[2L01-05] Engineering of Plasma Facing Components

[2L02] Hydrogen isotope retention behavior for damaged W exposed to QUEST hydrogen plasma discharge

*Yasuhisa Oya¹, Ayaka Koike¹, Shiori Hirata¹, Yuki Koyama¹, Kyosuke Ashizawa¹, Naoaki Yoshida², Kazuaki Hanada² (1. Shizuoka Univ., 2. Kyushu Univ.)

Keywords:hydrogen isotope , irradiation damage, Tungsten, QUEST

The Fe ion damaged W was installed on QUEST plasma facing wall to elucidate the impact of irradiation damages on hydrogen isotope retention. After QUEST plasma exposure, additional 1 keV D2+ implantation was performed to clarify the D retention in the damaged W. it was found that D trapping energy was reduced at Bottom area. The irradiation damages by energetic Fe ion were accumulated near the surface, which would enhance the re-emission of D. In addition, the accumulation of impurities would work as hydrogen diffusion barrier. For the long-term plasma operation, the TOP area was damaged by hydrogen plasma in QUEST. In addition, CHI discharge introduced irradiation damages in BOTTOM area. These plasma operations would influence on D retention behavior.