| Summary: | 氷結晶の方位, 特に氷床コア試料の結晶ｃ軸方位は, 氷床の変形履歴を反映し, 氷床の力学的性質を決定する主要因子として詳細に調べられてきた. 測定装置は, 多くの時間と労力, 操作に熟練を要するユニバーサル・ステージから発展し, 近年は自動測定装置が用いられている. 2000m を超えるような深層コアの解析には自動化された測定装置が有効に用いられているが, 氷床深部に存在する非常に強い単極大型などの特殊な結晶方位分布の詳細を明らかにするには, 十分な測定精度を有していない. そこで, 筆者らはＸ線を用いた半自動化された結晶方位測定装置を開発し, 高精度測定を実現した. 本稿では, この装置の開発について述べ, 研究への適用例について紹介する. Ice crystal c-axis orientation of ice core samples have been investigated in detail as a major controlling factor of the mechanical properties of ice sheets. The universal stage was a common measurement device for c-axis orientation. The measurement procedure using this device is very time-consuming, involving tedious work in a cold laboratory. Instead, automated measuring devices have been widely used in recent years. Those are very effective for the analysis of large amounts of samples with more than 2000 m long ice core. However, the automated devices do not have a sufficient measurement accuracy to reveal details of the exceptional crystal orientation distribution such as the very strong single maximum existing in the deep part of ice sheet. Therefore, in order to obtain high accuracy, a new ice crystal orientation measuring device has been developed using the Laue X-ray diffraction method. This paper describes the development of this new device and examples of applying it to various researches.
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