Takahiro Sato

All Publications

• Impulsive excitation of squeezed phonons in single crystal germanium by an x-ray laser APPLIED PHYSICS LETTERS Wang, N., Li, H., Sun, Y., Hanlon, D., Huang, Y., Sun, P., She, B., Ornelas-Skarin, C., Teitelbaum, S. W., Sutton, M., Fuoss, P. H., Hastings, J. B., Sato, T., Song, S., Trigo, M., Reis, D. A., Dunne, M., Zhu, D. 2025; 126 (22)

  View details for DOI 10.1063/5.0269800

  View details for Web of Science ID 001506885200008

• Observation of polarization density waves in SrTiO₃ (Apr, 10.1038/s41567-025-02874-0, 2025) NATURE PHYSICS Orenstein, G., Krapivin, V., Huang, Y., Zhang, Z., Munoz, G., Duncan, R. A., Nguyen, Q., Stanton, J., Teitelbaum, S., Yavas, H., Sato, T., Hoffmann, M. C., Kramer, P., Zhang, J., Cavalleri, A., Comin, R., Dean, M. M., Disa, A. S., Foerst, M., Johnson, S. L., Mitrano, M., Rappe, A. M., Reis, D. A., Zhu, D., Nelson, K. A., Trigo, M. 2025

  View details for DOI 10.1038/s41567-025-02940-7

  View details for Web of Science ID 001494709500001

• Femtosecond x-ray photon correlation spectroscopy enables direct observations of atomic-scale relaxations of glass forming liquids. The Journal of chemical physics Fujita, T., Sun, Y., Li, H., Albert, T. J., Song, S., Sato, T., Moesgaard, J., Cornet, A., Sun, P., Chen, Y., Mo, M., Amini, N., Yang, F., Lucas, P., Esposito, V., Vila-Comamala, J., Wang, N., Mamyrbayev, T., David, C., Hastings, J., Ruta, B., Fuoss, P., Sokolowski-Tinten, K., Zhu, D., Wei, S. 2025; 162 (19)

  Abstract

  Glass-forming liquids exhibit structural relaxation behaviors, reflecting underlying atomic rearrangements on a wide range of timescales and playing a crucial role in determining material properties. However, the relaxation processes on the atomic scale are not well-understood due to the experimental difficulties in directly characterizing the evolving correlations of atomic-scale order in disordered systems. Here, we harness the coherence and ultrashort pulse characteristics of an x-ray free electron laser to directly probe atomic-scale ultrafast relaxation dynamics in the model system Ge15Te85. We demonstrate an analysis strategy for determining the intermediate scattering function by extracting the contrast decay of summed scattering patterns from two rapidly successive, nearly identical femtosecond x-ray pulses generated by a split-delay system. The result indicates a full decorrelation of atomic-scale order on the sub-picosecond timescale, supporting the argument for a high-fluidity fragile state of liquid Ge15Te85 above its dynamic crossover temperature. The demonstrated strategy opens an avenue for experimental studies of relaxation dynamics in liquids, glasses, and other highly disordered systems.

  View details for DOI 10.1063/5.0264574

  View details for PubMedID 40371826

• Coupled order parameters and photoinduced domain walls in the charge density wave of (TaSe₄)₂I NPJ QUANTUM MATERIALS Duncan, R. A., Orenstein, G., Kim, S., Huang, Y., Wang, H., Teitelbaum, S. W., Stanton, J., Hurley, M., Miller, A., Leonard, N., Hanlon, D., Reis, D. A., Osaka, T., Kubota, Y., Togashi, T., Qu, K., Shoemaker, D. P., Sato, T., Trigo, M. 2025; 10 (1)

  View details for DOI 10.1038/s41535-025-00762-7

  View details for Web of Science ID 001479433100001

• Dynamics of nanoscale phase decomposition in laser ablation COMMUNICATIONS MATERIALS Sun, Y., Chen, C., Albert, T. J., Li, H., Arefev, M. I., Chen, Y., Dunne, M., Glownia, J. M., Jerman, M., Hoffmann, M., Hurley, M. J., Mo, M., Nguyen, Q. L., Sato, T., Song, S., Sun, P., Sutton, M., Teitelbaum, S., Valavanis, A. S., Wang, N., Zhu, D., Zhigilei, L. V., Sokolowski-Tinten, K. 2025; 6 (1)

  View details for DOI 10.1038/s43246-025-00785-4

  View details for Web of Science ID 001464672100001

• X-ray Absorption Spectroscopy of Dilute Metalloenzymes at X-ray Free-Electron Lasers in a Shot-by-Shot Mode. The journal of physical chemistry letters Bogacz, I., Szilagyi, E., Makita, H., Simon, P. S., Zhang, M., Doyle, M. D., Chatterjee, K., Kretzschmar, M., Chernev, P., Croy, N., Cheah, M. H., Dasgupta, M., Nangca, I., Fransson, T., Bhowmick, A., Brewster, A. S., Sauter, N. K., Owada, S., Tono, K., Zerdane, S., Oggenfuss, A., Babich, D., Sander, M., Mankowsky, R., Lemke, H. T., Gee, L. B., Sato, T., Kroll, T., Messinger, J., Alonso-Mori, R., Bergmann, U., Sokaras, D., Yachandra, V. K., Kern, J., Yano, J. 2025: 3778-3787

  Abstract

  X-ray absorption spectroscopy (XAS) of 3d transition metals provides important electronic structure information for many fields. However, X-ray-induced radiation damage under physiological temperature has prevented using this method to study dilute aqueous systems, such as metalloenzymes, as the catalytic reaction proceeds. Here we present a new approach to enable operando XAS of dilute biological samples and demonstrate its feasibility with K-edge XAS spectra from the Mn cluster in photosystem II and the Fe-S centers in photosystem I. This approach combines highly efficient sample delivery strategies and a robust signal normalization method with high-transmission Bragg diffraction-based spectrometers at X-ray free-electron lasers (XFELs) in a damage-free, shot-by-shot mode. These photon-out spectrometers have been optimized for discriminating the metal Mn/Fe Kα fluorescence signals from the overwhelming scattering background present on currently available detectors for XFELs that lack suitable energy discrimination. We quantify the enhanced performance metrics of the spectrometer and discuss its potential applications for acquiring time-resolved XAS spectra of biological samples during their reactions at XFELs.

  View details for DOI 10.1021/acs.jpclett.5c00399

  View details for PubMedID 40193717

• Observation of polarization density waves in SrTiO₃ NATURE PHYSICS Orenstein, G., Krapivin, V., Huang, Y., Zhang, Z., de la Pena Munoz, G., Duncan, R. A., Nguyen, Q., Stanton, J., Teitelbaum, S., Yavas, H., Sato, T., Hoffmann, M. C., Kramer, P., Zhang, J., Cavalleri, A., Comin, R., Dean, M. M., Disa, A. S., Foerst, M., Johnson, S. L., Mitrano, M., Rappe, A. M., Reis, D., Zhu, D., Nelson, K. A., Trigo, M. 2025

  View details for DOI 10.1038/s41567-025-02874-0

  View details for Web of Science ID 001461175200001

• Nanofocused attosecond hard x-ray free-electron laser with intensity exceeding 1019 W/cm2 OPTICA Inoue, I., Sato, T., Robles, R., Seaberg, M. H., Sun, Y., Zhu, D., Cesar, D., Ding, Y., Esposito, V., Franz, P., Guo, V., Halavanau, A., Sudar, N. S., Zhang, Z., Inubushi, Y., Osaka, T., Yamaguchi, G., Sano, Y., Yamauchi, K., Yabashi, M., Marinelli, A., Yamada, J. 2025; 12 (3): 309-310

  View details for DOI 10.1364/OPTICA.554954

  View details for Web of Science ID 001460637100003

• Dynamic motion trajectory control with nanoradian accuracy for multi-element X-ray optical systems via laser interferometry. Light, science & applications Koehlenbeck, S. M., Lee, L., Balcazar, M. D., Chen, Y., Esposito, V., Hastings, J., Hoffmann, M. C., Huang, Z., Ng, M. L., Price, S., Sato, T., Seaberg, M., Sun, Y., White, A., Zhang, L., Lantz, B., Zhu, D. 2025; 14 (1): 129

  Abstract

  The past decades have witnessed the development of new X-ray beam sources with brightness growing at a rate surpassing Moore's law. Current and upcoming diffraction limited and fully coherent X-ray beam sources, including multi-bend achromat based synchrotron sources and high repetition rate X-ray free electron lasers, puts increasingly stringent requirements on stability and accuracy of X-ray optics systems. Parasitic motion errors at sub-micro radian scale in beam transport and beam conditioning optics can lead to significant loss of coherence and brightness delivered from source to experiment. To address this challenge, we incorporated optical metrology based on interferometric length and angle sensing and real-time correction as part of the X-ray optics motion control system. A prototype X-ray optics system was constructed following the optical layout of a tunable X-ray cavity. On-line interferometric metrology enabled dynamical feedback to a motion control system to track and compensate for motion errors. The system achieved sub-microradian scale performance, as multiple optical elements are synchronously and continuously adjusted. This first proof of principle measurement demonstrated both the potential and necessity of incorporating optical metrology as part of the motion control architecture for large scale X-ray optical systems such as monochromators, delay lines, and in particular, X-ray cavity systems to enable the next generation cavity-based X-ray free electron lasers.

  View details for DOI 10.1038/s41377-025-01774-5

  View details for PubMedID 40108115

  View details for PubMedCentralID PMC11923231

• Dynamically patterning x-ray beam by a femtosecond optical laser. Science advances Tamasaku, K., Sato, T., Osaka, T., Osawa, H., Zhu, D., Ishikawa, T. 2024; 10 (47): eadp5326

  Abstract

  Modern science and technology have greatly benefitted from our ability to precisely manipulate light waves, in both their spatial and temporal degrees of freedom. In the x-ray region, however, spatial control has been virtually static mainly due to stringent requirements for realizing high-performance optical elements. The lack of dynamic spatial control of x-ray beam has prevented researchers from realizing more sophisticated use of the wave field, which has rapidly advanced in the optical region in the past decades. In this study, we propose a practical scheme to dynamically control local x-ray reflectivity of a perfect silicon crystal by a femtosecond optical laser and demonstrate a programmable spatial x-ray modulator. Our modulator aims for spatial manipulation of the x-ray amplitude and is shown to produce arbitrary grayscale patterns with spatial frequencies up to 25 per millimeter. The proposed modulation scheme opens up a platform to enable advanced x-ray sensing and imaging techniques that can fully harness the wave nature of x-rays.

