Results from helical axis stellarators

Helical axis stellarators produce magnetic surfaces of high rotational tran sform and moderate shear solely by means of external currents, with the pro mise of high beta. Several machines with quite different toroidal, helical, and "bumpy" Fourier components of magnetic field are now producing results , including high quality magnetic surfaces, confinement mode transitions, c onfiguration studies, and confinement consistent with International Stellar ator Scaling (ISS95) scaling up to T(e)similar to2 keV. These devices permi t concept evaluation over an unprecedented configuration space, and allow b asic comparisons with those designed by established and alternative optimiz ation strategies. (C) 2001 American Institute of Physics.