Contribution of Stark-Doppler broadening of carbon impurity lines to the analysis of tokamak divertor plasmas

We investigate the broadening mechanisms affecting carbon lines emitted from tokamak divertor plasmas with an emphasis on the C IV n=6−7 (γ=772.6 nm) line. We show how line profiles can contribute to the spatial characterization of tokamak divertors providing high-resolution line spectra along viewing chords can be measured. For simplicity, we ignore the Zeeman effect by considering only Doppler and Stark broadenings in the calculations. Therefore these calculations, which ignore the magnetic field effect, can be compared to spectra measured with the use of a linear polarizer transmitting only the π component whose polarization is parallel to the toroidal magnetic field. Comparison of theoretical profiles to high-resolution measured C IV n=6–7 line spectra allow the determination of the several plasma parameters.