Measurement of Bremsstrahlung Profile with a High - Spatial Resolution on LHD

Measurements of the bremsstrahlung emission profile have been made in order to measure the effective charge (Z.n) profile in Large Helical Device (LHD). The main diagnostic system consists of a 84 optical fiber array, an interference filter and 84 photomultipliers, which gives a spatial resolution of 5 cm at the plasma center. To evaluate the contribution of impurity line radiation, the wavelength spectrum was measured by a visible spectrometer with a CCD camera. Analysis of the emission was performed using data from the.two diagnostics during the quasi-steady phase of NBl-heated discharges. Based on the profiles obtained from the two diagnostics, the effect of line radiation from the edge plasma is discussed. As the results, it was found that the contribution of line radiation to the total radiation from p--4.9 to 60.9 is 20-30 Vo.