Equilibrium and stability control of heliotron/torsatron with driven current

In order to elucidate the role of the net toroidal plasma current in toroidal plasmas, many experiments for studying stellarator/heliotron plasmas with an ohmic heating current or current drive by lower hybrid waves have been carried out. The effects of the net toroidal plasma current on stellarator/heliotron plasmas are reviewed from both theoretical and experimental standpoints in order to understand the differences and similarities between the tokamak and stellarator/heliotron. Possibilities for improving the confinement in heliotron/torsatron devices are addressed.