低温工学
Online ISSN : 1880-0408
Print ISSN : 0389-2441
テーマ解説
純ニオブに含有される不純物に関する研究
梅澤 裕明
著者情報
ジャーナル フリー

52 巻 (2017) 2 号 p. 79-84

詳細
PDFをダウンロード (908K) 発行機関連絡先
抄録

The purity of niobium for a superconducting cavity refined using an electron-beam melting method was explained from RRR measurement, gas analysis and GDMS analysis. Metallic purity notation generally refers to the value obtained by subtracting the total of metal impurities other than gas components from100%. For example, it is 3N at 99.9% and 4N at 99.99%. In the case of niobium, since tantalum containing tens to hundreds of ppm is the majority of the impurities, it is 3N or 2N8 in a normal purity notation. However, with the agreement of customers, when tantalum, tungsten and molybdenum are excluded from the target elements, purity corresponding to 6N - 7N is obtained. Tantalum is not removed by electron-beam melting, so we select and purchase less tantalum at the raw materials stage.

著者関連情報
© 2017 公益社団法人 低温工学・超電導学会 (旧 社団法人 低温工学協会)
前の記事 次の記事

閲覧履歴
feedback
Top