Transport of heavy hydrocarbon and its redeposition on plasma facing walls

重い炭化水素の輸送とプラズマ対抗壁への再たい積

大宅 薫*; 井内 健介*; 菊原 康之*; 仲野 友英; 河田 純*; 川染 勇人*; 上田 良夫*; 田辺 哲朗*

Oya, Kaoru*; Inai, Kensuke*; Kikuhara, Yasuyuki*; Nakano, Tomohide; Kawata, Jun*; Kawazome, Hayato*; Ueda, Yoshio*; Tanabe, Tetsuo*

CH, CH及びCHのプラズマ対抗壁近傍での輸送と再たい積をEDDYコードを用いて調べた。計算結果では、CH及びCHはCHと比較して発生場所の近傍に再たい積することが示された。これはJT-60Uでの分光測定結果と定性的に一致する。また、EDDYコードで計算されたCの発光に対するCHの電離事象数及びCHの発光に対するCHの電離事象数は電子温度が10eV以上の範囲ではJT-60Uでの分光測定結果と定量的に一致した。

Redeposition of CH and CH chemically eroded from carbon walls is simulated by EDDY code incorporated with the reflection on a hydrogenated and amorphized carbon surface. The redeposition rate for heavy hydrocarbons is drastically decreased by introduction of the reflection. The redeposition patterns on the surface are enlarged by the reflection, but it is narrower for the heavy hydrocarbons than for CH. The photon emissions of C from CH (CH) decay faster than that of CH from CH in high-temperature (10 eV) plasmas, which reproduces the difference of the decay of the CD and C light intensities observed in the vicinity of the outer diverter plates of JT-60U. For such temperatures, the inverse photon-efficiency, which is defined as the ratio of the number of the launching hydrocarbons to the photoemission events of CH and C, is in good agreement with the values observed in JT-60U experiments.