@misc{oai:repo.qst.go.jp:00066800,
 author = {Ashikawa, N. and Asakura, Nobuyuki and Miyamoto, M. and Hara, M. and Y., Trikai and Oyaizu, Makoto and Nakano, Suguru and Kim, Jaehwan and Hatano, Y. and Suzuki, Takuya and Kurotaki, Hironori and Hamaguchi, Dai and Nakamichi, Masaru and Nakamura, Hirofumi and Widdowson, A. and Heinola, K. and Rubel, M. and 朝倉 伸幸 and 小柳津 誠 and 中野 優 and 金 宰煥 and 鈴木 拓也 and 黒滝 宏紀 and 濱口 大 and 中道 勝 and 中村 博文},
 month = {Sep},
 note = {Joint European Torus (JET) started operation with the ITER-like Wall (ILW) in 2011 using tungsten (W)-coated CFC/bulk-tungsten divertor tiles and beryllium first wall, respectively. The main aims are: development of an integrated operation scenario for ITER, power handling and material behavior with metal walls, assessment of fuel inventory and development of ITER-oriented engineering solutions, e.g. remote handling. The determination of dust characteristics, such as structures, material composition and hydrogen isotope retention are important issues. In particular, measurement of the total tritium amount and their relationship between amount and composition are required. Therefore, this study was focused on material composition and quantitative tritium amounts in JET-ILW dust particles. Retained deuterium concentration in C, Be and W deposits under co-deposition was reported. Retention in beryllium oxide is one order of magnitude larger than metal beryllium. Hence, chemical bindings of beryllium in ILW materials are important for estimations of hydrogen isotope retention and tritium inventories. Quantitative tritium measurements for ILW from the 2011 to 2012 campaign and carbon dust particles from 2007 to 2009 campaigns collected on the inner divertor targets were done using a liquid scintillation counting (LSC). Tritium specific activity of ILW dust particles of 120 MBq/g, is nearly the same as that of carbon wall dust particles of 10-60 MBq/g. Beryllium dominant dust particles show beryllium oxide on those surfaces measured by X-ray photoelectron spectroscopy (XPS) and one of these thicknesses is about two microns. This result was estimated that the reason of higher tritium inventory in ILW dust particles was related to thick beryllium oxide on those surfaces. It should be noted that producted conditions, such as after a vacuum vent or during plasma operations, of beryllium oxide is not clear due to the ex-situ measurements. However, the ratio of volume between beryllium oxide and metal beryllium into a dust particle is higher than that of beryllium tile specimens from JET, due to the estimated volume less than 5x10-4 mm3, in the case of 100 microns diameter. Therefor it is estimated that higher tritium specific activities on ILW dust particles, it is normalized amounts by weights, were observed. Evaluations of tritium specific activity measured by a combustion method and beryllium observations measured by an electron probe micro analyzer (EPMA) in ILW dust particles will be also presented., 13th International Workshop on Beryllium Technology,},
 title = {Beryllium oxide on dust particles produced by ITER like wall materials in JET},
 year = {2017}
}