  View details for DOI 10.1126/sciadv.adp5326

  View details for PubMedID 39565855

• Author Correction: Non-equilibrium pathways to emergent polar supertextures. Nature materials Stoica, V. A., Yang, T., Das, S., Cao, Y., Wang, H. H., Kubota, Y., Dai, C., Padma, H., Sato, Y., Mangu, A., Nguyen, Q. L., Zhang, Z., Talreja, D., Zajac, M. E., Walko, D. A., DiChiara, A. D., Owada, S., Miyanishi, K., Tamasaku, K., Sato, T., Glownia, J. M., Esposito, V., Nelson, S., Hoffmann, M. C., Schaller, R. D., Lindenberg, A. M., Martin, L. W., Ramesh, R., Matsuda, I., Zhu, D., Chen, L. Q., Wen, H., Gopalan, V., Freeland, J. W. 2024

  View details for DOI 10.1038/s41563-024-02044-2

  View details for PubMedID 39402217

• Nanometer-Scale Acoustic Wave Packets Generated by Stochastic Core-Level Photoionization Events PHYSICAL REVIEW X Huang, Y., Sun, P., Teitelbaum, S. W., Li, H., Sun, Y., Wang, N., Song, S., Sato, T., Chollet, M., Osaka, T., Inoue, I., Duncan, R. A., Shin, H., Haber, J., Zhou, J., Bernardi, M., Gu, M., Rondinelli, J. M., Trigo, M., Yabashi, M., Maznev, A. A., Nelson, K. A., Zhu, D., Reis, D. A. 2024; 14 (4)

  View details for DOI 10.1103/PhysRevX.14.041010

  View details for Web of Science ID 001335434300002

• Non-equilibrium pathways to emergent polar supertextures. Nature materials Stoica, V. A., Yang, T., Das, S., Cao, Y., Wang, H. H., Kubota, Y., Dai, C., Padma, H., Sato, Y., Mangu, A., Nguyen, Q. L., Zhang, Z., Talreja, D., Zajac, M. E., Walko, D. A., DiChiara, A. D., Owada, S., Miyanishi, K., Tamasaku, K., Sato, T., Glownia, J. M., Esposito, V., Nelson, S., Hoffmann, M. C., Schaller, R. D., Lindenberg, A. M., Martin, L. W., Ramesh, R., Matsuda, I., Zhu, D., Chen, L. Q., Wen, H., Gopalan, V., Freeland, J. W. 2024

  Abstract

  Ultrafast stimuli can stabilize metastable states of matter inaccessible by equilibrium means. Establishing the spatiotemporal link between ultrafast excitation and metastability is crucial to understand these phenomena. Here we utilize single-shot optical pump-X-ray probe measurements to capture snapshots of the emergence of a persistent polar vortex supercrystal in a heterostructure that hosts a fine balance between built-in electrostatic and elastic frustrations by design. By perturbing this balance with photoinduced charges, an initially heterogeneous mixture of polar phase disorders within a few picoseconds, leading to a state composed of disordered ferroelectric and suppressed vortex orders. On the picosecond-nanosecond timescales, transient labyrinthine fluctuations develop, accompanied by the recovery of the vortex order. On longer timescales, these fluctuations are progressively quenched by dynamical strain modulations, which drive the collective emergence of a single vortex supercrystal phase. Our results, corroborated by dynamical phase-field modelling, reveal non-equilibrium pathways following the ultrafast excitation of designer systems to persistent metastability.

  View details for DOI 10.1038/s41563-024-01981-2

  View details for PubMedID 39317816

  View details for PubMedCentralID 8024274

• Dynamical decoding of the competition between charge density waves in a kagome superconductor. Nature communications Ning, H., Oh, K. H., Su, Y., von Hoegen, A., Porter, Z., Capa Salinas, A., Nguyen, Q. L., Chollet, M., Sato, T., Esposito, V., Hoffmann, M. C., White, A., Melendrez, C., Zhu, D., Wilson, S. D., Gedik, N. 2024; 15 (1): 7286

  Abstract

  The kagome superconductor CsV3Sb5 hosts a variety of charge density wave (CDW) phases, which play a fundamental role in the formation of other exotic electronic instabilities. However, identifying the precise structure of these CDW phases and their intricate relationships remain the subject of intense debate, due to the lack of static probes that can distinguish the CDW phases with identical spatial periodicity. Here, we unveil the out-of-equilibrium competition between two coexisting 2 × 2 × 2 CDWs in CsV3Sb5 harnessing time-resolved X-ray diffraction. By analyzing the light-induced changes in the intensity of CDW superlattice peaks, we demonstrate the presence of both phases, each displaying a significantly different amount of melting upon excitation. The anomalous light-induced sharpening of peak width further shows that the phase that is more resistant to photo-excitation exhibits an increase in domain size at the expense of the other, thereby showcasing a hallmark of phase competition. Our results not only shed light on the interplay between the multiple CDW phases in CsV3Sb5, but also establish a non-equilibrium framework for comprehending complex phase relationships that are challenging to disentangle using static techniques.

  View details for DOI 10.1038/s41467-024-51485-5

  View details for PubMedID 39179535

  View details for PubMedCentralID 9950456

• X-ray optics for the cavity-based X-ray free-electron laser. Journal of synchrotron radiation Liu, P., Pradhan, P., Shi, X., Shu, D., Kauchha, K., Qiao, Z., Tamasaku, K., Osaka, T., Zhu, D., Sato, T., MacArthur, J., Huang, X., Assoufid, L., White, M., Kim, K. J., Shvyd'ko, Y. 2024

  Abstract

  A cavity-based X-ray free-electron laser (CBXFEL) is a possible future direction in the development of fully coherent X-ray sources. CBXFELs consist of a low-emittance electron source, a magnet system with several undulators and chicanes, and an X-ray cavity. The X-ray cavity stores and circulates X-ray pulses for repeated FEL interactions with electron pulses until the FEL reaches saturation. CBXFEL cavities require low-loss wavefront-preserving optical components: near-100%-reflectivity X-ray diamond Bragg-reflecting crystals, outcoupling devices such as thin diamond membranes or X-ray gratings, and aberration-free focusing elements. In the framework of the collaborative CBXFEL research and development project of Argonne National Laboratory, SLAC National Accelerator Laboratory and SPring-8, we report here the design, manufacturing and characterization of X-ray optical components for the CBXFEL cavity, which include high-reflectivity diamond crystal mirrors, a diamond drumhead crystal with thin membranes, beryllium refractive lenses and channel-cut Si monochromators. All the designed optical components have been fully characterized at the Advanced Photon Source to demonstrate their suitability for the CBXFEL cavity application.

  View details for DOI 10.1107/S1600577524003977

  View details for PubMedID 38904936

• The Liquid Jet Endstation for Hard X-ray Scattering and Spectroscopy at the Linac Coherent Light Source. Molecules (Basel, Switzerland) Antolini, C., Sosa Alfaro, V., Reinhard, M., Chatterjee, G., Ribson, R., Sokaras, D., Gee, L., Sato, T., Kramer, P. L., Raj, S. L., Hayes, B., Schleissner, P., Garcia-Esparza, A. T., Lim, J., Babicz, J. T., Follmer, A. H., Nelson, S., Chollet, M., Alonso-Mori, R., van Driel, T. B. 2024; 29 (10)

  Abstract

  The ability to study chemical dynamics on ultrafast timescales has greatly advanced with the introduction of X-ray free electron lasers (XFELs) providing short pulses of intense X-rays tailored to probe atomic structure and electronic configuration. Fully exploiting the full potential of XFELs requires specialized experimental endstations along with the development of techniques and methods to successfully carry out experiments. The liquid jet endstation (LJE) at the Linac Coherent Light Source (LCLS) has been developed to study photochemistry and biochemistry in solution systems using a combination of X-ray solution scattering (XSS), X-ray absorption spectroscopy (XAS), and X-ray emission spectroscopy (XES). The pump-probe setup utilizes an optical laser to excite the sample, which is subsequently probed by a hard X-ray pulse to resolve structural and electronic dynamics at their intrinsic femtosecond timescales. The LJE ensures reliable sample delivery to the X-ray interaction point via various liquid jets, enabling rapid replenishment of thin samples with millimolar concentrations and low sample volumes at the 120 Hz repetition rate of the LCLS beam. This paper provides a detailed description of the LJE design and of the techniques it enables, with an emphasis on the diagnostics required for real-time monitoring of the liquid jet and on the spatiotemporal overlap methods used to optimize the signal. Additionally, various scientific examples are discussed, highlighting the versatility of the LJE.

  View details for DOI 10.3390/molecules29102323

  View details for PubMedID 38792184

• A versatile pressure-cell design for studying ultrafast molecular-dynamics in supercritical fluids using coherent multi-pulse x-ray scattering. The Review of scientific instruments Muhunthan, P., Li, H., Vignat, G., Toro, E. R., Younes, K., Sun, Y., Sokaras, D., Weiss, T., Rajkovic, I., Osaka, T., Inoue, I., Song, S., Sato, T., Zhu, D., Fulton, J. L., Ihme, M. 2024; 95 (1)

  Abstract

  Supercritical fluids (SCFs) can be found in a variety of environmental and industrial processes. They exhibit an anomalous thermodynamic behavior, which originates from their fluctuating heterogeneous micro-structure. Characterizing the dynamics of these fluids at high temperature and high pressure with nanometer spatial and picosecond temporal resolution has been very challenging. The advent of hard x-ray free electron lasers has enabled the development of novel multi-pulse ultrafast x-ray scattering techniques, such as x-ray photon correlation spectroscopy (XPCS) and x-ray pump x-ray probe (XPXP). These techniques offer new opportunities for resolving the ultrafast microscopic behavior in SCFs at unprecedented spatiotemporal resolution, unraveling the dynamics of their micro-structure. However, harnessing these capabilities requires a bespoke high-pressure and high-temperature sample system that is optimized to maximize signal intensity and address instrument-specific challenges, such as drift in beamline components, x-ray scattering background, and multi-x-ray-beam overlap. We present a pressure cell compatible with a wide range of SCFs with built-in optical access for XPCS and XPXP and discuss critical aspects of the pressure cell design, with a particular focus on the design optimization for XPCS.

  View details for DOI 10.1063/5.0158497

  View details for PubMedID 38170817

• Nonthermal Bonding Origin of a Novel Photoexcited Lattice Instability in SnSe. Physical review letters Huang, Y., Teitelbaum, S., Yang, S., De la Peña, G., Sato, T., Chollet, M., Zhu, D., Niedziela, J. L., Bansal, D., May, A. F., Lindenberg, A. M., Delaire, O., Trigo, M., Reis, D. A. 2023; 131 (15): 156902

  Abstract

  Lattice dynamics measurements are often crucial tools for understanding how materials transform between different structures. We report time-resolved x-ray scattering-based measurements of the nonequilibrium lattice dynamics in SnSe, a monochalcogenide reported to host a novel photoinduced lattice instability. By fitting interatomic force models to the fluence dependent excited-state dispersion, we determine the nonthermal origin of the lattice instability to be dominated by changes of interatomic interactions along a bilayer-connecting bond, rather than of an intralayer bonding network that is of primary importance to the lattice instability in thermal equilibrium.

