レーザーを用いた衝撃変成手法の開発と地球惑星科学への応用

抄録

It is important to recover shock-compressed samples for understanding synthetic mechanism of highpressure phase, shock metamorphism, and shock-melt vein in meteorites. We developed recovery technique of the laser-shocked minerals at higher pressures (130-460 GPa) in high-power laser system. We used the single crystal olivine which is a major mineral of meteorites and Earth. The deformation, fracture, and phase identification of the recovered olivine were observed comprehensively by optical microscopy, field emission-scanning electron microscopy, electron backscatter diffraction, X-ray diffraction, and micro-Raman spectroscopy. There were three distinctive structures in the recovered sample. We estimated pressure attenuation rate of shock wave in the sample from the distribution of these structures. The attenuation rates of 2-3 in our experiments were larger than that in previous experiments and simulations.