Recent studies of heat and particle loadings in long pulse discharges and influence on PWI in JT-60U

Asakura, Nobuyuki; Nakano, Tomohide; Kawashima, Hisato; Masaki, Kei; Fujimoto, Kayoko; Ono, Noriyasu*; Tanabe, Tetsuo*

ELMy H-mode plasmas have been recently operated during long duration under the wall saturated condition in JT-60U. Investigation of the heat and particle handling and PSI studies such as erosion and deposition of carbon have been progressed. Deuterium gas balance has been studied in short term, and it was found that globally saturated condition of PFCs is caused mostly by an increase in wall temperature near the divertor. Increase in the divertor pumping was investigated to demonstrate particle control under the globally saturated condition. Erosion and deposition of the carbon target has been analyzed at the divertor tiles after the experiment campaigns. Deposition pattern and its rate on the tile surface were similar to those at other tokamaks such as JET. On the other hand, deposition depth of the tile edge was relatively smaller, which suggests difference of tile arrangement. Deuterium co-deposition was found to be smaller. Influence of operation temperature is discussed.