Line-shape code comparison through modeling and fitting of experimental spectra of the C II 723-nm line emitted by the ablation cloud of a carbon pellet

Abstract

Various codes of line-shape modeling are compared to each other through the profile of the C II 723-nm line for typical plasma conditions encountered in the ablation clouds of carbon pellets, injected in magnetic fusion devices. Calculations were performed for a single electron density of 1017 cm-3 and two plasma temperatures (T = 2 and 4 eV). Ion and electron temperatures were assumed to be equal (Te = Ti = T). The magnetic field, B, was set equal to either to zero or 4 T. Comparisons between the line-shape modeling codes and two experimental spectra of the C II 723-nm line, measured perpendicularly to the B-field in the Large Helical Device (LHD) using linear polarizers, are also discussed.