TRANSPORT PHYSICS OF STELLARATOR HELIOTRON PLASMAS/

For suppressing the neoclassical ripple transport in stellarator/helio tron plasmas substantially, magnetic spectrum are carefully controlled with using side-band helical magnetic fields. In order to realize bot h high MHD beta limit and suppression of ripple transport, L = 1 stell arators have advantages compared to L = 2 heliotrons, since freedom fo r magnetic configuration coming from helical magnetic axis is usable a nd L = 0 bumpy field generated by toroidal coils becomes the side-band of L = 1 helical field. For improving the particle confinement, radia l electric field is effective in all stellarators. Relations among the radial electric field, poloidal ion flow and toroidal ion how are giv en within the context of neoclassical transport theory, and a role of radial electric field in the energy exchange between ions and electron s is discussed. Finally two models for determining the ambipolar radia l electric field in stellarator/heliotron plasmas are discussed.