Spatial characterization of a divertor in the presence of an X-point MARFE by collisional-radiative modeling and line profile calculations.

Abstract: High-resolution C IV n =6–7 (λ =722.6nm) line spectra measured in the divertor of JT-60U in presence of an X-point MARFE are analyzed using line profiles accounting for Stark and Doppler broadenings but excluding Zeeman effect which was suppressed experimentally. Spectra are fitted assuming either a single or two plasma layers depending on the crossed part of the MARFE. The ion temperature is taken equal to that of the electrons, the latter being deduced from C IV line intensity ratios. A density of 1020 m−3 has been determined after fitting peripheral spectra with respect to the MARFE. For spectra related to central parts of the MARFE, two homogeneous plasma layers were assumed: a low-density layer and a high-density one with . For few values of , a fitting procedure was used in which (low-density layer temperature) and (high-density layer density) were searched for in the domains 1–25eV and 1020–1021 m−3. [Copyright &y& Elsevier]