Tungsten deposition distribution in divertor region in JT-60U

Watanabe, Jun*; Fukumoto, Masakatsu*; Soga, Yasuyuki*; Otsuka, Yusuke*; Ueda, Yoshio*; Arai, Takashi; Asakura, Nobuyuki; Nakano, Tomohide; Sato, Masayasu; Yagyu, Junichi; Ochiai, Kentaro; Takakura, Kosuke

Tungsten was mainly deposited on the inner divertor (around the inner strike point) and the outer wing of the dome. Tungsten deposition on the dome was found only near the top surface (within depth of a few micron m), while tungsten on the inner divertor was codeposited with carbon to the depth up to about 60 micron m. Discussion on the relation between depth distribution of tungsten and EDX signals are also presented. Significant difference between tungsten and other metallic materials (Fe, Ni, Cr) in terms of toroidal deposition distribution on the outer wing was observed. Tungsten deposition was toroidally localized in the P-8 section, where tungsten coated tiles were installed. On the other hand, other metallic materials (Fe, Ni, Cr) were not toroidally localized compared with the case of tungsten.