  View details for DOI 10.1103/PhysRevLett.131.156902

  View details for PubMedID 37897786

• X-ray free electron laser observation of ultrafast lattice behaviour under femtosecond laser-driven shock compression in iron. Scientific reports Sano, T., Matsuda, T., Hirose, A., Ohata, M., Terai, T., Kakeshita, T., Inubushi, Y., Sato, T., Miyanishi, K., Yabashi, M., Togashi, T., Tono, K., Sakata, O., Tange, Y., Arakawa, K., Ito, Y., Okuchi, T., Sato, T., Sekine, T., Mashimo, T., Nakanii, N., Seto, Y., Shigeta, M., Shobu, T., Sano, Y., Hosokai, T., Matsuoka, T., Yabuuchi, T., Tanaka, K. A., Ozaki, N., Kodama, R. 2023; 13 (1): 13796

  Abstract

  Over the past century, understanding the nature of shock compression of condensed matter has been a major topic. About 20 years ago, a femtosecond laser emerged as a new shock-driver. Unlike conventional shock waves, a femtosecond laser-driven shock wave creates unique microstructures in materials. Therefore, the properties of this shock wave may be different from those of conventional shock waves. However, the lattice behaviour under femtosecond laser-driven shock compression has never been elucidated. Here we report the ultrafast lattice behaviour in iron shocked by direct irradiation of a femtosecond laser pulse, diagnosed using X-ray free electron laser diffraction. We found that the initial compression state caused by the femtosecond laser-driven shock wave is the same as that caused by conventional shock waves. We also found, for the first time experimentally, the temporal deviation of peaks of stress and strain waves predicted theoretically. Furthermore, the existence of a plastic wave peak between the stress and strain wave peaks is a new finding that has not been predicted even theoretically. Our findings will open up new avenues for designing novel materials that combine strength and toughness in a trade-off relationship.

  View details for DOI 10.1038/s41598-023-40283-6

  View details for PubMedID 37652921

  View details for PubMedCentralID 7274792

• Ultrafast X-Ray Scattering Reveals Composite Amplitude Collective Mode in the Weyl Charge Density Wave Material (TaSe_{4})_{2}I. Physical review letters Nguyen, Q. L., Duncan, R. A., Orenstein, G., Huang, Y., Krapivin, V., de la Peña, G., Ornelas-Skarin, C., Reis, D. A., Abbamonte, P., Bettler, S., Chollet, M., Hoffmann, M. C., Hurley, M., Kim, S., Kirchmann, P. S., Kubota, Y., Mahmood, F., Miller, A., Osaka, T., Qu, K., Sato, T., Shoemaker, D. P., Sirica, N., Song, S., Stanton, J., Teitelbaum, S. W., Tilton, S. E., Togashi, T., Zhu, D., Trigo, M. 2023; 131 (7): 076901

  Abstract

  We report ultrafast x-ray scattering experiments of the quasi-1D charge density wave (CDW) material (TaSe_{4})_{2}I following ultrafast infrared photoexcitation. From the time-dependent diffraction signal at the CDW sidebands we identify a 0.11 THz amplitude mode derived primarily from a transverse acoustic mode of the high-symmetry structure. From our measurements we determine that this mode interacts with the valence charge indirectly through another collective mode, and that the CDW system in (TaSe_{4})_{2}I has a composite nature supporting multiple dynamically active structural degrees of freedom.

  View details for DOI 10.1103/PhysRevLett.131.076901

  View details for PubMedID 37656841

• Low-loss stable storage of 1.2 & ANGS; X-ray pulses in a 14 m Bragg cavity NATURE PHOTONICS Margraf, R., Robles, R., Halavanau, A., Kryzywinski, J., Li, K., MacArthur, J., Osaka, T., Sakdinawat, A., Sato, T., Sun, Y., Tamasaku, K., Huang, Z., Marcus, G., Zhu, D. 2023

  View details for DOI 10.1038/s41566-023-01267-0

  View details for Web of Science ID 001048092600001

• Room temperature X-ray absorption spectroscopy of metalloenzymes with drop-on-demand sample delivery at XFELs. Pure and applied chemistry. Chimie pure et appliquee Bogacz, I., Makita, H., Simon, P. S., Zhang, M., Doyle, M. D., Chatterjee, R., Fransson, T., Weninger, C., Fuller, F., Gee, L., Sato, T., Seaberg, M., Alonso-Mori, R., Bergmann, U., Yachandra, V. K., Kern, J., Yano, J. 2023; 95 (8): 891-897

  Abstract

  X-ray crystallography and X-ray spectroscopy using X-ray free electron lasers plays an important role in understanding the interplay of structural changes in the protein and the chemical changes at the metal active site of metalloenzymes through their catalytic cycles. As a part of such an effort, we report here our recent development of methods for X-ray absorption spectroscopy (XAS) at XFELs to study dilute biological samples, available in limited volumes. Our prime target is Photosystem II (PS II), a multi subunit membrane protein complex, that catalyzes the light-driven water oxidation reaction at the Mn4CaO5 cluster. This is an ideal system to investigate how to control multi-electron/proton chemistry, using the flexibility of metal redox states, in coordination with the protein and the water network. We describe the method that we have developed to collect XAS data using PS II samples with a Mn concentration of <1 mM, using a drop-on-demand sample delivery method.

  View details for DOI 10.1515/pac-2023-0213

  View details for PubMedID 38013689

  View details for PubMedCentralID PMC10505480

• Room temperature X-ray absorption spectroscopy of metalloenzymes with drop-on-demand sample delivery at XFELs PURE AND APPLIED CHEMISTRY Bogacz, I., Makita, H., Simon, P. S., Zhang, M., Doyle, M. D., Chatterjee, R., Fransson, T., Weninger, C., Fuller, F., Gee, L., Sato, T., Seaberg, M., Alonso-Mori, R., Bergmann, U., Yachandra, V. K., Kern, J., Yano, J. 2023

  View details for DOI 10.1515/pac-2023-0213

  View details for Web of Science ID 000973579500001

• Experimental setup for high-resolution characterization of crystal optics for coherent X-ray beam applications. Journal of applied crystallography Halavanau, A., Margraf, R., Robles, R., MacArthur, J., Qu, Z., Marcus, G., Wu, J., Sato, T., Zhu, D., Takacs, C. J., Arthur, R., Kraynis, O., Johnson, B., Rabedeau, T. 2023; 56 (Pt 1): 155-159

  Abstract

  Stanford Synchrotron Radiation Lightsource serves a wide scientific community with its variety of X-ray capabilities. Recently, a wiggler X-ray source located at beamline 10-2 has been employed to perform high-resolution rocking curve imaging (RCI) of diamond and silicon crystals. X-ray RCI is invaluable for the development of upcoming cavity-based X-ray sources at SLAC, including the cavity-based X-ray free-electron laser and X-ray laser oscillator. In this paper, the RCI apparatus is described and experimental results are provided to validate its design. Future improvements of the setup are also discussed.

  View details for DOI 10.1107/S1600576722010998

  View details for PubMedID 36777134

  View details for PubMedCentralID PMC9901917

• Influence of local symmetry on lattice dynamics coupled to topological surface states PHYSICAL REVIEW B Sobota, J. A., Teitelbaum, S. W., Huang, Y., Querales-Flores, J. D., Power, R., Allen, M., Rotundu, C. R., Bailey, T. P., Uher, C., Henighan, T., Jiang, M., Zhu, D., Chollet, M., Sato, T., Trigo, M., Murray, e. D., Savic, I., Kirchmann, P. S., Fahy, S., Reis, D. A., Shen, Z. 2023; 107 (1)

  View details for DOI 10.1103/PhysRevB.107.014305

  View details for Web of Science ID 000921610800004

• Observation of a Novel Lattice Instability in Ultrafast Photoexcited SnSe PHYSICAL REVIEW X Huang, Y., Yang, S., Teitelbaum, S., De la Pena, G., Sato, T., Chollet, M., Zhu, D., Niedziela, J. L., Bansal, D., May, A. F., Lindenberg, A. M., Delaire, O., Reis, D. A., Trigo, M. 2022; 12 (1)

  View details for DOI 10.1103/PhysRevX.12.011029

  View details for Web of Science ID 000761380600001

• A Contrast Calibration Protocol for X-ray Speckle Visibility Spectroscopy APPLIED SCIENCES-BASEL Sun, Y., Esposito, V., Hart, P., Hansson, C., Li, H., Nakahara, K., MacArthur, J., Nelson, S., Sato, T., Song, S., Sun, P., Fuoss, P., Sutton, M., Zhu, D. 2021; 11 (21)

  View details for DOI 10.3390/app112110041

  View details for Web of Science ID 000726897500001

• Generation of highly mutually coherent hard-x-ray pulse pairs with an amplitude-splitting delay line PHYSICAL REVIEW RESEARCH Li, H., Sun, Y., Vila-Comamala, J., Sato, T., Song, S., Sun, P., Seaberg, M. H., Wang, N., Hastings, J. B., Dunne, M., Fuoss, P., David, C., Sutton, M., Zhu, D. 2021; 3 (4)

  View details for DOI 10.1103/PhysRevResearch.3.043050

  View details for Web of Science ID 000708677100006

• Nonuniform Flow Dynamics Probed by Nanosecond X-Ray Speckle Visibility Spectroscopy. Physical review letters Sun, Y., Carini, G., Chollet, M., Decker, F. J., Dunne, M., Fuoss, P., Hruszkewycz, S. O., Lane, T. J., Nakahara, K., Nelson, S., Robert, A., Sato, T., Song, S., Stephenson, G. B., Sutton, M., Van Driel, T. B., Weninger, C., Zhu, D. 2021; 127 (5): 058001

  Abstract

  We report observations of nanosecond nonuniform colloidal dynamics in a free flowing liquid jet using ultrafast x-ray speckle visibility spectroscopy. Utilizing a nanosecond double-bunch mode, the Linac Coherent Light Source free electron laser produced pairs of femtosecond coherent hard x-ray pulses. By exploring anisotropy in the visibility of summed speckle patterns which relates to the correlation functions, we evaluate not only the average particle flow rate in a colloidal nanoparticle jet, but also the nonuniform flow field within. The methodology presented here establishes the foundation for the study of nano- and atomic-scale inhomogeneous fluctuations in complex matter using x-ray free electron laser sources.

