@article{oai:repo.qst.go.jp:00082911,
 author = {林, 孝夫 and 武智, 学 and 松永, 剛 and 諫山, 明彦 and Takao, Hayashi and Manabu, Takechi and Go, Matsunaga and Akihiko, Isayama},
 journal = {Fusion Engineering and Design},
 month = {May},
 note = {First divertor cassette covering a 10◦ sector in the toroidal direction has been manufactured for JT-60SA. Modularized plasma facing components such as inner and outer targets, baffles, and domes are assembled into the divertor cassette. All plasma facing components are actively cooled. Carbon armor tiles bolted to water-cooled copper alloy heat sinks are used to remove heat loads of 0.3–1MW/m2 for 100 s and 10 MW/m2 for less than 5 s. The divertor cassette has two pipe joints between it and the inlet and outlet pipes on the vacuum vessel side. After removing the divertor cassette, the inner target can be replaced by cutting and welding the other two pipe joints with the divertor cassette. A remote pipe welding tool has been developed both to install the divertor cassette into the vacuum vessel and to connect the inner target with the divertor cassette. The space around the cooling pipes is so limited that they are cut and welded remotely from the inside for replacement. The laser welding method was used, and the focusing mirror inside the pipe was rotated to perform circumferential welding. As a countermeasure for welding groove misalignment, the aiming accuracy of the laser was improved by simultaneously controlling the rotation and lifting of the tool. Thereby, reliable welding is achieved even with large gaps of up to 0.5 mm and grooves with a maximum angular deviation of 0.5 ° between connecting pipes. The outer diameter of the cooling pipe is 59.8 mm, the wall thickness is 2.8 mm, and the material is SUS316L. After connecting the inner target, the other plasma facing components have been assembled into the first lower divertor cassette. When installing the divertor cassette towards the vacuum vessel, the laser welding tool described above is used to connect the cooling pipes between divertor cassette and vacuum vessel in JT-60SA, because the outer diameter and wall thickness of the cooling pipe are the same as the inner target.},
 title = {Manufacturing of lower divertor cassette of JT-60SA},
 volume = {170},
 year = {2021}
}