Radiation processes of impurities in detached divertor plasmas of JT-60U

Nakano, Tomohide; Asakura, Nobuyuki; Shimizu, Katsuhiro; Konoshima, Shigeru; Fujimoto, Kayoko; Kawashima, Hisato; Higashijima, Satoru

WeThe intensity ratios of 9 C IV lines from the C IV emission peak were analyzed with a collisional-radiative model. From the analysis, it was found that the lowly-excited levels () were predominantly populated by the excitation from the ground state of by an electron impact with an electron temperature of 10 eV and an electron density of , while the highly-excited levels () by the volume recombination of and an electron with an electron temperature of 3 eV. With these parameters and the absolute intensity of C IV () and C IV () lines, the radiation power due to the excitation and the recombination process were determined to be, respectively, 40% and 0.5% of the total radiation power measured by a bolometer. Further, it was found that the recombination flux was comparable to the ionization flux.