  View details for DOI 10.1103/PhysRevLett.127.058001

  View details for PubMedID 34397240

• Nonuniform Flow Dynamics Probed by Nanosecond X-Ray Speckle Visibility Spectroscopy PHYSICAL REVIEW LETTERS Sun, Y., Carini, G., Chollet, M., Decker, F., Dunne, M., Fuoss, P., Hruszkewycz, S. O., Lane, T. J., Nakahara, K., Nelson, S., Robert, A., Sato, T., Song, S., Stephenson, G., Sutton, M., Van Driel, T. B., Weninger, C., Zhu, D. 2021; 127 (5)

  View details for DOI 10.1103/PhysRevLett.127.058001

  View details for Web of Science ID 000679183300006

• Measurements of nonequilibrium interatomic forces using time-domain x-ray scattering PHYSICAL REVIEW B Teitelbaum, S. W., Henighan, T. C., Liu, H., Jiang, M. P., Zhu, D., Chollet, M., Sato, T., Murray, E. D., Fahy, S., O'Mahony, S., Bailey, T. P., Uher, C., Trigo, M., Reis, D. A. 2021; 103 (18)

  View details for DOI 10.1103/PhysRevB.103.L180101

  View details for Web of Science ID 000655872300005

• Subterahertz collective dynamics of polar vortices. Nature Li, Q., Stoica, V. A., Pasciak, M., Zhu, Y., Yuan, Y., Yang, T., McCarter, M. R., Das, S., Yadav, A. K., Park, S., Dai, C., Lee, H. J., Ahn, Y., Marks, S. D., Yu, S., Kadlec, C., Sato, T., Hoffmann, M. C., Chollet, M., Kozina, M. E., Nelson, S., Zhu, D., Walko, D. A., Lindenberg, A. M., Evans, P. G., Chen, L., Ramesh, R., Martin, L. W., Gopalan, V., Freeland, J. W., Hlinka, J., Wen, H. 2021; 592 (7854): 376–80

  Abstract

  The collective dynamics of topological structures1-6 are of interest from both fundamental and applied perspectives. For example, studies of dynamical properties of magnetic vortices and skyrmions3,4 have not only deepened our understanding of many-body physics but also offered potential applications in data processing and storage7. Topological structures constructed from electrical polarization, rather than electron spin, have recently been realized in ferroelectric superlattices5,6, and these are promising for ultrafast electric-field control of topological orders. However, little is known about the dynamics underlying the functionality of such complex extended nanostructures. Here, using terahertz-field excitation and femtosecond X-ray diffraction measurements, we observe ultrafast collective polarization dynamics that are unique to polar vortices, with orders-of-magnitude higher frequencies and smaller lateral size than those of experimentally realized magnetic vortices3. A previously unseen tunable mode, hereafter referred to as a vortexon, emerges in the form of transient arrays of nanoscale circular patterns of atomic displacements, which reverse their vorticity on picosecond timescales. Its frequency is considerably reduced (softened) at a critical strain, indicating a condensation (freezing) of structural dynamics. We use first-principles-based atomistic calculations and phase-field modelling to reveal the microscopic atomic arrangements and corroborate the frequencies of the vortex modes. The discovery of subterahertz collective dynamics in polar vortices opens opportunities for electric-field-driven data processing in topological structures with ultrahigh speed and density.

  View details for DOI 10.1038/s41586-021-03342-4

  View details for PubMedID 33854251

• Visualization of dynamic polaronic strain fields in hybrid lead halide perovskites. Nature materials Guzelturk, B., Winkler, T., Van de Goor, T. W., Smith, M. D., Bourelle, S. A., Feldmann, S., Trigo, M., Teitelbaum, S. W., Steinruck, H., de la Pena, G. A., Alonso-Mori, R., Zhu, D., Sato, T., Karunadasa, H. I., Toney, M. F., Deschler, F., Lindenberg, A. M. 2021

  Abstract

  Excitation localization involving dynamic nanoscale distortions is a central aspect of photocatalysis1, quantum materials2 and molecular optoelectronics3. Experimental characterization of such distortions requires techniques sensitive to the formation of point-defect-like local structural rearrangements in real time. Here, we visualize excitation-induced strain fields in a prototypical member of the lead halide perovskites4 via femtosecond resolution diffuse X-ray scattering measurements. This enables momentum-resolved phonon spectroscopy of the locally distorted structure and reveals radially expanding nanometre-scale strain fields associated with the formation and relaxation of polarons in photoexcited perovskites. Quantitative estimates of the magnitude and shape of this polaronic distortion are obtained, providing direct insights into the dynamic structural distortions that occur in these materials5-9. Optical pump-probe reflection spectroscopy corroborates these results and shows how these large polaronic distortions transiently modify the carrier effective mass, providing a unified picture of the coupled structural and electronic dynamics that underlie the optoelectronic functionality of the hybrid perovskites.

  View details for DOI 10.1038/s41563-020-00865-5

  View details for PubMedID 33398119

• A self-referenced in-situ arrival time monitor for X-ray free-electron lasers. Scientific reports Diez, M. n., Galler, A. n., Schulz, S. n., Boemer, C. n., Coffee, R. N., Hartmann, N. n., Heider, R. n., Wagner, M. S., Helml, W. n., Katayama, T. n., Sato, T. n., Sato, T. n., Yabashi, M. n., Bressler, C. n. 2021; 11 (1): 3562

  Abstract

  We present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, while a femtosecond X-ray pulse arrives at an instant in between both pulses. Behind the sample the supercontinuum pulses are temporally overlapped to yield near-perfect destructive interference in the absence of the X-ray pulse. Stimulation of the sample with an X-ray pulse delivers non-zero contributions at certain optical wavelengths, which serve as a measure of the relative arrival time of the X-ray pulse with an accuracy of better than 25 fs. We find an excellent agreement of our monitor with the existing timing diagnostics at the SACLA XFEL with a Pearson correlation value of 0.98. We demonstrate a high sensitivity to measure X-ray pulses with pulse energies as low as 30 [Formula: see text]J. Using a free-flowing liquid jet as interaction sample ensures the full replacement of the sample volume for each X-ray/optical event, thus enabling its utility even at MHz repetition rate XFEL sources.

  View details for DOI 10.1038/s41598-021-82597-3

  View details for PubMedID 33574378

• The ePix10k 2-megapixel hard X-ray detector at LCLS. Journal of synchrotron radiation van Driel, T. B., Nelson, S. n., Armenta, R. n., Blaj, G. n., Boo, S. n., Boutet, S. n., Doering, D. n., Dragone, A. n., Hart, P. n., Haller, G. n., Kenney, C. n., Kwaitowski, M. n., Manger, L. n., McKelvey, M. n., Nakahara, K. n., Oriunno, M. n., Sato, T. n., Weaver, M. n. 2020; 27 (Pt 3): 608–15

  Abstract

  The ePix10ka2M (ePix10k) is a new large area detector specifically developed for X-ray free-electron laser (XFEL) applications. The hybrid pixel detector was developed at SLAC to provide a hard X-ray area detector with a high dynamic range, running at the 120 Hz repetition rate of the Linac Coherent Light Source (LCLS). The ePix10k consists of 16 modules, each with 352 × 384 pixels of 100 µm × 100 µm distributed on four ASICs, resulting in a 2.16 megapixel detector, with a 16.5 cm × 16.5 cm active area and ∼80% coverage. The high dynamic range is achieved with three distinct gain settings (low, medium, high) as well as two auto-ranging modes (high-to-low and medium-to-low). Here the three fixed gain modes are evaluated. The resulting dynamic range (from single photon counting to 10000 photons pixel-1 pulse-1 at 8 keV) makes it suitable for a large number of different XFEL experiments. The ePix10k replaces the large CSPAD in operation since 2011. The dimensions of the two detectors are similar, making the upgrade from CSPAD to ePix10k straightforward for most setups, with the ePix10k improving on experimental performance. The SLAC-developed ePix cameras all utilize a similar platform, are tailored to target different experimental conditions and are designed to provide an upgrade path for future high-repetition-rate XFELs. Here the first measurements on this new ePix10k detector are presented and the performance under typical XFEL conditions evaluated during an LCLS X-ray diffuse scattering experiment measuring the 9.5 keV X-ray photons scattered from a thin liquid jet.

  View details for DOI 10.1107/S1600577520004257

  View details for PubMedID 32381760

• Speckle correlation as a monitor of X-ray free-electron laser induced crystal lattice deformation. Journal of synchrotron radiation Plumley, R. n., Sun, Y. n., Teitelbaum, S. n., Song, S. n., Sato, T. n., Chollet, M. n., Nelson, S. n., Wang, N. n., Sun, P. n., Robert, A. n., Fuoss, P. n., Sutton, M. n., Zhu, D. n. 2020; 27 (Pt 6): 1470–76

  Abstract

  X-ray free-electron lasers (X-FELs) present new opportunities to study ultrafast lattice dynamics in complex materials. While the unprecedented source brilliance enables high fidelity measurement of structural dynamics, it also raises experimental challenges related to the understanding and control of beam-induced irreversible structural changes in samples that can ultimately impact the interpretation of experimental results. This is also important for designing reliable high performance X-ray optical components. In this work, X-FEL beam-induced lattice alterations are investigated by measuring the shot-to-shot evolution of near-Bragg coherent scattering from a single crystalline germanium sample. It is shown that X-ray photon correlation analysis of sequential speckle patterns measurements can be used to monitor the nature and extent of lattice rearrangements. Abrupt, irreversible changes are observed following intermittent high-fluence monochromatic X-ray pulses, thus revealing the existence of a threshold response to X-FEL pulse intensity.

  View details for DOI 10.1107/S1600577520011509

  View details for PubMedID 33147171

• Compact hard x-ray split-delay system based on variable-gap channel-cut crystals OPTICS LETTERS Sun, Y., Wang, N., Song, S., Sun, P., Chollet, M., Sato, T., van Driel, T. B., Nelson, S., Plumley, R., Montana-Lopez, J., Teitelbaum, S. W., Haber, J., Hastings, J. B., Baron, A. R., Sutton, M., Fuoss, P. H., Robert, A., Zhu, D. 2019; 44 (10): 2582–85

  Abstract

  We present the concept and a prototypical implementation of a compact x-ray split-delay system that is capable of performing continuous on-the-fly delay scans over a range of ∼10  ps with sub-100 nanoradian pointing stability. The system consists of four channel-cut silicon crystals, two of which have gradually varying gap sizes from intentional 5 deg asymmetric cuts. The delay adjustment is realized by linear motions of these two monolithic varying-gap channel cuts, where the x-ray beam experiences pairs of anti-parallel reflections, and thus becomes less sensitive in output beam pointing to motion imperfections of the translation stages. The beam splitting is accomplished by polished crystal edges. A high degree of mutual coherence between the two branches at the focus is observed by analyzing small-angle coherent x-ray scattering patterns. We envision a wide range of applications including single-shot x-ray pulse temporal diagnostics, studies of high-intensity x-ray-matter interactions, as well as measurement of dynamics in disordered material systems using split-pulse x-ray photon correlation spectroscopy.

