Stellarators with the magnetic symmetry of a tokamak

To meet the requirements of the U.S. Stellarator Power Plant Study, a Modular Helias-like Heliac (MHH) configuration was developed that has features in common with a quasihelically symmetric experiment proposed at the University of Wisconsin [D. Anderson and P Garabedian, Nucl. Fusion 34, 881 (1994)]. Improvements have been made in the design of the MHH that raise the beta limit, increase the confinement time, and simplify the geometry of the coils. In particular, specifications have been found for a stellarator with just two field periods that has a magnetic field spectrum B-min close to axial symmetry. This configuration has physical properties that make it an interesting candidate for a follow-on experiment to assess the equilibrium, stability and transport of advanced stellarators. (C) 1996 American Institute of Physics.