Long pulse operations scenario of LHD

The Large Helical Device (LHD) is a big non-tokamak type superconducting toroidal fusion facility. In both areas of physics and technology, the LHD project is expected to contribute to the exploration of necessary understandings of the currentless steady-state plasmas, which have high performance of temperture, density, confinement time and beta value extrapolatable to the reactor regime. This paper describes the necessary issues of major operation scenario especially concerned with the divertor functions, which realize the steady-state experiment in LHD. 16 refs., 8 figs., 2 tabs