Study of Impurity Ions Behavior in The Gamma 10 Plasma

Spatial and temporal spectroscopic measurements in the wavelength range from visible to soft X-ray lights are powerful tools for fusion research. We have constructed absolutely calibrated two-dimensional visible-ultraviolet (V/UV, 2500-7000 Å), Vacuum ultraviolet (VUV, 150-1050 Å) and soft X-ray (SX, 20-350Å) spectroscopic measurement systems for quantitative analysis of impurity ion behavior in the tandem mirror GAMMA 10. Carbon, oxygen and nitrogen ions are main impurity ions observed in the GAMMA 10 plasma. Using absolute emissivities of impurity lines and the collisional-radiative model, impurity ion density profiles are obtained. Moreover, we observed the plasma rotation velocity in order to measure the electric field profile by using V/UV spectrograph in the hot ion mode plasma at the first time. Then, the obtained electric field profile in the central cell is almost equal to the result of beam probe measurements.