic field in this work is...