@article{oai:repo.qst.go.jp:00082031,
 author = {Makoto, Fukuda and Yoji, Seki and Koichiro, Ezato and Kenji, Yokoyama and Hiroshi, Nishi and Satoshi, Suzuki and Takeshi, Hirai and Makoto, Fukuda and Yohji, Seki and Koichiro, Ezato and Kenji, Yokoyama and Hiroshi, Nishi and Satoshi, Suzuki},
 journal = {Fusion Engineering and Design},
 month = {Jun},
 note = {For the series production of the divertor outer vertical target (OVT) of the ITER, approximately 200,000 tungsten (W) monoblocks as plasma-facing material are planned to be manufactured. However, thus far, the variation in the properties of the W monoblocks has not been investigated. In this study, the chemical impurity level, material properties, and response to  cyclic heat loading (i.e., durability and surface deformation) of  W  monoblocks manufactured using W plates supplied by A.L.M.T. Corp., Japan (ALMT) and Nidec Sankyo CMI Corp., Japan (NSCM) were investigated. On examining the manufactured lots (four from ALMT and two from NSCM), it was concluded that the variation in the material properties might have been caused by variations in the impurity level of the raw powder, contamination during manufacturing, and changes in the processing parameters. The results of the high heat flux test indicated that all the examined lots met the acceptance criteria. Hence, the variations observed in the chemical impurity level and material properties (e.g., density, Vickers hardness, and grain size) of the W plates supplied by ALMT and NSCM were acceptable. Therefore, W from the two suppliers will be employed in the full-scale plasma-facing unit prototype, which will be used for the final qualification of the material and OVT manufacturing technology.},
 title = {Performance evaluation of tungsten for ITER divertor toward mass production},
 volume = {167},
 year = {2021}
}