Operations of LHD

The Large Helical Device (LHD) is a big non-tokamak type superconducting toroidal fusion apparatus, which is an on-going project under construction being completed in 1997. Based on the results of the developments in both areas of the physics and technology researches concerned, the LHD project is expected to contribute to the necessary understandings of the currentless steady-state plasmas, which have a high performance of temperature, density, confinement time and beta value extrapolatable to the reactor regime (Q~0.35). This paper describes the necessary issues of the major engineering operations scenarios of LHD, which are especially concerned with the SC magnet technology, the expected SC coil performance and obtained technological flexibility, the required functions for the coil power supply and protection circuit, the system control, and the developed closed divertor system for the edge control