Photoelectron spectroscopy for soft X-ray measurements in a small tokamak

Summary form only given. A new X-ray spectroscopy system using the principle of a photoelectron spectroscopy method is developed for the observations of soft X-ray radiations in the KAIST tokamak (R=53 cm, a=15 cm). The system uses a high voltage triangular wave generator to analyze photoelectron energy with a retarding potential grid and a current mode preamplifier to measure the signals from a microchannel plate (MCP). We measure the spatial distributions and time evaluations of some impurity line radiations from the plasma in the temperature range of a hundred of eV. The electron temperature is also measured from the continuous spectrum profile. The design of the spectrometer and the experimental results will be presented.