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Volume 45, Issue 8
Special Issue on Observation and Creation of Extreme Status of Matter with X-ray Free Electrons Laser
Displaying 1-11 of 11 articles from this issue
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Special Issue on Observation and Creation of Extreme Status of Matter with X-ray Free Electrons Laser
Special Issue
Laser Review
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Ryosuke KODAMA2017 Volume 45 Issue 8 Pages 464-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSDownload PDF (191K) -
Yoshikazu TANAKA2017 Volume 45 Issue 8 Pages 465-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSPhotoexcitation is one of the promising methods to realize exotic states in materials. It possibly provides us with ultrafast switching devices in the future. For research and development of such devices, it is essential to understand the underlying physics in the ultrashort transient states induced by photoexcitation. We have employed short-pulse x-ray free-electron laser to observe the dynamics of the magnetic structure of the photoexcitated Mott insulator Sr2IrO4. We have performed time-resolved resonant x-ray diffraction and time-resolved resonant x-ray inelastic scattering, and found that the nonequilibrium state, 2 ps after the excitation, exhibits strongly suppressed long-range magnetic order, but hosts photo-carriers that retain strong, non-thermal magnetic correlations. These findings show that the dimensionality of magnetic correlations is vital for our understanding of ultrafast magnetic dynamics.View full abstractDownload PDF (711K) -
Shunsuke NOZAWA, Shin-ichi ADACHI, Tokushi SATO2017 Volume 45 Issue 8 Pages 470-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSIn this work, using an X-ray free electron laser, we visualize in real time the birth of a gold trimer complex that occurs via photoinduced formation of Au-Au covalent bonds by the femtosecond timeresolved X-ray solution scattering. 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 freeelectron lasers and advanced analysis of time-resolved solution scattering data.View full abstractDownload PDF (613K) -
Michihiro SUGA, Fusamichi AKITA, Jian-Ren SHEN2017 Volume 45 Issue 8 Pages 475-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSPhotosystem II (PSII) is a huge membrane-protein complex which catalyzes light-driven water-oxidation reaction at its catalytic center, the oxygen evolving complex (OEC). The crystal structure of PSII has been determined at 1.9 Å resolution using synchrotron radiation which revealed that the OEC is a Mn4CaO5 cluster. Some of the manganese atoms of the OEC are, however, rapidly reduced by X-ray irradiation which results in slight elongation of the distances between manganese cations. Furthermore, high-resolution 3D structural information is only limited to the dark-stable S1 state and the structures in the other intermediate states are missing. X-ray free electron laser (XFEL) has the potential to address these unsolved problems, and unveil the water-splitting reaction mechanism of PSII. In this review, we will introduce the analyses of the damage-free structure and an intermediate structure of PSII using XFEL, demonstrating the potential to obtain high spatial resolution of biological samples by XFEL.View full abstractDownload PDF (620K) -
Norimasa OZAKI, Takeshi MATSUOKA, Kenjiro TAKAHASHI, Kohei MIYANIS ...2017 Volume 45 Issue 8 Pages 480-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSLaser-driven dynamic compression is used to study matters in extreme conditions. High-pressure and high-temperature states of matter are generated under the laser-shock compression, of great current interest for high-energy density physics, planetary sciences, and inertial fusion energy research. At the high P-T conditions, the micro-structure of material significantly influences the behavior and properties of material. X-ray free electron laser (XFEL) is a powerful tool to directly observe a structure and to reveal the time scale of the structural change under the dynamic high pressures. Here we present recent results of laser-driven high pressure experiments associated with strong shock equation of state and ultrafast observation of lattice dynamics.View full abstractDownload PDF (1802K) -
Takayuki YAMAZAKI, Yudai SEINO, Toshiaki INADA, Toshio NAMBA, Shoj ...2017 Volume 45 Issue 8 Pages 488-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSQuantum electrodynamics expects the vacuum is transformed into a polarizable medium under an intense electromagnetic fi eld. This vacuum polarization results in various macroscopic phenomena, such as vacuum birefringence, vacuum diffraction, and so on. An x-ray free electron laser (XFEL) is a powerful probe to detect these phenomena thanks to its short wavelength and high peak brilliance. We are searching for vacuum birefringence and vacuum diffraction using an XFEL and PW class optical lasers at SACLA. In this paper, we present an overview and the current status of our experiment.View full abstractDownload PDF (1515K) -
