[P-CG22] Shock responses of planetary materials elucidated from meteorites and dynamic compression experiments

[PCG22-07] Dynamic Compression at Pohang X-ray Free Electron Laser Facility (PAL-XFEL)

★Invited Papers

*Yongjae Lee¹ (1.Yonsei University, Seoul, Korea)

キーワード：dynamic compression, laser shock, iron, X-ray free electron laser

We have successfully commissioned dynamic compression studies at the Pohang X-ray Free Electron Laser facility (PAL-XFEL) in Korea by utilizing instrumentations at FXS (Femtosecond X-ray Scattering) – XSS (X-ray Scattering and Spectroscopy) beamline. As the first experiment, a polycrystalline iron foil has been illuminated by an 800 nm wavelength uncompressed optical laser with ~6 mJ in 150 ps pulse length, focused onto a 100 mm FWHM spot. The shock-compressed sample has then been probed by ca. 50 fs quasi-monochromatic (bandwidth 0.4%) X-ray pulse at an energy of ~10 keV with 10¹¹ photons per pulse, focused to ca. 30 mm diameter using a CRL optics. The sample is positioned normal to the X-ray pulse at a distance of ca. 12 cm from a Rayonix mx225 detector in a way to cover 2q angles up to ca. 65 degrees. Single-shot diffraction measurements were performed with ca. 100 ps. increment up to one nanosecond. We demonstrate that PAL-XFEL can provide a unique opportunity in probing ultrafast lattice dynamics with sufficient spatial and temporal resolution in intermediate pressure regime.