Delayed Onset and Directionality of X-Ray-Induced Atomic Displacements Observed on Subatomic Length Scales

Inverse Design of Light Manipulating Structural Phase Transition in Solids

“…This result also provides insights into the puzzles of melting time scale discussed in previous studies, − where a high-frequency laser requires a longer melting time. Similar results of delayed onset of the nonthermal melting event have been reported by X-ray pumping experiments in different semiconductors, such as Si, C, and Al 2 O 3 …”

“…Similar results of delayed onset of the nonthermal melting event have been reported by X-ray pumping experiments in different semiconductors, such as Si, 81 C, 82 and Al 2 O 3 . 83…”

Advantages of Using Hard X-ray Photons for Ultrafast Diffraction Measurements

“…Our simulations of X-ray-irradiated silicon crystals have shown that the electronic damage of the sample quantified by its average ionization degree (i.e., the number of excited conduction band electrons per atom) at a fixed absorbed dose decreases with the increasing X-ray photon energy. This also results in a much slower increase in the sample ionization degree with time for higher photon energies, increasing the onset for structural changes in the irradiated sample (see [10]). Therefore, it should be beneficial for the diffraction-before-destruction experiments to use higher-energy photons.…”

“…The latter can provide opportunities for the structure determination of radiation-sensitive samples, but they also introduce many challenges [8], such as a potential target disordering during diffraction, which can deteriorate the quality of structure determination. In an earlier work, we showed that the X-ray-induced electron cascading can cause a delay in the structural changes at high photon energies [9,10], which could improve the reliability of "diffraction-before-destruction" applications for sufficiently short pulse durations.…”

Spectral-brightness optimization of an X-ray free-electron laser by machine-learning-based tuning

“…X-ray free-electron lasers (XFELs) based on a self-amplified spontaneous-emission scheme are X-ray sources that generate femtosecond hard X-ray laser pulses (Pellegrini et al, 2016). In combination with their high transverse coherence and high photon flux, XFELs provide novel experimental opportunities, such as damage-free protein crystallography (Schlichting, 2015;Hirata et al, 2014), coherent imaging of nanomaterials (Clark et al, 2013;Kimura et al, 2014;Yumoto et al, 2022), time-resolved analysis of chemical reactions (Kim et al, 2015(Kim et al, , 2020Katayama et al, 2019), generation and diagnostics of materials with high-energy densities (Vinko et al, 2012;Inoue et al, 2016Inoue et al, , 2021aInoue et al, , 2022a, and exploring nonlinear X-ray optical phenomena (Glover et al, 2012;Yoneda et al, 2015;Tamasaku et al, 2018;Inoue et al, 2021b).…”