Impurity emission spectra from a fusion plasma have a lot of important information of the plasma, such as temperatures and densities of impurities, radiation loss and rotation velocity of ions. These informations are very useful to evaluate the impurity transfer and energy loss from a plasma. Moreover the radial profile of electron density, temperature and electric field in the plasma are obtained by using a collisional radiative model(CRM) and the relation between the profile of spectra and plasma parameters. By using the CRM, the ratios of excited states population density to ground state in the impurity ion are described as a function of the electron temperature and the electron density in the ionizing plasma. CRMs for carbon and oxygen have been developed. However verification and application of the model to experimental results were not enough. Then we applied CRM calculation results to the analysis of observed spectra in the GAMMA 10 tandem mirror to evaluate the impurity density profile and the particle balance of each charge state of carbon.
In the GAMMA 10 tandem mirror, two absolutely calibrated UV/Visible spectroscopic systems are installed on both the central cell and the anchor cell. Space and time resolved spectra are observed and analyzed in order to evaluate the plasma parameter and impurity transfer. In both cells, C⁺, C²⁺, O⁺, O²⁺, O³⁺ and O⁴⁺ are mainly observed. In any experimental setup in GAMMA 10, C⁰ and C³⁺ are not observed by any spectroscopic measurement systems. Then we calculated C⁺ and C²⁺ density profiles using both absolute calibrated spectra and CRM calculations in the ionizing plasma approximation. We estimate the C⁰ and C³⁺ density profile by charge balance of carbon ion and consider the impurity ion confinement.
In this paper, we present the results of CRM calculation for C⁺ and C²⁺ and experimental results of carbon ion emission in the GAMMA 10 tandem mirror. Moreover we discuss the particle balance of each charge state of carbon and the confinement of carbon in the plasma.

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