Mizuho FUSHITANI, Akiyoshi HISHIKAWA2017 Volume 45 Issue 8 Pages 493-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSCoherent light-matter interaction drives a variety of interesting processes in a quantum system. Rabi oscillation is one such process offering a periodic population transfer between quantum states in an ultrashort time scale. Here we demonstrate a robust and simple scheme to achieve femtosecond twophoton Rabi oscillations by intense NIR laser pulses, using excited He atoms prepared by EUV-FEL. The extension to multiphoton regime will expand the applicability to highly excited or dipole-forbidden states.View full abstractDownload PDF (632K) -
Hironobu FUKUZAWA, Kiyoshi UEDA2017 Volume 45 Issue 8 Pages 498-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSBy electron spectroscopy, we investigated various phenomena that are caused by the irradiation of extreme ultraviolet (EUV) and X-ray free-electron laser (FEL) pulses on rare-gas clusters. The results for the Ne clusters, which were irradiated by EUVFEL pulses at a photon energy of 20.3 eV below the ionization threshold, illustrate that novel interatomic processes yield low-energy electrons. The results for the Xe clusters, irradiated by EUVFEL pulses at a photon energy of 24.3 eV above the threshold, illustrate that nanoplasma is formed as a result of trapping the photoelectrons and consequently emits low-energy thermal electrons. The results for the Ar clusters irradiated by 5 keV XFEL pulses illustrate that nanoplasma is formed by trapping low-energy Auger electrons and secondary electrons in the tens of fs range, and continuous thermal emission from the plasma occurs in the ps range.View full abstractDownload PDF (606K) -
Hitoki YONEDA2017 Volume 45 Issue 8 Pages 503-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSPresent shortest wavelength of the atomic resonant laser reaches to be 1.5A. This length is beyond the lattice constant of many condensed matter and the photon energy exceed up to 8 keV, which is photoionization energy of the first transition metal. Here, the development of this inner shell excitation Kα laser is mentioned with fundamental model to consider the threshold condition of this laser oscillation. In addition, new mode selection method in hard x-ray laser is introduced. The present research activities related to such ultra-high intense x-ray filed becomes high and we consider it is good opportunity to consider future science with these new lasers.View full abstractDownload PDF (888K)
Laser Original
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Yoshinori NISHINO, Takashi KIMURA, Akihiro SUZUKI, Yasumasa JOTI, ...2017 Volume 45 Issue 8 Pages 508-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSX-rays are a powerful tool for imaging deep inside thick objects under various environments due to their high penetrating power. The ultrashort pulse duration of X-ray free-electron lasers (XFELs) adds a new possibility to achieve higher spatial resolution for radiation sensitive samples by performing X-ray snapshot imaging free from radiation damage. Coherent diffractive imaging (CDI), which allows X-ray nano-imaging without objective lenses, is a suitable tool for XFEL imaging. CDI can quantitatively image transparent phase objects, such as tiny biological samples, by numerically retrieving the phase of the diffraction data. In imaging dynamics in biology, it is critically important to perform measurement under controlled hydrated condition at physiological temperatures. The authors are developing a pulsed coherent X-ray solution scattering (PCXSS), which is an XFEL CDI for solution samples. This article describes the basics of PCXSS and its application to various samples, including living cells and the selfassemblies of gold nano-particles in solution, using the Japanese XFEL facility, SACLA.View full abstractDownload PDF (620K) -
Ryo HAZAMA, Norimasa OZAKI, Kento KATAGIRI, Takahiro MATSUOKA, Koh ...2017 Volume 45 Issue 8 Pages 513-
Published: 2017
Released on J-STAGE: December 17, 2020
JOURNAL FREE ACCESSWe performed XRD observations of laser-shock compressed highly oriented pyrolytic graphite along the [002] orientation using an x-ray free electron laser: SACLA. The x-ray diffraction detector recorded x-rays that are diffracted from multiple lattice planes. These diffracted x-rays indicate both uncompressed and compressed states. We observed diffraction lines from the (002) plane in both states as spots that resembled single crystals. From our analysis, we successfully observed the uniaxial compression anomalous lattice state in which the interlayer distance of graphite was compressed by about 16%. The diffraction line, such as the compressed (103) plane, also shows that the (002) plane is almost ideal to the compressed uniaxial.View full abstractDownload PDF (1565K)
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