J. Plasma Fusion Res. SERIES, Vol.l (1998) 398-401 LID Design for LHD KOMORI Akio*, OHYABU Nobuyoshi, WATANABE Tsuguhiro, SUZUKI Hajime,

A local island divertor (LID) has been proposed for the edge plasma control of the Large Helical Device (LHD), and technical and design studies of the LID have been done in detail. A clean m/n:t/t island for the LID has been demonstrated numerically to be surely generated with 20 island control coils and 3 electric dc power supplies, which have been already fabricated. Based on this island shape, an LID system has been designed, and especially, careful attention has been paid to the design of a divertor head and a pumping duct to achieve high overall pumping efficiency of> 30"h. Keywords: LHD, LID, edge plasma control, particle recycling, improvement of energy confinemen