  View details for DOI 10.1364/OL.44.002582

  View details for Web of Science ID 000467906400050

  View details for PubMedID 31090737

• A simple instrument to find spatiotemporal overlap of optical/X-ray light at free-electron lasers. Journal of synchrotron radiation Sato, T., Glownia, J. M., Ware, M. R., Chollet, M., Nelson, S., Zhu, D. 2019; 26 (Pt 3): 647–52

  Abstract

  A compact and robust diagnostic to determine spatial and temporal overlap between X-ray free-electron laser and optical laser pulses was developed and evaluated using monochromatic X-rays from the Linac Coherent Light Source. It was used to determine temporal overlap with a resolution of 10 fs, despite the large pulse energy fluctuations of the monochromatic X-ray pulses, and covers a wide optical wavelength range from ultraviolet to near-infrared with a single configuration.

  View details for PubMedID 31074427

• Pump-probe experimental methodology at the Linac Coherent Light Source JOURNAL OF SYNCHROTRON RADIATION Glownia, J. M., Gumerlock, K., Lemke, H. T., Sato, T., Zhu, D., Chollet, M. 2019; 26: 685–91

  View details for DOI 10.1107/S160057751900225X

  View details for Web of Science ID 000467526100009

• A simple instrument to find spatiotemporal overlap of optical/X-ray light at free-electron lasers JOURNAL OF SYNCHROTRON RADIATION Sato, T., Glownia, J. M., Ware, M. R., Chollet, M., Nelson, S., Zhu, D. 2019; 26: 647–52

  View details for DOI 10.1107/S1600577519002248

  View details for Web of Science ID 000467526100005

• Pump-probe experimental methodology at the Linac Coherent Light Source. Journal of synchrotron radiation Glownia, J. M., Gumerlock, K., Lemke, H. T., Sato, T., Zhu, D., Chollet, M. 2019; 26 (Pt 3): 685–91

  Abstract

  Experimental methods that use free-electron laser (FEL) sources that can deliver short X-ray pulses below a 10 fs pulse duration and traditional optical lasers are ideal tools for pump-probe experiments. However, these new methods also come with a unique set of challenges, such as how to accurately determine temporal overlap between two sources at the femtosecond scale and how to correct for the pulse-to-pulse beam property fluctuations of the FEL light derived from the self-amplified spontaneous emission process. Over the past several years of performing pump-probe experiments at the Linac Coherent Light Source (LCLS), new methods and tools have been developed to improve the ways experimental timing is measured, monitored and scanned. The aim of this article is to present an overview of the most commonly used techniques at LCLS to perform pump-probe-type experiments.

  View details for PubMedID 31074431

• The Macromolecular Femtosecond Crystallography Instrument at the Linac Coherent Light Source JOURNAL OF SYNCHROTRON RADIATION Sierra, R. G., Batyuk, A., Sun, Z., Aquila, A., Hunter, M. S., Lane, T. J., Liang, M., Yoon, C., Alonso-Mori, R., Armenta, R., Castagna, J., Hollenbeck, M., Osier, T. O., Hayes, M., Aldrich, J., Curtis, R., Koglin, J. E., Rendahl, T., Rodriguez, E., Carbajo, S., Guillet, S., Paul, R., Hart, P., Nakahara, K., Carini, G., DeMirci, H., Dao, E., Hayes, B. M., Rao, Y. P., Chollet, M., Feng, Y., Fuller, F. D., Kupitz, C., Sato, T., Seaberg, M. H., Song, S., van Driel, T. B., Yavas, H., Zhu, D., Cohen, A. E., Wakatsuki, S., Boutet, S. 2019; 26: 346–57

  View details for DOI 10.1107/S1600577519001577

  View details for Web of Science ID 000460859600007

• The Macromolecular Femtosecond Crystallography Instrument at the Linac Coherent Light Source. Journal of synchrotron radiation Sierra, R. G., Batyuk, A. n., Sun, Z. n., Aquila, A. n., Hunter, M. S., Lane, T. J., Liang, M. n., Yoon, C. H., Alonso-Mori, R. n., Armenta, R. n., Castagna, J. C., Hollenbeck, M. n., Osier, T. O., Hayes, M. n., Aldrich, J. n., Curtis, R. n., Koglin, J. E., Rendahl, T. n., Rodriguez, E. n., Carbajo, S. n., Guillet, S. n., Paul, R. n., Hart, P. n., Nakahara, K. n., Carini, G. n., DeMirci, H. n., Dao, E. H., Hayes, B. M., Rao, Y. P., Chollet, M. n., Feng, Y. n., Fuller, F. D., Kupitz, C. n., Sato, T. n., Seaberg, M. H., Song, S. n., van Driel, T. B., Yavas, H. n., Zhu, D. n., Cohen, A. E., Wakatsuki, S. n., Boutet, S. n. 2019; 26 (Pt 2): 346–57

  Abstract

  The Macromolecular Femtosecond Crystallography (MFX) instrument at the Linac Coherent Light Source (LCLS) is the seventh and newest instrument at the world's first hard X-ray free-electron laser. It was designed with a primary focus on structural biology, employing the ultrafast pulses of X-rays from LCLS at atmospheric conditions to overcome radiation damage limitations in biological measurements. It is also capable of performing various time-resolved measurements. The MFX design consists of a versatile base system capable of supporting multiple methods, techniques and experimental endstations. The primary techniques supported are forward scattering and crystallography, with capabilities for various spectroscopic methods and time-resolved measurements. The location of the MFX instrument allows for utilization of multiplexing methods, increasing user access to LCLS by running multiple experiments simultaneously.

  View details for PubMedID 30855242

• Direct observation of picosecond melting and disintegration of metallic nanoparticles. Nature communications Ihm, Y. n., Cho, D. H., Sung, D. n., Nam, D. n., Jung, C. n., Sato, T. n., Kim, S. n., Park, J. n., Kim, S. n., Gallagher-Jones, M. n., Kim, Y. n., Xu, R. n., Owada, S. n., Shim, J. H., Tono, K. n., Yabashi, M. n., Ishikawa, T. n., Miao, J. n., Noh, D. Y., Song, C. n. 2019; 10 (1): 2411

  Abstract

  Despite more than a century of study, the fundamental mechanisms behind solid melting remain elusive at the nanoscale. Ultrafast phenomena in materials irradiated by intense femtosecond laser pulses have revived the interest in unveiling the puzzling processes of melting transitions. However, direct experimental validation of various microscopic models is limited due to the difficulty of imaging the internal structures of materials undergoing ultrafast and irreversible transitions. Here we overcome this challenge through time-resolved single-shot diffractive imaging using X-ray free electron laser pulses. Images of single Au nanoparticles show heterogeneous melting at the surface followed by density fluctuation deep inside the particle, which is directionally correlated to the polarization of the pumping laser. Observation of this directionality links the non-thermal electronic excitation to the thermal lattice melting, which is further verified by molecular dynamics simulations. This work provides direct evidence to the understanding of irreversible melting with an unprecedented spatiotemporal resolution.

  View details for DOI 10.1038/s41467-019-10328-4

  View details for PubMedID 31160671

• Frequency-selective excitation of high-wavevector phonons APPLIED PHYSICS LETTERS Teitelbaum, S. W., Henighan, T., Liu, H., Jiang, M. P., Kozina, M., Zhu, D., Chollet, M., Sato, T., Glownia, J. M., Trigo, M., Reis, D. A. 2018; 113 (17)

  View details for DOI 10.1063/1.5047447

  View details for Web of Science ID 000449145700017

• Direct Measurement of Anharmonic Decay Channels of a Coherent Phonon. Physical review letters Teitelbaum, S. W., Henighan, T., Huang, Y., Liu, H., Jiang, M. P., Zhu, D., Chollet, M., Sato, T., Murray, É. D., Fahy, S., O'Mahony, S., Bailey, T. P., Uher, C., Trigo, M., Reis, D. A. 2018; 121 (12): 125901

  Abstract

  We report channel-resolved measurements of the anharmonic coupling of the coherent A_{1g} phonon in photoexcited bismuth to pairs of high wave vector acoustic phonons. The decay of a coherent phonon can be understood as a parametric resonance process whereby the atomic displacement periodically modulates the frequency of a broad continuum of modes. This coupling drives temporal oscillations in the phonon mean-square displacements at the A_{1g} frequency that are observed across the Brillouin zone by femtosecond x-ray diffuse scattering. We extract anharmonic coupling constants between the A_{1g} and several representative decay channels that are within an order of magnitude of density functional perturbation theory calculations.

  View details for DOI 10.1103/PhysRevLett.121.125901

  View details for PubMedID 30296113

• Direct Measurement of Anharmonic Decay Channels of a Coherent Phonon PHYSICAL REVIEW LETTERS Teitelbaum, S. W., Henighan, T., Huang, Y., Liu, H., Jiang, M. P., Zhu, D., Chollet, M., Sato, T., Murray, E. D., Fahy, S., O'Mahony, S., Bailey, T. P., Uher, C., Trigo, M., Reis, D. A. 2018; 121 (12)

  View details for DOI 10.1103/PhysRevLett.121.125901

  View details for Web of Science ID 000445177300013

• Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics NATURE COMMUNICATIONS Perakis, F., Camisasca, G., Lane, T. J., Spah, A., Wikfeldt, K., Sellberg, J. A., Lehmkuehler, F., Pathak, H., Kim, K., Amann-Winkel, K., Schreck, S., Song, S., Sato, T., Sikorski, M., Eilert, A., McQueen, T., Ogasawara, H., Nordlund, D., Roseker, W., Koralek, J., Nelson, S., Hart, P., Alonso-Mori, R., Feng, Y., Zhu, D., Robert, A., Gruebel, G., Pettersson, L. M., Nilsson, A. 2018; 9: 1917

  Abstract

  The dynamics of liquid water feature a variety of time scales, ranging from extremely fast ballistic-like thermal motion, to slower molecular diffusion and hydrogen-bond rearrangements. Here, we utilize coherent X-ray pulses to investigate the sub-100 fs equilibrium dynamics of water from ambient conditions down to supercooled temperatures. This novel approach utilizes the inherent capability of X-ray speckle visibility spectroscopy to measure equilibrium intermolecular dynamics with lengthscale selectivity, by measuring oxygen motion in momentum space. The observed decay of the speckle contrast at the first diffraction peak, which reflects tetrahedral coordination, is attributed to motion on a molecular scale within the first 120 fs. Through comparison with molecular dynamics simulations, we conclude that the slowing down upon cooling from 328 K down to 253 K is not due to simple thermal ballistic-like motion, but that cage effects play an important role even on timescales over 25 fs due to hydrogen-bonding.

