[B-PT03] バイオミネラリゼーションと古環境プロキシー

[BPT03-P05] 放射光マイクロX線CTによる珪藻の3Dイメージング精度の向上

*廣瀬 孝太郎¹、上杉 健太朗²、長井 裕季子³、豊福 高志³、瀬戸 雄介⁴、安武 正展²、佐田 侑樹²、上椙 真之²、竹内 晃久²、竹田 裕介² (1.兵庫県立大学　自然・環境科学研究所、2.高輝度光科学研究セ・散乱・イメージング推進室、3.海洋開発研究機構･超先鋭研究開発部門 (X-star）、4.大阪公立大・理学)

キーワード：珪藻殻、3Dイメージング、マイクロX線CT、放射光

Measurement of structure by X-ray micro- Computed Tomography (CT) is effective in obtaining morphological information and 3D images of microfossils. Some microfossils, such as foraminifera, have been studied by X-ray micro-CT, and new paleoenvironmental proxies focusing on the shell volume and pore geometry have been proposed. On the other hand, since diatoms are one of the smaller microfossils, the resolution of a laboratory-type CT system is insufficient, and there are currently few reports of measurements.
In this study, diatom shells were measured using a micro/nano CT system at SPring-8. The samples were placed on a CNT sheet laid on a SUS pin for measurement. The exposure times for the micro-CT and nano-CT modes were set to 30 msec and 300 msec, respectively, with an energy of 20 keV in both cases.The pixel size of the acquired data is 0.496 µm/pixel and 0.0415 µm/pixel in both modes, respectively, and clear 3D images of Coscinodiscus perforatus., Surirella fastuosa, and Pleurosigma sp. were obtained. Notably in nano-CT mode, sub-micron scale pores and process were resolved.