[1L15-18] Tritium in DEMO/LHD/JET

[1L16] Tritium retention in the first-wall and divertor tiles during the deuterium plasma campaigns in LHD

*Suguru Masuzaki^1,2, Miyuki Yajima^1,2, Masahiro Tanaka¹, Gen Motojima^1,2, Tomohiro Morisaki^1,2, Masayuki Tokitani^1,2, Teppei Otsuka³, Naoaki Yoshida⁴, Yasuhisa Oya⁵, Yuji Hatano⁶ (1. NIFS, 2. SOKENDAI, 3. KINDAI Univ., 4. KYUSHU Univ., 5. SHIZUOKA Univ., 6. Univ. TOYAMA)

Keywords:LHD, tritium, retention, divertor, first-wall

In LHD, a part of the tritium generated by the DD reaction in deuterium plasma was not exhausted and accumulated in the first-wall and divertor tiles. Calculations show that most of the fast tritons are mainly incident on the divertor tiles and the first-wall near the divertor tiles, which is consistent with the measured results by the full-combustion method and the thermal desorption method. On the other hand, a relatively large amount of tritium is retained in the deposition layer on the first-wall formed by the erosion and redeposition of carbon from divertor tiles even in places where fast tritons do not directly incident on them. We are trying to elucidate the mechanism of retention.