Carbon emission measurements on the RFP device ETA-BETA II

The emissivity of the CV 2271 A line has been measured on the RFP device Eta-Beta II along 7 plasma chords, using a 1-m Czerny-Turner spectrometer, equipped with a 2400g/mm grating. The spectrometer has been absolutely calibrated by a strip tungsten lamp to evaluate the carbon content in the discharge. An impurity transport model has been modified to simulate the impurity lines behaviour: for each ion, the ground and metastable state population densities are separately calculated. The simulation of the experimental data cannot account for the asymmetry of the plasma, because the diffusion model is cylindrically symmetric. Therefore, only a qualitative comparison between the calculated ans experimental time behaviour of the emission profiles may be obtained. (author) 2 refs., 6 figs