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

[1L15] Tritium retention in gaps of first wall and divertor tiles used in JET-ITER like wall experiment

*Yuji Hatano¹, Suneui Lee¹, Suguru Masuzaki², Masayuki Tokitani², Yasuhisa Oya⁴, Naoko Ashikawa², Hirofumi Nakamura³, Takumi Hayashi³, Anna Widdowson⁶, Marek Rubel⁵ (1. Univ. of Toyama, 2. NIFS, 3. QST, 4. Shizuoka Univ., 5. KTH Royal Inst. of Tech., 6. CCFE)

Keywords:Tritium inventory, Sputtering, Co-deposition, Beryllium, Tungsten

The first walls and divertor of ITER have castellated structures to prevent damages by eddy current and thermal expansion, and the tiles used in JET ITER-like wall experiments also have many gaps and grooves. In this study, tritium accumulation in these gaps and grooves was examined using imaging plate technique under Broader Approach Activities. The deposition layers consisting of Be, O and C were formed in the gaps and grooves, and tritium was co-deposited with these elements. The thickness of deposition layers was about 100 nm or less. The tritium concentration in deep regions in the grooves showed clear correlation with the concentration of C impurity.