| 研究実績の概要 |
During 2022 FY year we performed phase-contrast imaging (PCI) experiments at High Energy Density platform of SACLA XFEL(BL3) in the frames of 4 accepted proposal. Our the PCI method was further upgraded. Now the radiographic scheme operates in multi-imaging acquisition regime. The images of the object are recorded at three different distances from the object to detectors. At every distance the PCI effect is optimized for the specific absorption and scattering properties of the object. That improvement allowed to advance the quality and informative of radiography in the wide range of density variations and to increase the accuracy of density measurements.
By this method, we studied the complicated morphology of the high-energy-laser-induced shocks formed under pressure up to a few Mbar for numerous crystalline and amorphous materials of interest of precise determination parameters for equations of state (EOS) and for astrophysics related tasks (alfa-quartz, z-cut quartz, fused silica, Al, magnesium silicate Mg2SiO4, MgSiO2 glass ceramic).
We continued investigation of shock induced phenomena in diamond, in particular, the slip failure mechanism. In crystalline diamonds with three different orientations <100>, <110>, and <111> were examined on the difference in plasticity mediated by shock-induced defects.
In theory and simulations, for dynamic of elastic-plastic shock waves splitting in diamond the impressive matching obtained by 2D modeling using Smoothed Particle Hydrodynamics code. Developed the diffraction based model for measuring width of rising front in shock waves.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
The experimental program is 90 percent realized and will no doubt be completed early next year.
The multi-images PCI scheme was realized for the first time. We clearly demonstrated that, in the range of photon energy ranges of 7-12 keV the applied method allows direct precise 2D mapping of density distribution for almost any material with transmission from a few percent up to 96-98% during the experiencing of dynamic loads up to hundreds of GPa.
In this year, among a significant number of first observed phenomena developed in the matter under laser-induced extreme compression conditions, we may point out the discovery of fast motion of dislocation in the diamond (article is submitted to Science journal), multi-shock formation in Z-cut quartz (predicted by theory, but not being confirmed), appearance of metastable dense layer in quartz with high probability related to phase transition to Stishovite.
Published 2 articles, submitted 3 articles
Conferences: 4 presentations (2 oral, 2 posters)
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| 今後の研究の推進方策 |
The last year of the Proposal will be dedicated to (a) final collection and sorting of experimental results; (b) verification of computational approaches (SPH, Failure model, WavePropaGator); (c) performing of data simulation analysis; (d) writing of articles; (e) preparation the overview of scientific results and achievements for the Proposal final report.
We are planning to perform one more experiment at SACLA XFEL.
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