Impurity ion radiation measurements are important study for laboratory, fusion and astrophysical plasmas. They have a lot of important information in the fusion researches, such as plasma densities, plasma temperatures, and impurity transports etc. We have studied impurity ion radiation intensities in the fusion plasma GAMMA 10 with comparing the collisional-radiative model (CR-model) calculation results to the measured impurity ion spectra using absolutely calibrated spectrographs in order to apply the CR-model calculation results into the plasma spectroscopic diagnostics. In GAMMA 10 there are many useful diagnostic systems for time dependent radial profiles of the electron density, electron temperature, ion temperature, and impurity ion radiation spectra.
We calculated the impurity ion (especially carbon ions, CII (C⁺) and CIII (C²⁺)) line radiation intensities in the GAMMA 10 plasma using the CR-model calculation. However, there are very few lines, which can be used for plasma diagnostics. We compared the CR-model calculation results of CII and CIII lines to measured ultraviolet and visible (UV/V) and vacuum ultraviolet (VUV) line intensities in the GAMMA 10 plasma. The intensity ratio of CII (426.7 nm) to CII (657.8 nm) obtained by the CR-model calculation is about 1.5, which is comparable to that obtained by the spectroscopic measurements. Impurity ion densities of CII and CIII are measured by both UV/V and VUV spectroscopic measurements by comparing the CR-model calculation results. Both UV/V and VUV spectroscopic results show that the CII and CIII ion densities are about the order of 10⁸ cm^-3. The time dependent impurity ion density radial profiles are successfully observed in GAMMA 10. Then the CR-model calculation results for CII and CIII ions are consistent to the results of the plasma spectroscopy in our experimental conditions. We propose the new line pairs for plasma electron temperature measurements. The spectroscopic diagnostics with comparing the CR-model is useful in the GAMMA 10 plasma.