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    takahiro@SLAC.Stanford.EDU
    University - Staff Department: SLAC National Accelerator Laboratory Position: Staff Scientist
    • 2575 Sand Hill Rd
    • Mailstop 0019
    • Menlo Park,  California  94025 

Additional Info

  • Mail Code: 0210

All Publications

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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., 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., 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., 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