  View details for PubMedID 29765052

• State-selective preparation of Ar2+ and Kr2+ by resonantly enhanced two-photon double ionization via intermediate Rydberg states using high-order harmonics PHYSICAL REVIEW A Yamada, K., Iwasaki, A., Sato, T., Midorikawa, K., Yamanouchi, K. 2016; 94 (5)

  View details for DOI 10.1103/PhysRevA.94.053414

  View details for Web of Science ID 000387881800014

• Angular dependence of ionization probability of C2H2 in a linearly polarized intense laser field CHEMICAL PHYSICS LETTERS Hasegawa, H., Ikeda, Y., Sonoda, K., Sato, T., Iwasaki, A., Yamanouchi, K. 2016; 662: 235–39

  View details for DOI 10.1016/j.cplett.2016.09.024

  View details for Web of Science ID 000386860900041

• A beam branching method for timing and spectral characterization of hard X-ray free-electron lasers STRUCTURAL DYNAMICS-US Katayama, T., Owada, S., Togashi, T., Ogawa, K., Karvinen, P., Vartiainen, I., Eronen, A., David, C., Sato, T., Nakajima, K., Joti, Y., Yumoto, H., Ohashi, H., Yabashi, M. 2016; 3 (3): 034301

  Abstract

  We report a method for achieving advanced photon diagnostics of x-ray free-electron lasers (XFELs) under a quasi-noninvasive condition by using a beam-splitting scheme. Here, we used a transmission grating to generate multiple branches of x-ray beams. One of the two primary diffracted branches (+1st-order) is utilized for spectral measurement in a dispersive scheme, while the other (-1st-order) is dedicated for arrival timing diagnostics between the XFEL and the optical laser pulses. The transmitted x-ray beam (0th-order) is guided to an experimental station. To confirm the validity of this timing-monitoring scheme, we measured the correlation between the arrival timings of the -1st and 0th branches. The observed error was as small as 7.0 fs in root-mean-square. Our result showed the applicability of the beam branching scheme to advanced photon diagnostics, which will further enhance experimental capabilities of XFEL.

  View details for PubMedID 26958586

• Sub-nanometre resolution of atomic motion during electronic excitation in phase-change materials SCIENTIFIC REPORTS Mitrofanov, K. V., Fons, P., Makino, K., Terashima, R., Shimada, T., Kolobov, A. V., Tominaga, J., Bragaglia, V., Giussani, A., Calarco, R., Riechert, H., Sato, T., Katayama, T., Ogawa, K., Togashi, T., Yabashi, M., Wall, S., Brewe, D., Hase, M. 2016; 6: 20633

  Abstract

  Phase-change materials based on Ge-Sb-Te alloys are widely used in industrial applications such as nonvolatile memories, but reaction pathways for crystalline-to-amorphous phase-change on picosecond timescales remain unknown. Femtosecond laser excitation and an ultrashort x-ray probe is used to show the temporal separation of electronic and thermal effects in a long-lived (>100 ps) transient metastable state of Ge2Sb2Te5 with muted interatomic interaction induced by a weakening of resonant bonding. Due to a specific electronic state, the lattice undergoes a reversible nondestructive modification over a nanoscale region, remaining cold for 4 ps. An independent time-resolved x-ray absorption fine structure experiment confirms the existence of an intermediate state with disordered bonds. This newly unveiled effect allows the utilization of non-thermal ultra-fast pathways enabling artificial manipulation of the switching process, ultimately leading to a redefined speed limit, and improved energy efficiency and reliability of phase-change memory technologies.

  View details for PubMedID 26868451

• Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Inoue, I., Inubushi, Y., Sato, T., Tono, K., Katayama, T., Kameshima, T., Ogawa, K., Togashi, T., Owada, S., Amemiya, Y., Tanaka, T., Hara, T., Yabashi, M. 2016; 113 (6): 1492–97

  Abstract

  Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  View details for PubMedID 26811449

• A scintillator fabricated by solid-state-diffusion bonding for high-spatial resolution X-ray imaging Kameshima, T., Sato, T., Kudo, T., Ono, S., Ozaki, K., Katayama, T., Hatsui, T., Yabashi, M. edited by Shen, Q., Nelson, C. AMER INST PHYSICS. 2016

  View details for DOI 10.1063/1.4952905

  View details for Web of Science ID 000383222800126

• Visualizing the non-equilibrium dynamics of photoinduced intramolecular electron transfer with femtosecond X-ray pulses NATURE COMMUNICATIONS Canton, S. E., Kjaer, K. S., Vanko, G., van Driel, T. B., Adachi, S., Bordage, A., Bressler, C., Chabera, P., Christensen, M., Dohn, A. O., Galler, A., Gawelda, W., Gosztola, D., Haldrup, K., Harlang, T., Liu, Y., Moller, K. B., Nemeth, Z., Nozawa, S., Papai, M., Sato, T., Sato, T., Suarez-Alcantara, K., Togashi, T., Tono, K., Uhlig, J., Vithanage, D. A., Warnmark, K., Yabashi, M., Zhang, J., Sundstrom, V., Nielsen, M. M. 2015; 6: 6359

  Abstract

  Ultrafast photoinduced electron transfer preceding energy equilibration still poses many experimental and conceptual challenges to the optimization of photoconversion since an atomic-scale description has so far been beyond reach. Here we combine femtosecond transient optical absorption spectroscopy with ultrafast X-ray emission spectroscopy and diffuse X-ray scattering at the SACLA facility to track the non-equilibrated electronic and structural dynamics within a bimetallic donor-acceptor complex that contains an optically dark centre. Exploiting the 100-fold increase in temporal resolution as compared with storage ring facilities, these measurements constitute the first X-ray-based visualization of a non-equilibrated intramolecular electron transfer process over large interatomic distances. Experimental and theoretical results establish that mediation through electronically excited molecular states is a key mechanistic feature. The present study demonstrates the extensive potential of femtosecond X-ray techniques as diagnostics of non-adiabatic electron transfer processes in synthetic and biological systems, and some directions for future studies, are outlined.

  View details for PubMedID 25727920

• Direct observation of bond formation in solution with femtosecond X-ray scattering NATURE Kim, K., Kim, J., Nozawa, S., Sato, T., Oang, K., Kim, T., Ki, H., Jo, J., Park, S., Song, C., Sato, T., Ogawa, K., Togashi, T., Tono, K., Yabashi, M., Ishikawa, T., Kim, J., Ryoo, R., Kim, J., Ihee, H., Adachi, S. 2015; 518 (7539): 385–89

  Abstract

  The making and breaking of atomic bonds are essential processes in chemical reactions. Although the ultrafast dynamics of bond breaking have been studied intensively using time-resolved techniques, it is very difficult to study the structural dynamics of bond making, mainly because of its bimolecular nature. It is especially difficult to initiate and follow diffusion-limited bond formation in solution with ultrahigh time resolution. Here we use femtosecond time-resolved X-ray solution scattering to visualize the formation of a gold trimer complex, [Au(CN)2(-)]3 in real time without the limitation imposed by slow diffusion. This photoexcited gold trimer, which has weakly bound gold atoms in the ground state, undergoes a sequence of structural changes, and our experiments probe the dynamics of individual reaction steps, including covalent bond formation, the bent-to-linear transition, bond contraction and tetramer formation with a time resolution of ∼500 femtoseconds. We also determined the three-dimensional structures of reaction intermediates with sub-ångström spatial resolution. This work demonstrates that it is possible to track in detail and in real time the structural changes that occur during a chemical reaction in solution using X-ray free-electron lasers and advanced analysis of time-resolved solution scattering data.

  View details for PubMedID 25693570

• Ionization of Aligned O-2 by Intense Laser Pulse Sonoda, K., Hasegawa, H., Sato, T., Iwasaki, A., Yamanouchi, K. edited by Yamanouchi, Cundiff, S., DeVivieRiedle, R., KuwataGonokami, M., DiMauro, L. SPRINGER-VERLAG BERLIN. 2015: 147–49

  View details for DOI 10.1007/978-3-319-13242-6_35

  View details for Web of Science ID 000357738800035

• Highly efficient arrival timing diagnostics for femtosecond X-ray and optical laser pulses Applied Physics Express Sato, T., Togashi, T., Ogawa, K., Katayama, T., Inubushi, Y., Tono, K., Yabashi, M. 2015; 8 (1)

  View details for DOI 10.7567/APEX.8.012702

  View details for Web of Science ID 000348959300009

• Intense Field Ionization of C2H2 and (CCH2)-C-12-C-13 Aligned in Field-Free Space Hasegawa, H., Ikeda, Y., Sonoda, K., Sato, T., Iwasaki, A., Yamanouchi, K. edited by Yamanouchi, Cundiff, S., DeVivieRiedle, R., KuwataGonokami, M., DiMauro, L. SPRINGER-VERLAG BERLIN. 2015: 143–46

  View details for DOI 10.1007/978-3-319-13242-6_34

  View details for Web of Science ID 000357738800034

• Single-shot three-dimensional structure determination of nanocrystals with femtosecond X-ray free-electron laser pulses NATURE COMMUNICATIONS Xu, R., Jiang, H., Song, C., Rodriguez, J. A., Huang, Z., Chen, C., Nam, D., Park, J., Gallagher-Jones, M., Kim, S., Kim, S., Suzuki, A., Takayama, Y., Oroguchi, T., Takahashi, Y., Fan, J., Zou, Y., Hatsui, T., Inubushi, Y., Kameshima, T., Yonekura, K., Tono, K., Togashi, T., Sato, T., Yamamoto, M., Nakasako, M., Yabashi, M., Ishikawa, T., Miao, J. 2014; 5: 4061

  Abstract

  Conventional three-dimensional (3D) structure determination methods require either multiple measurements at different sample orientations or a collection of serial sections through a sample. Here we report the experimental demonstration of single-shot 3D structure determination of an object; in this case, individual gold nanocrystals at ~5.5 nm resolution using ~10 fs X-ray free-electron laser pulses. Coherent diffraction patterns are collected from high-index-faceted nanocrystals, each struck by an X-ray free-electron laser pulse. Taking advantage of the symmetry of the nanocrystal and the curvature of the Ewald sphere, we reconstruct the 3D structure of each nanocrystal from a single-shot diffraction pattern. By averaging a sufficient number of identical nanocrystals, this method may be used to determine the 3D structure of nanocrystals at atomic resolution. As symmetry exists in many virus particles, this method may also be applied to 3D structure studies of such particles at nanometer resolution on femtosecond time scales.

