ESTELL: A Quasi-Toroidally Symmetric Stellarator

This work presents the physics design for a simple quasi-axially symmetric stellarator. A plasma configuration described by a modest number of Fourier coefficients was found to establish this symmetry with good accuracy. The low rotational transform results in a relatively simple coil set exhibiting low curvatures and comfortable clearance between adjacent coils. As another consequence, the maximum achievable plasma pressure will be limited to about 0.5%. An experiment along the lines proposed would allow an exploration of the confinement properties of a quasi-axially symmetric configuration. ((c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)