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Morita, Shigeru*; Dong, C. F.*; Goto, Motoshi*; Kato, Daiji*; Murakami, Izumi*; Sakaue, Hiroyuki*; Hasuo, Masahiro*; Koike, Fumihiro*; Nakamura, Nobuyuki*; Oishi, Tetsutaro*; et al.
AIP Conference Proceedings 1545, p.143 - 152, 2013/07
Times Cited Count:30 Percentile:99.19(Physics, Applied)Tungsten spectra have been observed from Large Helical Device (LHD) and Compact electron Beam Ion Trap (CoBIT) in wavelength ranges of visible to EUV. The tungsten spectra from LHD are well analyzed based on the knowledge from CoBIT tungsten spectra. The C-R model code has been developed to explain the UTA spectra in details. Radial profiles of EUV spectra from highly ionized tungsten ions have been measured and analyzed by impurity transport simulation code with ADPAK atomic database code to examine the ionization balance determined by ionization and recombination rate coefficients. The ablation cloud of the impurity pellet is directly measured with visible spectroscopy.
Yanagibayashi, Jun*; Nakano, Tomohide; Iwamae, Atsushi; Kubo, Hirotaka; Hasuo, Masahiro*; Itami, Kiyoshi
Journal of Physics B; Atomic, Molecular and Optical Physics, 43(14), p.144013_1 - 144013_6, 2010/07
Times Cited Count:26 Percentile:72.14(Optics)We observe the vacuum ultraviolet spectra of highly charged tungsten ions in plasmas at electron temperatures of 8 keV and 14 keV. The observed emission lines in a wavelength range of 2.6 3.2 nm for the plasma at 8 keV are identified to be the transitions of . The observed emission lines at 2.0 nm and 2.3 nm at 14 keV are identified to be the transitions of and transitions of , respectively.
Yanagibayashi, Jun; Nakano, Tomohide; Hasuo, Masahiro*; Iwamae, Atsushi; Kubo, Hirotaka; Itami, Kiyoshi
no journal, ,
Tungsten is one of the candidates for the divertor material of ITER because of its low retention and low hydrogen inventory. However, it is a problem that tungsten ions accumulated in a core plasma emit intense radiation and cool the plasma. For preparation of investigating the mechanism of the tungsten ion accumulation, Vaccum Ultra Violet (VUV) lines emitted from tungsten ions are identified. A VUV spectrum from a JT-60U plasma ( keV) is observed with a flat-field grazing-incidence spectrometer. The observed spectrum is compared with a theoretical spectrum calculated with Flexible Atomic Code. It is found that the observed peaks around 3 nm are due to transitions between levels of W (), and that those around 5, 6 and 13 nm are due to transitions between levels of W (). It is believed that the former lines are useful to diagnose the tungsten ion accumulation in a high-temperature ( 10 keV) plasma of ITER.