[3H11-12] Divertor Particle and Heat Tranport

[3H11] Evaluation of high wall temperature effect on hydrogen isotope retention and impurities deposition behavior for plasma exposed tungsten in QUEST

*Shiori Hirata¹, Naoaki Yoshida², Kazuaki Hanada², Yasuhisa Oya¹ (1. Shizuoka Univ., 2. Kyusyu Univ.)

Keywords:Tungsten, QUEST, Hydrogen isotope behavior

It is essential for the realization of a fusion reactor to evaluate hydrogen isotope behavior in plasma facing wall. In this study, tungsten samples were exposed to hydrogen plasma during the QUEST 2020S/S and 2021S/S campaigns. The maximum wall temperature of QUEST 2020S/S and 2021S/S campaign were 473 K and 673 K, respectively. These samples surface was observed by transmission electron microscopy, and their chemical states were measured by X-ray photoelectron spectroscopy. After that, hydrogen retention behavior was evaluated by thermal desorption spectroscopy. The hydrogen retention of samples that introduced in 2021S/S was lower than that of 2020S/S, which will be caused by higher wall temperature. The effects of wall temperatures to impurities desorption and hydrogen isotope behavior will be presented.