TRANSPORT STUDY OF HELIAS-HELIAC HYBRID STELLARATOR

A new helical axis stellarator called Helias-Heliac Hybrid Stellarator (HHHS) is based on the modulated l = 1 helical coil. In order to obtai n Helias-like and Heliac-like configurations, toroidal coils, poloidal coils and an additional l = 1 helical coil are adjusted to control ma gnetic field spectrum. It is shown that the bumpy field with opposite sign to l = 1 helical field is essential to minimize the neoclassical ripple transport. An HHHS configuration with sufficient magnetic well and reduced neoclassical ripple transport is demonstrated.