抄録
In the Large Helical Device (LHD), of which the magnetic surfaces are surrounded by an ergodic magnetic field layer, the two-dimensional prole of electron density was for the first time measured by a newly developed sheet-shaped thermal lithium beam probe. The sheet beam was formed by guiding lithium vapor through three orifices placed in front of an aperture of an oven and injecting the vapor nearly vertically into the LHD plasma. The two-dimensional (2D) image of the LiI line was measured by using a CCD camera with an interference filter for LiI (670.8 nm). From the 2D image of LiI, we successfully obtained a two-dimensional profile of electron density in the plasma edge region.