著者
杉山 明 安田 秀幸 柳楽 知也 吉矢 真人 上杉 健太朗 梅谷 啓二 大中 逸雄
出版者
公益社団法人 日本鋳造工学会
雑誌
鋳造工学 = Journal of Japan Foundry Engineering Society (ISSN:13420429)
巻号頁・発行日
vol.83, no.3, pp.131-136, 2011-03-25
参考文献数
11
被引用文献数
1

It is well known that controlling the graphite shape in cast iron is a critical issue to achieve appropriate properties. It is of interest to know how the microstructure in cast iron evolves during solidification. So far, time-evolution of the microstructure has not been observed in-situ. This paper presents the in-situ observation results of cast iron solidification using X-ray imaging of synchrotron radiation. Transmission X-ray images with a spatial resolution of as small as 5<i>μ</i>m were obtained by an X-ray detector SATICON in an imaging beam line 20B2 at SPring-8. A 10 × 10 × 0.1mm specimen was melted and solidified in a mold made of Al<sub>2</sub>O<sub>3</sub> placed in a vacuum chamber. The observation showed that the solidification started with austenite dendrites, after which the eutectic structure was formed. Graphite clusters of about 100<i>μ</i>m in diameter were formed in the remaining liquid surrounded by the eutectic structure at a cooling rate of less than 10K/min. At a cooling rate of 10K/min, the primary dendrite and the eutectic grains moved up and down, respectively, due to the bouncy force.
著者
島 邦博 見原 猛 梅谷 啓二 三雲 昂
出版者
公益社団法人 日本アイソトープ協会
雑誌
RADIOISOTOPES (ISSN:00338303)
巻号頁・発行日
vol.29, no.8, pp.363-367, 1980-08-15 (Released:2010-09-07)
参考文献数
5

鉛を遮蔽材としてγ線バックグラウンドを測定する場合, 種々の放射性同位元素によるγ線, X線が観測される。このうち, 最も強く観測される鉛のKX線の発生要因について検討した。バックグラウンドスペクトルに表れる210Pbの47keVγ線計数をもとにして, 210Pbと放射平衡にある210Biのβ線の制動放射によって鉛のK殻光電効果の起こる割合を, 簡単なモデルを使って計算した結果, 観測される全Pb-KX線に, 上記過程が相当部分寄与していることがわかった。
著者
谷 啓二 飛田 健次 西尾 敏 飯尾 俊二 筒井 広明 青木 尊之
出版者
社団法人プラズマ・核融合学会
雑誌
プラズマ・核融合学会誌 (ISSN:09187928)
巻号頁・発行日
vol.80, no.11, pp.931-934, 2004-11-25
被引用文献数
1 1

Studies were made on ripple losses of fusion produced alpha particles in a low-aspect-ratio tokamak reactor (VECTOR) by using an orbit-following Monte-Carlo code. Alpha particles are well confined in VECTOR. In a low-aspect-ratio tokamak, the dependence of ripple losses on the number of toroidal-field (TF) coils N is very weak. Assuming a toroidal peaking factor of 2 for the heat load due to loss particles, about 1.5% and 1.0% of TF ripple at the outer edge of plasma might be allowable for the first wall with and without cooling system, respectively. In both cases, the number of TF-coils can be reduced to about 4.