  View details for PubMedID 24898682

• Time-Resolved Coherent Diffraction of Ultrafast Structural Dynamics in a Single Nanowire NANO LETTERS Newton, M. C., Sao, M., Fujisawa, Y., Onitsuka, R., Kawaguchi, T., Tokuda, K., Sato, T., Togashi, T., Yabashi, M., Ishikawa, T., Ichitsubo, T., Matsubara, E., Tanaka, Y., Nishino, Y. 2014; 14 (5): 2413–18

  Abstract

  The continuing effort to utilize the unique properties present in a number of strongly correlated transition metal oxides for novel device applications has led to intense study of their transitional phase state behavior. Here we report on time-resolved coherent X-ray diffraction measurements on a single vanadium dioxide nanocrystal undergoing a solid-solid phase transition, using the SACLA X-ray Free Electron Laser (XFEL) facility. We observe an ultrafast transition from monoclinic to tetragonal crystal structure in a single vanadium dioxide nanocrystal. Our findings demonstrate that the structural change occurs in a number of distinct stages attributed to differing expansion modes of vanadium atom pairs.

  View details for DOI 10.1021/nl500072d

  View details for Web of Science ID 000336074800027

  View details for PubMedID 24742218

• Generation of 10(20) Wcm (-2) hard X- ray laser pulses with two-stage reflective focusing system NATURE COMMUNICATIONS Mimura, H., Yumoto, H., Matsuyama, S., Koyama, T., Tono, K., Inubushi, Y., Togashi, T., Sato, T., Kim, J., Fukui, R., Sano, Y., Yabashi, M., Ohashi, H., Ishikawa, T., Yamauchi, K. 2014; 5: 3539

  Abstract

  Intense X-ray fields produced with hard X-ray free-electron laser (XFEL) have made possible the study of nonlinear X-ray phenomena. However, the observable phenomena are still limited by the power density. Here, we present a two-stage focusing system consisting of ultra-precise mirrors, which can generate an extremely intense X-ray field. The XFEL beam, enlarged with upstream optics, is focused with downstream optics that have high numerical aperture. A grating interferometer is used to monitor the wavefront to achieve optimum focusing. Finally, we generate an extremely small spot of 30 × 55 nm with an extraordinary power density of over 1 × 10(20) W cm(-2) using 9.9 keV XFEL light. The achieved power density provides novel opportunities to elucidate unexplored nonlinear phenomena in the X-ray region, which will advance development on quantum X-ray optics, astronomical physics and high-energy density science.

  View details for PubMedID 24781443

• Multiple application X-ray imaging chamber for single-shot diffraction experiments with femtosecond X-ray laser pulses JOURNAL OF APPLIED CRYSTALLOGRAPHY Song, C., Tono, K., Park, J., Ebisu, T., Kim, S., Shimada, H., Kim, S., Gallagher-Jones, M., Nam, D., Sato, T., Togashi, T., Ogawa, K., Joti, Y., Kameshima, T., Ono, S., Hatsui, T., Iwata, S., Yabashi, M., Ishikawa, T. 2014; 47: 188–97

  View details for DOI 10.1107/S1600576713029944

  View details for Web of Science ID 000330485100026

• Development of split-delay x-ray optics using Si(220) crystals at SACLA Osaka, T., Hirano, T., Yabashi, M., Sano, Y., Tono, K., Inubushi, Y., Sato, T., Ogawa, K., Matsuyama, S., Ishikawa, T., Yamauchi, K. edited by HauRiege, S. P., Moeller, S. P., Yabashi, M. SPIE-INT SOC OPTICAL ENGINEERING. 2014

  View details for DOI 10.1117/12.2060238

  View details for Web of Science ID 000343910300004

• Two-colour hard X-ray free-electron laser with wide tunability NATURE COMMUNICATIONS Hara, T., Inubushi, Y., Katayama, T., Sato, T., Tanaka, H., Tanaka, T., Togashi, T., Togawa, K., Tono, K., Yabashi, M., Ishikawa, T. 2013; 4: 2919

  Abstract

  Ultrabrilliant, femtosecond X-ray pulses from X-ray free-electron lasers (XFELs) have promoted the investigation of exotic interactions between intense X-rays and matters, and the observation of minute targets with high spatio-temporal resolution. Although a single X-ray beam has been utilized for these experiments, the use of multiple beams with flexible and optimum beam parameters should drastically enhance the capability and potentiality of XFELs. Here we show a new light source of a two-colour double-pulse (TCDP) XFEL in hard X-rays using variable-gap undulators, which realizes a large and flexible wavelength separation of more than 30% with an ultraprecisely controlled time interval in the attosecond regime. Together with sub-10-fs pulse duration and multi-gigawatt peak powers, the TCDP scheme enables us to elucidate X-ray-induced ultrafast transitions of electronic states and structures, which will significantly contribute to the advancement of ultrafast chemistry, plasma and astronomical physics, and quantum X-ray optics.

  View details for PubMedID 24301682

• Femtosecond x-ray absorption spectroscopy with hard x-ray free electron laser APPLIED PHYSICS LETTERS Katayama, T., Inubushi, Y., Obara, Y., Sato, T., Togashi, T., Tono, K., Hatsui, T., Kameshima, T., Bhattacharya, A., Ogi, Y., Kurahashi, N., Misawa, K., Suzuki, T., Yabashi, M. 2013; 103 (13)

  View details for DOI 10.1063/1.4821108

  View details for Web of Science ID 000325284500005

• Time-interleaved multienergy acceleration for an x-ray free-electron laser facility PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS Hara, T., Tamasaku, K., Asaka, T., Inagaki, T., Inubushi, Y., Katayama, T., Kondo, C., Maesaka, H., Matsubara, S., Ohshima, T., Otake, Y., Sakurai, T., Sato, T., Tanaka, H., Togashi, T., Togawa, K., Tono, K., Yabashi, M., Ishikawa, T. 2013; 16 (8)

  View details for DOI 10.1103/PhysRevSTAB.16.080701

  View details for Web of Science ID 000323320500001

• Double Core-Hole Creation by Sequential Attosecond Photoionization PHYSICAL REVIEW LETTERS Tamasaku, K., Nagasono, M., Iwayama, H., Shigemasa, E., Inubushi, Y., Tanaka, T., Tono, K., Togashi, T., Sato, T., Katayama, T., Kameshima, T., Hatsui, T., Yabashi, M., Ishikawa, T. 2013; 111 (4): 043001

  Abstract

  X-ray fluorescence spectroscopy demonstrates that a single core-hole krypton with a 170-as lifetime can be photoionized again to a double core-hole state by an intense x-ray pulse. The observation indicates that unconventional interaction between intense x rays and atoms is no more negligible in applications with x-ray free-electron lasers. Quantitative analysis of the double core-hole creation including effects of a pulsed and spiky temporal structure enables estimation of the x-ray pulse duration in the sub-10-fs range.

  View details for PubMedID 23931361

• Investigation of ablation thresholds of optical materials using 1-mu m-focusing beam at hard X-ray free electron laser OPTICS EXPRESS Koyama, T., Yumoto, H., Senba, Y., Tono, K., Sato, T., Togashi, T., Inubushi, Y., Katayama, T., Kim, J., Matsuyama, S., Mimura, H., Yabashi, M., Yamauchi, K., Ohashi, H., Ishikawa, T. 2013; 21 (13): 15382–88

  Abstract

  We evaluated the ablation thresholds of optical materials by using hard X-ray free electron laser. A 1-µm-focused beam with 10-keV of photon energy from SPring-8 Angstrom Compact free electron LAser (SACLA) was irradiated onto silicon and SiO2 substrates, as well as the platinum and rhodium thin films on these substrates, which are widely used for optical materials such as X-ray mirrors. We designed and installed a dedicated experimental chamber for the irradiation experiments. For the silicon substrate irradiated at a high fluence, we observed strong mechanical cracking at the surface and a deep ablation hole with a straight side wall. We confirmed that the ablation thresholds of uncoated silicon and SiO2 substrates agree with the melting doses of these materials, while those of the substrates under the metal coating layer are significantly reduced. The ablation thresholds obtained here are useful criteria in designing optics for hard X-ray free electron lasers.

  View details for DOI 10.1364/OE.21.015382

  View details for Web of Science ID 000321288400046

  View details for PubMedID 23842324

• Beamline mirrors and monochromator for X-ray free electron laser of SACLA Ohashi, H., Yabashi, M., Tono, K., Inubushi, Y., Sato, T., Togashi, T., Senba, Y., Koyama, T., Yumoto, H., Miyokawa, K., Ohsawa, T., Goto, S., Ishikawa, T. ELSEVIER SCIENCE BV. 2013: 139–42

  View details for DOI 10.1016/j.nima.2012.10.094

  View details for Web of Science ID 000318128600026

• Anomalous signal from S atoms in protein crystallographic data from an X-ray free-electron laser ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY Barends, T. M., Foucar, L., Shoeman, R. L., Bari, S., Epp, S. W., Hartmann, R., Hauser, G., Huth, M., Kieser, C., Lomb, L., Motomura, K., Nagaya, K., Schmidt, C., Strecker, R., Anielski, D., Boll, R., Erk, B., Fukuzawa, H., Hartmann, E., Hatsui, T., Holl, P., Inubushi, Y., Ishikawa, T., Kassemeyer, S., Kaiser, C., Koeck, F., Kunishima, N., Kurka, M., Rolles, D., Rudek, B., Rudenko, A., Sato, T., Schroeter, C., Soltau, H., Strueder, L., Tanaka, T., Togashi, T., Tono, K., Ullrich, J., Yase, S., Wada, S., Yao, M., Yabashi, M., Ueda, K., Schlichting, I. 2013; 69: 838–42

  Abstract

  X-ray free-electron lasers (FELs) enable crystallographic data collection using extremely bright femtosecond pulses from microscopic crystals beyond the limitations of conventional radiation damage. This diffraction-before-destruction approach requires a new crystal for each FEL shot and, since the crystals cannot be rotated during the X-ray pulse, data collection requires averaging over many different crystals and a Monte Carlo integration of the diffraction intensities, making the accurate determination of structure factors challenging. To investigate whether sufficient accuracy can be attained for the measurement of anomalous signal, a large data set was collected from lysozyme microcrystals at the newly established `multi-purpose spectroscopy/imaging instrument' of the SPring-8 Ångstrom Compact Free-Electron Laser (SACLA) at RIKEN Harima. Anomalous difference density maps calculated from these data demonstrate that serial femtosecond crystallography using a free-electron laser is sufficiently accurate to measure even the very weak anomalous signal of naturally occurring S atoms in a protein at a photon energy of 7.3 keV.

