Development of time-resolved small-angle X-ray scattering system using soft-X-ray laser

X線レーザーを用いた時間分解X線小角散乱法の開発

熊田 高之   ; 乙部 智仁*; 錦野 将元*; 長谷川 登*; 林 照剛*

Kumada, Takayuki; Otobe, Tomohito*; Nishikino, Masaharu*; Hasegawa, Noboru*; Hayashi, Terutake*

軟X線レーザーを用いた時間分解反射型X線小角散乱装置を構築した。今回はポンプ光を同期させずに赤外・可視光用回折格子を用いて散乱パターンを測ったところ理論予測どおりの散乱パターンが得られた。一方で縞状パターンがあらわれた高強度フェムト秒レーザーの集光スポットの散乱を測定したが、測定に用いた軟X線用CCDカメラの熱ノイズ以上の信号は得られなかった。今後の開発に向け、CCDカメラの選定が重要になる。

The non-thermal effect on femtosecond laser ablation has been focused on for development of high-precision micromachining technique. In this study, we newly focused on a time-resolved grazing-incidence small-angle X-ray scattering (GI-SAXS) measurement. In principle, the GI-SAXS can measure time-evolution of the morphology of the voids, which would be stretched in normal to the sample surface by the non-thermal effect. We can quantitatively evaluate the non-thermal effect from the asymmetric morphology of the voids. We succeeded in observing the scattering from a gold-deposited optical grating (1740 lines / mm), but not from a post-ablated crater on a gold plate. We have to decrease the noise level of the camera to pick up dispersed signal from disordered system such as the crater.