Characterization of the edge plasma in JET from the C V and C VI XUV spectrum
M G O'Mullane; M Mattioli; R Giannella; I H Coffey; N J Peacock
Журнал:
Plasma Physics and Controlled Fusion
Дата:
1999-01-01
Аннотация:
The extreme ultraviolet (XUV) spectrum of C V and C VI from the edge plasma in JET has been analysed and a collisional radiative model (CRM) is used to simulate the line emissivities. We view, in the XUV range, the scrape-off layer (SOL) during the limiter phase of the discharge evolution, whereas, when the divertor configuration is established, the X-point region is viewed. A zero-dimensional model of the SOL has shown that the line ratios are sensitive to the peripheral profiles (T<sub>e</sub>, n<sub>D</sub> fraction and carbon ionization degree) and these parameters are inferred as a function of time for an ohmic JET discharge. We find that charge exchange of carbon ions with deuterium (the filling gas) is an important process in the SOL and near-edge plasma and is included as an integral part of the CRM.
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