  View details for DOI 10.1107/S0907444913002448

  View details for Web of Science ID 000318240200018

  View details for PubMedID 23633593

• Time-resolved Bragg coherent X-ray diffraction revealing ultrafast lattice dynamics in nano-thickness crystal layer using X-ray free electron laser JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Tanaka, Y., Ito, K., Nakatani, T., Onitsuka, R., Newton, M., Sato, T., Togashi, T., Yabashi, M., Kawaguchi, T., Shimada, K., Tokuda, K., Takahashi, I., Ichitsubo, T., Matsubara, E., Nishino, Y. 2013; 121 (1411): 283–86

  View details for DOI 10.2109/jcersj2.121.283

  View details for Web of Science ID 000316771200006

• A Bragg beam splitter for hard x-ray free-electron lasers OPTICS EXPRESS Osaka, T., Yabashi, M., Sano, Y., Tono, K., Inubushi, Y., Sato, T., Matsuyama, S., Ishikawa, T., Yamauchi, K. 2013; 21 (3): 2823–31

  Abstract

  We report a Bragg beam splitter developed for utilization of hard x-ray free-electron lasers. The splitter is based on an ultrathin silicon crystal operating in the symmetric Bragg geometry to provide high reflectivity and transmissivity simultaneously. We fabricated frame-shaped Si(511) and (110) crystals with thicknesses below 10 μm by a reactive dry etching method using atmospheric-pressure plasma. The thickness variation over an illuminated area is less than 300 nm peak-to-valley. High crystalline perfection was verified by topographic and diffractometric measurements. The crystal thickness was evaluated from the period of the Pendellösung beats measured with a highly monochromatic and collimated x-ray probe. The crystals provide two replica pulses with uniform wavefront [(<1/50)λ] and low spatial intensity variation (<5%). These Bragg beam splitters will play an important role in innovating XFEL applications.

  View details for DOI 10.1364/OE.21.002823

  View details for Web of Science ID 000315991400029

  View details for PubMedID 23481739

• Thin crystal development and applications for hard x-ray free-electron lasers Osaka, T., Yabashi, M., Sano, Y., Tono, K., Inubushi, Y., Sato, T., Ogawa, K., Matsuyama, S., Ishikawa, T., Yamauchi, K. edited by Khounsary, A., Goto, S., Morawe, C. SPIE-INT SOC OPTICAL ENGINEERING. 2013

  View details for DOI 10.1117/12.2023465

  View details for Web of Science ID 000326748800002

• Focusing of X-ray free-electron laser pulses with reflective optics NATURE PHOTONICS Yumoto, H., Mimura, H., Koyama, T., Matsuyama, S., Tono, K., Togashi, T., Inubushi, Y., Sato, T., Tanaka, T., Kimura, T., Yokoyama, H., Kim, J., Sano, Y., Hachisu, Y., Yabashi, M., Ohashi, H., Ohmori, H., Ishikawa, T., Yamauchi, K. 2013; 7 (1): 43–47

  View details for DOI 10.1038/NPHOTON.2012.306

  View details for Web of Science ID 000312835200012

• Development of ultrafast pump and probe experimental system at SACLA Sato, T., Togashi, T., Tono, K., Inubushi, Y., Tomizawa, H., Tanaka, Y., Adachi, S., Nakamura, K., Kodama, R., Yabashi, M. edited by Susini, J., Dumas, P. IOP PUBLISHING LTD. 2013

  View details for DOI 10.1088/1742-6596/425/9/092009

  View details for Web of Science ID 000320403700154

• Determination of the Pulse Duration of an X-Ray Free Electron Laser Using Highly Resolved Single-Shot Spectra PHYSICAL REVIEW LETTERS Inubushi, Y., Tono, K., Togashi, T., Sato, T., Hatsui, T., Kameshima, T., Togawa, K., Hara, T., Tanaka, T., Tanaka, H., Ishikawa, T., Yabashi, M. 2012; 109 (14): 144801

  Abstract

  We determined the pulse duration of x-ray free electron laser light at 10 keV using highly resolved single-shot spectra, combined with an x-ray free electron laser simulation. Spectral profiles, which were measured with a spectrometer composed of an ultraprecisely figured elliptical mirror and an analyzer flat crystal of silicon (555), changed markedly when we varied the compression strength of the electron bunch. The analysis showed that the pulse durations were reduced from 31 to 4.5 fs for the strongest compression condition. The method, which is readily applicable to evaluate shorter pulse durations, provides a firm basis for the development of femtosecond to attosecond sciences in the x-ray region.

  View details for PubMedID 23083249

• A compact X-ray free-electron laser emitting in the sub-angstrom region NATURE PHOTONICS Ishikawa, T., Aoyagi, H., Asaka, T., Asano, Y., Azumi, N., Bizen, T., Ego, H., Fukami, K., Fukui, T., Furukawa, Y., Goto, S., Hanaki, H., Hara, T., Hasegawa, T., Hatsui, T., Higashiya, A., Hirono, T., Hosoda, N., Ishii, M., Inagaki, T., Inubushi, Y., Itoga, T., Joti, Y., Kago, M., Kameshima, T., Kimura, H., Kirihara, Y., Kiyomichi, A., Kobayashi, T., Kondo, C., Kudo, T., Maesaka, H., Marechal, X. M., Masuda, T., Matsubara, S., Matsumoto, T., Matsushita, T., Matsui, S., Nagasono, M., Nariyama, N., Ohashi, H., Ohata, T., Ohshima, T., Ono, S., Otake, Y., Saji, C., Sakurai, T., Sato, T., Sawada, K., Seike, T., Shirasawa, K., Sugimoto, T., Suzuki, S., Takahashi, S., Takebe, H., Takeshita, K., Tamasaku, K., Tanaka, H., Tanaka, R., Tanaka, T., Togashi, T., Togawa, K., Tokuhisa, A., Tomizawa, H., Tono, K., Wu, S., Yabashi, M., Yamaga, M., Yamashita, A., Yanagida, K., Zhang, C., Shintake, T., Kitamura, H., Kumagai, N. 2012; 6 (8): 540–44

  View details for DOI 10.1038/nphoton.2012.141

  View details for Web of Science ID 000307046800014

• A photodiode amplifier system for pulse-by-pulse intensity measurement of an x-ray free electron laser REVIEW OF SCIENTIFIC INSTRUMENTS Kudo, T., Tono, K., Yabashi, M., Togashi, T., Sato, T., Inubushi, Y., Omodani, M., Kirihara, Y., Matsushita, T., Kobayashi, K., Yamaga, M., Uchiyama, S., Hatsui, T. 2012; 83 (4): 043108

  Abstract

  We have developed a single-shot intensity-measurement system using a silicon positive-intrinsic-negative (PIN) photodiode for x-ray pulses from an x-ray free electron laser. A wide dynamic range (10(3)-10(11) photons/pulse) and long distance signal transmission (>100 m) were required for this measurement system. For this purpose, we developed charge-sensitive and shaping amplifiers, which can process charge pulses with a wide dynamic range and variable durations (ns-μs) and charge levels (pC-μC). Output signals from the amplifiers were transmitted to a data acquisition system through a long cable in the form of a differential signal. The x-ray pulse intensities were calculated from the peak values of the signals by a waveform fitting procedure. This system can measure 10(3)-10(9) photons/pulse of ~10 keV x-rays by direct irradiation of a silicon PIN photodiode, and from 10(7)-10(11) photons/pulse by detecting the x-rays scattered by a diamond film using the silicon PIN photodiode. This system gives a relative accuracy of ~10(-3) with a proper gain setting of the amplifiers for each measurement. Using this system, we succeeded in detecting weak light at the developmental phase of the light source, as well as intense light during lasing of the x-ray free electron laser.

  View details for DOI 10.1063/1.3701713

  View details for Web of Science ID 000303415300009

  View details for PubMedID 22559516

• Determination of the absolute two-photon ionization cross section of He by an XUV free electron laser JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS Sato, T., Iwasaki, A., Ishibashi, K., Okino, T., Yamanouchi, K., Adachi, J., Yagishita, A., Yazawa, H., Kannari, F., Aoyma, M., Yamakawa, K., Midorikawa, K., Nakano, H., Yabashi, M., Nagasono, M., Higashiya, A., Ishikawa, T. 2011; 44 (16)

  View details for DOI 10.1088/0953-4075/44/16/161001

  View details for Web of Science ID 000294890800001

• Extreme ultraviolet free electron laser seeded with high-order harmonic of Ti:sapphire laser OPTICS EXPRESS Togashi, T., Takahashi, E. J., Midorikawa, K., Aoyama, M., Yamakawa, K., Sato, T., Iwasaki, A., Owada, S., Okino, T., Yamanouchi, K., Kannari, F., Yagishita, A., Nakano, H., Couprie, M. E., Fukami, K., Hatsui, T., Hara, T., Kameshima, T., Kitamura, H., Kumagai, N., Matsubara, S., Nagasono, M., Ohashi, H., Ohshima, T., Otake, Y., Shintake, T., Tamasaku, K., Tanaka, H., Tanaka, T., Togawa, K., Tomizawa, H., Watanabe, T., Yabashi, M., Ishikawa, T. 2011; 19 (1): 317–24

  Abstract

  The 13th harmonic of a Ti:sapphire (Ti:S) laser in the plateau region was injected as a seeding source to a 250-MeV free-electron-laser (FEL) amplifier. When the amplification conditions were fulfilled, strong enhancement of the radiation intensity by a factor of 650 was observed. The random and uncontrollable spikes, which appeared in the spectra of the Self-Amplified Spontaneous Emission (SASE) based FEL radiation without the seeding source, were found to be suppressed drastically to form to a narrow-band, single peak profile at 61.2 nm. The properties of the seeded FEL radiation were well reproduced by numerical simulations. We discuss the future precept of the seeded FEL scheme to the shorter wavelength region.

  View details for PubMedID 21263571

• Extreme ultraviolet free electron laser seeded by high-order harmonic Togashi, T., Takahashi, E. J., Midorikawa, K., Aoyama, M., Yamakawa, K., Sato, T., Iwasaki, A., Owada, S., Okino, T., Yamanouchi, K., Couprie, M. E., Hara, T., Kumagai, N., Matsubara, S., Nagasono, M., Ohshima, T., Otake, Y., Shintake, T., Tanaka, H., Tanaka, T., Togawa, K., Tomizawa, H., Watanabe, T., Yabashi, M., Ishikawa, T., IEEE IEEE. 2011

  View details for Web of Science ID 000295612402166

• Characterization of beryllium foils for coherent x-ray applications of synchrotron radiation and XFEL beamlines Goto, S., Takahashi, S., Inubushi, Y., Tono, K., Sato, T., Yabashi, M. edited by Morawe, C., Khounsary, A. M., Goto, S. SPIE-INT SOC OPTICAL ENGINEERING. 2011

  View details for DOI 10.1117/12.894506

  View details for Web of Science ID 000297556300033

• Dissociative two-photon ionization of N-2 in extreme ultraviolet by intense self-amplified spontaneous emission free electron laser light APPLIED PHYSICS LETTERS Sato, T., Okino, T., Yamanouchi, K., Yagishita, A., Kannari, F., Yamakawa, K., Midorikawa, K., Nakano, H., Yabashi, M., Nagasono, M., Ishikawa, T. 2008; 92 (15)

  View details for DOI 10.1063/1.2911742

  View details for Web of Science ID 000255117100122